Engine Rebuild Advice Needed - 1960 245HP

[Duke W.]

Re: Engine Rebuild Advice Needed - 1960 245HP

Get "How to Hot Rod SB Chevies". It explains how to "blueprint" the oil pump and also has a very good writeup on head rework and valve seating.

There is also "How to rebuild SB Chevies" which might have similar information.

All you have to do is disassemble the pump (a few bolts) inspect the gears and make some end play measurements with a feeler gage and dress down the housing and one gear to get the minimum end play spec.

At shop rates it's probably cheaper to just replace the pump, which is why most shops do so, but owners can resuse a lot of OE parts with a little "hobby time" effort, and in the case of oil pumps, the original may be superior to the current new replacement pumps.

Duke

[Mark P.]

Re: Engine Rebuild Advice Needed - 1960 245HP

Duke - Yesterday I ordered "How to Rebuild Your Small-Block Chevy" by David Vizard. I'll look for the other book too.

I don't have an original engine so I have no OE OIL pump to use. My car has a mid-80's 350 crate motor hwich runs great but hope to sell it complete.

I have most of the parts to build an original motor though so I am getting closer.

Thanks,

Mark

[Tom B.]

Re: Engine Rebuild Advice Needed - 1960 245HP

I haven't heard of that problem with the Melling pumps. You can bet if they had that problem back 4 years ago that it has been fixed by now. I know a lot of guys that use Melling without any problems. I have the Melling 55HV in my 350. It comes with the high pressure spring installed but the standard pressure spring comes in the box. I would suggest the standard pressure spring for a street application where high rpm is not a regular thing.

[Duke W.]

Re: Engine Rebuild Advice Needed - 1960 245HP

Under no circumstances do you want a "HV" pump in a road engine. Regardless of the pressure relief spring, the pump will move waaaaaaay more oil than necessary. The "surplus" is just bypassed back to the inlet when the relief valve opens, but the pump churns up and heats up this surplus oil and costs power and fuel economy.

The only correct application for a HV pump is a loose-clearanced racing engine that has to move more oil to generate the required 80-90 psi pressure at very high revs that is recommended for a vintage Chevrolet racing engines.

BTW, NASCAR engines only run about 40 psi with 5W-20 oil for the race and sometimes 0W for qualifying. They use the minimum oil pressure/flow to keep the engines alive at 9500 revs in order to reduce internal parasitic loss, which maximizes HP at the crankshaft. A lot of work has gone into the design of the oiling system to allow very "thin" oils and "low" pressure,

Duke

[John H.]

Re: Engine Rebuild Advice Needed - 1960 245HP

Photo below is of the GM-redesigned Melling pump which has proven unreliable in modified high-performance applications; note the two diagonal ribs between the pump cavity and the mounting flange. The Melling "Select" line uses the original bulletproof casting, and they have a standard volume/pressure pump in that line.

[Mark P.]

Re: Engine Rebuild Advice Needed - 1960 245HP

Thanks John. The pump that is causing problems is the $20 M55 Model, right ?

The 10553 model appears to be the standard volume standard pressure Select model you are referring to and this goes for $84 from Summit. Here is a picture. This is the one I plan to buy.

[John H.]

Re: Engine Rebuild Advice Needed - 1960 245HP

Thanks John. The pump that is causing problems is the $20 M55 Model, right ?

The 10553 model appears to be the standard volume standard pressure Select model you are referring to and this goes for $84 from Summit. Here is a picture. This is the one I plan to buy.

Yup - that's the one you want.