Cracked j heads

-
M

MHEAD

Well-Known Member
Joined
Jul 26, 2009
Messages
195
Reaction score
231
Location
Maryland
Any one see the j heads crack here below the exhaust?It's leaking most of the way across the length of head where the pour boxes came together.
20200222_091016.jpg
 
I used some block sealer back in the 80's on a Ford 400 that froze and broke the block in the left front corner from top to bottom. It actually worked, I was amazed because it was a very long crack. I know it worked for 5 years because I seen the car all the time.

I have never seen a crack in a head in that spot, I think it must have froze at some point.
 
OP, how about what appear to be water stains up nearer to the header flanges above both those leaks? Are you sure it is not something from the exhaust area leaking out/around the header gaskets?
 
nm9stheham said:
OP, how about what appear to be water stains up nearer to the header flanges above both those leaks? Are you sure it is not something from the exhaust area leaking out/around the header gaskets?
Click to expand...
 
No I actually thought it was the bolts in each end that go into the head since there in the water.I put studs in it with sealer but it still leaked.I then remove the header and pressurized the coolant system and saw two leaks at each end below spark plug.I been running these heads since the late 90's on now three different builds so maybe there times up.
 
I think i saw a W2 that had a crack down there too. Torquing down on a bad head gasket or piston interference? Try some blue devil block sealer. Stuff works.
 
pishta said:
I think i saw a W2 that had a crack down there too. Torquing down on a bad head gasket or piston interference? Try some blue devil block sealer. Stuff works.
Click to expand...

I agree. There are a lot of good things on the market that will take care of that. Even K&W has some new formulated stuff out. Some of the Blue Devil brand products offer a money back guarantee, so keep the container. It has the information right on the label.
 
I figured someone would notice the plugs lol.Pistons are forged icons .005 in the hole with .040 cometic gaskets so I doubt there hitting.This is the second time I've used the gaskets though.I pulled the head yesterday and didn't find anything abnormal.Only thing I can figure is the head didn't like the header flange being separate.
 
Me too.There expensive but it's more than paid for its self by now.
Here's the truck I built for my son to bracket race.My plan of a cheap leftover parts build sure got a little lopsided.
20200217_162129.jpg
 
Stop leak.
Yes. I have seen that. Once.
Block was cracked too. 1976 or 79 block iirr

You have a 72 block, j heads are 71-73. Are they original to the block?
 
MOPAROFFICIAL said:
Stop leak.
Yes. I have seen that. Once.
Block was cracked too. 1976 or 79 block iirr

You have a 72 block, j heads are 71-73. Are they original to the block?
Click to expand...
No they aren't original to the block.The more I think about this is the 4th block I've had them on.
 
You must log in or register to reply here.
-

Back
Top