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Smoke out the exaust


Well-known member
Have a 500 Caddy and this past weekend the waterpump belt came off and the engine over heated. Now I have smoke coming out of the right side exaust. I belive it to be more steam and a blown head gasket. My question is. Can I run it this weekend or is it something that needs to be fix before the next time I take it out.
Aww cmon now this is a test right ?? surely you wouldn't leave the dock on a boat that wasn't right ?? I mean drivin one back in is one thing but starting off that way ??? no way get it fixed
Run it. The worst thing that can happen is a cracked head or maybe a hole in a piston or two
No it's not a test, It's a three day weekend. I ran it Sunday all day,couldn't tell a diffrance. I just don't have the time to fix this weekend. Would the water that is leaking in hurt the pistons? Should I do both head gaskets or just the one that is bad?
well if you have another motor and someone to pull you in then I would go get some k-w block sealer at the NAPA store and put it in it per the directions and give it a go.
Well I may, but first, I've got a buddy of mine that has a truck shop. I'm going to call him tomorrow and see if I can talk him into using his shop, and him, to put some head gaskets in Friday night.
Cadilacs are notorious for blowing head gaskets when overheated, unless the head and block are pinned. Cadilac Performance in Tampa and CadCo out west drill the block and head in the corners and install roll pins to keep the head gasket from blowing out in the corners. Works wonders. Caddi heads have fewer bolts than Chevy heads and are therefor more prone to gasket blowouts.

It is NEVER a good idea to allow water into any combustion chamber. best bet is to pull both heads - the engine overheated, not just one side - and replace both head gaskets.
a1mudpuppy":17qinydu said:
Should I do both head gaskets or just the one that is bad?

Well, you have to take the intake off to do a head gasket, so the only thing left to do the other head is the exhaust manifold and the head itself. While you're in there you may spot a bad piston or questionable valves. It's worth doing them both. Just buy a head set for it and you'll get all the gaskets you need. I recommend new head bolts too while you're at it.

There's getting to be less and less old Caddys out there, you should try to preserve yours if you can.
BigDaddy":u5gx93oo said:
Caddi heads have fewer bolts than Chevy heads and are therefor more prone to gasket blowouts.

Chevy has 5 bolts around each cylinder.

Most engines only use 4.

I think this is one of the factors in the Chevy engine's reliability and therefore, it's popularity.

If I ever designed an engine, I would put 6 head bolts per cylinder.
when you pull the heads check real close for any cracks , cad heads crack when they get real hot
All conventional Fords, Small block Dodge’s, Caddies, Buick’s and Old’s use ten head bolts per head. Pretty much only Chevy and big block Dodges use more and Dodge just copied the Chevy. Once again proving the Chevy engineers were the most brilliant!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! The reason for only ten head bolts is it’s next to imposable to locate all the head bolts with out protruding an intake or exhaust port. If you pull your spark plugs you will probably find one with corrosion on it if so you know you have a water leak. It will only get worse and all you will accomplish by running it now is damaging more parts than you already have. Don’t run it fix it because your going to fix it anyway.
Does anyone know the head bolt specs? I plan on pulling the heads of tonight. Gettig all the gaskets for it today. when I pull them off I'll run them by a machine shop and have them check out.
I know the 472 is 115Lbs. I will look up the 500CUI motor when I'm back in the shop and post the torque numbers.
Thanks!!! Now all I have to do now is find a head. Yes I took it off today and it was cracked. So now I'm looking for a 493 (120cc) replacement head. I've got a freind that just gave me a 500 today that was seating in his yard . With my luck it didn't have the 493 heads but the 902 (76cc) heads. Nobody so far that I've called has the 493 heads. Looks like a head swap is coming and I'm off all next week with no boat to run. DAMMIT
The 76cc heads and pistons are a 10 to 1 comp. motor, that is a good motor to have. I have a friend that has put 425 heads on a 120cc chamber motor just to get it uo to about 9.5 to 1 comp. Is there anything wrong with that motor? Or you could put the 76 cc heads on your motor and have about 13.5 to 1 comp :shock: .
Spoke with a Caddy man today he said that if I was to but those 76cc heads on I would get a 13:1 which wouldn't be good for me. Not only would it ping but I would have to run high octane fuel. I also would have to wait and send the 76cc heads off to get work. The boat runs great with the 120cc heads and I pick up a set from the guy today ready to go.