SBC Engine Intake and Carb Setup Recommendation/Help

Im building a 305 Chevy. It's a late 80's camaro motor. The motor has been bored w/ flattop pistons. Its got Camel hump heads with dual springs (1.94 valves) and a 275/450 camshaft. Stock stroke w/ 350 crank.

I will be running a T-10 4-speed or Corvette Saginaw 4-speed trans behind it.

I would like to run a multi carburator setup on it but not quite sure which I can run proper.

Ideas I have are 3x2 setup w/ 94's or 97's or 4x2 setup or a crossram w/ (2) 4bbls.

Im unclear on motor setups so any help would be greatly appreciated.

Thanks

 

I would think the crossram w/ 2 4 bbls's would be too much for that motor. I think your other choices would work much better.

 

ummm... yea 2 4's on a 305? no i dont think thats a good idea, flood it out everytime you floor it, chevy did make a really cool cross ram in the 80's for 305, they got tbi's on em...of course those suck(imo) but you could just make something to adapt a pair of other carbs on to it....

 

If it's in a heavy car, with a modest rear end ratio, use the Tri-power. You would be better off with 2GC's over the Leakers. If you've got a light car, with a steep rear, you could get away with the cross ram and some vacuum secondary Holleys.

 

The Engine is going into a 55 Chevy.

 

Don't know as I would recommend a cross-ram, unless you are talking all out race; but an inline 2x4 with a pair of Carter 9400/9410 AFB's running solid linkage works exceptionally well. We have done it.

Jon.

 

tri-power with progressive linkage and Rochester 2GC carbs's like a GTO

very streetable and stripable too

 

I beg to differ Dude. Chevy themselves did it from the factory in the late 50's to early 60's on a 283 no less.

Plus, that's what I'm running on my A and no, it doesn't flood out everytime you floor it.

 

2 Carter WCFB's on a factory GM aluminum dual quad intake manifold would be OK for your motor. They're small carbs, something like 385cfm each.

I also have camel hump heads on my engine, however with 2.02x1.60's (1957 283 block stroked with a small journal 327 crank that's been turned down to fit in the block)

 

Is it possilbe to run (2) Carter WCFB's on a cross ram? Is there too much plenum space in the intake?

Im just thinking of any 'crazy' combination.

 

What size are vacuum secondary Holleys?

 

Many sizes. scroll down the page in this link.
http://www.holley.com/types/Street Performance - Traditional.asp

 

Don't let a few carbs scare ya ! The key is in the propper re-building of the carburators, and the propper tuning. The runner length on intake plays in etc.

I run 6x2 set up with small base rochesters. All the idle circuits are intact and able to be tuned. this set up is run on the street and works just fine. My engine is stock displacement pontiac with factory 10-1 compression. Ignition is Hot Rodded a bit ....another key factor. My two cents hope this info helps you get over your "TOO MUCH CARB" fobia.

P.S. also run a big, long duration solid camshaft ! he he

 

I did the same thing to my 55. 1981 HO 305 with the Crane 274=450 cam. Pertronix ignition, Hooker Supercomps, Muncie M-22 and 410 rrear. Engine was otherwise stock. I added an old Team G tunnelram with 2 Edelbrock 500 carbs. After dropping the accel. linkage to the bottom hole and careful tuning on both carbs I had no problems. It didn't run rich, pulled really hard for a 305 and I could get 17 mpg on a steady cruise of around 2600 rpm. It's ok for local cruising but at highway speeds it did lose on the mpg and it suprised some guys around here that tried to play with it. No problems pulling away from 350 4 bolt cars with a performer intake and 600 carb. Even a guy with a L-79 vette tried to get away from me on a short run through the gears. He had a 6 or 7 car length jump on me and I still caught him in 3rd gear from a dead stop at an intersection. I don't mean to say that I endorse street racing but sometimes you can't help yourself if you're in the right place at the right time. All that said, the 305 can do a tunnelram and multicarb setups as long as you take the time to set it up properly. Mine has been together for 3 years with no trouble but now I'm doing a 450 hp 350 for it to get into trouble with. Go for it

 

If you go with dual carbs you will want to stay real small on the cfm on them but if you want to go with 3 of the 3 bolt carbs I think those would work fine on it. Here's a pic of our AeroRam with 3 of them on our Chevelle test car and definitely go with progressive linkage.

 

That was the old Cross Fire Injection . I had thought the same years ago but when I got one of the intakes in my hands and pulled the top off the runners are tiny and I do mean tiny.

 

Here are several different ideas for multiple stuff including a 6-2 .

 

I'm running a 1990 roller cam block 305 with #416 HO perimeter valve cover bolt heads.Using a mild roller cam with 206-212 duration at .050 lift,total lift .490.Compression is an actual 9.25-1,Rams Horn exhaust manifolds,Weiand's basic street 4 bbl intake and an Edelbrock 600 CFM carb.This is in a 3200 pound El Camino.
The engine runs runs very nicely in this state of tune,maybe 260 hp at 5000 rpm.Good spread of torque,idles with a slight lope at 700 rpm.This engine was also built for good fuel mileage.
It's my opinion it's slightly over carbureted with the Edelbrock 600 CFM at 5000 rpm's.But it's really not bad and the 600 carb was a steal so to speak

 

You building a hot rod or a kustom?

Sticking a bunch of carburetion on a 305, even a decent one, is about eye candy not performance.

So dual 4bbl versus 3x2...just decide what you like to look at, since that's the primary concern. Carbs, again, whatever pleases your eye as long as they don't sum up over 850cfm it outta run good enough.

If all this carburetion is about performance, then take the thousand bucks you're gonna blow on exotic induction, sell the 305 to the high bidder.....take the exact amount of money in your hand and get a single 4bbl 350 or 400.

good luck either way!

 

Shifty, you know better. Half of what we do is about 'the look'.

A tripower with progressive linkage should work very well. I run three Rochester 2gcs (Factory triple carbs) on my pops 265" with only a solid cam and Fenton headers. They work fine so long as you have the linkage set up so that the outer carbs come in after the engine has enough RPM to use most of the air.

If you are looking for 'all out' performance, singe 4bbl is usually the best way to go, but that is not so cool to look at is it?

 

I want performance; (not a MPG 'Green thumb' mile saver) and visual. In that order. Doesnt do any good if you put a over carb'd setup on your motor and it doesn't run good. or cause damage in the long term.

I dont want a single 4bbl setup. I have that, not what im looking for.

The motor is in a 55 Chevy Gasser project.

From what I can see, 3x2 or a 4x2 may be the ticket.

I have a lead on a 4x2 setup (with 94 3-bolt carbs), will this be over-doing it?

 

ok, let me refraze then, and state im a dumbass, a stock 305 would flood out with 2-4's, and as i see it dont have stock heads, i assume it wont be useing a stock cam, and i didnt think about those tiny 4's, sorry, im still young and learning

 

I agree

 

First I would like to thank you for giving me credit for knowing better. Not so sure I agree with the rest (or about knowing better) and don't want to start a pissing match. But with multiple carbs, especially with an engine that small, it's ENTIRELY about the look. A single 4bbl will outperform them all hands down. So he really should buy what pleases his eye. It sounds flippant, but is actually a serious statement.

Back to the Chopped50's original concern....FWIW millions of 305s were produced with 750 Qjets and smaller cams than yours. Don't go too far past that number for your carb setup's sum and it should have reasonable response.

You sound concerned about performance. Having had my hands in 305s that were very similar and went into similar weight cars......prepare for disappointment. Buncha guys with single 4bbl 350s are gonna beat up on your eye candy tri-power/dual quads. Sorry, that's just how it is. Sounds like it'll be a really cool looking car though.

good luck

 

WTF? You don't put a 305 out of an 80's pile of shit into a 55 chevy gasser.

Go find a better motor.

 

LOL, so true but in the nature of todays economy; we have to use what we have on hand. I have another "correct" motor that is currently being built for the car.

 

Then why the heck are you intent on blowing good money on a multi-carb setup that's selected for the small motor and doesn't make any more power than a $150 holley?

You have a wicked case of false economy about using what's on hand.

 

This motor will be used to break in the car and see what needs to be addressed to the chassis mainly. It's a 305 HO motor, and was in a 11 second car. Problem is we don't know the previous setup on it, so we are trying to get it as good as possible. We're not spending alot of money on this motor, and can reuse the intake and carbs on the next motor.


By "correct", he means wicked, nasty, and will scare little children.


It'll be fun.

 

I have a 305 chevy, stock except for headers and intake, running an accel points distributor. It has a single AFB, and it runs hard.

Free motor, and im lookin for better heads.