Technical 2X2 =4BANGER CARB SCIENCE PROJECT QUESTIONS

So, the banger is 4 cyl.. but only 2 intake ports... the motor fires 1243..my thinking is it's 2, 2 cylinder motors.... next, when you put a header on... the intake gets real hokey ...

what I wanna do is run 2 one barrel carbs and split the intake... and weld the intakes to the header flange... seems to me tuning would be a breeze with a carb for each intake port.... might even find where they hid all the horse power to these motors...as it sits the banger is the secound worst motor built... @ 10 and less hp per cyl... first place for the worst goes to the 32 flat head v8 with a little less than 8 hp per hole.... I know the blame goes to the flat head design..... but what about the intake on the banger.... think 2 carbs spit intake will wake it up???

 

what was the thought here???

 

The 235.5 cid engine was first used in 1941 trucks. All of the six cylinder engines had panels retained by binding head screws with the nickname "stove bolts", so the engines picked up the nickname "stove bolt". I'm not sure when the term Blue Flame started, but I expect it was in 1941 on the 235.5 cid engine.
All Corvette six cylinder engines had three side draft single barrel carburetors. From 1953 to mid-'54 all carburetors had a bullet-like air cleaner that did little more than keep out small gravel. In mid-1954 the 3 carbs were fitted with a manifold and two air cleaners that actually worked. That's probably what you saw and assumed it was 2 carbs.
There were problems with the carbs. When idling, very little air was pulled through each carburetor and they are touchy. There's just not much air passing through the carb at that speed.
Although the fuel pump only produced 2 1/2 to 3 psi, this was too much pressure for most of the needle valves. As a result, most 6 cylinder carbs leak at low speed or just after the engine is stopped.
Like someone else said, the leftover '54 and '55 Corvettes were slowly sold off. I owned a 1954 in 1955, and Chevrolet dealers were reluctant to sell a two passenger sports car with a plastic body.
Cheers,
Noland Adams, President
Solid Axle Corvette Club


this is why I was thinking 2 one barrel carbs...down draft...

 

I was also thinking down draft would work better at idle at lower manifold pressure than side draft carbs....????

 

so no one has tried this???? will it work... or won't

 

Noland - we have never experienced leakage issues with these carbs, as long as the original Carter spring-loaded small orifice fuel valves were used.

The commercial aftermarket rebuilding kits had/have a solid needle and too large an orifice.

Jon

 

what about about direct carb to each intake.... and welding it to the header flange??? im still on the 2 v twin idea... like having 2 harley motors hooked to gether??? there gotta be some thing wrong with the fuel system to only make 10 hp.... does the combustion loose it's compression at the top because of the side opening flat head valves??? some times looking at a stock banger I think compression ratio is just a myth... with the compression getting bigger at the top..

 

I wanna try 2 WO style carbs....and I like the idea of 2 1 barrels... seems idle would be much better and cleaner...

 

sO THE IDEA WAS TO TRY TO GET THE ATTENTION OF A REAL CARB GUY.... i'VE NOTICED THAT OF ALL THE 4 BANGERS... MODEL A&T seem to be the worst... and of the carbureted ones, hp ones have more than one carb... also noticed most go straight to the intake port.... is there an advantage to a log type multi carb manifold... , or is it best direct to the intake port???

 

Directional changes to the airflow reduces efficiency. Dual carbs reduce the amount of direction changes the air must make. Direct coupled side drafts additionally still. Now introduce several dynamics that cause fuel to drop out of the air column, and you may find that direct coupled connections are best performing at high flow rates, while large plenums and long runners perform better at low flow rates. If you are on the salt, you design and tune the engine to operate at the top of the rpm range. On the street the engine needs to perform thru the full range, but primarily off idle. Very different manifold designs.

I had converted these carbs to sidedraft and had em running for a bit, but never had em on the road. I like em better as downdraft, despite the potential loss of efficiency

 

thanks a million for the post.... so is 6'' manifold runner enough???

 

so what you are say'n ,a log manifold is better off idle to mid range??

 

Everyone expects different results from their engine. Some will run what they brung, and others will test and refine till the cows come home. If you are expecting more, you will no doubt try many options

 

i'm kinda too old for too much test and tune and looking for those that have went down the path...simple as it sound... manifold runner length vs close to intake port... aluminum manifld vss short steel on... how to figure how much cfm per cylinder...is a log manifold better than direct to intake port??????

 

There use to be short elbow downdraft manifolds that were direct to port. Apparently they didnt work well because if you ever saw them in use a balance tube was installed between them. A log manifold works.

 

are you running a banger motor??? I think I have 6, so If I can figure some thing out to make them more drivable, I wanna at least try...the real brains behind ford was Edsel...henery was an ass, and if it wasn't for chevy putting them out of business in 1926...he'd still be making the model T.. edsel re designed the T,.. and its told that henry took a hammer to it

 

An ass or not… Henry designed these engines around what we consider today to be crappy oils, crappy gas, and crappy roads, for utilitarian purpose.

I have created several manifolds for T and A engines. The manifold pictured above was custom cast, then cut apart and reconfigured to resolve drivability problems on my T. If you want to think outside the box you better be prepared to invest time and money. Or you can always just order what already is available…

 

Kevin, do you have a picture of the manifold before cutting it apart?

 

any pics, or a link with more info???? thanks for posting..

 

I have 1,2, and three carb manifolds for the banger.. I wanna try to have the header and intake one piece.... I could add a balance tube from port to port if I knew why??? and why not..but in looking around, the hi performance inline motors I see seem to be separate carb to each cyl...

 

I found this carb I wanna try, it's a hp version of the carter WO.... it's 26mm and is suposed to add 10% ho to the early jeep banger.. I wanna run 2..



the base appears to be an adapter to the jeep manifold. and has a vacuum port, I could delete that to get the carb closer to the intake port and build the manifold to the carb base.... but non knowing of what to expect to happen drags my heels... being open minded and not affraid to try some thing out of the box to see results is ok by me... but before I jump off the high dive I wanna know how deep the water is...

 

I also have the thought that this carb would perform great on a stock banger as a single down draft..

 

also, Speedway sells an adapter to bolt this carb to a ford/ holley/ stromberg manifold..30 bucks

 

what were the problems aand how did you fix it

 

i think this might be a business for him as opposed to just talking about these-these might be sale items that he has or will have...he has made jewelry of all sorts!

 

Hey, AD;
I get the "I'm old & don't have much Time" deal. Doubt you're gonna find your exact answer here.
I'm gonna guess that some of the reasons you don't see IR induction on bangers is;
1) true IR is not possible on a Siamese-port induction,
2) back then, Dellortos/Webers weren't common & when found were very expensive.
3) Mostly, the firing order nets you 2 subsequent hits(gulps) then a waiting period. I do believe Hilborn found this out on his 4-carb manifold experimentations, which was problematic enough he went to & perfected FI(well, mechanical, anyways). & iirc, Winfield did a changed-firing-order on his T, helped tremendously. Which is why balance tubes & plenums were(are) used, so's the ports could "steal" as needed from the available mix. I don't see why the individual-port - not IR - shouldn't be doable, but I'd opt for a properly-sized good quality Dell/Weber(aftermarket or OEM) for exceptional tuneability, a properly-sized slide-valve car carbs like S.U., or properly-sized m/c slide-valve carbs like Mikuni. They'll be different sized than the usual approach. You'll probably still need a very small dia vacuum-balance-tube to even out the vacuum-pulses.
You might start chasing info on how they did it back in the teens->early30s, w/the aftermarket racing stuff. Fronty, Green, Hal, Winfield. You'll find some answers there, which might save you time doing what didn't work. & what did. While a different application, the concept(s) can still be used.
To speed things up, I'd slow down & read: Scientific Design of Exhaust & Intake Systems by Phillip H. Smith(he has more, & they're all good), books by David Vizard, exhaust header info/tech by Headers by Ed(you're gonna be surprised at the sizes you *don't* need). All will get you easily thru the math needed for a decent sizing-for-application-approch. I'd also look at english bangers too, as they had a nasty habit of using siamesed-porting on most everything, & twin carbs were some of the 1st things done to hop-up the little mills. & finally, I'd search Ned Ludd here & some other hi-po forums, to see what, if anything, he's postulated on siamesed-ports & IR-type carbs. Actually, I'd chase Neds' thoughts here, & elsewhere, 1st... , just to see. .

I get this ain't Instant Gratification, so;
Or just throw shit at the wall & see what sticks... .

Eventually, I'll end up going down this road, as my favorite mills, Stude Champ6, uses these ports. Bleah...
Now all I need to do, is to design, cast-up, & machine a DOHC-AF-16 version for the Stude champ6. Sigh...
Marcus...

 

I still have the vision that the Siamese single port separate from the other it will make more power.. it will have a more constant fuel mix... when # 4 fires it drags the left over fueled air from 1 & 2.... i know i'm not the first to think of this, and for sure not the first to try it.... but I did think of it by looking at what I have

 

seems to me that it should be easy to get 20 hp a hole.... 80 hp is still scraping the bottom.. a 40 hp vw has a manifold that feeds both sides... take that off and the hp doubles quick with a set of webbers..

 

The custom cast manifold that I cut up was originally designed to mount 2 Winfields close together for a plenum style manifold. Very similar to the “Equalizer” produced by Yapp. It worked great…! While the car was sitting still. My carbs were mounted sideways (as so many early race car pics supported was possible), but this led to extreme lean/rich running conditions during turning, accel, and decel. I suspected this would happen, but dramatically underestimated the severity. With the carbs oriented properly the carbs perform very well

 

The symptom was progressively worsening, and eventually horrible popping out the carbs under load. Since I had machined absolutely everything from scratch, of course I assumed that something I made was functioning improperly. Endless tuning of the carbs ensued, resulting in no improvement. Sidedraft adapters were made so they the front and rear ports were isolated, problem was more noticeable with rear port.



Carbs were swapped and the problem stayed with the rear port. Head came off to reveal that the valve seats were not installed properly and so were causing the Siamese intake charge to ignite.



New seats and a valve job later, the popping was fixed, but the carbs had been heavily tweaked. Started with each carb individually, then after the manifold was reconfigured, the carbs were tuned as a pair




Also made some venturi reducers to correct some overcarbing “bog”



Still some work to do to clean up a few details, but it’s finally runnin better than ever!