[ahaeragain]

As an internet mechanic (ie lots of reading, no doing) working with a non-buick mechanic to re-assemble my motor (don't ask) we have now come to the timing cover and oil pump and are looking for some guidance.

The machinist, returned the motor with a high-volume oil pump kit. Given that this block has been redone does a high volume pump make sense?

My other question is given our lack of buick experience would we be better off buying a assembled cover such as as
http://www.specialadditions.com/store/proddetail.asp?prod=TimingCover
?

Lastly I have found the excellent write ups on the front cover and oil pump on vortex-buicks.com but can't seem to find Earl Brown's cover/oil pump modification write up again... Anyone have a link to that or any other site that may help?

Thanks

 

[Ormand]

The oil pump should be matched to the lube system. There are guys on this board who build engines using high volume pumps. But they don't use the tightest clearances possible. Basically, if the engine is built "loose", it can use more oil flow than if it is built "tight". But things like restricting the flow to the lifters, or adding grooves to allow oil to go the cam lobes will affect the oil flow, so the engine builder has provide enough pump to maintain pressure, with the details all considered. Give more details on the engine you built, and the suggestions you get will be more specific.

 

[ahaeragain]

Unfortunately I don't have many more details of the actual work and/or the specs that the machinist followed as there was a middleman between myself and the machinist.

I know the the cylinders were bored .020 and that everything was balanced. Other than that I have to assume that any other needed work was done to factory specs...

 

[Just a Six??]

Being a non Turbo Buick mechanic he probably built it on the looser side than the tighter side? Just a Guess of course? Although if he does 350's all day long its probably loose so the HV cover may not be a bad idea? Of course this is all speculation? :dunno: Mine is tight but I went HV this year & I like 30-35lbs hot with 10-30 oil but I tear mine down every winter?

 

[ahaeragain]

If you can give me specific questions to ask the machinist I'll see if I can get some real answers so we don't have to assume...

 

[Just a Six??]

Bearings are the main thing. I'll let someone post numbers or Steve may have them on his site?

 

[Steve Wood]

It seems that oil pumps are the latest thing that we tend to obsess over. There has not been any evidence that the typical street engine needs any more pump than the factory installed yet we increasingly continue to try to fix something that ain't broke.

The rest of the automotive world seems to be turning away from high volume pumps as they have more downsides than up while we have made a u turn and reinvented them.

I guess if the engine was assembled incorrectly, a hv pump is a futile bandaid that makes us feel better.

Now, if one has built a 7000 rpm engine, that would have different requirements in all aspects than the typical 109 block that we drive on the street and the factory system may need enhancement.

 

[ahaeragain]

If I put in the stock oil pump gears what psi should I expect to see on a "correct" rebuild with normal 10w30?

More importantly at what psi should I get worried?

I will be installing an oil pressure guage so I can keep a close eye on things...

 

[Steve Wood]

Less than 10# at idle is probably the correct answer, but, I would expect 15-25 hot idle with normal clearances if the pump meets spec and the engine has normal clearances.

There is a section on my site showing the factory set up and specs for an oil pump.

 

[earlbrown]

If I put in the stock oil pump gears what psi should I expect to see on a "correct" rebuild with normal 10w30?

Depends on what spring you put in.

 

[Steve Wood]

Depends on what spring you put in.

That is correct for the maximum pressure....not anything less than that