I asked this question in the Under the Hood Forum with no response. I guess there aren't many engine builders there so I thought I would try here. Does anyone know the difference between the AP2 oil pump and the AP1 pump? They are different part numbers and I have heard that the new one is a better design. I'm getting ready to put together my Laskey engine and was wondering whether I should stick with the 2002 pump I have or order the new one.

 

I've heard the same but I don't think anybody ever did an exactly side by side or in car comparison/testing. For what its worth, I stuck with my old oil pump when I got my block back from Laskey.

 

From the parts list, it looks like the AP2 pump housing might have some difference, but all the parts that go into it are the same as AP1. I think I'll just use my '02 pump and shim the relief spring for a slightly higher pressure.

 

Change of plan. I just ordered an '05 pump. I'll report if there are any differences.

 

Subscribing because I want to know also.

I would do a high vol version that you can get made from 2NRWERKS on the FL forum.

 

Are you going to do testing with all else the same? That way we know for sure that the oil pump made the difference and by how much.

 

You don't want to run too much pressure. I think oil pressure is fine as is.

I'd like to know the difference as well since Earl was telling me they were different as well several months back.

How would a high volume oil pump do anything? You would still reach same oil pressures due to the restrictions caused by the passages and etc. It could give you more oil pressure at low RPM's but the oil pressure is already pretty stable at 90psi once you get past 2,500rpm's.

 

No, but I will take them apart and do a side by side comparison to see if there is any difference.

 

I've got one of those installed. My overall oil pressure when driving is pretty much the same, but I've noticed that the dips when the rpm's drop quickly aren't nearly as severe. Gives me a little piece of mind.

 

You got one I left at Todd's to get worked on. I gave it to him about a year ago to get done for me. Next thing I know Jeff has one done and you have one done. I didn't get one done.

There is actually no data showing an increase in volume but I heard it is about 30%.

I am sending one off to the guy he uses to get it done an then find out what was done.