I need you guy expertise,

My newly rebuild engine with about 3000 miles used about 1/2 quart of oil every 500 miles. The PVC valve is new. There are no oil leak.

Is this normal for rebuild engine to use this much oil even after 3000 miles?

What do I need to check?

Thanks,

 

That is excessive consumption given that the rings need time to adjust. From your post, it appears that you have used 3 quarts of oil over the 3000 miles. With no apparent external leaks, the oil must be entering the combustion chamber, which would cause noticable smoke from the exhaust.


[Modified by Oldman, 6:52 AM 2/20/2003]

 

What does it mean "the oil must be entering the combustion chamber, which would cause noticable smoke from the exhaust.". I don't see any noticable smoke from the exhaust. How many miles for the rings to sit? I have total seal rings if that make any difference in break in period and rings sit...

 

Which method of breaking it in did you use?

 

Drive the car easy for the first 1000 miles, varies the speed while driving. All speed were under 65 mph. After 1000 mile I increase the speed to 70-75 mph. Within the first 1500 miles I had to redo the heads studs because water leak, we didn't put enough Permatex sealant on the threads. Does that has anything to do with sitting the rings?


[Modified by VQT88Vette, 1:24 PM 2/20/2003]

 

Hmm, dino or synthetic oil??

Are you certain you installed the rings properly? They have a chamferred edge and need to be installed a certain way. Just an idea.

Have you checked the plugs for oil fouling? That could point to one or all cylinders?

 

Last Friday 14 Feb, I drove ~550 miles to Ohio. I was driving a constant 70-75 mph most of the trip but I had the car up to 85-88 mph for about 30 minutes. Check the oil at fill up and it about 1/3 qt low. Drove back to Philadelphia on Tuesday within speed limit at all time, 1/3 qt low at fill up (~360 miles). :confused:

 

I use dino oil, and I am sure that we put the rings in correctly. I'll have to check the plugs condition when the weather permit.

Thanks for the suggestion

 

"There is no oil leak"......"There is no smoke".......
Try placing some newspapers under the engine after driving, and ensure there is no oil leak.
At 70 mph I hope you are not watching the rear view mirror for smoke. You will not see billows of smoke if you are burning oil, just a trace that may not be noticable while driving.

Oil has only three places to go after you pour it into the pan...the engine, the ground, or out the exhaust. Placement of newspapers under the engine will determine if oil is leaking to ground. That leaves one path to worry about, that is, passing by the rings into the combustion chamber and out your exhaust. Inspection of the exhaust tips for traces of oil, and inspection of the plugs for evidence of oil will help solve your problem

It is possible that your rings are allowing pressure into the pan and you are losing oil out of the pan gasket only while you are driving. If this is true, you should find traces of oil around the pan gasket.


[Modified by Oldman, 11:41 AM 2/20/2003]

 

Thank you for all the suggestions. Checking the plugs have to wait until it is warm enough for me to work on the driveway, by that time I will check to compression pressure also. What compression should I be expected? Less than 200 psi and more than 180 psi?

 

I don't have the compression specs for your '88. The manual for the '93 (LT1) suggests that no cylinder reading should be below 100 psi, and that the lowest cylinder reading should not be less than 70% of the highest reading.

 

VQT88Vette:
I Hate to be the bearer of bad new, but I suspect it’s your Rings. Total Seal “Gap-Less” rings do produce less blow-by, and slightly more cylinder pressure. But they do it at a cost, which is oil consumption! Although the sales campaign & theory sound good on paper, their real world performance leaves much to be desired!

The oil consumption issue with “Gap-Less” rings is inherent to their design. A natural side effect of standard rings normal 2-6% blow-by, is enhanced oil control due to the rings getting blown clean of oil! “Gap-Less” rings are design to not permit this blow-by, which results in greater amounts of oil entering the cylinder.

The other contributing issue is more esoteric; it has to due with ring flutter. Standard gaped rings allow blow-by gasses to pass the 1st and the 2nd rings gap. The “Gap-Less” second ring (like all SBC 2nd rings) is an oil control device, and when subject to trapped high dynamic cylinder pressures, it starts to flutter which causes seal loss. This seal loss on the second “Gap-Less” ring causes oil contamination of the cylinder, which equals high oils consumption, & sensitivity to knock & ping.

I was warned by 4 engine builders to stay away from “Gap-Less” rings for a street/strip engine, just for these issues.

If this sound likes horse poopy to you, I’d call Speed Pro or any number of aftermarket Piston MFG’s and ask if they recommend ZG (zero gap) rings for a street EFI/Smog vehicle!

Sorry:nonod:!

:crazy:NanoBrain:crazy:

 

:iagree: My machinist told me the same thing do not use Gap-less rings or I would use a lot of oil.

 

:cry :cry