Best Carbs for use

[jam019]

Hello I have question about which carburator is the best for a 350 Corvette eng.

90 Vette automatic 700R4, any info will help, needs to be with good gas and performance.

[DarkShark]

Originally Posted by jam019

Hello I have question about which carburator is the best for a 350 Corvette eng.

90 Vette automatic 700R4, any info will help, needs to be with good gas and performance.

I think you are asking the C3 guys which carb to use since most C3s have carbs...

Well, I personally don't like Quadrajets (although that seems like blasphemy). I think they are very particular and temperamental. They do provide the best gas mileage due to the design (small primaries / huge secondaries).


I'm partial to Holley. With the exception of the power valve- they are virtually fool proof. They do dump more gas than Quadrajets... mainly because they have larger primaries.



I've heard great things about Demon though. Had I not decided to go modified TPI, then I would have gone with a Street Demon.



I can't forget about Edelbrock... I have no personal experience with them.


As you can see, there are many options. What is "best" is really up to you given what your needs and expectations are. Do some research though. Depending on what HP your engine will produce, you have a lot of choices.

I'd recomend 600-700 cfm depending on your modifications. If your block is bone stock, then you'll be fine between these. Don't get caught up in the hype that more cfm means more power- your engine may not need a Barry Grant 1000 cfm carb.

I'd PM grumpyvette or GMJunkie. They'd be able to help determine the size you'll need better than me.

[Sensei]

Quadrajet! Yes you have to get them set up right, but it is not hard, just harder than a generic aftermarket carb. It will perform better and also give you the best fuel economy. No other carb can do that (although someone will probably claim otherwise). God bless, Sensei

[Evolution1980]

Originally Posted by jam019

Hello I have question about which carburator is the best for a 350 Corvette eng.

90 Vette automatic 700R4, any info will help, needs to be with good gas and performance.

Just so we are clear...You are asking about putting a carb on a 1990 vette? As in, you removed the all the fuel injection and want to go to a carb setup on an L98? Also, just stating "a 350ci Corvette engine" is really quite ambiguous. There were A LOT of various engine configurations based on the 350ci engine. Ranging anywhere from 165hp all the way up beyond 400hp. Which 350 engine are you referring?

Those things aside, the answer to the best carb for gas mileage AND performance is definitely going to be a Q-jet. The base 750cfm that was used on most of the vettes is plenty big enough (when retuned) to supply the demands of any 350ci up to at least a 450hp.

[GerryLP]

Originally Posted by Evolution1980

Just so we are clear...You are asking about putting a carb on a 1990 vette? As in, you removed the all the fuel injection and want to go to a carb setup on an L98? ...

Good point Andre. To me however, it begs the question -why do that, if this is the case?

Even in racing, there are a lot of fuel-injected set-ups, and it would be superior to a carb set-up, for IF electronic-tuning knowledge is at hand, THEN manipulation of engine parameters on a particular day's conditions (weather) could be achieved easily and quickly.

On street applications perhaps could be of no consequence, except if you were to travel with your Vette between sea level and 5'280' of altitude (for example). The lower atmospheric pressure requires a different air/fuel mixture.

When I moved from the San Francisco Bay Area to New Mexico, I drove my Vette. And I remember that we spent the night in Flag Staff, Arizona. It was September, so the Monsoon season was in full swing, and I stepped-out in the middle of a downpour to buy somethings in Wall-mart, and I drove the Vette there. At least I tried to drive it. It was sputtering, and hesitating like crazy. It could only idle normally, but when I placed it in "drive" it shook like it was running in between 6 and 8 cylinders. When I used the A/C, it got even worse. Next day, the day started fresh and clear, and even though it had still something wrong with it, it was not as bad as it had been the night before.

The little research I was able to make in books at the time (I believe that the L81 Corvette Registry hadn't been born yet...), motivated me to disconnect the battery for a few seconds, and then reconnect it to see if the computer would take a fresh sample of atmospheric readings. After that, the Vette worked just fine.

When I went to Cruise Fest I in Auburn, Indiana, I had to change jet sizes in the Holley DP carb I had set-up, for it was running too lean (the heat emanating from my engine at that time and backfiring was a good sign of that).

So definitely there are more disadvantages for carburetion than fuel injection. And I would recommend to leave the original set-up in place unless you have some very good reasons to part with it.

[Drjohn]

Originally Posted by GerryLP

So definitely there are more disadvantages for carburetion than fuel injection. And I would recommend to leave the original set-up in place unless you have some very good reasons to part with it.

I tend to agree. As much as I'd like to see everyone buy a new carb or 12, I'm not sure that's the application for one.

What is on it now?

[Vettehead Mikey]

Convert from TPI to Carburation