Oil consumption & smoke on a 327/350 hp

[Gerald C.]

Re: Oil consumption & smoke on a 327/350 hp

Let's see how the PCV works and I'll go from there.

[Gary R.]

Re: Oil consumption & smoke on a 327/350 hp

Good luck Jerry, I know how frustrating it can be. In my case the only thing I subbed out was the block bore & hone, Cam brg's, crank polishing and piston/rods. The final fit and assembly I did. I hope you don't have to pull the engine. Keep me posted on what you find out.

[Gerald C.]

Re: Oil consumption & smoke on a 327/350 hp

Will do Gary,

Thanks

[Gerald C.]

Re: Oil consumption & smoke on a 327/350 hp

Well, the saga is solved. I have a local mechanic with a Corvette specialist on board. The took the valve coves off and took the rockers off, etc. The valve seals were of the "plastic" variety and the guide plates were worn! The engine builders replaced all the parts (free of charge of course) and now I have no more smoke, oil usage for the first 100 miles anyway! The rebuilder states a bad batch of parts. He is also going to pay the labor charges associated with the fix. Oil pressure gauge still reads above 60 lbs until warm. Then drops to about 45. I may take it out this winter and see what's going on.Thanks everyone for their comments.Jerry

[Leif A.]

Re: Oil consumption & smoke on a 327/350 hp

Thanks for the follow-up, Jerry. Always nice to hear a positive end result. Best of luck going forward with your L79...my personal favorite engine

[Gary R.]

Re: Oil consumption & smoke on a 327/350 hp

Glad you got it resolved, now enjoy the car. I drove about 1200-1300 miles so far & no oil usage.

[Gerald C.]

Re: Oil consumption & smoke on a 327/350 hp

Okay, now: I have an oil pump and it has a tag on it that states DM 55 and 98317A. It also has a casting number on it # 307 and a stamping of 419. Do you have any idea what the pump is from? Also, if I try to change the spring in my existing pump in the 67, how will I know if I have the High pressure spring or the standard pressure spring? Thanks, Jerry

[Jack H.]

Re: Oil consumption & smoke on a 327/350 hp

M55 is a typical aftermarket part number, i.e. Melling, etc. but they also use the same part number with alpha suffixes for high pressure and high volume applications, so I don't know definitively what you have.

Regarding the spring identification, the springs are often color-coded on one of the ends, and/or you can count the number of coils and measure the wire diameter and compare to known springs.

Here's ONE thread that has some discussion about spring colors, number of coils, etc., and I know there are others:

https://www.forums.ncrs.org/showthread.php?107764-melling-oil-pump-correct-spring&highlight=oil+pump+springs

Melling springs:

http://www.melling.com/Portals/0/SPRING PACKS SPRING COLOR CORRECTED.pdf

[Duke W.]

Re: Oil consumption & smoke on a 327/350 hp

Oil pressure gauge still reads above 60 lbs until warm. Then drops to about 45.

The oil pressure specification is 40-45 psi HOT at 2000-up.

There is no cold oil pressure specification, but cold pressure at any RPM will be higher. You should not rev the engine over 2500 until the coolant temperature is at least 120F, and oil temperature will not reach steady state of 160-230 until several minutes after the coolant temperature is up to the thermostat opening point depending on ambient temperature and average engine RPM and load.

There is no idle oil pressure specification, but 15-30, hot, is typical depending on idle speed, and the higher the idle speed the higher the idle oil pressure, so SHP engines will show higher idle pressure than base engines.

It sounds to me like your oil pressure is normal.

Duke

[Michael H.]

Re: Oil consumption & smoke on a 327/350 hp

Well, the saga is solved. I have a local mechanic with a Corvette specialist on board. The took the valve coves off and took the rockers off, etc. The valve seals were of the "plastic" variety and the guide plates were worn! The engine builders replaced all the parts (free of charge of course) and now I have no more smoke, oil usage for the first 100 miles anyway! The rebuilder states a bad batch of parts. He is also going to pay the labor charges associated with the fix. Oil pressure gauge still reads above 60 lbs until warm. Then drops to about 45. I may take it out this winter and see what's going on.Thanks everyone for their comments.Jerry

Jerry,

I had a simular problem on my L79 as my engine started using oil real bad like 100 mikes to a quart. Turned out to be an intake gasket was allowing oil to be sucked in. After changing the gasket know I'm up to 1000 miles to a quart. Engine has never been apart except for the intake and valve seals with the heads on. I'm glad you found your problem.

Mike

[Jim R.]

Re: Oil consumption & smoke on a 327/350 hp

I agree with Joe I had the same problems this guy is having rough running fouling plugs as it turns out mine was sucking oil from inside the motor as Joe has explained, I had to pull the intake manifold and have it machined true along with a new set of gaskets and she ran like a top, easy thing to try anyway.

Gary-----


I once had a problem just like this with an engine I built from a brand new Chevrolet short block assembly. I used original re-conditioned heads. Major oil burning problems from the get-go. I tried EVERYTHING to solve it----a new set of GM heads, 3 different intake manifolds, every type gasket you could imagine, every type sealer you could imagine including aerospace and fluroelastomer, every type valve seal you could imagine. I NEVER succeeded in stopping the oil burning.

I even re-ringed the engine even though I knew the problem had to be coming from "up-stairs"------there's no way that a ring problem could be causing raw oil in the intake runners.

My hypothesis is that the genesis of the problem is oil vapor being drawn in from the lifter valley because of a leak in the intake gaskets (despite every attempt to seal it) OR oil being drawn in through the PCV system.

By the way, my problem was not caused by a high volume oil pump. I installed the pump and it was without question a GM standard volume, standard pressure pump.

[Dennis O.]

Re: Oil consumption & smoke on a 327/350 hp

Gerald, Jack supplied you with good information on spring colors, etc. I am in Florida for 6 months and have no access to any of my stuff, so I can't help you with parts numbers, etc. However, I did post a picture of a HV pump on one of my earlier posts on this thread alongside a scale. By comparing the length of the body on your pump to the one in the picture should give you a good idea of what you have.

[Gerald C.]

Re: Oil consumption & smoke on a 327/350 hp

Okay, ready to address my pegged oil pressure gauge. I guess I'll pull out oil pump over the winter and where would I order the correct spring for my 327/350?

In addition, I have another oil pump in my parts shelf that has a tag on it that states: DM55 98317A. Anyone know what this tag represents?

Thanks,

Jerry

[Joe C.]

Re: Oil consumption & smoke on a 327/350 hp

Okay, ready to address my pegged oil pressure gauge. I guess I'll pull out oil pump over the winter and where would I order the correct spring for my 327/350?

In addition, I have another oil pump in my parts shelf that has a tag on it that states: DM55 98317A. Anyone know what this tag represents?

Thanks,

Jerry

Dynagear pump:

http://www.pmeracing.com/dynagear/dynaoilpumps.htm

[Gerald C.]

Re: Oil consumption & smoke on a 327/350 hp

Joe,

Thanks! I just took the spring out of this pump and it looks like it was yellow and seems to be pretty "springy". Let me check this site out to see if they sells low pressure springs that would fit this DM 55 pump.

Jerry