SoCal Jet Boats
Tech Talk => Engine Mechanical / Electrical => Topic started by: Stevecat on November 24, 2008, 02:12:43 PM
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This is after just one season. Burnt sides were up. What did I do wrong? I have a BBF, logs and snails. Log bolts were torqued to 40 ft-lbs I think. Too loose? Wrong gaskets? Warped log faces?
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I'd guess your flanges are warped, You may be able to ban-aid it by running 2 gaskets per side.
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shitcan the gaskets, try runnin w/o them. maybe a LITTLE red sillycone
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Does that really work? Do you think it would still worky with warped flanges?
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I never use them with cast manifolds (cars), the factories dont use them.
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How do you warp a water cooled manifold?
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Steve those OEM style gaskets dont work well ,let me send you some of mine (18 bucks) you'll definatley have better luck! Orange or Red high heat silicone doesn't hurt and yes the manifolds do distort , hit them lightly on a head surfacer or belt sander Tom
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Thanks everyone for the advice! OK Tom I will call about the gaskets after I weld and powder coat them and am ready for install.
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How do you warp a water cooled manifold?
Update to my own post. Logs and Snails are now welded together. Next step was to kiss the flanges on a surfacer before powdercoat. Took mine to the local auto engine machine shop and they called back about 20 minutes later and sure enough the left log was warped 1/16th of an inch or better. Right side was OK but left was not.
Yeah maybe this warp happened during my recent snail welding, but more likely this was long term issue.
Logs are aluminum sand castings and alum alloys are more prone to warp than cast iron. Also alum alloys can warp (stress relieve) over a long time. What happens is when they cool after the pour in the mold, they develop internal stress. When the casting flanges were machined they were probably straight. But 30+ years later on after numerous temp cycles hot and cold, the left casting musta had some "issues" to work out and it did.
I'll post pics after powder coat.