Rebuild cylinder heads

[BRog]

I bought a 340 motor with paperwork showing that the block had been professionally rebuilt, but later learned that the heads were rebuilt by the seller himself. I wasn't able to hear engine run before I bought, so I took a chance since it was a good price.

I've since installed the engine and have put a few thousand miles on it. Engine runs and sounds strong, but I'm burning oil. I'm guessing that the problem is either valve seals or valve guides since the heads were rebuilt by seller. What symptoms should I look for to determine the source?

 

[Breadburner]

Smoke on start up would indicate worn guides or seals......If it continues to smoke your looking at worn cylinders.....

 

[BRog]

It blows a pretty good cloud of smoke at start up after it has been sitting 10 to 15 minutes. That goes away though. I don't notice any smoke when I'm on the gas, but I do notice it when the engine is up to temperature and I am idling at a stop.

 

[pozest]

Put new valve seals in and see if that helps.