Sircajun

Helle Guys
Since Oldsmobiles aren´t that common in Denmark, there are no Olds engine experts here.
I have my engine at a local machine shop. He is very talented but i doubt he has any or atleast very little experience with Olds engines, since he´s into Chevy´s.
What is the most commom mistakes made when rebuilding Olds engines?
Mine is a 1969 400 out of a 442.

Thanks

oldcutlass

Valve stem length.

cutlassefi

Actually that's a good point. That probably causes more problems than anything.
Good machining and assembly practices are pretty much the same on everything. Common automotive sense goes a long way.

don71

The rear oil galley plug in the rear perhaps. Its often replaced with one that doesn't have the hole in it for oiling the distributor gear.

MDchanic

Or, to phrase it another way, valve seat depth.

Seats should all be cut to the same depth, so that stems are all the same height.

- Eric

Octania

The oil passage plug replaced with a generic one w/o a spurt hole

https://classicoldsmobile.com/forums...g-removal.html

Pistons [forged] too tight in the bore => scuffing and overheating

sealer on every bolt everywhere [few Olds engine bolts need sealer]

Seff

Had a Danish shop screw this up on my first rebuild.

Same shop didn't even take out the plugs, much less clean the galleys. They were so dirty that two lifters weren't getting any oil.

Yup, this too.

Off the top of my head, it's one or two of the water pump bolts, the mech. fuel pump bolt, and thermostat housing bolts that require sealer. Any others I've forgotten?


In my experience it's been impossible to find anyone with a torque plate for Olds in Denmark. IIRC you don't need to bore up the engine, though.

oldsconv

If they install hardened valve seats, make sure they use Olds specific ones and that they don't cut too deep and go into water passage. Common issue if they use Chevy ones or generic size.

Sircajun

Thanks guys. At the moment I know that my heads don´t require any work. The valves perform an excellent seal and have hard seats from a previous build. Cylinders only needs to be honed and pistons will be given new rings. More to come when he has it torn apart.