All Small Six lets talk tubular....custom intake on the falcon log head.

This relates to all small sixes
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Interesting.
I think if you are going as far as to press and seal in tubes into the existing intake ports removing the log, I'd keep them short and have a flat flange, Then you can bolt on a custom intake, box, or individual runners.

Very neat! I'm subscribing.
 
Wish you the best and totally encourage you in your efforts.....what you are suggesting will work brilliantly. Your down the road to avoiding a multiple carb solution, which is always the standard United States reponse to reliable, long term maintenace free horsepower generation. The dislike for balancing throttle linkages is the reason for going to a tunnel ram single carb.


I personally ditched further work on the single 2-bb or 4-bbl Holley carb 6PT intake adaptor I was working, not because it didn't work...I just found out what was the best way to make independent runner systems reliable and more powerfull with less effort. Again, the United States guys taught me that multiple throttle body induction could be blanaced via IAC and kept servicable from aftermarket worked versions on the CrossFire 82 and 84-86 Corvette and 305 F car versions of the twin CFI setups. http://www.thirdgen.org/techboard/tbi/4 ... odies.html

I will never be going back to single carb options, you and I are at philosphical different postions, and I've spent 2 years of my own time looking at what your doing.


Since I know that the log head isn't a pinch point if its worked, cutting off the log is a bold move I won't be bothering with becasue there are easier ways. My 6VO and 6Ri adpators bolt to the log head, and make three carbs work reliably, and allow port EFI. Its personal, not a vote of no confidence in the idea's you have.


Powerband is where you at, your just doing the same thing in tube.


Some ideas follow which will help you on your way.

Powerband and I did discuss the idea of a 6-bbl intake on one log head, a sort of 6-bbl version of the EAO Lima 2300 efi turbo intake manifold. That could take one 2-bbl Holley. The 2305 eliminates the worst problem on the 2300 series carb...it has much better air fuel distribution, without biasing flow to any particular cylinders.




Seams to me you are simpliying it a step further, like building an upturned Frenchtownflyer intake with just on Holley 2-bbl.

Like this, only down draft.


Seams like your halfway there, and you may not even need tubes




Plenty of times, a side draft version of the a tunnel ram concpet has been done.


More impressive than the triple DCOE 45 conversion to Datsun 24/26 and 28 Ounces is the 4-bbl 390 #8007 Holley adaptor to the stock engine that came with twin Hitachi SU intake manifolds.

There are two types, an Arizona Z fully cast 4-bbl and a more interseting stock Z car two SU adaptor to 4-bbl. Seams to me a nice 1:1 linkage 2305 or a good old 2300 500 cfm 2-bbl would work.

http://www.datsunclassifieds.com/auto-p ... -4071.html

http://forums.hybridz.org/topic/69355-4-barrel-intake/

http://arizonazcar.com/cars.html

http://arizonazcar.com/azcM2506.JPG

http://bringatrailer.com/2012/09/29/bat ... -race-car/
 
thanks xstacy,

I've always been a fan of multiple carburetor engines at shows. it shows a lot of building and fabrication skills and I always give a thumbs up to the guys who can maintain and tune a port on port fuel system.

the third gen corvette link with the crossfire intake and multiple throttle bodies sure is a good read and love the pictures in it, true ingenuity.

how far did out go with mounting up the four barrel adaptor or a two barrel set up?

I've been playing with the idea of modifying a log head for two years now as well and this first attempt is very similar to that you and powerband mentioned with the six port intake and a two or four barrel on top but I've seen some close designs but I'm really looking forward to bringing my own design to life.

I hope this leads me to other ventures down the road if this bolt on flange works well it will be possible to have different intake setups on it like the tunnel ram and ya I guess you could say its a tunned down tunnel ram with one carb instead of three 2300s like frenchtown flyer but same concept. as well as the side draft tunnel ram custom rectangular intake that is a sweet picture! I think the log will have a better shot of making the forced induction effect because the intake does have the angle straight into the cylinder so it should really flow some cfm.

all the aluminum supplies should be in this week and I ended up going with 6063 t5 thick wall pipe and all the flanges for the runners and plenum are pretty thick at .375" inch so the runners will be set up on a jig to shape and bend as much as possible then cut and weld and turns that can't be bent as well as weld the flanges to the new aluminum runners, weld up the plenum and carb base.

I believe od of inserted runners are 1.315 and inner diameter is 1.049" so its got a real thick wall. had to get an adjustable counterbore for the machine work to fit the pipes and I hope these are not to much of a pain to work with and fabricate.

but I wanted the tube as thick as possible so it can be machined in the future for fuel injector rails and a single throttle body as that's a viable upgrade down the road.
 
I enjoyed the links about the Nissan racers as well some of those four barrel intake look nice as well as the triple webbers.

I was going to say I foundsome viton o rings the right size I want to try to seal the tubes in the runners so I will have a groove machined on the tube for the o rings that will slide into thr counterbored head so what do you guys think.....go with the viton o rings which are up to spec or does anyone have a source for copper o rings I've not been able to find them online.
 
time to port and polish this turd.

its actually nice to finally get to the log intake runner for porting which otherwise can't be done. the outside diameter of the runners are 1.5 and the inside roughly 1.25-1.3" because they are not circular(more of an oval 0 ).

so valve train gear ill get from classic inlines and plan to use their stainless steel intake and exhaust valves. Iintake valve will be the 1.75 which in perfect theory can support 310hp on a 1 intake valve six cylinder.

so the more I get into it this log does have relatively small intake runners which will produce peak hp at 5200rpms or more when ported. so the runnerscross section is the main power limiting factor.

based of engine simulation software my 207circular at 80% volumetric efficiency with 509 cubic feet of air per minute could put the 200 at 340 crank hp in a perfect world. but some of the joys in dealing with 50 year old engine technology a big lack of any available head to make power about 5500rpms so my intake design will unfortunatly not improve the rpm band as much as I hoped but I believe it will make a true peak hp appearance at that 5200-5500 rpms and if I was going to race it I'm sure a modern camshaft could carry the usable rpm band up a good amount very similar to a small log with a single barrel 1100 for example which would never make peak power near 5000rpms but that's why people upgrade the cam so they can actually use the higher rpms even though they are not making true power there. similar to if I wanted to cam it up I'm sure I could carry this engine upwards of 6200rpms with the big carb but this is not a race engine just trying to improve efficiencies and drivability.

and my cut off log is coming a good way but as ironic as it is to say the log is still the pinch point with small intake runners 1.3" or less and the terrible flowing exhaust and small valves so the aluminum head is really sounding nice right now because even after modifying whatever intake you think is best the small valves and runners still are a big limit. so I really doubt to see huge power gains by this maybe just more efficient so this is certainly a street intake and I think the large log cut off like fast64ranchero and gt turbo at 90degrees with the flange is the only way to make real power but that's still limited by the 1.75" intake valve too so I hope this explains why they say port on port carburation for power if peak hp is your concern.

this build is certain to see improvements over the log but the log really is not so bad when worked right it will still make power in the street rpm band very similar to the aluminum head but there is really no option to make true peak power at high rpms with the 200/250 so great street engines they remain and as for power I don't think a large log done right with port on port could beat when built to race specs.

so off to porting out my cut up log I go and ill do a little on each port...repeat ...repeat and see how far I get and all my metal supplies spent 85 on the tubing and flange and plenum hardware so ill be excited to start fabricating the intake and even though it may not make much more power then a large log 2v it will be sure to catch some eyes and by next week should take shape.
 
so when they say the log is the pinch point they are not talking about the intake design as the pinch point its really just the whole head is the pinch and is limited to low - mid range street use with small valves being the biggest pinch but the only really benefit I see to cutting off the intake is to port it and hopefully so to come get it on a dyno to see what it will do.
 
this is my first time working the exhaust ports on about 5+ log heads I have built so I'm a little nervous about some velocity loss but I think it will be a good improvements because the stock ports are so small barely an inch square. I've got two of the ports all the way to 1.25*1.25 squares so that's a pretty big improvement and ports look noticeably bigger...I'm trying to not go to wide on the runners and giving more attention to the hieght of the runner but still a long way to go on porting I spent about 1.5 hours this evening and still have a long way to go so ill get a pic of it all ported out by the week end.
 
autoX65":lybkevof said:
so when they say the log is the pinch point they are not talking about the intake design as the pinch point its really just the whole head is the pinch and is limited to low - mid range street use with small valves being the biggest pinch but the only really benefit I see to cutting off the intake is to port it and hopefully so to come get it on a dyno to see what it will do.
A straight runner has got to be better than a 90 corner. I am playing with the same thing waiting on my alloy head. My head with the most of the log cut off looks exactly like the posted pic.
I used pieces of 1 1/2 exhaust tubing -close to 1.4 ID. The pieces are cut from 90 deg bends with enough bend left to get about 11 degree runner. The curved end was worked rectangular on the curved end close to the port shape with about 2 in straight at the 11, deg. extending out. Used a filler-build material called "lab metal" to seat and seal the tube about 3/4 in. in the port, with a concave fillet on the outside for strength and looks. The log is 16 ga. sheet metal 3x6x2x6x20 in. The difference of one in. on the wall portion allows the bottom to follow the 11 deg incline of the runner and top to be level for the two barrel carb mounted between 3 and 4. The tubes 6 in long with flared ends enter at the bottom of the 3 in side and end 2 in from the 2 in side with 2 in sticking out the head side. 3 in sections of 1 1/2 radiator hose slips over the tubes and makes the connection. porting and valve mods-.060 milled all on 72 head.
Main point was to describe the lab-metal & radiator hose approach to this verses a machined-bolted-welded flange attachment approach. This leaves a bit of adjustment for fit.
The total runner length about 11 in with room for a bit of adjustment. Wonder how that comes out for RPM tuning on a 3rd wave??
Alloy head in route so this may take a back seat priority :unsure:
Haven't done pics, soo words will have to do.
MYway
 
very cool I have not had a chance to look into fillers for chemically bonding but sounds like you've found the right product for it. as for the 11 inch length that would be fourth induction wave creating the tunnel ram effect at 7200rpms so a little longer might be ideal but your plenum design ontop of it sounds sweet.

pictures please!
 
http://s1292.photobucket.com/user/autoX ... sort=3&o=0

check out the link above that is pretty much the flange and pipe ill be fabricating for the intake runners. everything looks to spec from my measurements so I'm still finishing the port and bowl work then will get serious mocking up the intake and I also have spare pipe and bends of course that needs to be cut and welded so I can mock up the collector under the plenum then carburetor base , then to the machine shop for valve job. and yes that's all high grade aluminum for the intake :nod:
 
finished porting the exhaust very carefully as well as blended the intake and exhaust bowls and they are sooo much cleaner with the bosses blended as well as grinded out the excess meat for the thermactor emissions. I didn't want to get to carried away porting but I made the ports more rectangle taking away from the top and bottom of runners and minimal on the sides. then gave it a little downward lip which I know is real successful on 302 Australian Cleveland heads and gives it a much better exhaust sound. I took the whole exhaust from a 1" square to a 1.26" square and then gave it a little more of that lip I described where it will meet the header.

a pic of the exhaust ports and side view of the cut off log.
http://s1292.photobucket.com/user/autoX ... sort=3&o=0

still need to port the intake runners and polish all of it! I'm very pleased with the exhaust work since this is the first time porting it on over five of the log heads I've built over the years.
 
http://s1292.photobucket.com/user/autoX ... sort=3&o=0

wouldntt that be cool six carburetors or the mini squirt would be awesome as mentioned its just a lot to take in but id say the large log custom flange with port on port in a 250ci would be sweet.

I posted one in the two you tube videos of the large log with six carbs. id love to see more links or video or any of these ford sixes running that have been modified like power band or if any one else has more links or pictures post them up.
 
I would love to do something like this but I had my I on my fuel system for quite some time so I've really built everything around the 2305 holley in design for best drivability and mileage so ill still be running off one venturI with this holley and just the one barrel is 250cfm with annular booster and its already calibrated for the inline six.

MustangSix":t3legzj9 said:
I'm going to recommend a slightly more radical approach - Individual Runners. Motorcycle carbs are cheap and very tunable or you could go with the EFI throttle bodies as well. Microsquirt that thing for under $500.

Several years ago I tried an IR approach using Mikuni carbs on the Locost. While it ran well at speed I had difficulty getting it to settle into a good idle. Mostly I attribute that to my lousy approach to linking all six carbs together.

But my recent experience with my son's Zetec powered MGB has been really good. We used Keihins from a Kawasaki ZX9R. With no tuning at all it fired up and ran extremely well and was only just a little lean on top end. We richened up the main jet a little and it is a blast to drive. It pulls from idle to the 7500rpm redline with no hesitation or flat spots and holds idle smooth and solid. We had to use a regulator to keep the fuel pressure down to under 2psi.

Eventually we plan to switch the carbs for EFI Hayabusa throttle bodies. Cheap and easy to adapt - you just clamp them to an intake tube. The injector bungs are integral and the end carb holds the TPS sensor. The bodies separate by taking the threaded rods off. You can then add two more with the appropriate spacers and link them by just tacking on a straight flat tab to the linkage.

Carb or EFI, it is super easy to add these to the ex-log head by just brazing on some tubing for the intake. As far as length, don't overthink it. There are so many variables that go into tuning the total engine and intake tract length, volume, and cross section are only part of the equation. Point is, it won't really make a big difference if you made the runner 4 inches or 15 inches. Just do whatever is most easily packaged under the hood.
 
The big problem is "FIT". It's 25 in between front spring housings. Might be able to notch out a half in. or so, but really need more room for ram tube type intake. Splitting it up into two plennums and carb's with #3 port curved, and a balance tube connection might be a possibility. Get's complicated!!
I do think individual straight runners weather FI or NA would be good for higher rpm. The ram effect or momentum of the port velocity AFTER bdc affect cyl fill .
Myway
 
so I should be able to finish a good about of Machine work on the mill to clean up the surface, counterbore the runners and groove the tubes for o rings so I should have the flange part all set tomorrow then just will focus on shaping the runners this week. that's about my main concern now just to package and fit it all nicely and wish I could keep it below the hood but chances look slim of that so we should see some good progress this week.
 
Soldmy66":lbmd5m72 said:
Any thought of having the intake runners cross over the the driver's side of the head?


of course I think that crossing it to the drivers side would be the best way to get a long length runner packaged under the hood.

I didn't want to have any issues with not being able to get the valve cover off so I am putting the center of the carb base directly where the 1.5" carb hole was just only up higher so I can still easily take off the valve cover.

I've already got runner dimensions and bends made up and each runner has the minimal amount of bends I could get away with.

so unfortunatly no it will not cross over the engine but I did debate it.

I can't believe I am going from one 1.5" venturI to now six runners I've been able to port and bore out too 1.45" inch cross section on each runner and the log has a two 90 degree turns one at the carb base to the runner and another 90 from log to the individual runners inside plus in the log all of the runners are fighting each other for air. so I've got a lot more potential with the runners ported as well as less turns then the log and I plan to keep 1,2,4,6 equal length and 3,4 with the large combined exhaust port I went for shorter in hopes to keep equal A/F ratios across cylinders and well as took into account firing order for the best plenum effect.

ill upload pictures of progress as the week goes along but plan to have the flange with runners attached all bolted on this week as well as tubes formed so stay tunned and keep involved in the discussion.
 
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