"Hard Blok" question!!
 

I am using Hard Blok water jacket filler and have heard that a sealer of some sort should be put over the filler to keep water from penetrating it. Is this true.. do I have to put a sealer on it? If I do what should I use.

Thanks

Traviss;

I have added hard block on several car drag race motors. I never used or heard of any sealer to cover the top of the filler. I never had a problem. BUT, I never tried to use Hard Block in a marine application. Could there be an issue with salt water causing some type of corrosion to this stuff? Maybe it would be best to contact the company themselves.

Why are you thinking of adding this to your boat motor? I understand that it strengthens the block, but it does make for horrible cooling of the block. Remember, NO water will be flowing to most of the block, the only area that is cooled is the upper most section. From the water pump holes on down there will be no water. I don't know how long the motor would run before it overheats. I have used it in drag cars simply because cooling was not an issue.

In my other life (over on the Corvette Forum) there has been a lot of discussion on block fillers. The concencous was that for street motors it was ok to fill up to the bottom of the core plugs, but not higher.

Since most of the fillers are concrete based, and salt DISTROYS concrete (ask me about my new $9000 driveway :) ) I would be concerned about using it in a salt water environment.

The main reason given for using it on street motors was to help strengthen the block when notching it for stroker cranks.

-Greg

It will be used in fresh water. Let me tell the story. I had to make rod clearance on my stroker and ended up breaking into the water jacket. We had the few holes soldered up by a good welder and to reinforce these area's we put hard blok in the water jackets. The filler is only about 1" deep just to make the area a little more stable. We should not have to much of a problem with cooling, the guys around here were talkin about a sealer of some sort but I guess i don't need it. good we can stat building the motor now! I talked to a guy at JEGS and he said no sealer should be put on it.. I guess hes right.....


Thanks guys...