Repairing Cracked BB Valve Cover

[Gene M.]

Re: Repairing Cracked BB Valve Cover

Jerry, that is like the lost art of body work using lead and a torch......... good idea.

[Greg W.]

Re: Repairing Cracked BB Valve Cover

Mark, The JB weld may work, but it is the cheap and easy way to fix it. If it fails you may have a mess on your hands inside the engine. Being a welder the tig is the way to go. Mig will heat it up to much and harder to control the heat in a small place. Lead and solder will not stick to the metal in the long run. Back up the valve cover with aluminum to disapate the heat and any one good with a tig can put a small amount of heat to it and it will do a better job in the long run. Tried to stay out of this but just my thoughts. I would not use JB on the inside just to much to lose.
Greg

[Mark E.]

Re: Repairing Cracked BB Valve Cover

Greg,

Your comments give me pause, and reflect my original concern about applying a substance inside the engine.

Bob P's experience with epoxy is positive. It would be reassuring to hear from others who have actually used JB Weld or another product inside an engine.

[Greg W.]

Re: Repairing Cracked BB Valve Cover

Mark,
I was not trying to say it would not work, Myself would not take the chance. Someone may have had a good experience and will share it, but the one's who did not, You will never hear from I think.
Greg

[Mark M.]

Re: Repairing Cracked BB Valve Cover

Mark there's two lines of thought here in which way to fix your cover. Cold method with JB weld which is a great product or various hot methods. If you use JB weld , as said surface prep is key. I would scuff surface very coarsely for the epoxy to have a good bit . Use brakkeen to flush out any oil. As I weld in many processes , I would agree with tig welding the crack since it must be visible on the outside anyway and you said the alternator is over it too. The tig weld is permanent and a good welder using a small tungsten could make a very small weld with limited heat on the part. No doubt the heat affected zone will affect the chrome on the other side. It's thin steel. How much depends on the crack and the welder. Form or worry free function! You could flip a coin! Good luck

[Joe L.]

Re: Repairing Cracked BB Valve Cover

Greg,

Your comments give me pause, and reflect my original concern about applying a substance inside the engine.

Bob P's experience with epoxy is positive. It would be reassuring to hear from others who have actually used JB Weld or another product inside an engine.

Mark------


I have used JB Weld in "challenging" environments. The most challenging has been carburetors with exposure to gasoline. Gasoline is a solvent that will attack and destroy most adhesives and sealers. This includes adhesive and sealers that are impervious to engine oil. However, JB Weld has proven to be impervious gasoline. Experienced carb rebuilders use it all the time to permanently seal soft plugs in Q-Jet carbs which are chronic leak sources.

If you use it as I and others have described, the JB Weld repair is going to still be there long after it's not going to matter to you anymore.