VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1937-1945 Carb question

My 41 is in the project stage, I put a 1952 rebuilt 216 in it.

When it was time to get the motor up and running I put a new NOS ROCHESTER B 1BBL CARB.

So when firing up the 41 the motor ran good but needed some carb adjusting , when messing around with the it I made the carb flooded out. Gas was seeping out of the base of the carb where the lower flap thing goes threw the carb base.

Ok so I know the carb is new it was in the original Delco box when I got it and I could tell it has never been installed.

Then I sprayed some carb cleaner at the base when I got it running again and the motor ran a little faster.

So I took off the carb and put Carter YF that I picked up at an auto swap meet and the motor ran even better but again when dialing the motor in I flooded it out again and gas seeped out at the same as the other carb. Is this common for gas to seep out there?

My plan it to either get a new re-pop Carter W1 or get one I have professionally rebuilt, any thoughts out there and what would be the best type of carb to run?

I suspect you have some crud in the gas tank that is being carried to the carburetor. That will cause the carburetor to overflow after running a while. Adding a filter might help for a while. The long term solution is clean the entire fuel system.

All these downdraft carburetors will seep a little gas past the throttle shaft after it is shut down. It may be possible to reduce the amount but can't be eliminated as there needs to be some gap between the body and throttle shaft.

The carb might have to be cleaned out or maybe I'm pumping it too much before cranking it , but as for the gas tank or line being dirty na. I have a new tank and lines but since the car isn't ready for the road for at least another year, it isnt connected to the motor.

I have a quart size round ball oxygen tank that I converted to run the motor that sits on a mount by the fuel pump. The fenders and hood are not on .

So with some seepage that means there a bit of a vacuum leek too. Well my carbs may just might need some fine tuning cause the motor runs nice I just want the motor done before I get into the last part of the body work.

Also since its a new motor and I had to put the heads on myself I want to make the valves are adjusted right and everything is seal good to have any oil leeks too but I know the rear crank rope seal arnt promising.

If the rochester carb was NOS it most likely needed rebuilding unless it was stored under ideal conditions seeing that it is about 65 years old.. One pump of the accelerator should be plenty. I would even crank it a couple times before pumping.

When working on gas line and fuel system it is common for "junk" to loosen up and get caught nder the needle valve. Usually just racing the engine to increase gas flow will flush it out.
I would stay with the new Rochester if it were mine.....if it is a 1952 or later high cover model. What part number was on the box?

The needle valve being open (not shutting off incoming gas) will cause overfilling of the reservoir. Ease the top off (it may be difficult without tearing the gasket) and clean the meedle valve. Should help.

Good luck,
Charlie

Since two different carburetors "flooded out", I would suggest placing a fuel pressure gauge right at the carburetor to see what kind of fuel pressure you have. Even brand-new name-brand pumps made on the other side of the world have incorrect pressure. We have actually measured pressures exceeding 10 psi on some of the brand-new name brand pumps.

If you have too much pressure, the fuel level in the carb will be too high causing a stall (at idle) from excessive richness. Excess fuel will run out of the throttle body in the clearance area between the throttle shaft and the throttle body.

As to the engine speeding up slightly with the application of carburetor cleaner sprayed on the throttle body in the vicinity of the throttle shaft, THIS IS COMPLETELY NORMAL!!!!! Millions of internet pixels have been unnecessarily disturbed advocating this practice. THERE HAS TO BE CLEARANCE, OR THE THROTTLE SHAFT CANNOT TURN! Design clearance was 0.004~0.006 inch. An additional 0.003 wear is acceptable. Thus, a measurement of the clearance with a dial indicator not exceeding 0.009 inch is acceptable.

As to the carburetor you use: ask three enthusiasts and you will get four answers (someone will change their mind). Here at our shop we SELL Carters, and attempt to GIVE AWAY Rochester B's with a nominal order. So far, NO ONE that has met the criteria has even asked about the free Rochester B

If you had called with this question, I would have suggested to rebuild your original Carter W-1 (I am unaware of any repro's, no reason, there are thousands of originals available).

Technically, the Carter YF has better circuitry than the W-1, but the YF uses a diaphragm type accelerator pump (will give issues unless the car is close to a daily driver if you are required to use ethanol-laced fuel) whereas the W-1 has a leather accelerator pump which is totally impervious to any percentage of ethanol in the fuel.

As to the comparison of either of the Carters to the Rochester B, re-read the third paragraph above.

Remember the ABC's of carburetion: (A)lways (B)uy (C)arter

Jon.

Thanks for your input, I would say it could be too high of pressure cause when trying to get the motor to idle at a low speed was around that time it would cut out then hard to restart. That's when I would notice gas seeping out of the base.

It is time to purchase a gauge to check the pressure. Most present day vacuum gauges also check pressure of fuel pumps. It is a two way gauge.