Super M head

[Rob Mazza]

I brought my head for my Super M to the machine to have a valve job done and when they magna fluxed the head they found six small cracks around the combustion chamber, they said should be no problem, what do you guys think?

Rob
 

[rustred]

if thats what he said then ok, as we cannot see the head. post a pic.
 

[minnemoman]

when you put it back togeater you should defunetly use some block seal.

good luck and have fun
 

[Janicholson]

If they go from, or into a valve seat, or spark plug hole, or on the edge into a water jacket, they are serious. if they start and stop, and are no longer than 1/2" to 5/8" I would leave them alone and use Bars leak in it as directed. If they ar bigger, Metal Stitching is a great repair. Jim
 

[the tractor vet]

OK so they found cracks BUT DID THEY PRESSURE CHECK THE HEAD with HOT WATER to see if they leaked????? NOBODY DOES THIS ANYMORE .
 

[rustred]

block seal is useless on a compression leak. that garbage hardly will work on a gravity crack. it is only good if you want your rad cores plugged up.
as i suggested to post a pic then get advise, other than that its shooting in the dark. kind of a funny question ... the machinist looks at it and gives his version then we get asked ... "what do you guys think" i think the machinist is correct.
 

[rustred]

my head doctor does the pres. test. but few and far between. i have seen these heads with cracks and affect nothing.
 

[Duner Wi]

My M head was RECAST 30 years ago and fails magna fluxe test but it does not leak anti freeze.
If it did not bother before it could work.
 

[Rob Mazza]

Its already off the mag table, they say it will be ok. I really want to put the high compression pistons in it, I have talked to guys who have done it and really like it. Where's the best place to buy them?

Rob
 

[Janicholson]

On this site. Tisco is a solid brand. Good prices and nobody has complained about the quality ot fast delivery. Jim
 

[sflem849]

[stonerock]

tisco pistons are fine.one M I have has 11 cracks in the head daily runner at 75 hp it is ok. most power is in the cam have a new one ground for the hp you want. don't plane the head you need the cc's for fuel mixture. make the compression up with the thickness of your head gasket. use a LP intake and exhust. drill the carb out. open the head up but don't polish. you should have a strong runnin M. I have six of them for play
 

[sflem849]

[ss409]

before you pour 500 or more into it n risk it, please keep in mind that the new 450LP cyl heads can be bought for 1100 or less n never worry bout it again n pick up some power. just a thought.
 

[stonerock]

open the runners up in the head you want it to breath easy and match intake and exhust and gaskets.but leave it rough so it causes turbulence to mix gas and air better. rocker rollers will also help.[250.00] for about 4 hp.you will need them if you take too much off of the head