Inliners International Forums General Discussion Engines 250 fuel pump

I am currently running an electrical fuel pump, but considering switching to original style mech pump on Chevy 250. I'd like to hear pros and cons from the many experts resident here. On another site I saw reference to a spacer between the block and the pump. Also talk of whether or not there is a pushrod which rides on the cam lobe to actuate the pump, or if the pump arm rides directly on the cam. Thanks for any info you experts can provide.

There is no pushrod.
It opperates directly from the lobe of the camshaft.


If you are running a mild to stock engine ,the stock pump works good.
Less noise,pressure goes down with idle (won't overcome needle & seat)IE no flooding issues.




MBHD

Thanks, Hank. That pretty well confirms what I was thinking. Can you comment regarding the presence of a spacer between the block and the pump? Is it normally there, or have I received bum info?

I don't think there is need for a spacer because the cam lobe will just rotate without interference, They make blank covers to cover the hole. Just make sure you have a good gasket on there.

The downside to electric fuel pumps is most of them are inside the fuel tank, they always go out when the tank is full (Joke).
But seriously, with an electric fuel pump, keep the tank at least half-full because the fuel keeps the electric pump cool.

Most of the fuel pumped by electric pumps is just recirculated, this keeps the pump cool and helps prevent the gas from Gelling or waxing up.

No spacer is used. Bum info.

MBHD

Thanks again, to you both. It's certainly a blessing to have found a place to get good reliable information.

I'm a fan of electric fuel pumps. They eliminate vapor lock (for you hot climate guys), give a constant fule pressure, which can be regulated on a lot of pumps, and if wired through a toggle switch located inconspicuously, they work as an anti-theft device. For carbureted applications, electric pumps are NOT mountet inside the fuel tank, but are mounted on the chassis somewhere. Preferably at the rear of the car near the fuel tank so that they push the fuel toward the carb rather than trying to suck it through the fuel lines. There are two types of electric pumps, centrifugal and reciprocating. Centrifugal pumps make a whirring or whining noise when running, and reciprocal pumps click when running. Several manufacturers market electric pumps, such as Holley, Purolator, Summit racing, Carter, Trick Flow, Edelbrock, MagnaFuel, and Aeromotive, and one of them in that group will match up with just about any budget. Pries range from about $25 to $300. If the pump is mounted at the rear of the car and isn't bolted directly to the frame of the car, the noise isn't that noticeable. However, if you mount the pump in the engine compartment and it's bolted solidly to the frame, the noise will be real noticeable, and may tend to drive you nuts after a while. All in all, I'm in favor of electic pumps over mechanical ones, especially for modified/high performance vehicles.

Can someone tell me if a small block mechanical pump will fit the 250?

NO. NO. NO. !!!!

Be sure and put the mechanical pump upside down.

I think some of the problems and strange fixes are the result of some people thinking the 230, 250, 292 pump should look like a V8 pump when mounted.
The inline Chevy six is mounted with the line fittings on the top.
When I bought my truck, the pump had been mounted with the fittings on the bottom. They had added an electric pump that was pushing through the mechanical pump.

Thank you very much, Richard. Fortunately, I'm not near the car right now (away at work) but had a mental image of the pump installed just as you had described: fitting side down. You caught me in time! Much appreciated.