Click Here -> Please Consider Making a PayPal Contribution to the FordSix Forum!
2018 Contributors:
StarDiero75, curts56, DannyG, B RON CO, wsa111, Captainslow42, falconcritter
Econoline, THE FRENCHTOWN FLYER, 95FordFleetside, turbo6, Max_Effort, WorldChampGramp
cr_bobcat, C.S.Designs, pmuller9, gus91326, rwbrooks50, rocklord, drag-200stang, Big64my79Effie, CNC-Dude, gb500

2019 Contributors:
NJwpod, 1strodeo, mightynorseman, maxtrux, 6d7coupe, broncr, Phase3, 68Flareside240, bmbm40,
mustang6, WorldChampGramp, justintendo, BigBlue94, ags290, motorsickle1130, Rooster, ousooner919, ethanperry

Unknown->> M.Ketterer, T.Smith, J.Myers, P.McIntire - Please PM me (1966Mustang) and lemme know who you are!

Triple Weber DCOEs

Moderator: Mod Squad

Matthew68
Registered User
Posts: 241
Joined: Tue Aug 15, 2017 11:45 am

Triple Weber DCOEs

Post #1 by Matthew68 » Fri Feb 22, 2019 2:20 pm

Hi Folks,

I'm looking to be schooled on triple Weber DCOEs. I have a manifold coming for my aluminum head (coming March), and I'm deciding if I want to try and use triple Webers. It will be in a 1968 Mustang 200, with the CI/VI aluminum head and custom intake made by Does10s from way back. Car isn't going to be raced, just a driver. I'm interested in knowing a few things:

1. Will I have an issue with shock tower clearance with the DCOE trumpets?
2. There are Weber DCOE 40s and 45s. Since this is going on a 200, does it make a difference which ones I pick up, as long as they are all the same model numbers? I didn't want to "over" or "under" carb it.
3. How do people handle running the fuel line to all 3 carbs?
4. What sort of throttle linkage do folks use from the pedal to the linkage itself from Weber?

Is this more trouble than it's worth? Undecided on cam (stock bottom end at this time). Have a set of YT rockers I'll be using as well. Just haven't seen this setup hardly ever, and wanted to try something different.

Any info is appreciated!

Cheers,
Matthew
Last edited by Matthew68 on Fri Feb 22, 2019 5:10 pm, edited 1 time in total.
1968 Mustang Coupe 200ci - Pertronix + Coil
Gulfstream Aqua - Interior + Exterior

User avatar
bubba22349
Global Moderator
Posts: 8826
Joined: Sun Jan 03, 2010 4:46 pm
Location: Flagstaff, Az. 86005 near the old Route 66

Re: Triple Weber DCOEs

Post #2 by bubba22349 » Fri Feb 22, 2019 2:45 pm

Matthew68 wrote:Hi Folks,

I'm looking to be schooled on tripe Weber DCOEs. I have a manifold coming for my aluminum head (coming March), and I'm deciding if I want to try and use triple Webers. It will be in a 1968 Mustang 200, with the CI/VI aluminum head and custom intake made by Does10s from way back. Car isn't going to be raced, just a driver. I'm interested in knowing a few things:

1. Will I have an issue with shock tower clearance with the DCOE trumpets?
2. There are Weber DCOE 40s and 45s. Since this is going on a 200, does it make a difference which ones I pick up, as long as they are all the same model numbers? I didn't want to "over" or "under" carb it.
3. How do people handle running the fuel line to all 3 carbs?
4. What sort of throttle linkage do folks use from the pedal to the linkage itself from Weber?

Is this more trouble than it's worth? Undecided on cam (stock bottom end at this time). Have a set of YT rockers I'll be using as well. Just haven't seen this setup hardly ever, and wanted to try something different.

Any info is appreciated!

Cheers,
Matthew


To this day the Weber DCOE and IDR carbs are the cream of the crop for a normally asperated engine and when they are tuned correctly are on par with fuel injection. Today most people use a cable type throdle linkage from the peddle to the intake. A simple fuel log will connect and supply fuel to all the carbs. You will need to pick the right cam to get the best from them. Good luck :thumbup: :nod:
A bad day Drag Racing is still better than a good day at work!

I am still hunting for a project car to build but with my current low budget it's not looking so good. My Ex- Fleet of Sixes these are all long gone! :bang: 1954 Customline 223 3 speed with O/D, 1963 Fairlane project drag car with BB6, 1977 Maverick 250 with C4, 1994 F-150 a 300 with 5 speed.

User avatar
wsa111
FSP Moderator
Posts: 3141
Joined: Sat Jan 24, 2004 5:28 pm
Location: South Carolina
Contact:

Re: Triple Weber DCOEs

Post #3 by wsa111 » Fri Feb 22, 2019 5:07 pm

Matthew68 wrote:Hi Folks,

I'm looking to be schooled on tripe Weber DCOEs. I have a manifold coming for my aluminum head (coming March), and I'm deciding if I want to try and use triple Webers. It will be in a 1968 Mustang 200, with the CI/VI aluminum head and custom intake made by Does10s from way back. Car isn't going to be raced, just a driver. I'm interested in knowing a few things:

1. Will I have an issue with shock tower clearance with the DCOE trumpets?
2. There are Weber DCOE 40s and 45s. Since this is going on a 200, does it make a difference which ones I pick up, as long as they are all the same model numbers? I didn't want to "over" or "under" carb it.
3. How do people handle running the fuel line to all 3 carbs?
4. What sort of throttle linkage do folks use from the pedal to the linkage itself from Weber?

Is this more trouble than it's worth? Undecided on cam (stock bottom end at this time). Have a set of YT rockers I'll be using as well. Just haven't seen this setup hardly ever, and wanted to try something different.

Any info is appreciated!

Cheers,
Matthew

Since you are going to run the Yella-Terra 1.65 rockers make sure you plug the oil galley on the rear left side of the block.
Reason, the headgasket cannot handle full oil pressure.
This blocks oil going to the head for rocker shaft oiling.
You also need to use lifters for a small block Ford engine which supplies oil to the pushrods for valve train oiling.
Camshaft call Jerry @ Schneider Cams for the best grind for your engine.
If you run a C-4 trans make sure you get a 112 L/C cam. A 110 L/C roughens the idle.
67 mustang,C-4, with mod. 80 hd, custom 500 cfm carb with annular boosters, hooker headers, dual exh.-X pipe, flowmaster mufflers, DSII dist. MSD-6al & MSD-Blaster 8252 Coil. Engine 205" .030" over with offset ground crank & 1.65 roller rockers. 9.5 comp., Isky 262 cam.
2003 Ford Lightning daily driver. Recurving Distributors. billythedistributorman@live.com
Image

Matthew68
Registered User
Posts: 241
Joined: Tue Aug 15, 2017 11:45 am

Re: Triple Weber DCOEs

Post #4 by Matthew68 » Fri Feb 22, 2019 6:44 pm

Bubba - thanks for the info on the linkage and log. I think I might need to research the linkage that connects them all to see where the cable attaches. They sure are pretty, but not sure if they’ll fit with the shock towers still.

Bill - thanks, yes I’ve got the plug and lifters already. Haven’t pulled the motor just yet, so will he installing all of that once I have the motor out. I have a C4 now, but may look to go T5 down the road. I’ve talked to Jerry a few times, I’ll give him the rundown before I purchase a cam.

Any thoughts from anyone on fit?
1968 Mustang Coupe 200ci - Pertronix + Coil
Gulfstream Aqua - Interior + Exterior

User avatar
wsa111
FSP Moderator
Posts: 3141
Joined: Sat Jan 24, 2004 5:28 pm
Location: South Carolina
Contact:

Re: Triple Weber DCOEs

Post #5 by wsa111 » Fri Feb 22, 2019 7:25 pm

Matthew, this is the time to pull the engine & go with flat top pistons & zero deck the block to get close to above 10-1 compression ratio.
Keep this in mind before choosing a camshaft.
The Webers are going to cost a fortune & a nightmare tuning them.
I would go with a Holley 2bbl or a small 4 barrel.
What distributor are you running??
67 mustang,C-4, with mod. 80 hd, custom 500 cfm carb with annular boosters, hooker headers, dual exh.-X pipe, flowmaster mufflers, DSII dist. MSD-6al & MSD-Blaster 8252 Coil. Engine 205" .030" over with offset ground crank & 1.65 roller rockers. 9.5 comp., Isky 262 cam.
2003 Ford Lightning daily driver. Recurving Distributors. billythedistributorman@live.com
Image

User avatar
bubba22349
Global Moderator
Posts: 8826
Joined: Sun Jan 03, 2010 4:46 pm
Location: Flagstaff, Az. 86005 near the old Route 66

Re: Triple Weber DCOEs

Post #6 by bubba22349 » Fri Feb 22, 2019 7:52 pm

Matthew68 wrote:Bubba - thanks for the info on the linkage and log. I think I might need to research the linkage that connects them all to see where the cable attaches. They sure are pretty, but not sure if they’ll fit with the shock towers still.

Bill - thanks, yes I’ve got the plug and lifters already. Haven’t pulled the motor just yet, so will he installing all of that once I have the motor out. I have a C4 now, but may look to go T5 down the road. I’ve talked to Jerry a few times, I’ll give him the rundown before I purchase a cam.

Any thoughts from anyone on fit?


I have seen the triple Webers DCOE's on the 200's before but it's been quite awhile so can't speak with 100% on them fitting with a stock spring / shock tower. I think they will fit a Lynx type Weber intake. On my 1963 Fairlane the build plan was to have a 300 Big Ford Six I had severial intakes to try out but was planning to use the Clifford triple Weber IDR intake with a set of 48's to maybe the bigger and harder to find 58's (if I found them) as the final drag engine build. The Fairlane was an old Bracket Racer and didn't see much street use, the spring tower where removed along with the stock supention system, then an Econoline I beam axel was installed. The shock towers with the stock suspension can also be shaved a little to get a bit more room depending on what you want to do with the car.

Here is a link from our old Tech site on the Weber DCOE with a good picture of a complete triple Weber intake for the small six'es, shows carb's mounted on intake, the linkage setup, fuel system lines. Good luck :thumbup: :nod: Edited

Tech Article on Installing the Side Draut Webers
ci/WeberDCOE.html
A bad day Drag Racing is still better than a good day at work!

I am still hunting for a project car to build but with my current low budget it's not looking so good. My Ex- Fleet of Sixes these are all long gone! :bang: 1954 Customline 223 3 speed with O/D, 1963 Fairlane project drag car with BB6, 1977 Maverick 250 with C4, 1994 F-150 a 300 with 5 speed.

User avatar
xctasy
VIP Member
Posts: 6732
Joined: Sat Nov 09, 2002 10:40 am
Location: PO Box 7072 Dunedin 9011,South Island, NEW ZEALAND
Contact:

Re: Triple Weber DCOEs

Post #7 by xctasy » Fri Feb 22, 2019 8:40 pm

xctasy wrote:....I've used the following Weber call size jets from another website application. Each graph is a generic one for 1.6, 1.9, 2.1, 2.2 and 2.4 liter DOHC Alfa Romeo engines. Adding two cylinders the same size gives you 144, 170, 188, 200 and 221 in line six Triple Weber DCOE jetting and venturi sizing.

Twin DCOE 40 Weber with 28 mm chokes for a 1.6 liter DOHC Alfa Romeo engine= 144 cid Ford Falcon six reving to 5000rpm. 115 micron Weber =152 cc/min=115 microns is a 45.28 thou jet, or close to a 149 cc/min or 44 thou nominal, 44 call size Holley 2300 jet


Image

Twin DCOE 40 Weber with 31 mm chokes for a 1.9 liter DOHC Alfa Romeo engine= 170 cid Ford Falcon six reving to 5000rpm. 125 mircron Weber = 201 cc/min=125 micron is a 49.21 thou jet, or close to a 198 cc/min or 50 thou nominal, 51 call size Holley 2300 jet. Very close is the 205 cc/min or 52 thou nominal, 52 call Holley 2300 jet. Note that Holley also makes some Close Limit jets in the 51 to 52 jet size.

Image

Twin DCOE 40 Weber with 33 mm chokes for a 2.1 liter DOHC Alfa Romeo engine= 188 cid Ford Falcon six reving to 5000rpm. 135 micron Weber = 251 cc/min=135 microns is 53.15 thou jet or close to a 248 cc/min or 56 thou nominal, 57 call size Holley 2300 jet


Image

Twin DCOE 40 Weber with 33 mm chokes for a 2.2 liter DOHC Alfa Romeo engine= 200 cid Ford Falcon six reving to 5000rpm. 135 micron Weber = 251 cc/min=135 microns is 53.15 thou jet or close to a 248 cc/min or 56 thou nominal, 57 call size Holley 2300 jet
.
Image

Twin DCOE 40 Weber with 34 mm chokes for a 2.4 liter DOHC Alfa Romeo engine= 221 cid Ford Falcon six reving to 5000rpm. 140 micron Weber = 275 cc/min=140 microns is 55.12 thou jet, or close to a 267 cc/min or 58 thou nominal, 59 call size Holley 2300 jet jet

Image

Last edited by xctasy on Sat Feb 23, 2019 11:00 am, edited 1 time in total.
Image
XEC Ltd ICBE's Inter Continental Ballistic Engines-
FAZER 6Bi (M112 & EEC5) or FAZER 6Ti (GT3582 & EEC5) 425 HP 4.1L/250 I-6
FAZER 6V0 3x2-BBL Holley 188 HP 3.3L/200 I-6 or 235 HP 4.1L/250 I-6
X-Flow Engine Components Ltd http://www.xecltd.info/?rd=10

User avatar
xctasy
VIP Member
Posts: 6732
Joined: Sat Nov 09, 2002 10:40 am
Location: PO Box 7072 Dunedin 9011,South Island, NEW ZEALAND
Contact:

Re: Triple Weber DCOEs

Post #8 by xctasy » Fri Feb 22, 2019 8:52 pm

When going over the normal 4800 to 5200 rpm power peak, you then go into the 5500 to 8500 rpm zone.

The venturi size is based on peak power rpm for a given size of cylinders in "cc's".

144= about 393 cc
170= about 464 cc
188= about 513 cc
200= about 546 cc
221= about 604 cc
250= about 682 cc

You have to read and extrapolate the right venturi size in mm, then find a carb size that matches the venturi without going too big on the ventiri verses carb size.

You don't want this.

Image


The whole reason the GT 3500 Maserati of the 60's had either DCOE 42's, DCOE 40's or Lucas Injection was this reason.


http://www.performanceoriented.com/throttle-body-and-main-venturi-sizing/ wrote:The following main venturi selection chart was generated using classical venturi sizing formulas and is based on a sizing coefficient of .80 for the venturi diameters. Additional tailoring of the formulas was performed to help fit the data to agree with actual OEM production and race engine configurations.


I took a risk and used PMO's copywrited material.

Image
Image
XEC Ltd ICBE's Inter Continental Ballistic Engines-
FAZER 6Bi (M112 & EEC5) or FAZER 6Ti (GT3582 & EEC5) 425 HP 4.1L/250 I-6
FAZER 6V0 3x2-BBL Holley 188 HP 3.3L/200 I-6 or 235 HP 4.1L/250 I-6
X-Flow Engine Components Ltd http://www.xecltd.info/?rd=10

Matthew68
Registered User
Posts: 241
Joined: Tue Aug 15, 2017 11:45 am

Re: Triple Weber DCOEs

Post #9 by Matthew68 » Fri Feb 22, 2019 10:32 pm

Thanks, X.

Should I be on the lookout for Weber 40s instead of 45s? Based on the charts and programs above, the calculations point to Weber 40s with a 33mm choke. Isn’t it true I can get the 45s in a 33mm choke as well?

As hard (and expensive) these DCOEs are, there seems to be much more 45s vs. 40s available.
1968 Mustang Coupe 200ci - Pertronix + Coil
Gulfstream Aqua - Interior + Exterior

User avatar
wsa111
FSP Moderator
Posts: 3141
Joined: Sat Jan 24, 2004 5:28 pm
Location: South Carolina
Contact:

Re: Triple Weber DCOEs

Post #10 by wsa111 » Fri Feb 22, 2019 10:50 pm

X You are the man on Webers.
That being said since it is going to be a daily or weekend driver go with the Holley or Autolite.
Another option Edelbrock has a 500 with annular discharge primary boosters & an adjustable secondary airflow.
For your use don't waste money on the Webers.
Tuning the Holley, Edelbrock or the Autolite parts availability is great.
67 mustang,C-4, with mod. 80 hd, custom 500 cfm carb with annular boosters, hooker headers, dual exh.-X pipe, flowmaster mufflers, DSII dist. MSD-6al & MSD-Blaster 8252 Coil. Engine 205" .030" over with offset ground crank & 1.65 roller rockers. 9.5 comp., Isky 262 cam.
2003 Ford Lightning daily driver. Recurving Distributors. billythedistributorman@live.com
Image

User avatar
xctasy
VIP Member
Posts: 6732
Joined: Sat Nov 09, 2002 10:40 am
Location: PO Box 7072 Dunedin 9011,South Island, NEW ZEALAND
Contact:

Re: Triple Weber DCOEs

Post #11 by xctasy » Sat Feb 23, 2019 9:02 am

Matthew68 wrote:Thanks, X.

Should I be on the lookout for Weber 40s instead of 45s? Based on the charts and programs above, the calculations point to Weber 40s with a 33mm choke. Isn’t it true I can get the 45s in a 33mm choke as well?

As hard (and expensive) these DCOEs are, there seems to be much more 45s vs. 40s available.


:thumbup: :nod: Go for DCOE 45's if your using 33 venturis. Less than that 42DCOE's, which are ideal for 33 mm venturis. Maserati really did the most excellent work on DCOE's in the early 60's. 42 DCOE's aren't very common. In the USA, thankfully, 45DCOE's predominate, and thats just great because even a 2 liter Pinto runs better with 45s than 42's or 40's.

Biggest issue is the problem with the low venturi gospel. You never want to downgrade venturi size unless the graphs for your cylinder size and rev range say you can. If you ignore the advice which streams from Edaurdo Webers WWII areo tests, and fall prey to the "it'll run better with smaller venturis" brigade, you'll be in for heartache.

An independent runner system on a 6 cylinder car (triple DCOE's) needs to have the venturi size exactly right for the application, and the carb size (40, 42, 45 or, gasp, 48DCO, 50DCO, 56DCO etc) has to fall in line with the venturi size.

Going down in venturi size if your DCOE45's come with, say, 38 or 40 mm venturis is fine though, if your 200 is only going to make power at 5000 rpm, and maybee over rev to 5500. 33's will run real nice everywhere in the rev range if the ignItion advance is as great as the carb tuning.


An example might be someone with a 300 cube six. They get some 42DCOE's and decide to stay with 36 mm venturis.


viewtopic.php?f=2&t=77685&p=608817#p608817
pmuller9 wrote:....

If this 300 six makes peak power (maybe 250 hp) at 4500 rpm and will rev limit to 5000 rpm, what would the ideal venturi size be?

If the present Weber 45 DCOE with 36mm venturi are used at what point would you expect power to be sacrificed?

Thanks for your input.



For a 300 in line six, its 819 cc per cylinder.

I get 40 mm from the graph for power at 4550 rpm, Thats about the biggest venturi you can get in a DCOE45.


The calculation variable for 819 cc per cylinder is Critical Flow condition. An Air restrictor would be Venturi meter with Cd about 0.85.

As the venturi to carb size gets more divergent, the Cd figure goes down, becoming more streamlined, and you get a hp and torque gain from it.

http://www.performanceoriented.com/throttle-body-and-main-venturi-sizing/ wrote:The following main venturi selection chart was generated using classical venturi sizing formulas and is based on a sizing coefficient of .80 for the venturi diameters. Additional tailoring of the formulas was performed to help fit the data to agree with actual OEM production and race engine configurations.


I took a risk and used PMO's copywrited material.


"Weber_pmo_derived" is the extrapolated result.


Image

I get 43 mm at 5500 rpm, and the black line is for a 36 mm venturi on a 300 six, about 3600 rpm.

Way too low for a 300 cubic inch six with 819 cc per cylinder.

Image

3600 rpm with the 36 mm venturi is a huge restriction to the elastic rev range required to run an IR system, and conventional US multiple carb logic doesn't work unless the air speeds are dropped.

CFM is a truley bad way of rating a multiple carb installation on a 300 cube six.

Although the flow losses of the 45 DCOE will flat line well below 36 mm, the losses between 38 to 40 mm are huge on a DCOE 45

Its better to find a set of DHLA 48's or 48DCO's or downdraft IDA 48's to get a better flow rate.

At the end, though, Aston Martins and Charger E49's used 40 mm venturis in DCOE 45's and they worked great on 314 to 325 hp 4 liter Hemi DOHC and 302 hp 265 cube Polyspheric OHV engines. The same thing happens with 38 to 40 mm venturis in 45 mm carbs, they become a lot more restrictive than 38 or 40 mm venturis in 48 or 50 mm carb bodies. Your loosing flow.

If your breaking the budget just to get an independent runner Triple Weber, then the only thing important is the venturi sizing. You can comprimise on air flow....Aston Martin and Chrysler Australia did, and those DB6'S, DBS's and Six Pack Chargers sang like Italian or Spanish tenors at 6000 rpm, 500 rpm past the point of maximum power. Because the venturis sizes were bang on, even if the carbs were techncially too small compared to some 48's or 50's. The extra cost in bigger Webers or Dell Ortos is just massive....

wsa111 wrote:....
For your use don't waste money on the Webers.
Tuning the Holley or the Autolite parts availability is great.



*The best carbs aren't DCOE's but the much more rare down draft DCNF carbs used in V6's (Fiat Dino, Ferrari, Maserati, [early BiTurbos]) and quad carb quad cam V8's by Lamborghini, Ferrari, Lancia [Stratos], Maserati, Aston Martin. Some of them are just big enough internally to use on a 200-250 cube six and allow you to get a bigger venturi with "much less" space wastage. Space was at such a premium in those 60 and 90 degree quad cam engines with no space between the rocker covers. Aston Martin made a brace of routed out DCNF 48's for the 440 hp X pack Aston Martin V8 Vantages.

Frances 1976-1986 Simca 1307/1308 and Englands Chrysler and Talbot Alpine/ Solara briefly used them on the little 1294/1442/1594 cc Hemi headed OHV fours. And the twin carb 1600 cc version of the MG Maestro.

With the exception for the Countach, European Lotuses (um, Loti) and non injected Alfetta GTV's, DCOE's and Dell Orto DHLA's were ancient and absolete technology by 1979, and anyone copying them hasn't really thought through the costing verses space issues properly. Especially on a Falcon based unibody.


Retroject 38/38 Throttle Bodies

Image
Image
and Jenvey's DCNF TC body 40-45mm
[ TC42i TC body 42mm. DCNF - Bosch EV1 / EV6 (long 64mm between 'O' ring centres, 14mm boss)]

Image
Image

Image
the above are much better bets.

Don't use ATB or Jenvey's ECM's, use a USA MegaSquirt computer, and see FOX Engineering Co, and save all the heat soak and tuning hassles, and forget all the sizing issues above.

About U$ 1200 for three 42 mm ITBs, aiming for 255 hp at 5800 rpm is very possible.

https://foxinjection.com/collections/dc ... tle-bodies

The guys there do it so simply


Basic ITB references for BHP per cylinder,

assuming a 5 inch from butterfly to valve head and a max of 9,000 rpm are;

Up to 30 BHP - 30mm, 180 hp six
up to 33 - 32mm, 198 hp six
up to 39 - 35mm, 234 hp six
up to 46 - 38mm, 276 hp six
up to 51 - 40mm, 306 hp six
up to 56 - 42mm, 336 hp six
Up to 65 - 45mm, 390hp six
up to 74 - 48mm, 444 hp six
up to 80 - 50mm, 480 hp six
up to 87 - 52mm, 522 hp six
up to 93 - 54mm, 558 hp six.
Image
XEC Ltd ICBE's Inter Continental Ballistic Engines-
FAZER 6Bi (M112 & EEC5) or FAZER 6Ti (GT3582 & EEC5) 425 HP 4.1L/250 I-6
FAZER 6V0 3x2-BBL Holley 188 HP 3.3L/200 I-6 or 235 HP 4.1L/250 I-6
X-Flow Engine Components Ltd http://www.xecltd.info/?rd=10

User avatar
rocklord
Registered User
Posts: 1317
Joined: Sat Jul 21, 2007 11:25 pm
Location: Hurricane, WV

Re: Triple Weber DCOEs

Post #12 by rocklord » Sat Feb 23, 2019 12:02 pm

Two problems tuning fuel injection with individual throttle bodies (ITB) are getting a clean vacuum signal, and the initial tip-in off idle.

One way to get a clean vacuum signal is to route the vacuum lines from each ITB runner into a common plenum, then run a single hose to the manifold absolute pressure (MAP) sensor. Some have even plumbed an idle air control (IAC) into the plenum.

The initial tip-in off idle causes the vacuum on the ITBs drop significantly with just a slight input from the throttle positioning sensor (TPS).
An ECU using Speed-Density mode has trouble resolving this, so some use Alpha-N mode and by-pass input from the MAP.
Alpha-N mode is not as refined as Speed-Density mode but a way around this is to blend Alpha-N with Speed Density to compensate for the lack of map stability at low throttle settings. Megasquirt calls this ITB Mode. The trick with ITB mode is figuring out the switch point between the two in the VE Table.

Using ITBs with multi-port fuel injection (MPFI) is the best way to get more power from the EFI system, but it's a PITA to tune.
Dan

Currently Own
1965 Mustang, 200CID, 3Spd
1964 Corvair Coupe, 164CID, 140HP, 4Spd
1961 Corvair Lakewood wagon, 145CID, 80HP, 2Spd Powerglide Auto.
2017 BMW X3, 3.0L Dual Turbo, 300HP, 8-Spd Auto

User avatar
wsa111
FSP Moderator
Posts: 3141
Joined: Sat Jan 24, 2004 5:28 pm
Location: South Carolina
Contact:

Re: Triple Weber DCOEs

Post #13 by wsa111 » Sat Feb 23, 2019 12:46 pm

Another is the Holley Sniper. Check it out.
67 mustang,C-4, with mod. 80 hd, custom 500 cfm carb with annular boosters, hooker headers, dual exh.-X pipe, flowmaster mufflers, DSII dist. MSD-6al & MSD-Blaster 8252 Coil. Engine 205" .030" over with offset ground crank & 1.65 roller rockers. 9.5 comp., Isky 262 cam.
2003 Ford Lightning daily driver. Recurving Distributors. billythedistributorman@live.com
Image

User avatar
xctasy
VIP Member
Posts: 6732
Joined: Sat Nov 09, 2002 10:40 am
Location: PO Box 7072 Dunedin 9011,South Island, NEW ZEALAND
Contact:

Re: Triple Weber DCOEs

Post #14 by xctasy » Sat Feb 23, 2019 7:24 pm

Okay. All that work has been done. ITB's are way easier! ITB's can be run bank fire (by alternating the injector sequence from odd to even), or sequential, but importantly, even if they have six injectors, they don't have to be port EFI with welded in or drilled in bungs. That makes a port on port set up hugely easier with MegaSquirt 2 or 3.

If going it alone, you need to find better people and companies who will work with you rather than guiding you down THEIR preferred path.

Choices are about what you want. In my humble opinion, side drafting an in line Ford small six is not a great idea. With side draft Webers, you cannot match the efficiency of a correctly set up & calibrated MAP system from an unleaded gas 185 to 216 hp 3.9 or 4 liter six from 1988 to 1993. They were down drafted in the 1984 to 1992 EFI x flow 4.1 liters, and then updrafted for the 88 to 93 OHC sixes.

Since 1984 to 1997 in Australia, EECIV was Fords chosen way to integrate igntion, EFi and meet emissions and reliablity requirements, without a MAF sensor, and just one really big 70 to 75 mm throttle body.


Moving to a Weber triple carb system, well, it can work fine, but probably not in a cramped engine bay like the Vintage Inlines intake and Falcon has. No real room exists.

Normally, switching to an aftermarket ecu will bring huge and completely unnecessary cost, both in hardware and tuning. Almost certainly won't drive as well as a stock Speed Density EECIV EFI from a 4 liter OHC Ford. Again, either V6, or the Australian 3.9 or 4 liter OHC from 1988 to 1993 always gives good results, and you can ITB it.

Since the USA just doesn't have as many hard core 4 liter in line six Fords, you have to decide if you want to triple Weber it or ITB EFi or go to some less than ideal stand in non port Throttle Body system (EZ EFI, FITECH, Holley Sniper et al ) which has a whole bunch of other issues, especially on an in line six.

a91what "SendMeUrDataLog" does it all for ITB's from base maps, and he's done everything with a M52 BMW ITB on Mike1157's 4.1 Maverick engine.
Image

So that's everything from normally aspirated 3.2 liter to unturboed or turboed 4.1 liters. 195 cubes to 250 cubes, boosted or non boosted. Big cams or little ones.

The cross over point is easy, GM did it first with its speed density TBi for years and years. GM guys provided the 3 bar MAP sensor, the rest is easy.

Turbo

https://www.youtube.com/watch?v=RGvzTMlJ3-U
https://www.youtube.com/watch?v=RGvzTMlJ3-U

Non turbo
https://www.youtube.com/watch?v=7T_tM-FYwnI

https://www.youtube.com/watch?v=7T_tM-FYwnI

And the first day out with ITB'S and no turbo and an a91 what? Stevie MegaSquirt tune...

https://www.youtube.com/watch?time_cont ... b37v0Zb6lA
https://www.youtube.com/watch?v=Vb37v0Zb6lA


Easy.

Three DCNF style ITB's from Jenvey or some ATB400's from DellOrto or Weber, and you don't even need anything other than a log head to mount it on.

ITB's are way easier than single throttle body systems.
Image
XEC Ltd ICBE's Inter Continental Ballistic Engines-
FAZER 6Bi (M112 & EEC5) or FAZER 6Ti (GT3582 & EEC5) 425 HP 4.1L/250 I-6
FAZER 6V0 3x2-BBL Holley 188 HP 3.3L/200 I-6 or 235 HP 4.1L/250 I-6
X-Flow Engine Components Ltd http://www.xecltd.info/?rd=10

slowhoon
Registered User
Posts: 8
Joined: Wed Sep 24, 2014 6:47 am
Location: Lower Hutt, New Zealand

Re: Triple Weber DCOEs

Post #15 by slowhoon » Sun Feb 24, 2019 11:50 pm

Hi Matthew,

About a year ago, we had a similar thread:

viewtopic.php?f=1&t=77782

Needless to say, I'm still the process of getting a proper race motor built.

- Alan.

User avatar
xctasy
VIP Member
Posts: 6732
Joined: Sat Nov 09, 2002 10:40 am
Location: PO Box 7072 Dunedin 9011,South Island, NEW ZEALAND
Contact:

Re: Triple Weber DCOEs

Post #16 by xctasy » Sat Mar 02, 2019 3:55 am

slowhoon and Jac Mac from Gore should get together.

http://www.clubcobra.com/forums/small-b ... ded-3.html
As an aside to this I built a 200cu in straight six Falcon to compete alongside a 202 cu in Holden straight six many years ago. Holden was 3.25" stroke with a 5.25" rod ( 1.61/1 Rod Ratio), Falcon was 3.125 stroke with 6.25 rod (2.0/1) rod ratio.
Series tech guys insisted we initially run the same cam specs, with this the Falcon idled like a baby where the Holden had a distinct lopey idle...just as the article you posted suggests- with the long rod the piston is 'parked' @ TDC during the cam overlap phase that the scavenge effect is virtually killed off at low RPM, now while some might say this was a negative it worked fine in this car & it was competitive from day one...later I plotted out the piston dwell @ TDC versus valve overlap & transferred this on to a 'new' cam profile to suit the Falcon. The Holden guys were not amused
I should point out this was the 'old' cast in head inlet manifold Falcon engine, not the later seperate intake setup.



JM ran a triple Weber 45 club racer. The long rod 1972 log head 200 is a favorite of mine., even thoug is way heavier than the 170 based 200 used in the US and earlier Aussie Fords.

In a unibody Falcon, proper consideration of how the Italians managed Independent Runner carbs have made DCOE 45's absolete in a dollar for dollar basis.

I really don't like the non Bosch injector quality assurance, but three Falcon EA CFi throttle bodies are a direct bolt on to a log head, and the space saving is imenese, no heat soak from the exhaust, and if you can fire the ignition, you can fire the injectors.

All the jets and venturi sizes are above if you wanna go back to simple DCOE's, but you still have heat soak unless you try a set on long branch adaptors.

Good luck, and great input everyone. Nice to have you here Alan! Awesome work!
Image
XEC Ltd ICBE's Inter Continental Ballistic Engines-
FAZER 6Bi (M112 & EEC5) or FAZER 6Ti (GT3582 & EEC5) 425 HP 4.1L/250 I-6
FAZER 6V0 3x2-BBL Holley 188 HP 3.3L/200 I-6 or 235 HP 4.1L/250 I-6
X-Flow Engine Components Ltd http://www.xecltd.info/?rd=10

Matthew68
Registered User
Posts: 241
Joined: Tue Aug 15, 2017 11:45 am

Re: Triple Weber DCOEs

Post #17 by Matthew68 » Fri Mar 15, 2019 6:31 am

Alright, haven’t had any action on this post because I’m keeping an eye out for deals. The Webers are pricey, and I already have an Autolite 2100 1.23 for my build with the VI head/intake.

I did locally find two Weber 44 IDFs. I know I would need another and want it to match, but the price seems right ($200 for both). One has been rebuilt and the guy says one has a clogged port (trying to find out what exactly).

Thoughts? Are the IDFs down draft only? The triple Weber manifold from Does10s that I have looks to be for side draft only, so not sure these will even work. Also, does the Breettato stamping mean these are Italian?

B2F30259-0A17-42DE-AEAB-8ED0249049A1.jpeg

5754FBB2-00F5-4F7B-AED2-0E49E219DD68.jpeg
You do not have the required permissions to view the files attached to this post.
1968 Mustang Coupe 200ci - Pertronix + Coil
Gulfstream Aqua - Interior + Exterior

User avatar
bubba22349
Global Moderator
Posts: 8826
Joined: Sun Jan 03, 2010 4:46 pm
Location: Flagstaff, Az. 86005 near the old Route 66

Re: Triple Weber DCOEs

Post #18 by bubba22349 » Fri Mar 15, 2019 9:20 am

Matthew68 wrote:Alright, haven’t had any action on this post because I’m keeping an eye out for deals. The Webers are pricey, and I already have an Autolite 2100 1.23 for my build with the VI head/intake.

I did locally find two Weber 44 IDFs. I know I would need another and want it to match, but the price seems right ($200 for both). One has been rebuilt and the guy says one has a clogged port (trying to find out what exactly).

Thoughts? Are the IDFs down draft only? The triple Weber manifold from Does10s that I have looks to be for side draft only, so not sure these will even work. Also, does the Breettato stamping mean these are Italian?

B2F30259-0A17-42DE-AEAB-8ED0249049A1.jpeg
5754FBB2-00F5-4F7B-AED2-0E49E219DD68.jpeg


You found a great deal! Yes IDF's are Down Draut to use on your side draft intake you would need to fasen an elbow type adapter. The 40 & 44 Weber IDF's were comminly used on the VW engines. Yes the Weber's were originally designed and made in Italy but are also made in many other countries too. When made in other countries they will have the country of origin stamped on the intake flange, plus there are some knock off's made. Good luck :thumbup: :nod:
A bad day Drag Racing is still better than a good day at work!

I am still hunting for a project car to build but with my current low budget it's not looking so good. My Ex- Fleet of Sixes these are all long gone! :bang: 1954 Customline 223 3 speed with O/D, 1963 Fairlane project drag car with BB6, 1977 Maverick 250 with C4, 1994 F-150 a 300 with 5 speed.

User avatar
xctasy
VIP Member
Posts: 6732
Joined: Sat Nov 09, 2002 10:40 am
Location: PO Box 7072 Dunedin 9011,South Island, NEW ZEALAND
Contact:

Re: Triple Weber DCOEs

Post #19 by xctasy » Fri Mar 15, 2019 12:42 pm

At last, someone using the simple things you can get. Great score. For every dollar spent, a perfect response! I'd personaaly shop around for just one more....

With the exception of the needle valve for the floats, the IDF 44 never really go out of tune and they produced the same peak power as ITB EFi or Mechanical Fuel injection.

This avoids the problems assciated with hood height, and upwards curving the manifold to the intake ports which is such an issue with the SP 221 and ME 188 intakes you see in Argentina.

The outboard space used is as good as a log heads bolt on Offy 3 carb

Image


For the Classic In lines or Vintage Inlines head, it just needs a box section intake manifold with a 90 degree turn to the ports, but any log intake head will take three IDF44's as a straight bolt on.


As a note, Ford's AVO division in England made a factory down draft Solex twin carb intake for the Ford Escort RS 2000 to which people added Fords Group 1 or Group X Weber 44 IDF's to. Stock engine was 98 hp, the early Group 1 2x 2-bbl Solex version had 110, the 2 x Weber IDF44's, 117 to 120 hp IIRC, still with the same 264 degree cam all early High Compression 9.2:1 Pinto engines ran.


They used a BMW 2001 Fram CA7245 air filter for 4 cylinder engines with bore spacings of 3.78 (BMW) to 4.0157 (early Pinto engined Escort)

The overall external filliment size is 420mm x 270mm x 55mm for 4 cylinders.

If you want to filter three IDF 44's on an in line Ford six, the average center spacing from bore to bore is 4.08", so you would idealy need a filter at least 627 mm long. The 613 mm long filter used on the carburretored 1963 LP350 - early 1985 LP500S "Bizzarrini 95 Centre Spacing" Lamborgini V12 engines have 3.74" bore spacings,

The Kiwi enginerr Bob Wallace was employed by Lamborghini from 1963 to 1974, and he got Fram organised as the OEM supplier.

Its continued 22 years of production supply have ment this realitively common 613 mm long filter is only about 125 bux each from K&N, and will just fit if you space three IDF 44 carbs out right. With a perspex cover to top it, you can make trim external metal shroud to encase it, and run under the shock tower brace arm on the shallow deck 200.

The way Lamborghini did the cool air induction eventually(1982-1985) was to run a 3-3/4 " reinforced HVAC hose to the stern.

Image

The filter is for one of the banks of the Six DCOE Weber series versions, not the IDC3's on the various versions of some Miura's.

K-N-Air-Filter-Lamborghini-400GT-Countach-Espada-Islero-Jarama-Miura-#E-2950

Image


Height: 2.438 in (62 mm)
Inner Wire: Yes
Inside Length: 22.75 in (578 mm)
Inside Width: 4.25 in (108 mm)
Outside Length: 24.125 in (613 mm)
Outside Width: 5.625 in (143 mm)

The carb Bore center spacing is 90mm ( 3.543 " ) with standard Weber IDF bolt pattern

Image

Image

Image


They were stamped 40/41, but just two go for over $1000 down here.

Image

These are new 71'S

Image

search Group1 RS2000 44IDF Webers w/Ford Manifold

Image

This was the early 1969-1974 small bore spacing Pinto 2000 engine that was used continually in the 1975-1987 Ford Capris in Europe and England.



https://www.youtube.com/watch?v=rTXakWIgyk0

https://www.youtube.com/watch?v=T89Y9_Zz0cQ


https://www.youtube.com/watch?v=rTXakWIgyk0
https://www.youtube.com/watch?v=T89Y9_Zz0cQ


If you use an intermediate idler shaft like TheFrenchtownFlyer uses on his triple carb racers, you'll be good to go.


Jetting, I find the stump pulling nature of the old type 1915 to 2165 VolksWagen engines works simiar to the 3.3 in line six.

Its not an Alfa Romeo or Fiat twin cam, but with the great VI head, your doing as well as a modified VW for air flow figures, and better for compression and general efficency. Nothing really changes with ITB tuning, as it size and ratio based, with really only two emulsion tubes, and F11 is normally the one.

Porsche and Volkwagen guys have gotten there cr@p well and truly sorted, so I'd use the bottom line on PMO's original graph, and that gells perfectly with what VW Bug guys have used in this link.

https://www.speedsterowners.com/topic/w ... size-motor
TEUBANKS wrote:
Idle jets 55
Main jets 145
Air 200
Emulsion Tubes F11
Venturi 36

This probably looks rich on the Mains to most folks and at times can act a little rich. However, I tried so many combinations and this gives the best all around performance I experienced in all the testing.

Additionally, I came across a formula (I forget where I got it) to help calculate what jets should be close for a given setup. Here's how it calc'd for my carbs:

Idles jet size = 36 (venturi size) * 1.6 = 57.6
Mains jet size = 36 (venturi size) * 4.2 = 151.2


Matthew, rev range takes you to 5500 rpm, with just over 6000 rpm possible without it falling flat. Potential power is 5.0 OHV EFi Mustang like 220-240 hp at 5500 rpm if you use the right Clay Smith cam lift and duration. The 490 thou lift is about all you can accommodate with the stock SI valve length and springs, so a 278 CS cam with a 110 lobe spread like Gene uses on his 250 Maverick might work best. You can back down on cam and venturi size to suit a lower rpm spread if you don't want to go past 5000 rpm very often. The curves above would suggest that 550 cc per cylinder is a 3300 cc 200 cube engine, and 36 mm venturis are bang on for a 5500 rpm power peak. Torque should sit down at about 225 lb-ft at 4400 rpm, depending on how the cam is set. At 5252 rpm, power and torque in bhp and lb-ft are always equal, so 225 hp and lb-ft might yield 240 hp at 5500 rpm, and something else at 4000 to 4500 rpm.


To de tune it further might be a crime, but stock, the old 1800 and 2000 Fiat 124's would only run 34 mm venturis to get more low end torque, and Fiat 124 CSA ran 44 IDF 20/21 with:

36mm chokes
4.5 Aux Vent
1.45 main jets
2.10 Air correctors
F11 emul Tubes
55 idle jets with 1.15mm air hole

For more info see
http://www.fiatspider.com/f15/viewtopic.php?f=5&t=14494


Mark Allison from Allisons Automotive.com wrote:
Basic set up for 40 or 44 IDFs:

Emulsion Tubes - F-11 or F-9 emulsion tubes (usually f-11 for 40s and f-9s for 44s)

Aux Venturis – 4.5 for MOST street applications

Venturis – The starting point is a venture that is 8mm smaller than the bore of the carb. So for 40’s it would be 32mm. For 44s, it will be 36mm (for MOST performance street motors). For more torque lower in the rpm range/smoother response/but less max HP on 40s, go to 30mm; for less torque/more max HP, go to 34mm. For 44s’, it would be 34 mm for more torque/less HP, and 38 for max power/less torque. I would not go beyond these limits, and I usually settle for a venture that is 8mm smaller than the carb bore.

Main Jets – Multiply the size of the venture by 4.1, and then by 4.3. This will get you in a range that will be very close to what you need. The more extensively you modify the engine and the larger the size of the engine’s cylinders, the closer you will need to be to the top of the range, and vice versa. So for my 44 IDFs on the coupe, I am running 36mm venturis. So my jet main range is (4.1 x 36) = 147.6, to (4.3 x 36) = 154.8. Because I have made extensive mods to make it breathe deeply at very high rpms and it is a bored out 2.0L, I am running 150s, and it is just about right. I may end up with either 147s, or 152s, but the 150s are just fine, and if I don’t change them, I will be very happy.

Idle Jets – Multiply the venture size by 1.6 and 1.7. So for my 44’s, my idle jet range is (1.6 x 36) = 57.6 to 1.7 x 36 = 61.2. I am currently running 60s, but also like 57s in there. For trip to FFO from Texas, I’ll run the 57s, but when I want to really have fun, I’ll run the 60s.

Air Correctors – Simply add 50 -60 to the size of your main jet if it is between140 -160, and add 60-70 to the main jet size if it is 140 or below. So on my 44s with 150 mains, I am running 200s, but will still get good results with 205s. This will ensure you get a really strong signal when transitioning from the idle to the main/air corrector circuits and get that instantaneous throttle response and relentless pull when accelerating from the 3500-4500 rpm range, to higher rpms.

Needle Valves – 200s will work for all the twin cams) (1438-1995). They usually come with 175s, which will not get those fuel bowels filled under WOT and cause a lean condition. It will still rev well and make all the right noises, but you will be down on HP and not even know it unless you are on a dyno doing comparisons.

Bleed Backs – Start with 00s. They usually come with 55s, but on a modified TC, that will normally result in a stumble on acceleration. Depending on the mods you have made, you may be able to use a 35. I just go with 00s and adjust using the pump jets/accelerator pump rod.

Pump Jets – On our TCs, 55s seem to be a good size. The smaller the jet, the longer it takes to deliver the fuel into the airstream, and vice versa.
Accelerator Pump Rods – These are found on the newer Webers, and can drive you nuts if they are not set equally. I simply back them both out to the end of the lip on the rod, and then turn them each in 10 turns. This seems to be about right as it relates to the compression of the pump. If they are 3 turns or more out from each other, you will get very inconsistent response upon acceleration.

Floats – Set them at 1mm closed (with gasket on the carb top – 10mm without), and 32mm open. Make sure the float carrier is not slightly bent and allowing the float to hit the side of the fuel bowl. This will drive you nuts
Horns – These are really important, and the way the horns are radiused is even more important. I have a chart produced by a guy 35 years ago who air flowed a variety of common horn shapes to empirically show the difference the horn shape makes. I am not at home and don’t have access to it now, but perhaps Alvon can post it (Is sent it to him), because some of our most popular shapes actually reduce air flow! The more room you have over the top of the horns, the better. As a rule, you need as many mm over the horns as the venturis are wide. So for my 44s, I need 36 mm over the horns to get a full air column. They will work with less – this is optimum.

Balancing and Synching – This is a whole different discussion, but after you have the carbs tuned (jetted) right, you have to get this right or all is for naught. You may read in some tuning guides that you don’t have to use the air bleeds to balance the carbs. This is wrong if you in fact you want to get all the cylinders drawing equally, which is one of the benefits of multiple carb set ups. It is very rare to get all the cylinders on a rebuilt engine to draw equally, so use them to optimize the performance of your engine and those carbs you just bought. And use a Synchrometer to synch the carbs. It is almost impossible to get it right with the eyeball or a tube, and it really makes a difference in performance and tractability. Imagine four trumpets playing the same note, but all four are either a little flat or a little sharp – just a little. It will sound like crap. And if your carbs are not CLOSELY balanced and synch’d, your motor will run like those trumpets sound. Get this straight forward tuning step right, and you’ll never get tired of listening to that puppy run.

Again, just one way to approach the conversion to IDFs. There are an awful lot of experienced tuners who may disagree, and there are surely a lot of other approaches, but these observations are made based on a lot of experience and experimenting, and a lot of dyno time observing the differences in power output playing around with all these parameters. If you do all these things, you will get a strong, reliable, smooth and tractable engine that brings your 2200lb car to life and puts a smile on your face, without having to go to a dyno.
Image
XEC Ltd ICBE's Inter Continental Ballistic Engines-
FAZER 6Bi (M112 & EEC5) or FAZER 6Ti (GT3582 & EEC5) 425 HP 4.1L/250 I-6
FAZER 6V0 3x2-BBL Holley 188 HP 3.3L/200 I-6 or 235 HP 4.1L/250 I-6
X-Flow Engine Components Ltd http://www.xecltd.info/?rd=10

User avatar
xctasy
VIP Member
Posts: 6732
Joined: Sat Nov 09, 2002 10:40 am
Location: PO Box 7072 Dunedin 9011,South Island, NEW ZEALAND
Contact:

Re: Triple Weber DCOEs

Post #20 by xctasy » Sat Mar 16, 2019 8:38 pm

The Escort RS 2000 Group 1 44 IDF had a terriably restrictive BMW air cleaner, and a very mild stock cam, so they used an odd ball F19 to trim the air fuel mixture for European Union emissions. Unplugged, it will need more fuel as well.

Generally, try the the F9 on smaller 34 venturi's

carb: 44 IDF 40/41 (Mark II Group 1 Escort 2000 RS)
choke size: 34
Auxilary venturi: 4.50
main jet: 1.45
idle jet: 0.55
air idle jet/hole: 1.30
Emulsion tube: F19
air corrector jet: 1.80
starter jet: 0.90 F55
accelerator pump jet: 0.40
accelerator pump back bleed: 0.80
needle valve: 1.75
Last edited by xctasy on Sat Mar 16, 2019 8:43 pm, edited 1 time in total.
Image
XEC Ltd ICBE's Inter Continental Ballistic Engines-
FAZER 6Bi (M112 & EEC5) or FAZER 6Ti (GT3582 & EEC5) 425 HP 4.1L/250 I-6
FAZER 6V0 3x2-BBL Holley 188 HP 3.3L/200 I-6 or 235 HP 4.1L/250 I-6
X-Flow Engine Components Ltd http://www.xecltd.info/?rd=10

User avatar
chad
Registered User
Posts: 4541
Joined: Sat Oct 24, 2009 9:51 am
Location: Lawrence Swamp, S. Amherst, MA

Re: Triple Weber DCOEs

Post #21 by chad » Sat Mar 16, 2019 8:43 pm

IDF...$75
You do not have the required permissions to view the files attached to this post.
"Big thing is only make one change at a time. Change 2 or more things at a time it becomes difficult to figure which change helped or hurt" turbo2256b » 1/16/2017
Chad - '70 LUEB on '77 frame (i.e. PS, D44, trapezoidal BB 9", 4.11), 250, NV 3550 & DSII to B transplanted, "T" D20/PTO, 2" SL, 1" BL, 4 discs, 33"X15", tool boxes, etc. Seeking: Hydraulic gear motor for Koenig pto. chrlsful@aol.com (413) 259-1749

User avatar
xctasy
VIP Member
Posts: 6732
Joined: Sat Nov 09, 2002 10:40 am
Location: PO Box 7072 Dunedin 9011,South Island, NEW ZEALAND
Contact:

Re: Triple Weber DCOEs

Post #22 by xctasy » Sun Apr 21, 2019 6:42 pm

In 1979 to 1984, Lotus and also Alfa Romeo's AutoDelta made Dell Orto equiped Independent runner side draft carb cars with 7:1 compression ratio, 9 psi boost turbos. Based on the twin cam 16 valve Lotus or 8 valve DOHC Alfa engines

Stock 1974 or 2174 cc Esprits were either 155 to 160 hp on 9.5:1 compression with DHLA 45's and various choke sizes, but normaly 37 mm chokes, with any one of about five different E tubes. Rpms at peak power were 6000 for the 1974 cc, and a little less with the 2174 cc.

When turboed, the carb size was kept the same, and just the emulsion tubes retrimmed. Hp when up to 230 to 265 hp, depending on the model. Still at about 6000 rpm. 44% to 71% increase in power, with no increase if carb venturi size.

Key thing is the carbs were not upsized, so if you want to use a less than huge Weber or DellOrto, then you can go turbocharged if you keep the turbo away from the carbs.

Specfic interest is the Alfa Romeo GTV 2000. Only being 8 valve per cylinder, they were about 35 to 40 hp down on the same sized Lotus engines

The 1962 Alfa DOHC, with the exception of the one year only US SPICA MFI,

it always used the 32 mm choke DHLA 40 carbs in European tune, and when AutoDelta turbocharged, the 120 hp at 5500 rpm 1962 cc engine went to 168 hp at 5500 rpm and 174 lb-ft at 3500 rpm with about 9 pounds of boost.

jetting and calibration was the "19116" Dellorto DHLA40H for the 168Hp to 175 PS Alfa Romeo Alfetta GTV Turbo ...

32mm Chokes
7848.2 Auxillary venturi,
140 Main jets;
7772.14 Emulsion tubes;
230 Air correctors;
62 Idle jets;
35 Pump jet;
150 Needle valves.


The stock non turbo 120 hp

For the standard Dell'Orto 40DHLA as fitted to the stock 'Euro' 2000cc engine, the following setting apply -

Choke size 32
Main jet 135
Air corrector jet 200
Idle jet 50
Pump jet 33
Emulsion tube 7772.10
Choke jet 70
Float needle 1.5

Image

The non intercooled install was very neat. The internal changes were compression and liner to head gasket related, and the 1975 to 1987 competion sucess of the Alfetta/GTV based cars was expetional.

If any of you are stuck with sub optimal choke sizes that strangle the power peak downwards to 3500, 4000, 4500 or 5000 rpm, just take the leaf out of Lotus and Alfas book.

add a turbo :twisted: :beer:

The issue is that some of us want to use DCOE 40'S OR 42'S with smaller chokes, so in thoise cases, you stuck with 32 mm chokes. On a 200 cube engine, the peak power rpm is down around 4500 rpm. Add a turbo, and you can keep the small size chokes, and get a 44% power boost without moving your peak power rpm upwards at all.

So a triple DCOE 40 or 42 engine with 180 hp at 4500 rpm 3.3 liter engine with 32 mm chokes would move into 260 hp to maybee 290 hp at 4500 rpm pretty easily with just a small T03 60 series turbo at 9 pounds boost. Your c/r would have to suit the application, but its possible to run 10.5:1 with boost modulated control of the turbo, as long as you have the right kind of MegaJolt/EDIS waste spark ingition ramps.
Image
XEC Ltd ICBE's Inter Continental Ballistic Engines-
FAZER 6Bi (M112 & EEC5) or FAZER 6Ti (GT3582 & EEC5) 425 HP 4.1L/250 I-6
FAZER 6V0 3x2-BBL Holley 188 HP 3.3L/200 I-6 or 235 HP 4.1L/250 I-6
X-Flow Engine Components Ltd http://www.xecltd.info/?rd=10

Who is online

Users browsing this forum: No registered users and 18 guests