2 piece fuel pump

[mrdetails]

Hello: I have been having a problem with a 2 piece fuel pump (AC) on my aluminum big block 1969 Camaro. The first one I used leaked engine oil from the vent holes. I sent it out for rebuild, re installed it and got about 3 miles before engine quit. I sent it back for repair and when I got it back it leaked fuel. The rebuild guy had left the screws loose and striped out a couple. I got a new/rebuit pump from Heartbeat city, installed it and the same oil leak appeared. They replaced it and now I'm leary of installing it. My friend at the engine shop gave me a special gasket which blocks the engine oil from the fuel pump. The instructions from the gasket say to grease the pump rod and recomends putting a grease fitting on the pump. I don't really want to do that.

Has anyone had any experiance with these 2 piece pumps? Did they all leak oil. I think it was an over the counter perforamance part and the only production car it was used on was the ZL1. I tried to get a different pump (not 2 piece) but the line to the carb would interfere with the smog pump. I tried pumps from other big block Canaro apps. but they were all the same.

Thanks for the help:
Sam

[rat pack]

I have a new Carter 2-pc pump on my car and it hasn't leaked since installed in 2004. It looks just like the one installed by the owner in 68 other than it is new. I will try and get you a picture later this evening................RatPack...............

[mrdetails]

Rat Pack: I tried this (Carter) pump but it wouldn't  fit between the block and the frame.
Thks:
Sam

[william]

Has anyone had any experiance with these 2 piece pumps? Did they all leak oil. I think it was an over the counter perforamance part and the only production car it was used on was the ZL1. I tried to get a different pump (not 2 piece) but the line to the carb would interfere with the smog pump. I tried pumps from other big block Canaro apps. but they were all the same.

Thanks for the help:
Sam

The 2-piece rebuildable AC fuel pump was used on literally thousands of production cars and Corvettes from the late '50s into the '60s. There are several versions of it.

We did a ZL-1 many years ago and initially used the standard L-72/78 pump on it with no problems. It now has the correct pump but has not been run with it.

Do you have the correct pushrod?

[mrdetails]

William: Thks. for your response. How would I know of I have the correct push rod?
Sam

[william]

Just about all Chevy engines use the same one: .50" x 5.75". It should be solid of course.

[Charley]

I would be looking into your oil level. Those are just holes that are basically open to the crankcase as I recall. Oil level and how well your engine is vented. PCV working ? Breathers on valve covers ? If there is no easy way to vent the engine you will get pressure out those little holes in the pump and possibly bring oil with it.

[JohnZ]

I agree with Charley - you have an oiling/venting/PCV problem, not a fuel pump problem; can you describe your PCV system configuration?

[william]

I did not mention this before but we had an odd fuel pump problem with ours. With the car nearly done we simply could not get the push rod in the block so the motor had to come apart. We got the block via McLaren Racing and since they ran fuel injection, they had tapped and plugged the push rod hole, perhaps creating a path for oil to get through. May have been standard practice for Can-Am ZL-1 blocks.

Additionally, ZL-1 blocks have provision for dry-sump oiling and coolers that iron blocks do not have. Some need to be plugged, some do not. I have attached drawings from the ZL-1 engine manual.

[mrdetails]

JohnZ: The PVC configuration is stock for a ZL1.
William: I am using the Mark 5 block with the standard push rod.

I will check all PVC components. I've only ever put 5 qts of oil in the engine with a filter change. I'm thinking the oil has to be getting by the oil seal in the fuel pump and the diaphram is pushing it out the vent holes.

Thks. for the help
Sam
Sam