Developing a thirst for oil!!

[gtr-gaz]

I can't work out where it all goes. I had to top it up with nearly 3 litres when I got back from Stoneleigh

No obvious leaks and no clouds of smoke out the back. Did anyone in yesterdays convoy notice anything out the back of mine??

Any ideas as to what happens to it all? I'm baffled

[tuxman]

Hi Gaz , you could check your breather tank to see if there was any in there ,i used a bit but not 3L (about 1/2L) ,perhaps its the motorway stuff,never seen you car smoke ,i would give Tom acall tomorrow .

[gtr-gaz]

Thanks Simon, I'll check the breather tank tomorrow.

[GTRMikie]

gtr-gaz said:

I can't work out where it all goes. I had to top it up with nearly 3 litres when I got back from Stoneleigh

No obvious leaks and no clouds of smoke out the back. Did anyone in yesterdays convoy notice anything out the back of mine??

Any ideas as to what happens to it all? I'm baffled

Hi Gaz, see my post in "Countdown to Stonleigh" thread, although I didn't notice anything coming out of your car.

[luckyp]

GTRMikie said:

gtr-gaz said:

I can't work out where it all goes. I had to top it up with nearly 3 litres when I got back from Stoneleigh

No obvious leaks and no clouds of smoke out the back. Did anyone in yesterdays convoy notice anything out the back of mine??

Any ideas as to what happens to it all? I'm baffled

Hi Gaz, see my post in "Countdown to Stonleigh" thread, although I didn't notice anything coming out of your car.

Hmmmmm..could that have been me?

[tuxman]

Gaz,while your at it take off the carb and have a good look in the inlet manifold ,it should be clean , if there is oil in there could be oil out of the valley ,might be worth having the dizzy cap of as well just to check for oil .

[boosted ls1]

If your running open breathers then your crankcase has no vacuum which keeps oil in. Basically you're just pumping oil mist out to atmosphere. moreso if your engines done a few miles.

Boosted.

[Graham-P]

boosted ls1 said:

If your running open breathers then your crankcase has no vacuum which keeps oil in. Basically you're just pumping oil mist out to atmosphere. moreso if your engines done a few miles.

Boosted.

I'm running a PCV to the carb base plate on the right bank and a open breather on the left bank, when I got home Sunday I noticed a streak of oil from the top left hand vents running to the back of the car, looked like as you described Boosted, an oil mist from the breather sucked out the top of the clip. I also have a small K&N breather from the fuel pump block off cover.
I guess that it's OK to run two PCV's to the carb base plate?

[GTRMikie]

Graham-P said:

boosted ls1 said:

If your running open breathers then your crankcase has no vacuum which keeps oil in. Basically you're just pumping oil mist out to atmosphere. moreso if your engines done a few miles.

Boosted.

I'm running a PCV to the carb base plate on the right bank and a open breather on the left bank, when I got home Sunday I noticed a streak of oil from the top left hand vents running to the back of the car, looked like as you described Boosted, an oil mist from the breather sucked out the top of the clip. I also have a small K&N breather from the fuel pump block off cover.
I guess that it's OK to run two PCV's to the carb base plate?

I am also running a PCV on the right bank to the carb base plate, but the left bank breather vents into the air cleaner base. This is the way the engine was set up by Real Steel and I have no leaks and low oil consumption even after 7 years on the road.

[boosted ls1]

If you look at a rover v8 the air entry into the n/s rocker cover is just a pinhole with a foam cover to keep it clean. So air is restricted when entering the engine. On the o/s rocker cover the pipe from it to the engine inlet below the throttles is 1/2" or so i/d. So the engine is producing a lot of vacuum downstairs trying to suck air in through a pinhole. Air can't exit anywhere. Any open vent will allow air in/out, so it isn't working as a true pcv circuit.

Boosted.

[ultimacz]

Oil consumption was the main reason why I went from SBC to LS7. Judging by the first test drives with the LS7, it does not use any oil really - though we filled in ultra slick 5W-30 according to GM specification.

At previous engine re-builds we have actually never really found the reason for the enormous oil consumption (3-4 litres of oil after some 5k miles engine use). Yes, there was some oil in the intake, and possible cylinder walls a bit scratched and piston rings not sealing perfectly, but still nothing where you can point at and say this was it.

I am starting to believe that the main difference on a SBC makes the dry sump. One of the cars here in CZ was last year equipped with a new AS 600HP engine with dry sump, it does not consume yet much oil if any and the exhaust are clean as on my new LS7, despite that it is carbed (Holley DP) and pretty much abused on track and 1/4mile.

Peter

[boosted ls1]

An interesting thing about the lsx engines is that they have a pcv circuit but I've never found a hole letting air into the engines. They must be under a lot of vacuum in the crankcase but hey, that just stops the leaks. Not sure how it purges any blowby gasses though. Maybe a smidgen of air is allowed in via the filler cap or n/s rocker plug seal.

Boosted.

[k wright]

You can't run two PCV vavles to the carb base plate. You can keep your current PCV valve attached to the carb base plate and use a valve cover vent on the other side that links a hose to the interior of the air cleaner.

Make sure that your PCV vavle is working well prior to doing this.

ken