jyeager

Of course most of us know that for a performance rebuild you'd use torque plates, but no factory engines are built that way....who would have expected a factory engine to burn oil and lack proper ring seal unless it were honed with torque plates?
You expect that torque plates are an extra step in blueprinting...not a mandatory step to get normal function.
So when long threads like this come along complaining of oil consumption on a factory engine, everyone throws up their hands in dismay saying it must be the PCV valve, or it must have bad valve seals...well it looks like the factory block may very often be the problem.

Squintz Palladoris

iTrader: (1)

Good Point Man!

pkincy

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Don't forget that oil has a very poor octane reading. So stay conservative on your tune and don't zero out the knock retard. Ask me how I know that is a problem and I will show you a piece of piston missing.

Perry

Squintz Palladoris

iTrader: (1)

Actually a small amount of oil in the intake charge will help to prevent detonation. Its when it builds up hard deposits in the combustion chamber that it will cause detonation because it increases compression. Not to mention it will continue to burn and make hot spots therefore further contributing to PreIgnition/detonation.

Thats what probaly caused your problem and its not really something you can tune for.

Brad

jyeager

That's a great point. Oil consumption of that magnitude will cause knock problems.
Brad, I think you're wrong about the oil. Even fresh oil in the chamber will cause pinging...although you're right that the carbon buildup will cause it too.

Squintz Palladoris

iTrader: (1)

Jyeager,

Think about it this way. A higher Octane fuel burns at a slower rate than a lower octane fuel.
The oil actually will slow the combustion down a bit. Not speed it up.

Brad

CharlieLed

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If this shop did not know enough about LS engines to use torque plates then they probably didn't know that the hone is much smoother than other engines. With the low ring to cylinder wall pressures and thin rings in these engines there's no need for a coarse hone and long break in, these rings should be good to go as soon as you fire it up. I wouldn't put too much hope in these rings seating anytime soon. BTW, valve seals won't leak more under higher RPMs...you may have an issue there but I don't feel that it's your biggest problem. Good Luck.

jyeager

I don't think that reasoning holds true here. Oil doesn't vaporize like fuel, it remains as little droplets which become hot spots that cause pre-ignition. A brand new engine, perfectly clean inside that's consuming oil will ping, I've read probably a dozen threads on this site over the last year alone who were experiencing pinging because of oil consumption and were able to solve the problem with the PCV change...they did NOT need to do the top engine clean to remove the deposits first (although it's advisable anyway).
Yes, the oil has a very high octane rating...you can't set it on fire. But it gets super hot and ignites the fuel mixture nearby.

zamboxl

iTrader: (1)

so if you got pinging becasue of oil being burnt up, can you retard the timing to fix this or, do you have to stop the oil from getting to the CC. For someone with this kind of severe ring problem the catch can aint going to help, and doing another rebuild or a new engine may not be an option. so what could one do about it????

fozziejared

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ttt...

CAT3

iTrader: (9)

fozziejared-
Have you performed a leakdown?

Whats the results if you did?

Have you talked to the shop to inquire whether they did or did not use a Torque Plate? If not you may want to start talking about why not!

Also, everyone is quick to go to the PCV system, or valve seals, but an often neglected area or two, is the Valve guides often ignored during rebuild and when loose will leak.... a lot. And the other one is the intake rocker bolt boss on ported heads. If they are not sealed up after porting it will SUCK oil into the intake system and lots of it also. You will get more oil out of rocker bolt bosses being left unsealed than the shittiest PCV system.

So, were the heads rebuilt or no? If so were new or knurled guides used? Seals to satisfy that question too? and during assembly did you seal the rocker bolt bosses if the heads were ported?

I agree the Torque Plate not being used to me is just plain lazy and uneducated on the shops part. I wouldnt do the machine work half assed if you didnt have the $ to do it right just to get you out the door, and have my name go to **** later for being a tool. But lessons learned.

Good luck.

Charlie

fozziejared

iTrader: (1)

the heads were bought from lg motorsports and have been untouched since as far as i know..but you never know, i have no idea what lg did to these heads what they put in them or anything.. i bought the car mostly as is. i am trying to have a leak down test put on it,but with the holidays here everything is outta whack..i will have this test done asap though..what should i know going into the leak down test..anything in particular to notice? will the test distinguish if the leak is in the pcv system? let me know thanks.

fozziejared

iTrader: (1)

ttt...

CAT3

iTrader: (9)

Not really. It will tell you if your losing compression in a cylinder('s) and by rings or guides/seals by wet vs dry. Each cylinder should be within 10% (if I recall) of eachother.

If LG machined and installed the heads I would be less worried about guides, or bolt sealing issues. Seals, well thats a hit or miss since the quality of the seal may have been shitty and unknown at time of install. Pointing more towards rings I would have to say...

fozziejared

iTrader: (1)

i think its most likely the rings...i still havent been able to do the leakdown.. considering the holidays..i will soon tho and that should let me know if its the rings..correct?

fozziejared

iTrader: (1)

ttt...

fozziejared

iTrader: (1)

the leakdown should let me know where the oil consuming culprit is located correct?

jyeager

Sort of. If you have a leaking cyclinder, you squirt a bunch of oil in that cylinder and perform again. If it leaks down less than you suspect rings. Otherwise you suspect valves. A leakdown test will not show a problem with valve seals or guides, or rocker arm bosses.

I do think that if you pull the heads that you'll be able to visually see where the oil had been going (and coming from).

Good luck.

Oh, and since one of the suspects is an out of round cylinder, then you might try doing a leakdown test on your cylinders both at TDC and BDC because it will likely be round at one of the two locations, just not the other.

fozziejared

iTrader: (1)

thanks..good info.