400 sbc bearings?

Question

i jus bought a 400 sbc that has dynp time only o nthe short block and the problem was theat the head gasket blew and a little water got in the oil should the bearings be replaced? the builder told me just to put some assembly lube on them and button it up. i have never heard of that i dont want to put money in this and it spin a bearing.

Answer 1

Bearings are cheap and if you have to pull the rod bearing caps to check for wear anyway I'd just put in a new set rather than just spreading the assembly lube on them. The main bearings should be okay (I'm sure you don't want to go pulling the crank to replace them)--the chances of damaging a main bearing are remote.

hope that answers your question

Answer 2

From engine builder's point of veiw... I would be digging into the engine..

Some reason that the gasket blew on the dyno.. Head gaskest should last many many many pulls w/o blowing unless something went wrong

Was a blower/turbo used on it?
Was it on N20 during the pulls?

Why did the gasket blow?

Detonation will cause it, and if that was the prob then there could be damage to the bearings, and/or rings.

Was the engine ran long once it blew the gasket.. If cyl filled with coolant at the top side of one of the pulls, then the piston could have tried to compress coolant and tweaked/bent a rod.

I would pull the rods/pistons out, crankshaft, etc and look over everything very closly and replace rod and main bearings with out thinking twice.

Answer 3

if it was me,and i work with a very small budget, i would replace the bearings, water is oils worst enemy, it would only take you alittle time to do that right now,compaired to removing the motor and finding that you may have got into the crankshaft and having to replace it too.
good luck