I am gathering the parts to build a 30 Av8 coupe. It will be full fendered and am planning to run a Tremec RTS 4 speed overdrive and a Bronco 9" with 4.11 Detroit locker. This is to use up some parts I already have. A good friend of mine offered me a set of 59A weiand heads and Edelbrock 4x2 intake complete with Holley 94s and air cleaners. There is a cam and offset generator mount also but I haven't looked for any numbers on the cam. He said he bought these parts over 40 years ago and if he gets to see them run on my car that I can have them. So obviously I intend to do so, however I realize that the 4 carb intakes aren't ideal. Not knowing what kind of short block these parts were once on, I mainly wanted to ask opinions on if you think it is imperative to run a 4" crank. Obviously the more cubes the better it may run with so much carburation, but do you think it could have functioned well with a 3.75" crank? I have an 8BA Ford engine and was wondering if I could get away with an 1/8th overbore and 3.75" crank. Thoughts? Sent from my iPhone using The H.A.M.B. mobile app
That's what I was thinking. It'll look cool with 4 carbs, but probably run better on two. And it's hard to turn down speed parts when they're free.
You can't successfully block off ANY carbs on that manifold. On a 3X2 you can block off the 2 end carbs and run as a single, but the 4 carb manifold is almost totally blocked between carb bosses, only a small balance passage between the 4 carbs. Block off ANY carb and the cylinders it feeds will STARVE for gas. Perfect recipe for burned pistons. And yes, the bigger you build it (in cid) the more chance you have something you can drive on the street, but even with it big, your chance of success is minimal.
You might also check with the old timers on the fordbarn.com web site. Lots of experience there. I run three carbs with straight linkage on a 286 Cu.In. flathead with no problems. Also if you run multiple carbs you will have to change your distributor to full centrifugal advance and not vacuum advance. Someone on the barn may be able to advise you on proper jet sizes and power valves.
Here's a thread i did on the subject awhile back. http://www.jalopyjournal.com/forum/threads/edelbrock-quad-carb-flathead-intake.980694/
Hi, I had a buddy that had a built flathead with 4 carbs.....it was dumping so much gas into the engine that it washed out the rings and rod bearings and ruined the engine. Just some thing to think about, hope that this helps you.
Thanks for all the responses except Olcars, please delete that. I do value the input. I have read about the ineffectiveness of blocking off carbs on this manifold. Thanks speed gems for the links and flathead 4d for input on distributor mods. Definitely going to have to be jetted right down for any possibility of making it work. I will keep hoping to stumble on a Merc crank and possibly consider an aftermarket kit and justify the cost by having the donation of the hop up parts. Any recommendations on best supplier of 4" crank, rods and pistons kit? Sent from my iPhone using The H.A.M.B. mobile app
It sounds stupid to say this, but I sometimes wonder if there is a way to choke down the airflow of the 94's. Have them flow as a smaller carb and use direct linkage and the direct distribution of the manifold. Probably best to build a huge displacement stroker Sent from my iPhone using The H.A.M.B. mobile app[/QUOTE] s
Walt Dupount in Maine is a old time engine builder and has been building engines for 50+ years. He runs a 4X2 with 97's set-up by Uncle Max on his '40. I don't know the details of the engine build, but guys like Walt and Ol' Ron (Ford Barn regulars) say this engine runs incredible and has the best throttle response of any engine they've driven and built. Plus, Flatdog (RIP) ran 4X2 for a while and I heard and saw his car run. It sounded like a SBC and ran like stink. I would run a 4" crank if you have it. Flow is going to be your friend here, so some hi flow SBC valves and other port work would be a good idea. Google Mike Bishop's porting guide. It's the bible of all things flathead porting. It can be done, just need to be smart about it. Those that say it can't are wrong.
Seek out the older posts for theory and experience on these things. Pay particular attention to Pete (very experienced dangerous radical who has raced flatheads for last hundred years, always with 4 carbs) and Flatdog (Ran 3,000 pound '34 into the 12's, and the thing was perfectly streetable...)
Thanks banjo and Bruce At this point I am planning to buy a Scat stroker kit, leaning toward the 4 1/8" crank and planning to go straight to 3 3/8 bore as I don't plan to put a ton of miles on the car. I have read that some guys recommend leaving some meat there for a future rebore but If I can get 20k miles longevity out of it that should be good for about 20 to 25 years of occasional use. Sent from my iPhone using The H.A.M.B. mobile app
If it was mine, I'd go to a 3 5/16 bore - with a 4 1/8 crank, you still have 284 cubes of flathead fun. If you're going to invest the time/energy into porting/relieving the block, you'll want to know that you can bore it again at a future date. There are reasons to rebore engines that are not always due to wear - can be a component failure, water/rust in a bore from a leaking head gasket, etc.. Keep the future in mind - you'll be glad you did.
s[/QUOTE] Why not just sell the intake to someone that knows how to use it, and get a two carb, that way everyone is happy?
Not being a professional engine guy, I have what I think is a pertinent question. If you have a 3 3/8" flathead block that won't take an overbore, can it be re-sleeved ? Unless there's a good reason, I would think that these things would last forever!
Well over $1000, and there are usually problems with deck integrity and water seal when you sleeve all 8. Its do-able, Guys do it on Ford FE's (427's) but I don't think flathead blocks are expensive enough to make it worthwhile as a rule, unless there was a lot of trick port work, you would probably be ahead to just start over with another block.
Why not just sell the intake to someone that knows how to use it, and get a two carb, that way everyone is happy?[/QUOTE] And whom is this "everyone" that will be happy? Perhaps we should skip the Flatty altogether and go straight to a SBC because it's the easy way to make a hot rod. I have the opportunity to have this stuff given to me from a pal of mine who wants to see it run on an engine. I am not the kind of guy that takes something that another guy spent good money on and turn around and sell it. This post was to query the guys that have done it and if it's not possible I would kindly decline my friend's offer. I appreciate the positive feedback and information from the Flathead guys here and am determined to give it a try based on the fact that there are guys out there who are making it work. It may not be ideal, but it will be a rather unique setup at least in my neck of the woods, and most importantly it will get dusty parts off a shelf and back on an old Ford they were made for. Sent from my iPhone using The H.A.M.B. mobile app
Uh, I was responding to stllrng's post?? But its all good, I'll put you on ignore anyway. Thanks for the heads-up.
I have a four carb intake(home built and named Pacific Jackrabbit) that in theory should work well;each throat feeds an intake valve and in theory(untested) each individual throat should be tuneable.All of my flat motors are always big inch,big intake valves,big cam shafts;usually lots of fun in a 2160 lb Henry cabriolet highboy
How come you haven't tried it yet? If I had your resources, I'd have it on one of those "big inch, big etc." engines in a New York second.
With a 4-carb setup you will have very little vacuum signal so the power valves will open sooner, causing a rich condition. 2.5 PW's or blocking them off should be considered. (one trick to making the power valve change easier is to put a hex bolt in place of the center bowl to body screw) The 4 carb intake was initially designed for racing and thus does not have the open plenum like the 3x2. Sounds like a great build......
Quote "It sounds stupid to say this, but I sometimes wonder if there is a way to choke down the airflow of the 94's. Have them flow as a smaller carb and use direct linkage and the direct distribution of the manifold. Probably best to build a huge displacement stroker" End quote. It IS possible to do this, just take a look at how Holley did it in limiting the air flow on the haystack Holleys used on the 1956 and 1957 dual quads. Brass rings were machined to go around the boosters, and then the boosters were spread to keep the rings in place. This effectively limited the airflow. As mentioned above, power valves can be an issue. MUCH easier to use Strombergs with the mechanical power valve or Carters with their metering rod technology rather than the Holleys with the vacuum power valve. Jon.
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