Bud2

This week a post was up about oil in a guys’ intake runners. Got me thinking about my issue. I built a 383 last year. Ran great and was strong. The plugs showed soot and I assumed it was running too rich even tho I’ve never seen black smoke from the rear and the LM1 A/F ratio was between 13-14.

Engine BROKE (my fault) in the fall and I rebuilt it this winter. Had a test run last week for 20 min. Next day found some oil on the floor coming from the lifter valley rear seal. Took the manifold off and redid the seals and it’s ok now. But when I took the intake off, I noticed a fair amount of oil in the runners too. It surprised me but I put it back together thinking I’ll ask about the possible causes later.

I’m running 195 AFR, pre-assembled heads – do you think oil could be seeping around the threads of the intake rocker studs? I don’t know if they are blind holes or not.

Thanks for your time.

Bud

bluedawg

maybe seeping past the intake gasket.

Bud2

Maybe, I didn't see any obvious evidence of that tho.

Bud.

bluedawg

Sometimes its not real visible that or were its leaking by, if you pull the intake and it were the roker studs leaking, it might be evident by oily fluid on the bottom of the studs and if it were only on the runners with stud holes in the top. If it were every runner it might be varnished fuel in the runner bottoms.

dochorsepower

If oil was leaking around rocker stud threads, you would have bigger problems, the studs would be unscrewing themselves. More likely is intake gasket seal or valve seals. When you lift the throttle you can suck a lot of oil past the valves if the seals aren't good.