small block chevy engine smokes after rebuild,is it possible the intake gasket could cause this?

depends what color smoke it is…more details please, white smoke is condensation, water, head gasket leak..while black smoke means the ring’s are worn, I would asume scince you said it’s rebuilt that it’s not the ring’s, so it’s probobly the head gasket wasn’t sealed properly, or torqued down properly.

if it’s dark smoke like blueish to get smoke it has to be getting to the cylinders. So I would guest you don’t have the valves adjusted right or are not seat ting.white smoke is from the heads it may be missed toque or gasket didn’t seal

yes its possible,but some of them will smoke a little until the rings have a chance to seat good in them,id give it a few days and see what happens,you don’t have nothing to loose,most of them wont smoke none,but there’s always a few that will,i have seen them break a ring before they ever got started,id run it a day or two if it was me to see if it cleared up,other wise id tear the whole thing back down,something may have went wrong with the re-build,good luck on it.

when you say rebuilt do you mean completely or just partially?
If you had it bored…which most chevy 350′s will need during a rebuild…and you bought new pistons and got the proper ring kit….it’s normal for them to smoke for a little while…let it run and see if the smoke goes away. takes awhile but if it was rebuilt properly then the smoke will go away….blue smoke is oil…black smoke is gas…white smoke is coolant…if it’s black or white then there is someting else wrong…blue smoke…just let it run for awhile and it’ll clear up if the engine was rebuilt properly.

Hope this helps

don’t think of my 350 as a small block,,got bout1000 mi since rebuild 3/4 cam,hand craft headers ,p.t. rear.rebuildit trans4 da1/4+2,4 bs. mine smoked the first 600,,run time down just a little and blowed it out bout3-4 times ,gettin better,every run o’yea its in a 79 el comino(named EL DIABLO)

No, not possible….. it is either the valve seals or piston rings…..

Had this happen to me with a 350 ci engine. Found out that the machine shop performed an improper ream on the valve guides and I had to replace two heads

Another cause could be the valve seals on how they were installed.

There’s a few reason and causes..

Yes an intake gasket leak can and will cause engine to oil smoke (oil in liftter valley, pulled into port by vac, through leaking gasket, into chamber, burnt with air/fuel mix and get’s sent out the exhaust)

However I don’t think that’s your prob.

You said it’s a fresh rebuild..

Make sure synthetic or synthetic blend oil was not put into the engine. Synthetic oil is too slick for the rings to “grab” the bore and make a seal.

Next was the engine broke in right?

Cam break in (for flat tappet cam) 20-30 min run time at 2,000 to 3,000 rpm.. Change oil and filter.

Road drive it.. Easy on the throttle, norm driving.. Get it up to 50-60 mph, and take foot off throttle, let it coast down to about 15 mph, then use alittle heavier throttle to get it to 50-60 mph, then let it coast down to 15 mph.. Do that 8-10 times.

That helps to seat the rings quicker.

With out doing that, ity’s somewhat norm for a fresh rebuild to smoke for a 200-400 miles.

Now rest of break in.. Drive car 500 miles with out dogging it, no faster than about 65 mph, no higher than 3500 rpm ever.

Change oil and filter after that 500 miles, and drive the next 500 miles about the same.. You can be alittle rougher with it, but no racing, hot rodding, etc.

Change oil and filter again.

At 2,000 miles you can switch to synthetic oil if you wish too.

Other causes for oil smoke would be the valve seals, or valve to guide clearance.

Other smoking like a dark black smoke would be fuel smoke due to fuel not burning.. Weak ing. system, foulded spark plug, carb jetted too rich, etc.

White smoke with no smell could be an auto trans mod. valve blown and ATF being sucked into engine.

White steam, or steam with sweet smell would be a leaking head gasket