I am toying with the idea of picking up an Edelbrok 4x2 intake from a friend for my 59AB. My question is, will this engine be over-carborated? Carbs are 97's, andI know I can down-jet, but that seems like a lot of carbs for a "street" engine. It will have a pot-vin Elliminator cam, .125 over, mer crank, 1.6 intake valves and releived. Heads (compression) is up in the air at this point. I would love to run it, but don't want to if it will be troublesome and worthless for my engine. Any thoughts? This will be in my 34 Tudor backed with a three speed and a columbia.
The cool factor is probably worth it but I'm guessing you'll need to block off a couple carbs to run on the street. Most of the 4X2's I've seen on flatties were race applications.
Thanks I'll do a search. I do not want to block any carbs, I feel the intake would be "worthless" if you have to fake it. Thanks fella's!
4 inline carbs were used in "race" cars, not street cars. Blocking off two carbs will give very poor fuel distribution. If you just want to look cool I guess it would be OK, but if you want to show your Wheaties go with a two carb or tripower setup. It's a little difficult to make a progressive 4 carb linkage unless you get a manifold like in the enclosed picture. Two or three carbs will be better for a street motor, or you can put a blower on the motor and make some serious flattie power. IMHO
Bruce, the information between this thread and the one you reffered me to are completly different....After reading your thoughts, I'm gonna go for it!!!!!
Talk with the guys who actually ran them...Flatdog, Pete. This is clearly not as radical as it seems...lots of people forget that CFM demands vary considerably between 180--360--isolated runner setups.
And on CFM...Detroit often put more CFM on engines that actually had to idle and live out guarantee periods than rodders who use those formulas.
why doesn't it work? This cis 2007 ,not 1972 where this set up worked perfectly ,and today we have digital exhaust ****ysers,laser temp guns,ignition ****ysers,etc so it is a damn sight easier to get one run properly now than back then.
It's not that it wouldn't work... It's HOW it'll work. I'm not sure about all the new thinking on running 4 carbs. I had a friend who is a pretty good flathead mechanic and engine builder who had an A-V8 with a 276 in it. He had an Isky400jr in it and ran an edelbrock 3 pot. He took me for a ride and we had a blast. Lots of speed, torque etc. After the ride, he asks me if I noticed anything odd about the intake setup. I said no and then he pointed out that only the middle carb was connected. He said that after constantly trying to get the 3 carbs to work right, and then trying the 2 outer ones, he eventually settle on the single. He said it ran stronger and more smoothly on one carb. This was a guy who's worked on perormance flatheads for years... Barney Navarro said to me that 3 carbs were too much on anything but a full-out racing flathead, but that with his 3-carb intake and it's correct runner design, you could run 3 carbs and have better performance than most super dual intakes. But he suggested blocking off a carb or two for the street. Jere Jobe has a 4 carb, monster flatty and has set that intake up for the lakes/salt and offered it as a replacement for guys trying to run injection and having trouble. He said he's always been faster. But he also says 4 carbs would offer less performance on the street. Flatdog is a modern flathead hero so I'm sure he knows what he's talking about. I'm intrigued by that... If I were to try it, I'd have a 300+ci flatty with a Climax cam and I'd use straight linkage on a Thickston 4. It'd be way cool but I bet it would be just barely streetable. And I bet I'd loose street races to smaller flatys with fewer carbs. Namely RYAN...
A four carb (typical Edelbrock flathead type, similar) is not directly comparable to a 3 carb...the area seen by the engine is much more like an isolated runner setup, I believe, working from theory and from those who have run them. The typical flathead fours are much closer to isolated runner setups than they are to true manifolds.
So it's like running a Weber intake, on an overhead, right? Only with antiquated, difficult to manipulate, carbs, on a block that doesn't '****' too good... ;-) The Thickston intake I indicated is more of a manifold design. I see how the theory is developing. I'd really like to try it, but with the cost of flathead parts what they are and the PITA it is to find good Srom 48s, I think it might have to stay a theory for this bench racer.
Out of curiosity...wouldn't that hurt them in the same "streetable" fashion that old log manifolds, and Mech. injection are? sorta all or nothing? rpm/velocity=good. idle/light throttle=not so good. ???
I think it's sort of the same but not quite... The design of the log manifold created it's own environment which added to/hindered the performance of the engine... With a direct port design, you're eliminating the manifold and all it's potential hinderances and benefits and relying soley on your abillity to tune the carbs. Manifolds distribute mixture and vacuum in unique ways that can help or hinder performance. Direct port and port injection systems take the manifold out of the equation to varying degrees.
gotcha...more like direct-port injection, then...but p***ive...o.k. I would still think it would be trickier, and the returns would be limited, given typical street parameters...??? ahhhh...science!
Hello..It's hard to agree or disagree with the info..to each his own thinking..Mine is a 4x2 inline for a Flathead will work. Porgressive linkage can be made for the two center 97s as primaries and the two outside 97s as secondaries..I don't believe that you will lean out any cylinders. With a mild cam, and "GOOD" headers the engine will breath just fine. 300 CFMs is OK at low and mid-range RPMs.. Once you get the Flatty up in RPMs the other 300 CFMS should be OK. With your engine 2 CFMs per CI is not over kill real close..??????????????????????? Here is the answer, try it, if you like the way is runs..BINGO..YOur happy.. Duane
Use 81 carbs with the smallest jets you can find & it will run great.Been there and done that 30 yrs ago & got 18mpg with 3:08 gears in my t bucket.You have to run all the carbs all the time or you will lean out 4 cylinders.
Unfortunately the engine in the pic I posted earlier no longer exists,but it utilised the theory of one bbl per port as mentioned. In New Zealand there was also a company .'Hogan' ,who made a 4 carb set up.Mainly designed for boats and stock cars it consisted of base which bolted to the block ,then a cover on top of that.the whole thing was one open chamber.A **** house design actually but it looked the part. You could also get twin or triple plates to have two or three carbs. My favorite was this triple of 94's .An unknown make of manifold,I've never seen another like it,it worked perfectly on the street with a progressive linage.
Not really, only if you sell off your project then build the motor for the next car. Sell an arm or a leg?
http://www.youtube.com/watch?v=osQxpAKFVH8&mode=related&search= http://www.youtube.com/watch?v=qK2uiF3i8gw&mode=related&search=
Here is our 4x2 setup. The carbs are run straight on. As you can see though - itis not somethig we drive to the grocery store in. The motor is 296 ci, Chevy valves, huge 433 Isky cam. Does it get the spark plugs wet - of course - does it run strong - ask any one who has heard it . We tried to run it on alcohol using (4) 48's. Just too much cam - it would idle, but we could not get enough volume of alcohol into the motor - we would need Hilborn for that. We are looking for one of the very early units - any leads are welcome... Thanks! John R.
I fully intend to run 4x2 on the street when I build my next engine (hopefully this winter). I have four 48s or four 81s (strangely, I only have two 97s) & will try them both to see which are easier to tune.
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