Oil smoke at start up

Keith Clements · Post by **Keith Clements** » Mon Aug 13, 2007 7:50 pm

The first few times I started up had a fair quantity of oil smoke emanating from the exhaust. Thought it may be caused by overfiling as oil level was 1/4inch above max. Thought it might be excessive oil in rocker cover either blocked return hole or broken delivery pipe. Thought it might be balance pipe seal. Thought it might be pintel valve.

Put finger over valve hole, plenty of suck, engine slows down. Engine has some blow by from pistons; but not excessive. Engine note does not change when oil filler cap replaced. Checked this on Jup same result.

Anyway the finger over pintel valve seems to have cured smoke. Perhaps sticking valve? Note car has now done 200 miles.

Keith Andrews · Post by **Keith Andrews** » Fri Aug 17, 2007 1:38 am

Worn valve guides/seals

Keith Clements · Post by **Keith Clements** » Sat Aug 18, 2007 10:16 am

No seals on the JAv. Although I have seen some people have modified and added seals. Guides should not be worn they are new.

Mike Allfrey · Post by **Mike Allfrey** » Mon Aug 20, 2007 7:18 am

G'dday From The Clear Blue Skies Over Melbourne,

An interesting topic here.

Both my Jupiter engines have blue-smoked at start-up after a lengthy spell of no use. I put it down to how long the engine had run at low idle before switching off the ignition. Valves are good, guides are good and oil feed to rocker gear is minimal.

I also have another theory - I wonder if oil gathers as mist and condenses in the breather valve and its pipe? Then with a pretty good suck, on full choke, at the breather/balance pipe - presto - blue smoke at start-up for a short spell.

On the same, or similar, topic - with my Javelin, after an emergency stop pointing down hill, clouds of blue smoke at the exhaust. This has happened with the original engine and with the engine that was taken out of my Jupiter a couple of years ago. Only component that stayed with the Javelin? You guessed it - the breather valve.

The extent of the smoke, for a few minutes, is such that I worry about being reported to the environment mob. By the time I am out of the car to investigate, the smoke has cleared!

Any comment on this condition?

Regards,

Mike Allfrey.

Post by **Forumadmin** » Mon Aug 20, 2007 11:10 pm

After following Geoff McAuley down a particularly steep special stage on the leJog and suffering a smoke screen when he braked, I fitted a flap that closed when oil moved forwards in the sump. This stops oil hurtling up the filler pipe and being sucked into the brether and into the combusion space. You can see this on barrier across the picture of the aly sump (when you remember your password). This is not a flap but a slightly less efficient fixed barrier.

Regarding smoke at start up;it seems to be getting better, so still theorising on that.