Blown02Camaro

iTrader: (4)

I had a motor 383 stroker ls1 built by a local shop and its been using 1-2 quarts of oil every 3000-4000 mile oil change. I called the builder and a few other places to see if this was normal for an N/A motor built for boost to use this much oil. When I had talked to the shop I had the work done at he said when they built it they used a fairly loose ring gap, and also with this my pcv system was ruined from the added crank case pressure so they added a non vented catch can. Does this seem normal for it to use this much with a ruined pcv system, no crank case venting, and a very loose ring gap???

stevieturbo

Ring gap will have virtually no impact on oil used. Especially if just normal driving, so if all those miles were normal easy driving, the consumption does sound high.

But what exactly do you mean by a "ruined pcv system" and "no crankcase venting"

The crankcase MUST have venting or breathing of some description.

A recent article found on ring gaps.

http://www.diagnosticengineers.org/j...dge%20Gaps.php

But oil usage assuming there is some sort of sensible crankcase ventilation will most likely be down to bore finish, and piston-bore clearance.

Also, what oil are you using ? A very thin oil or running in oil may get consumed in larger quantities than a proper oil.

Monte4ever

iTrader: (2)

What he said^^^^^^ and please vent your crankcase before you blow your rear main seal gasket amongst others.

Blown02Camaro

iTrader: (4)

When I say ruined pcv system, according to the shop "due to the added crank case pressure the pcv system couldn't handle it, so that is why we had to add a catch can" This is what they told me as to why it was quote on quote ruined.
Now I don't know if the stock ls1 has any sort of crank case vent system. Id guess thats what the pcv system does. Im fairly to this motor so im still learning the ins and outs of it. I have not added any sort of breather filter to the valve covers or any type of vented catch can to aid in the venting of the added pressure.
From the few other shops I called to see what there thoughts were the most common answer / question I got was what weight oil are you running and try adding some sort of breather. The oil I have always ran in the car in a mobil 1 10w30 full synthetic.
The car is going back to the builder to get a leak down and a compression test as well as getting the plugs checked then I will go from there once I know the results.

stevieturbo

The crankcase on any engine MUST be able to breathe.

OTT308

Sounds like it could possibly be valve stem seals? Does it smoke on start a little? Or on decelaration a little? Valve stem seals can cause major oil usage. Check to see if your plugs have sign of oil on them also

Blown02Camaro

iTrader: (4)

I usually can't tell because my windows are fairly dark and my exhaust bumps before my rear axle so its kind of hard to tell. the heads have 90000 on them would they go bad at with that many miles on them.

Im waiting to hear back from the shop for the results from the leak down, compression, and plug check before I go add or do anything.

OTT308

It is possible. As far as the heads go it could be valve guides worn and have excessive play and valve stem seals. A higher viscosity oil may help mask the problem? If the heads haven't been touched I would start there. Another thing you can do is take the oil cap of while car is idling and see if it pops off ( indicating crankcase pressure) and see if there is excess smoke coming from oil cap opening (indicates excess blowby)

Blown02Camaro

iTrader: (4)

Well I head back from the shop today. They are pulling the motor. The compression test was good on all around but when they checked the plugs is when s#@% hit the fan. Plugs were coated in oil so they went further and found the intake was also coated now im just waiting to hear back to see what the final verdict is. The only good thing coming from this is Im getting to change my pistons from 10.5-1 to 9.5-1 so I guess its not all bad.