datsunfish Posted December 1, 2007 Report Share Posted December 1, 2007 I have been smelling a little oil smoke lately on my 510s L16 with w53 head and today I found that my valve cover vent is sending oil to the carb base.Lots of it.Its dripping onto the exhaust.I suppose it needs a pcv valve? It still runs good and doesnt smoke out of the exhaust.I just want to know what causes this. Quote Link to comment
RacnJsn95 Posted December 1, 2007 Report Share Posted December 1, 2007 I've always heard it's cuased from worn rings with excessive blow by. I'm not certain though... The air filter housing on my 620 was full of oil being blown into it by the vent when I got it... It was pretty amazing. Quote Link to comment
datzenmike Posted December 1, 2007 Report Share Posted December 1, 2007 I have been smelling a little oil smoke lately on my 510s L16 with w53 head and today I found that my valve cover vent is sending oil to the carb base.Lots of it.Its dripping onto the exhaust.I suppose it needs a pcv valve?It still runs good and doesnt smoke out of the exhaust.I just want to know what causes this. Properly set up, the PCV valve uses a small amount of vacuum to empty the crank case of oil, water and gas fumes that would otherwise escape and pollute and or, condense inside the block and 'pollute' the oil. The valve allows one way drawing of fumes into the intake and thus into the motor to be burnt. The make up air is drawn from the clean side of the air filter housing, and drawn down into the valve cover. Under hard acceleration, when vacuum is lowest, or if there is excessive blow by from worn rings, enough pressure is produced to reverse the flow, out the valve cover vent, and back to the air filter. You absolutely should run a PCV valve. It prevents pollution and has absolutely NO effect on performance and mileage, but most important it keeps condensation from diluting your oil. With it, your oil stays cleaner and engine lasts longer. As for the oil dripping out. (assuming rings are fine) It could be worn rod and main bearings throwing too much oil spray around inside. At higher RPMs this spray gets whipped up into an oily fog and any blow by will push it past the baffles in the top of the valve cover and out the tube. The only fix would be to run a catch can to collect this oil. Possibly, have you over filled the oil???? Oh yeah, you could try not pounding on it so much.:D:D:D Quote Link to comment
datsunfish Posted December 1, 2007 Author Report Share Posted December 1, 2007 I dont think I meant pcv.I mean the one in line from the vc to the carb.I never needed one before.I have the lower mani pcv all set up. When I had the head off the cylinder walls were pretty glazed up and before the w53 it had a compression of 90 psi or so.So maybe its the rings. I just need it to be reliable for a while.I plan to keep the auto and need a ton more low rpm power for take offs. I want to do a LZ22 or 24. Quote Link to comment
datzenmike Posted December 1, 2007 Report Share Posted December 1, 2007 Got-cha. There is usually just a hose from valve cover to air filter. Any blow by would get sucked into the carb. In severe cases it will drip all over. If it's that bad, run the hose into a catch can to collect it. This won't help with the fumes you smell though. 90 PSI is quite low but as long as it's even it will run smooth. The higher compression with the P-nut head does not help. Low speed take offs can be improved by swapping in a lower ratio rear end like a 3.90 or 4.11. I've heard that the '80-'82 720 4X4 front diff will fit the 510. It has the 4.11 ratio. An LZ22 auto with 4.11 gears....Mmmmm. Your 510 isn't a wagon by any chance is it? Quote Link to comment
datsunfish Posted December 1, 2007 Author Report Share Posted December 1, 2007 By changing the ratio to allow quicker take offs will it make it rap out more in 3rd?I scrapped a 80 720 4x4 a few months back so I should look to see if it is still around.I really do want to do the LZ for this since its an auto. I am aware of the issues of doing a lz24 as far as deck height.I could get around that but what about the crank?Can I have it fully counter balanced?Or is that a waste of time? Quote Link to comment
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.