455 issues... blowby??

[wskirvin]

Well sadly had to drop the short block off at my builders shop this morning. had a rough last 2 weeks between this and having my dog put down. finally got back into the car last weekend and it ended up being rings not seated due to washing down the cylinders when i was having issues with the quadrajet. finally got the carb redone at Everyday performance and put on about 2 weeks ago but by then it was too late and already smoking. so new bearings, and a complete go through and cleaning are in its future as well as replacing the cast high compression pistons with speedpro forged ones since it will all be apart anyways.

 

[Kennybill]

Sounded like a coolant leak and/or your engine is sucking automatic trans fluid. Coolant has a sweet smell. I don't buy the "washing" new rings out. Weld a bung on each exhaust pipe for evacuation tubes. Moly rings take a while to seat. Put a set of iron rings in it now it's out if the thick it the rings. Jmo.

 

[L92 OLDS]

Is the condition still present after changing the oil? If you were tuning the carburetor and contaminated the oil with fuel you will have issues.

 

[500/600]

Look on the bright side, you’ll be nitrous ready with those pistons. That will seat the rings

 

[olds307 and 403]

I know the Speedpro are cheap but heavy as hell and the thick rings which take longer to seat vs a modern thin ring packs.

 

[fleming442]

.004 piston to bore clearance on the SpeedPros. Anything less, and you're asking for problems. I'd shoot for a. 018-.022 ring gap.

 

[wskirvin]

Sounded like a coolant leak and/or your engine is sucking automatic trans fluid. Coolant has a sweet smell. I don't buy the "washing" new rings out. Weld a bung on each exhaust pipe for evacuation tubes. Moly rings take a while to seat. Put a set of iron rings in it now it's out if the thick it the rings. Jmo.

Much appreciated for the info. Trans fluid wasnt a possiblity since trans was on its own separate cooler and is electronically controlled. Very well could be coolant though but even after changing the oil, it still smoked and then when i pulled the engine apart you could still smell fuel in the pan and lifter valley


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[500/600]

.004 piston to bore clearance on the SpeedPros. Anything less, and you're asking for problems. I'd shoot for a. 018-.022 ring gap.

I had speed pro forged in my old Buick 455. Yep they were heavy and strong and with beam polished stock rods and ARP bolts they went 6500 rpm and 6.85 in the 1/8th with no nitrous. With a 175hp shot that car was a handful. Good pistons for reasonably abusive use. Correct skirt clearance and ring gap is crucial on any high rpm engine.

When you get it back I’d spend more miles under load getting it broken in.

 

[G.P.]

i wouldn't be afraid to continue breaking it in . however checking the torque on your heads isnt a bad idea.
Also invest in a catch can. you built a new motor to be awesome, not to recycle Pcv gases. oil in the plenum is the work of the devil .

Whoever said condensation isn't bad must be drinking.. mix in a water.

not sure about iphones but for alot of droids and sich you can get a 20dollar bore scope that will knock the socks off any expensive one. go and check the bores, valveguides etc. Knowing is one thing. the rag over the tailpipe test is like sacrificing a chicken in comparison. ive used one of these el cheapo scopes to id crosshatch, and even see overbore numbers on pistons. well worth it even if you have to buy a cheap obsolete phone to make it work.

 

[fleming442]

I had speed pro forged in my old Buick 455. Yep they were heavy and strong and with beam polished stock rods and ARP bolts they went 6500 rpm and 6.85 in the 1/8th with no nitrous. With a 175hp shot that car was a handful. Good pistons for reasonably abusive use. Correct skirt clearance and ring gap is crucial on any high rpm engine.

When you get it back I’d spend more miles under load getting it broken in.

I only mention it because the spec that comes with the slugs is like .002- .0025 which is too tight and gives a lot of Olds guys fits.
There are much better pistons available these days like Mahle and CP.