So, I have had a problem with some bad oil pressure recently and decided to just put a HV oil pump in. Has anybody done this with the motor in the vehicle? I need to get this in ASAP. My Camaro is a 1985, z/28, with a 305. I've already purchased the pump and oil pan gasket.

 

Yup...

DON'T.

Pull the motor. You'll be glad you did. Not least, because it'll take less time; but also, because you'll have a better chance of being able to get it back on leeeek-free.

But the question MUST be asked: WHY are you replacing the oil pump AT ALL? That part almost NEVER goes bad in a SBC. As close to NEVER as it can be, and it still have happened ... once.

 

It lost oil pressure, I cant get any out of it unless you count to 20psi it gets on startup. It's starting to knock pretty bad. Do you think it could just be a clogged galley?

 

No.

And before you ask, no.

Needs a crank, maybe some rods. Bearings of course.

You're DEFINITELY wasting your time messing with the oil pump and thinking you're gonna put it back together and it be OK. That's fantasy land.

 

Agree with sofa on this one. I build engines for a living - you will accomplish absolutely nothing (you won't even increase the oil pressure) by changing out the pump.

Remember - the pump doesn't provide ANY pressure. It provides flow, and pressure is achieved by the resistance of that flow through the bearings and lubrication passages. So trying to change the PRESSURE, by changing the thing that creates FLOW and has ZERO effect on the PRESSURE won't work will it? That would be like changing a fully charged battery because your alternator isn't charging. It would be basically an exercise in futility.

Just get a crate motor - it will be cheaper than trying to rebuild that one unless you happen to have a machinist in your pocket and some extra unmolested parts laying around. I'm guessing probably not.

GD

 

No oil pressure and knocking = blown up motor.
Your engine is done.

 

Yeah but it's only an upper motor knock so the lower motor must have some pressure right?

 

If you lost oil pressure then the space in your lower end bearings is too large. Even with a HV pump you wont see an increase in oil pressure and you will be wasting time and money.
stop and google search it.

 

Please define "upper motor"

How do you know what is knocking?

GD

 

That's pretty funny!

 

Sounds like your motor is on its way out. If it was me I would start searching for a good deal on a crate and shove in some 20W-50 to try to boost the pressure for the next couple weeks before the swap.

 

When you take apart the crank bearings you will probably see surfaces that look like they spun on the edge of a file instead of mirror-polished surfaces. Replacing the oil pump is an exercise in futility. Time for a replacement engine. No band-aids this time. Years ago I helped a co-worker in the same situation.