The Stovebolt Site Forums The Shop Area Engine Shop AC 429 Fuel Pump

I have a NOS AC 429 Pump. It is listed to up to a 1951 216, on the box. The outside of the pump looks exactly like the glass bowl fuel pump on my truck now. The only difference that I can see is, the inlet and outlet on my current one are not parallel with the block. They are more like 8 o'clock(inlet) and 2 o'clock(outlet), as you look at it from the right fender. The AC 429, would mount with the inlet and outlet parallel to the block. I would like install it on my 1953 216 3100. Is anybody else using an AC 429, on their later model 216 engines?

Thank you in advance for your advice and guidance.

Rugo

Rugo,

Maybe that fuel pump was designed for the automobile engine mount locations?

The fuel pumps with inlet/outlet parallel to the block are appropriate for trucks prior to the change in the location of front motor mounts. Someone else might post the year of the change - for trucks, it was after Advance-Design trucks (47-55), sometime in the New Design trucks years (55-59).

Rugo,
I am concerned that a NOS pump may have a diaphragm that is not resistant to the ethanol that is in our gas nowadays. I would get a rebuild kit with the modern diaphragm material and while doing that I think you can rotate the the upper part of the pump so that the inlet and outlet are oriented correctly for your truck.

If the diaphragm fails you dump gas into the crankcase and if that happens slow enough the pump keeps up with the carb and you get dilution of your oil. Don't want that to happen!

Kent

Kent,

Thank you for your suggestion and concern. I have a rebuild kit ready to install in the NOS fuel pump. I did plan to rebuild it, prior to installing it. I think that my fuel lines to could be manipulated to fit the parallel inlet and outlet of the NOS pump. If not, I will take your suggestion and change the orientation of the ports. However, I just want to make sure this AC 429, is compatible with my 53 216. Hope to catch with you, when you get down to Mesa again.

Thanks,
Rugo

Rugo, you've discovered the very reason why it's sometimes a challenge to buy parts for these old vehicles. The fuel pump on my '38 has parallel fuel ports while many, as you've discovered, are offset. I personally have no clue which vehicles used which pump. If you have a tubing bender and are determined you can make either work. Now you have a bit of trivia to file away in the gray matter AND you know a question to ask the next time someone wants to sell you a fuel pump.

RE: Angled inlet vs parallel inlet

I believe that the in/out on fuel pumps changed from parallel to the block to angled 20-degrees in 1952. Possibly to clear the motor mounts in passenger cars, or to clear PowerGlide components in passenger cars. An 20-deg angle adapter was available to use 1952+ fuel pumps on pre-1952 vehicles.

> 1929-54 Master Parts Catelog - 3.900
http://chevy.oldcarmanualproject.com/parts/1929_54/214.htm

> 1929-57 Master Parts Catelog - Sec 3.900
http://chevy.oldcarmanualproject.com/1929_57chevyparts/57cmpc0319.htm

- Lonnie