S10xGN

iTrader: (11)

I replaced a perfectly good rear main seal because of this, although mine leaked from the lowest point of the main seal itself. The problem was removing the PCV system and NOT installing valve cover breathers. That's been corrected and all is well now...

Whistler

iTrader: (46)

Did you use the Kent-Moore tools to align the covers?

racecar

It has good compression on all cyls and it pulls vacuum even at WOT, so I don't think it has high pressure. I do understand the logic because it only blows at high rpm.
My PCV setup worked on other motors so I don't see any problem there. I'm pulling the trans tomorrow to replace the rear main seal and cover gasket. I hope I find some problem there. I have replaced everything else.

I didn't use any tool to align the rear cover, other than to level it with the bottom of the block, but nothing side to side. I will check that this time.

racecar

Wooooo, say that again. You replaced the rear main seal, but the problem was no valve cover breathers. I have a vent tube on the valley cover vent, but nothing on the valve covers. There is a hose that connects the two valve covers toether. The PCV is close to the intake on the tube that runs to the back of the motor, then to the valley cover. All of the pressure that you are trying to vent is blowing past the rings and pressurizing the crankcase. The valley vent should work fine for that, right?

frito1

iTrader: (12)

Post a picture of your engine showing the PCV system... your problem might be right there.

racecar

The intake is off right now so I can't get a good picture. I have a hose that runs from one valve cover to the other, but it is not connected to the PCV system. I have one other hose from the valley vent tube that runs to the back of the motor, makes a U, then up front to the intake vacuum port behind the throttle body. So I'm not pulling a vacuum on the valve covers, just on the valley cover.

The valley cover has a good baffle system, and it connects to the crankcase, so do I really need to vent the valve covers also. All of the pressure that needs to vent is coming from the bottom end, any pressure in the valve covers is the same pressure that is in the valley, right ???
I ran this setup on my LS6, it never leaked.
Or does everyone vent valve covers and valley?

ChucksZ06

iTrader: (9)

Hey racecar. Sorry for the difficulties with new engine. Did you put in a higher volume oil pump? I would make sure oil is not coming from higher up on the engine before tearing into it further. Also what guys are saying about pcv system. Hope to run into you at PIR this summer...sounds like you are putting out good power.

racecar

Not the high volume pump. ZO6 pump with a shimmed spring. 40 lb at idle, 60 at WOT, that should not be a problem. Looks like rain next Friday, when are you going out next Chuck??

frito1

iTrader: (12)

I understand that you have the valley cover connected to the intake which is your vacuum source, but where is your filtered clean air source coming from? Has to have an "in" and "out" source. The balance tube going from your valve covers is really doing nothing. You need to give your PCV a clean air source for the air to come in. And at high RPM, the "clean" air source will actually get gases pushed out of it, which is what is happening to your seals and gaskets most likely....

S10xGN

iTrader: (11)

Right, I had already decided to not run a PCV setup but had yet to install the VC breathers. I just didn't realize how tight these engines are and the short duration I ran the engine pushed oil out the rear main. After pulling it, the seal looked cherry (longblock had 23k miles)...

Beaflag VonRathburg

iTrader: (176)

I am going to have to figure out a proper pcv setup for my new engine. You guys have me worried about these block porosity and starter bolt issues. Why do you have to grease the starter bolts?

1lejohn

iTrader: (9)

I'm running basically a stock Z-06 type PCV system. The fresh air comes off the T-body and enters the pass side cover at the front. The pass side back port is capped off as well as the driver side port. The PVC hose comes off of the valley cover and into a catch can then into the PVC (valve) then back into the T-body. IMO this is the cleanest and easiest PVC system for a street driven car. You need to still check your system and get rid of the hoses between the covers and make sure it has fresh air feeding the engine.

cam

iTrader: (9)

As a quick test for your PCV system you could simply pop the oil fill cap off and go for a quick spin and see if it still leaks at high RPM. It might make a bit of a mess at the oil cap but i ran a breather set up on my last LS1 with no pvc like this with zero issues for four years. Buzzed it to 7K all the time.

At least if you try this you'll know for certain if its your PCV system or something with your seals, block etc.

A lot of guys make their own breather

https://ls1tech.com/forums/generatio...-20-guide.html

racecar

Thanks for all of your input guys, that is what makes this forum work, throw all of the ideas on the table and try to decide which one will work !!

Frito: I'm not following this fresh air inlet. A PCV system has to be closed or you will have a vacuum leak.

SX: That makes sense, without any breather or PCV pulling vacuum, the crankcase will be pressurized and will blow oil out of everywhere.

Beaflag: I put silicone on the inside starter bolt threads, thought that was the source of the oil leak because the bolt was covered with oil. Now I'm thinking it was oil running onto that bolt from somewhere else.

lejohn: What do you mean by fresh air, is that a vacuum tube on the throttle body, and your PCV port is farther back on the intake?

Cam: Without the cap, there would be no vacuum, and all of the crankcase pressure would come out of the cap, yes it would not build pressure in the block. That's how we ran them old school. It may be worth trying to see what happens.

I have the trans out now (what a job) and I am replacing the rear cover and rear main seal. Then I am going to make some changes in the PCV, install a Y tube to connect the valve covers to the PCV system. I'm pulling vacuum from the intake, right behind the throttle bod, that's all.

If you have another tube from the TB to valve cover, is that what you guys are calling fresh air? It sounds like a huge vacuum leak to me, is that how the stock LS1 is setup?

frito1

iTrader: (12)

^^ Exactly!! Valvecover breathers would be the fresh air inlet too. It is a vacuum leak... a controlled one. The PCV valve controls your rate of leak. At high RPM the fresh air becomes the "exhaust" when the rings start to flutter. That will allow the gases to push out instead of pressurize the crankcase. Then under low rpm (vacuum) conditions, it returns to the inlet air source of your PCV system. Right now, your PCV is worthless. Air has to have an "in" and "out" path.

1lejohn

iTrader: (9)

Yes I ment the intake has the PVC fitting on it. Good explaination Frito

ChucksZ06

iTrader: (9)

I recently transfered my stock z06 engine into a gen 1 camaro I am building. I had an f body oil pan that I put on the engine. I used the used fbody oil pan gasket which I have done numerous times in other ls applications and the sucker leaks in the oil filter area. It will not be fun putting in the new gasket. Not saying this is your problem but you never know. Alfa club is having a track day on 6/20...maybe I can make that one. Did you put sealant on the flywheel bolts? That is something I have started to do.

racecar

I have an LS6 pan on a L92 block. I replaced my LS6 pan gasket last winter. There is a new L92 pan gasket part number that is different near the starter. It fits the L92 block better. That is the same gasket that is used on 2010 Camaro. It may work better for you. Sealer on the flywheel bolts? What for? May see you 6/20.

racecar

Interesting! I thought that the more vacuum that you pull on the crankcase, the better. But at high rpm, there is little or no vacuum so a vent would be good. I will try that. Where do you tap this fresh air. In front of the throttle blade so it is not pulled by vacuum? My 90 mm TB has no port to tap into fresh air..

Petraszewsky

iTrader: (28)

Any updates on this?!?! I seem to be having a similar but at idle and blipping the gas a bit at standstill...i haven't let the engine warm up yet since it's spiiting out so much oil at the starter bolt closest to the block but my oil pressure is at 60 at idle and when I blip the gas it pegs out past 80!!!!???