What does the stock weber intake flow? X?

Has anyone ever had it flowed?

Not many people spend much time with it and usually put an aftermarket REDLINE on instead.

Any ideas on the fuel distrubtion of it also? I have never noticed the inner two plugs being a different colour on the number one cylinder (is this because the water pump is right there and runs cooler???)


Did dick johnson use this intake to be emission friendly xecute? Looks like it nearly would be.

Pete

Any brillant intake flows a maximum of 10% less than one bare intake port.

At about 435 thou, intake flow is 145 cfm at 10 inches of H20. A good mainfold would flow about 130 cfm if it was an Ultra flow, and about 25% (116cfm) of the bare port figure if its was a bad one.

Mine was opened up at the top to a siamesed Holley 500 plenumb, and a gentle radius put on the two inlet runners. The bulls eye casting remained there. I followed David Vizards Cortina/Pinto 2.0 intake mods.

D i c k Johnston used the stock intake in a cleaned up form in an early SVO experimental. The gains are definately in the intake manifold it self. The Brisbance Engine Centre did some gas flowing, his XE ute was used as the development mule.and there was an ex F1 developement technician/engineer who came up with 146 Kw as being the best power availiable with a 280 degree cam, and still a carb. The first previw of the SVO was as a leaded XF with 280 degree cam and EFI engine.

The articles from Modern Motor (cf 1980, head flow, cf 1985 Group A Mustang), Street Machines info (cf 1988) on the 1980 to 1984 rounds of the ATCC where they talked about DJR's influences from the Brisbane engine centre, and the Wheels Feb 1987 article on the SVO are where I got my info from. Those articles are like good old wine!

Would this standard webber intake work well with a gas research sc400 (+the gra adapter) on an alloy head 250 crossflow?

Im tossing up whether to use it, or to use an ed inlet plenum modified to fit a crossflow. They look like this;

http://cgi.ebay.com.au/ws/eBayISAPI.dll ... %3AIT&rd=1

Which would work better? Any idea how much better?

Thanks

No, bad idea, but a good try.

LPG flows like a wet carb, and there will be a mixture inbalance with any EA/EB/ED multi set-up. Basically, if its works on a petrol carb, it'll woRk with a GRA.

The exception is the XE/XF EFI intake. It will work, but not very well, with a GRA carb.

The intake runners must be big but short. The 12" runners are only 1.4 inches in daimeter in an XE/XF EFI intake, and are likely to need a huge reduction in spark advance to ensure it never lean misfires on over-run.

Best options are the Ultaflow, Torker, Cain, Redline, Lynx 2 or 4-bbl carby intake, with the stock Alloy Head II a good second choice. The SC 400 can mount to it, they've been doing it since 1996. I've never liked the GRA goose neck to ADM 34 adaptor becasue of the 90 degree bend, but I'm sure if Leigh from GRA designed it, then it should work okay.

Deano

xecute®™© he he":12zxu6e6 said:

No, bad idea, but a good try.

LPG flows like a wet carb, and there will be a mixture inbalance with any EA/EB/ED multi set-up. Basically, if its works on a petrol carb, it'll woRk with a GRA.

The exception is the XE/XF EFI intake. It will work, but not very well, with a GRA carb.

The intake runners must be big but short. The 12" runners are only 1.4 inches in daimeter in an XE/XF EFI intake, and are likely to need a huge reduction in spark advance to ensure it never lean misfires on over-run.

Best options are the Ultaflow, Torker, Cain, Redline, Lynx 2 or 4-bbl carby intake, with the stock Alloy Head II a good second choice. The SC 400 can mount to it, they've been doing it since 1996. I've never liked the GRA goose neck to ADM 34 adaptor becasue of the 90 degree bend, but I'm sure if Leigh from GRA designed it, then it should work okay.

Deano

Click to expand...

Thanks for the info Deano. But I must say I am really surprised. I have heard from several sources, including GRA themselves, that LPG works really well with inlet plenums designed for petrol fuel injection (or perhaps they say this because it's very self-serving???)

It has to do with the LPG displacing more air in the intake thus requiring a larger plenum (a la injection intakes) to opperate well. The petrol carby intakes ar'nt as effecient, apparently, as there's not enough room to accomodate both air and LPG.

I'm left a little confused now....

I really hope you're right because its a hell of a lot easier for me to waltz down to the wreckers and pick up a stock intake and use the gra adapter on it, than it will be to get the ed plenum modded to fit the crossflow, then modify my heater box to suit.

Would there be any difference to which plenum is better if boost (via turbo) was introduced?

Thanks.

I make heaps of mistakes often...

The intake has an offcentre throttle body. I can't see how one tract having to travel 39 inches can deliver the same power and chamber filling as another having to travel 8 inches.



All the long branch EFI manifolds have a problem in that all the gas must be used before the ignition can be advanced. There is a risk of a lean backfire if the part throttle advance is too great. That's why the latest E gas Falcons have a shorter intake runner, centraly mounted.

The EA to ED item won't make the grade

xecute®™© he he":1evpsoko said:

I make heaps of mistakes often...

The intake has an offcentre throttle body. I can't see how one tract having to travel 39 inches can deliver the same power and chamber filling as another having to travel 8 inches.

All the long branch EFI manifolds have a problem in that all the gas must be used before the ignition can be advanced. There is a risk of a lean backfire if the part throttle advance is too great. That's why the latest E gas Falcons have a shorter intake runner, centraly mounted.

The EA to ED item won't make the grade

Click to expand...

All that seems pretty logical to me. So I think I will go for the cain or redline manifold with the gra adapter.

Would it make a difference performance wise if I got a 4bbl or 2bbl manifold?

Also, what would a custom manifold like this work like? Is it better because the runners are shorter?



Thanks.

Hey Deano,

How come there will be a mixture imbalance with a GRA throttle body on an EFi intake?

I was under the impression that since LPG is 100% miscible with air, and since LPG doesn't drop out of the charge like wet fuels do, one 680cc charge going to cylinder one will have the same AFR as the 680cc charge going to cylinder six (on EA-ED MPEFI intake).

As per the comment on the intake runners needing to be big but short, would you mind going into that with a bit more depth? In my mind I interpret that as going from 12"x1.4" runners to say 8"x1.7", with the net result being the runner volume being somewhat in the same ballpark, as well as changing the ram tuning efficiency of the intake further up the rev range, away from peak torque..

discokin6":20quoyot said:

Hey Deano,

How come there will be a mixture imbalance with a GRA throttle body on an EFi intake?

Click to expand...

Best options are the Ultaflow, Torker, Cain, Redline, Lynx 2 or 4-bbl carby intake, with the stock Alloy Head II a good second choice. The SC 400 can mount to it, they've been doing it since 1996. I've never liked the GRA goose neck to ADM 34 adaptor becasue of the 90 degree bend, but I'm sure if Leigh from GRA designed it, then it should work okay.

Click to expand...

The 2-bbl GRA adaptor for the SC350 or 400 carb has a 90 degree bend in it. Propane is indeed fully vapourised, but it is still a fluid, and if a fluid stays in suspension, then why do propans carbs behave poorly when passed through a petrol carb venturi? Becasue propane can drop out of suspension at 150 to 250 feet a second just like petrol.

discokin6":20quoyot said:

I was under the impression that since LPG is 100% miscible with air, and since LPG doesn't drop out of the charge like wet fuels do, one 680cc charge going to cylinder one will have the same AFR as the 680cc charge going to cylinder six (on EA-ED MPEFI intake).

As per the comment on the intake runners needing to be big but short, would you mind going into that with a bit more depth? In my mind I interpret that as going from 12"x1.4" runners to say 8"x1.7", with the net result being the runner volume being somewhat in the same ballpark, as well as changing the ram tuning efficiency of the intake further up the rev range, away from peak torque

Click to expand...

The EA-ED Multi has an offset throttle body, and at a certain critical velocity, it will develop a flow distribution like all gases.

The long EFI runners on the EA-ED Multi cause a 'time of concentration' flow bias so each cylinder has a different mixuture velocity, ram charge and resultant mixture strength . Since power is turning force with a speed factor, then number six cylinder will have low speed torque but will be unable to respond in revs as well as cylinder no 1. No 6 will be the waek link becasue it willnot be as throttle responsive as No 1. Each cylinder will recieve different slugs of propane (No 1 may have 14:1, No 6 may have 16:1). Any time one cylinder is fuel starved by a longer distance of travel, peak power trhough the rev range will be hurt. Power is greatest with a certain range cc per inlet tract for a given rev range. This is the law of pulse tunning Italians (Weber and DellOrto) and Poms (Amal) pionered in the 30's and 40's. Dellorto and Weber Marelli perfected the art with dry flow EFI throttle bodies, first with the 400i Ferrari in 1980, got into the Testa Rosa V12 in the mid 80's and then kept on with it to the Ferrari F40, 50 and Enzo.



It is possibly one reason why Ford went to equal runners with the EF/EL/AU/BA/BF propane versions. It solved the LPG issues and gained petrol power in one 'Fal' swoop.

When you inlarge the runner and make it shorter space limitations result in a much, much shorter inlet tract and a slightly greater plenumb area. The 12 by 1.4 and 8 by 1.7 case (both totalling 1.8 litres or the factory 2.5 litres with the throttle body) isn't coomon. Most people doing manifold mods do so for Turbo performance, not for normally aspirated EFI. 'They' end up with a 6.5 litre plenumb, not the same voulme at all. In that case flow bias is reduced, and the amount of backloged gas is even greater,creating a worse problem with lean backfires. The ignition advance then has to be pealed back to 25 degrees, espeically with high boost propane turbos. That 750 hp masterpiece above works because the manifold is as close as possible to being an equal length runner type and it has about 6 litres of runner volume, by my questimate.

LPG canny changes the laws of Fluid dynamics, Captain.

Xecute,

With all those flow number above do you think i will see much over 200fwhp with the stock carb and progessive 500 high compression and port water injection? Id love to stay stock even if an aftermarket was a bolt on extra hp.

Im considering tapping the stock inlet for my atomizing water jets or maybe even using my e1 head and EFI lower intake welded to the stock intake.

Pete

Are you sure one of the problems with LPG through a carby, isn't in fact the interruptions to developing flow?

It comes from the idea I've seen postulated, that opening and closing of the throttle plates in a carb is one of the hurdles to it regaining power after a shift - and hence the use of an ignition interrupt on the clutch pedal so that accelerator position may be held (and with it the streamline of air).

Of course, it'd make for some juicy flames out the rear!

(Of the car, before you all snicker too much! )

Do what you can with the intake manifold. Space is limited unless you get a sideways mount Cain 2-bbl becasue the EFI injector rail is very bulky and hits any stock position carb on an XD 1/2, or XE/XF intake. The XD 1/2 intake is very compact, but it isn't easy to sideways mount a 2-bbl carb ansd still get the air flow and power ypou need.


Cam wise, there are plenty of very specialised cams which can cater for your combination.

In New Zealand, the Ford Stock car guys are stuck with using a restrictor plate and only a 2-bbl carb. They have cams which build intake velocity by running a mini 'Nascar' cam profile. Kelford have made heaps of them to suit these econo racer engines. There is a nitrous or supercharger grinds, cheater cams, the whole nine yards

http://www.camshaftshop.com/camshafts/view/37/ford-6-cylinder-camshaft/


Best option is the wild street 155-E Fast street cam, rough idle, great midrange NZD$295.00 2500-5500rpm . It's a high intensity cam with lots and lots of 50 thou duration but not a lot of total duration. With a huge compression ratio, good detonation control you have massive effective compression great part throttle economy, and can run any of our more common 'little' 2-bbl carbs.

A couple of things.

The Holley 500 2300 series is not progressive.

The very rare 2305 350 and 500 Holley is.

There are a few 465 4160 series carbs which are 4-bbl vac sec or mechanical sec, and whatever Avenger and other carbs Holley makes these days. They are semi progessive carbs.

The 2300 500 Holley is cheap, effective, and can be tuned to suit. It runs clean and is very easy to be set up to be lean at part throttle, and rich at wide open throttle with the right power valve and jetting. It can yield 350 hp with the right cam and manifold on a 289.

The stock 34ADM is a bit too small, its only a 226 cfm at 1.5"Hg carb. The Essex 3000V6 used in Aussie Capris ran a brillant Weber 40 which can flow a lot of air, over 338 cfm at 1.5 "Hg. It can be bored out in the venturis to 35 mm, and looks very much like the ADM 34 to the passer by. It's the ultimate in stealth. Similer is the Weber DGAS 38...it is another good bolt on item which can be honed out to the 33 mm venturi size, can take the electric choke, and can flow a similar amout to the 500 cfm Holley (which is only a 354 cfm at 1.5"hg).

The Webers have a stock 46 by 93 mm bolt pattern, return line and can fit some of the aftermarket 14" air cleaners for the X-flow, along with the later electric choke.

xecute®™© he he":2302k2s1 said:

The long EFI runners on the EA-ED Multi cause a 'time of concentration' flow bias so each cylinder has a different mixuture velocity, ram charge and resultant mixture strength . Since power is turning force with a speed factor, then number six cylinder will have low speed torque but will be unable to respond in revs as well as cylinder no 1. No 6 will be the waek link becasue it willnot be as throttle responsive as No 1. Each cylinder will recieve different slugs of propane (No 1 may have 14:1, No 6 may have 16:1). Any time one cylinder is fuel starved by a longer distance of travel, peak power trhough the rev range will be hurt. Power is greatest with a certain range cc per inlet tract for a given rev range.

Click to expand...

But would'nt this uneven distribution still be a problem with the redline, cain or stock webber type manifolds? The two cylinders in the middle would surely get more LPG to them than the two on the very end.

Oh and I found the part on the gas research site that discusses inlet manifolds;

http://www.gasresearch.com.au/epg.html

The XE/XF and EF/EL/AU/BA/BF EFI intake is as close to an equal runner as any ever made. The intake plenumb is designed to balance the flow. Even on a 2-bbl Alloy Head II engine.


The EA/EB/ED EFI multi just isn't equal runner. It's that simple. One corner gets the gas first, the others starve more and more until the poor one at the far corner misses out on the free drinks

Bit like hanging out at the far end of the bar when your best mate is hanging out with a pealer bar maid, getting all your beer.

Just when i think i have things sorted you throw a curve ball X.

Those cams look wild. I love em!

Yes i have two 500 holleys with one being progressive with the accel cable at the back of the carb not on the side. It also has two vacuum ports not one like the std version. It has been alloy welded on a totally ported stock intake from a speedway car. 74 and 76 jets atm.

The other counter sinking redline adapter mod i have also done (as posted by you) and tried to stack multiple weber spacers to get the height to clear the rocker cover but are still not high enough. No choke. Just doing it for fun.

Im thinking of using the EA cfi air filter cover to cover up the holley and look stockish incase any cops want to have a look. All emissions gear will be on.


That fast road cam(155E) has specs like ive never seen before. You say this will be good with 98RON and water/methanol injection X?

Wonder how a weber would go with the 155E and 155-F (CHEATSTOCK) cam? Do they run the weber in this class?

Pete

Weber is the stock carb, from memory.

The 155-F is great if your cheating, but a bit of a dead loss on the street.

The cam is the heartbeat.

These cams are high intensity grinds, where performance is everything. Other Aussie grinds look to be far more conservative, with a nice, quiet, lifter- friendly acceleration rates. I couldn't see Crow, Speco or even some of the bolder American cam maker risking grinds like this because there are quite a few specific restrictions to running them. Like 750 bucks worth of parts including the cam, and not including a good leakdown test, harmonic balancer, front cover, ignition , fuel set-up, dyno tuning.

Hang on to that carb. Sounds great!

what is cheating?

(Cheating =Bending the rules for competitive advantage and then claiming you just were following the loophole in the rule book) .

I thought cheater cams were within the max lift and duration, but got there sooner and stayed there longer.

addo":2w9or8k4 said:

I thought cheater cams were within the max lift and duration, but got there sooner and stayed there longer.

Click to expand...

Yep, so they comply with the letter of the law, but are not stock 20, 50 thou durations.Therefore the profile is not stock at all, becasue the ferensics are not the same. In our contracts, one rotten apple, one piece of dog shyte in a nice complying sallad, and it fails the acid test.

It Depends on the level of detail in the rule book. If there is nothing on the 50 tou duration figures, or no control on lob centre angles or other specific detail, then you've got a loophole cam. Lots of them about!