OK, I think I know what almost everyone will say, but I gotta ask anyways.

I am re-building a G54B motor. It is now bored 0.030 over, flat topped hypers, rings, crank ground and balanced, new timing chain, etc., new water pump, 1.6 ratio roller rockers, balance shafts removed, decked block, re-conditioned con rods, etc.

The dealership (stealership) wants $130 for a new oil pump. If the motor was never blown up, do I need to replace the oil pump?

So far I have spent more money than just outright purchasing a crappy re-manufactured engine and I haven't even started to assemble it.

So, do I really need to replace the oil pump? Is there a re-build kit? Does the FSM have clearance numbers for checking the condition of the current one?

OK, you get the idea, Tell me what I should do.

Thanks, Racer4 <img src="/forums/images/graemlins/cheers.gif" alt="" /> <img src="/forums/images/graemlins/kewl.gif" alt="" /> <img src="/forums/images/graemlins/cheers.gif" alt="" /> <img src="/forums/images/graemlins/kewl.gif" alt="" />

I like the factory pump better than the cast iron aftermarket units. There is nothing wrong with measuring and inspecting a used pump. Its its still well within new specs there is no reason not to reuse it.

BTW.... I am going to do some measurments on what happens to your valve timing when putting roller rocker arms on a factory cam. I have a spare head and cam to test with, I just need some spare time.

I am not convinced that its the hot setup.

Kevin

I'd be interested to hear why you like the factory aluminum pumps over the steel aftermarket. I currently have a melling steel pump and get some pretty noisy lifters during startup when warm. No idea if this has anything to do with the pump or not.

I did not like the machining in the Mealling pump. The surface finish was very course in the one I had.

They do work, I just though the factory pump was a better part.

Kevin

Kevin:

You bring up a good point. I am going to check the valve timing on my motor as I assemble it. If it is wacky, I will have to find out how to modify it so it will time correctly.

I have looked at the duration of the stock cam and it is not what I would consider a great cam.

Thanks, Racer4 <img src="/forums/images/graemlins/kewl.gif" alt="" />

I think you'll find a concensus here about the factory pump vs. say a Melling.

That said, I have a Melling in my Turbo engine, but it was already there by the time I realized it <img src="/forums/images/graemlins/barf.gif" alt="" /> and it was too late to turn back.

Still, so far, so good. The oil pressure looks good and there are no funny noises. I just hope it holds up.

In as much as reusing a pump - well - I wouldn't do it. I know the arguments are compelling to do so, but, hell you've put a ton of money into the thing already. You knew going in that what you're doing isn't a budget rebuild. Shop the web or some other Mitsu. stores, but I'd replace the pump and I'd go OE.

Wish I had insisted...hindsight's always 20/20.

My aftermarket pump (can't remember the brand) came with some sort of an anti-drainback valve so that the top end wouldn't have to wait so long for oil on start up. Anybody else seen this?

John B.

I put a used truck pump in my first turbo conversion. It has been running two years now. The motor was out of an 83 Starion with over a 100,000 miles. I drove it to Pismo Beach and back with a cracked head. It has a new used head on it now, and a new timming set. Same old oil pump and it sounds great.
My black truck has a Melling pump in a fresh rebuild. They come with a piece of rubber that fits behind the plunger. This is to help with pressure at start up?

The piece of rubber is a stock part to help keep the timing chain tensioned.

Kevin