Heddde

I need some thoughts on this one, at high RPM at WOT the car starts smoking white/grey and after a hard drive you see oil/gasoline marks all over the back of my z06. Also i need to fill it with oil frequently.

I took the intake of (MSD ATOMIC airforce) its like full of oil.(Pictures)
I took the heads of noticed some clearence in the intake guides nothing on the exhaust side. New bronze sleeves put in on intake side and new seals.
I took a feel on the pistons some rocking at top but didnt think it was too bad.

Put it all together again and still the same smoking and oil consumption of course.

Did a Leakdown test before on a COLD ENGINE was getting between 10-18%

My thoughts:
1. Oil separators are needed, because of the higher intake flow the oil is forced from the dry sump tank into the intake. (ordered Elite engineering cans.)
2. The car has a too rich fuel mixture! (new tune needed)
3. The pistonrings cant hold the pressure at WOT and high RPM.
(new rings/pistons needed)
4. Is it Normal?

Setup on the car:
Lingenfelter GT-21 cam (high lift)
Ferrera valvespring kit for that cam
Rocker Arm Trunnion Upgrade
102mm Nick williams
Halltech air intake
MSD atomic airforce intake manifold
Pfadt Headers
Borla Atak exhaust
This setup got 680hp on the dyno.

Now Sweden need some help from you guys "Over there" feel free to write your ideas and i appreciate every answer!

140K_GXP

Definitely not normal. But I think I know what is going on. Did you use Teflon or RTV sealant on the rocker arm bolts? The bolt holes for the intake rocker arms go into the intake runner. This could cause excessive oil in the intake and to pass through the engine out the exhaust.

Heddde

I did use blue Loctite for the bolts, think thats the problem?
!! Looking at it right now and unscrewed one of the rocker arms, looks like its a "stop" down in the thread. So the oil cant go out that way?

Jimbo1367

I've heard the sealant on the rocker arm bolts but not sure if it was on LS7s too.

dr_whigham

iTrader: (49)

You only need the sealant if the heads pave been ported to the point of exposing the rocker arm bolt holes. I'd use RTV Ultra Black for that.

Heddde

Good to know 👍🏼

140K_GXP

Is that picture of an intake rocker arm or an exhaust rocker? Typically on ported heads, its the intake bolt hole that gets exposed to the ports. And it is possible that the bolt holes won't be exposed on every one of them.

I would take off all the rocker arms, use a good RTV sealant, re-install, and check oil consumption.

Check out this thread: https://ls1tech.com/forums/generatio...oke-works.html

This person had the same symptoms you have and re-sealing the rocker arm bolts pretty much fixed it.

Krom

holes to the intake ports (or exhaust ports) has nothing to do with leakdown numbers.

140K_GXP

You are right. Not sure what I was thinking.

truckdoug

iTrader: (25)

do you have a catch can/separator on the car currently? what is the routing?

American Heritage

Have you done simple wiggle test?
Have you done a leak down test?
If so what are the results?

pantera_efi

iTrader: (1)

The chance of an intake oil leak is easy to determine, just watch the exhaust at the time of throttle "lift" for Blue Colour
Not stated in your observation.

The stated observation of oil film, gray/black smoke at WOT is a result of rings passing oil.
There could be a leak though that result would be oil film only, not smoke from the exhaust pipes as stated.

The cause could be the tune, too much spark advance.

My question is about your Spark Instant at WOT, max RPM.

What is that value ?
Spark plug heat range?
Fuel octane, though in Sweden it is high ?

YES, too Rich at WOT though you would be down on power.

Lance

slojoeracing

Did you ever find a solution for this? My 09 z06 having the same issue on track days. Consuming oil and coating my back bumper.

G Atsma

Heddde hasn't been here for eight years. Check post dates.....

LilJayV10

iTrader: (39)

I had the same issue on a SBC 406 I built in my 20's.

I installed the second ring upside down.

Car ran great but smoooookkkeed.