Hey guys. I have a 54 235 that im doing Fenton headers and dual intake on, but i need carbs. I would like some input on what carbs to run. Would Holly 94s work? I see that evilbay have some yf carbs ment for Ford inline6 engines cheap. Could those work? Thanks!
Most of those setups are way over carbed (CFM) for street use, cause they don't get enough vacuum signal anymore. WOT they can be okay, but still not optimal. Also - with a dual setup on a sixbanger, you're pretty likely to discover that you've either got one carb too many, or one not enough. The firing order on an inline six makes it perform best with either one, or three carburetors. If you choose the 3-carb route, you'll need carburetors that would work best on the displacement of one cylinder of your 235. Your options: Get a tripple intake and use 3 Keihin "Constant Vacuum" carbs for an 80 cubic inch Harley Davidson motorcycle (pretty much a downsized version of the Stromberg carbs) - or if you wanna be fancy - 3 Tillotson carbs. If you really want 2, make sure that the combined CFM is not much more than the single carb, or you hurt your vacuum signal (mileage/drivability/response/torque etc.) 32/36 progressive Webers are an option. Frank
Well, i dont see that a single carb mounted in the middle of the intake like normal could be that good for the fuel flow. The outer ports must see less fuel than the middle port. Must be better to have two carbs. But ofcourse, the best is one for each port. But now i have a dual carb fenton intake so i will use that and find carbs that work with my setup.
I also firmly believe that the 235 engines are astmatic. They NEED better breathing both in and out. So a dual carb, dual out MUST be better than orginal. Its all down to find the right carbs
That's why - for single carb - you want an intake with a big plenum like a Clifford. And yes, those stovebolts are asthmatic, but mostly because of the head design, which is pretty much the bottleneck. Dual exhaust definitely helps though (if proper sized). It's always a question what RPM range you want to use the engine with. A street/cruising setup is way different, than a WOT/strip setup. And it's not like bolting on one piece of speed equipment does the trick, all components need to work hand in hand, since they depend on each other. What's your cam?
@carbking has a great write up on his website . In my 261 I ended up using 3 zenith carbs that came off a ford inline 6 project on a offey 3 carb intake with split exhaust . Worked very well .
Frank McGurk drilled his dual intakes for 216 sized carburetors, figuring that two 235 carbs would be overkill for the street. He recommended Stromberg BXOV 2s, which is what I used on the McGurk intake on the '58 235 in my '53 Chevy. They worked well.
Also, you're right about them being undercarbureted in stock form. Even an otherwise stock engine will benefit from a properly tuned dual carb setup.
Thats what Im thinkin. Ofcourse i could do i single carb setup but i dont think Thats the right way, due to the center location. Must be better to spread 2 carbs so the outer ports see more gas. Plus it looks way cooler with 2 carbs.
I think the CFM rating is somewhat similar between the BXOV2 and holley 94. About 150. If so, why would it be ok with the strombergs and overcarbed with the holleys?
Dual exhaust is the biggest improvement you can make to a Blueflame! That was the first performance modification I made to the 261 in my 53. It is amazing how much that woke the engine up! I did do a vintage Edelbrock two one barrel set up but found in didn't improve the performance as much as the spilt exhaust. I have since done a full rebuild machine work, Isky cam etc.
A properly tuned duel carb intake on a 235 is more fuel efficient and responsive than a single barrel unit . I know stove bolt or Langdons used to have a 2 barrel carb set up that looked ugly but worked fantastic . not sure if they still make them or are in business any longer , heard some not so good stories in the past about them .
https://www.thecarburetorshop.com/Dual1barrelcarbs.htm https://www.thecarburetorshop.com/Triple1barrels.htm As has been mentioned in this thread, you are probably going to find either 3 or 1 is better than 2. The reason is quite simple once you are aware of the issue. The Chevy 6 cylinder head has three (3) sets of siamesed sets of 2 ports. Consider that. With 2 carbs: Front set is fed almost exclusively by the front carb. Rear set is fed almost exclusively by the rear carb. The two carbs fight over which one gets to feed the center set of two. You really want the fight to go on indefinitely, and both feed equally. This means that instead of the center two ports receiving the most fuel, and the outer cylinders being slightly lean; now the outer cylinders receive the most fuel and the inner cylinders run slightly lean. If you are REALLY good in the selection of the carbs, adjustment of the carbs, and synchronization of the carbs; maybe a 10 percent increase in performance is possible. If you are just good (not really good), all you will do is break even. If you are just average, quite possible to LOSE power with two carbs, but of course gain eye candy. In the modification of engines, physics and math are your best friends; followed closely by large amounts of money! Jon
Imma gonna let em fight over 2 instead of 1 don’t care which ports win as long as it cruises If I wanted to go fast I wouldn’t use a 235 poor ole thing spent 60+ years starving those front and rear ports. Bout time the center ones suffered for a while
The dual carb setup on my '53 did little or nothing for acceleration from 0-40 mph, but from there on up, there was a noticeable improvement. Also, like the old speed manuals promised, once dialed in, the fuel mileage actually increased.
I have a matched pair of Carter WA 1 Pontiac carbs on a Tattersfield intake. Carbking supplied me with two rebuilding kits a lot of years ago. This intake has curved ends which seem to allow a better flow of the fuel air mixture. I'm also using a water heated intake which makes a better air fuel mix and an HEI for ignition. She can run along with traffic on the highway with 373s in the rear, but the brakes and steering box keep me away from the four lane. It's more a slow cruising kind of ride anyway. If we want speed, it's either the SS Camaro or the C-5 Corvette that we will take.
Thanks for all the input. Im pretty set on using the fenton intake i have. So i need some carb ideas, Thats all. The engine is stock for now hence the fenton headers, but thinkin 848 head and maybe a cam down the road.
Mine is .060 over and the 848 head with a slight mill. Running the a truck cam. Was a lot of fun to drive. Plan on running this Edmunds set up got this water pump with a an extra port. Thinking it could be used to heat the intake pulled this updraft set up off a step van. Looks like a great it split exhaust candidate
On the 235 I did for my 52 chev that I built back in the eighties I used a pair of early 40's chev carter YF carbs on a thickstun intake. It ran great. If I remember correctly, I chose those carbs because they were recommended in an article Pat Ganahl wrote in Street rodder magazine. I will look for my copy and reply back
Here is that great article by Pat, One of the advantages for me doing this car over 40 years ago was that I was able to drive 10 miles from here to the junkyard where there were 2 40 chevs, I bought the 2 carbs. stopped at the auto parts store and ordered the kits and they were there that afternoon. I rebuilt the carbs, installed the Thickstun intake (50 dollar swap meet buy) and the Fenton cast iron headers (10 dollar swap meet buy!) on the 54 235 that I had bored .060 over and rebuilt at a shop here in town. I paid them for the labor by R&R ing automatic ******'s after work until we were even. That 52 chev with the 235 was way peppier than the 265 powered 55 I had at the time.... Man I miss that car....
Great article, still have one of those Mallory coils on the shelf. I totally forgot that I have one, till I saw the picture - ahhh too much stuff. Frank
If your intake is flanged for the larger 2 15/16 inch bolt pattern carbs, both Stromberg BXUV3 and BXVD3 would bolt to it. Of course, there are several variations of them, and you'd need to come up with an identical pair to start with.
its a 235 a gas soaked sponge would work. They do not have a huge air requirement, a pair of '94s would work fine. Think of it this way, the blue flame in '54 with the export package had 3 very small side draft one barrels. it ran as well as any 235 to ever come off the line.
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