When to re-build Chevy 283

[lnewcom2]

I am spending my first summer with a 36' 1962 CC Constellation. The twin 283's were last rebuilt at 500 hours and I will probably be at about 1500 hours at the end of the summer. Other than poor performance is there anyway to tell if rebuild is necessary?

[drrot]

Oil consumption seemed to be the second reason older motors got rebuilt. Not as much a problem now.

[evansjw44]

There are a number of symptoms that will tell you its re-build time. At 1500 hours you should be concerned. If its not using oil you need to check for excessive blow-by. Blow-by tells you that the rings are not sealing very well anymore. Next you need to listen for piston slap and bearing noises. Outside of valve train noise, 283's are very quiet engines if they are still tight. The small block cev's are also famous for bad cam shafts. If you have a "soft" cylinder as noted by a rythmic thump in the exhaust and loss of full power RPM you could be looking at a bad cam. Anyway, at 1500 hours there are a lot of things that can be tired. The opposite rotation engine get tired first because of piston pin offset. One would expect that the heads have been of the engones and bee reconditioned, otherwise you get worn valve guide, dry seals and broken rocker arms. Get a very experienced mechanic to look at them, one you can trust. But you might want to look at re-powering instead of re-building as 283's are a bit small for boat I would think. A lot of folks buy new GM 350 long blocks and do the conversion to replace the 283 and 327. Its not quite as simple as it sounds as there can be some bracket issues and you have to change the rotation.