Crack in head near combustion chamber **PIC**

[Mike000]

What do you think of this? Will I have any problems with this?

Picture is large. Im only concered about the one near the combustion chamber. Its not that deep either.


http://www.members.shaw.ca/mike000/head.jpg

 

[GTM]

What do you think of this? Will I have any problems with this?

Picture is large. Im only concered about the one near the combustion chamber. Its not that deep either.


http://www.members.shaw.ca/mike000/head.jpg

I don't see a crack but I do see a couple of voids, one on the edge of the combustion chamber and another just down from it. The small one looks more like corrosion as does the larger but it may have had some pinging damage.

Do you have some pictures of water passages or the complete head?

It's fixable whatever it is, the proper way is to take to a machine shop and have them Heliarc both spots. They will probably grind it out with a die grinder and then arc weld and machine it flat.

If you are really pressed for money you could dig out all the mineral inclusions and fill with JB Weld or Devcon Aluminum. Once set you can then use a large "Mill Bastard" file and file it flat. Been there and done both types of repairs.

I can' determine how large or deep but you might try kissing them with a drill bit just to get to clean metal before applying the epoxies. You might put a head gasket back on and position with a 3-4 bolts to see where the sealing ring will rest. Again I just can't tell how much will be in the combustion chamber and how well it seal. Might take a picture of it with the head gasket in place so we can get a better idea.

Would like to see you clean the cooling system while you have it apart but I'll wait for pictures before I advise.

Cheers,
GTM

 

[diab0liK]

I don't know if you've ever heard of this stuff before, but I found out about it like 9 years ago, on some community tv late nite ad.

It's called alumaloy, it's an aluminum based alloy, that is malleable to be melted w/ a propane or map-gas torch, and you can grind and sand it down, etc. Relatively inexpensive, and if there's suggestion of jb welding it, I'm sure this would be a good bit better than that, and considering those voids aren't too bad at all, I think it would do you fine.

Alumaloy

I've used this stuff myself in several small applications, and have had nothing but amazing experiences with it. It's really impressive shit.

g'luck m8

diab0liK

 

[diab0liK]

Ok, just another note...

I bought a lb. of this stuff several years ago, and still have some left, and when I bought it, it was over the phone, that was the first time I've even seen the website.

Anyway, now they apparently have steel based, and iron based alloy's that can also be used w/ a simple propane torch.

Crazy stuff mang....

diab0liK

 

[GTM]

I don't know if you've ever heard of this stuff before, but I found out about it like 9 years ago, on some community tv late nite ad.

It's called alumaloy, it's an aluminum based alloy, that is malleable to be melted w/ a propane or map-gas torch, and you can grind and sand it down, etc. Relatively inexpensive, and if there's suggestion of jb welding it, I'm sure this would be a good bit better than that, and considering those voids aren't too bad at all, I think it would do you fine.

Alumaloy

I've used this stuff myself in several small applications, and have had nothing but amazing experiences with it.

I've heard of the product but never seen it.

A quick read of the instructions it indicates heating the item (in this case head) to 728 degrees to get the suff to melt. That is pretty hot, actually I would almost guess that would be impossible with a propane torch in that location. You might stand a chance if you stuffed it in an oven at 500 degrees for a couple hours and then put the torch on it. Then you have the issue of cooling and warping.

The advantage of Heliarc is it's fast (actually slower than MIG/TIG) but fast enough that it doesn't disturb great areas and is the prefered method.

I'm not trying to be a nay-sayer but I've straightened warped aluminum heads in a 20 ton press and an acetylene torch and know just how much heat it takes to even get to 500 degrees. You have valve seats an inch or so away and if they become loose you can imagine the consequences. I just have reservations and would want to consult the company before subjecting the bridge between 2&3 cylr to those temps.

I think those are not inclusions but corrosion at the sealing ring, it's too bad he sanded the head before he took the picture. I'm thinking it must have been seeping for a long time which allow the electrolysis to eat those holes

Cheers,
GTM

 

[Mike000]

A little of the gasket seal runs over the void near the combustion chamber. Do you think there would be a problem if I leave it like that?

 

[GTM]

A little of the gasket seal runs over the void near the combustion chamber. Do you think there would be a problem if I leave it like that?

Yes I do think there would be a problem, you have no support for the sealing ring which has to hold back 2,000+ psi generated each time you have combustion. It also poses a significant hazard of supporting pinging (pre ignition) by acting like a glow plug. The sharp point can't loose it's heat fast enough and rather than the spark plug starting ignition it goes first and then the plug fires. The first part of the explosion kicks the piston one way and the second kicks the piston the other way, this in turn causes additional wear on piston, pin, and cylr walls. There are two schools of thought to what causes the noise, either the collision of the two different flame fronts colliding or the actual kick of the piston as it rocks and slambs up against the cylr wall.

It is this member's opinion that it should be repaired by conventional methods of Heliarc, MIG or TIG and then machined flat. The alternatives mentioned earlier will produce positive results for some undetermined length of time but should not be considered as being reliable especially for the one pictured which intrudes into the combustion chamber. If it's not been done the head should be checked for flatness and that there is no warpage or twist. The same should be done on the engine block for they can be distorted when significantly overheated.

The question must be asked as to the cost effectiveness of repairs, it might be better to find a used head which does not have the problems shown from the original. As previously mentioned there may also be cooling system issues and every attempt should be made to resolve these while the engine is apart. If there is significant scale and rust it should be removed by using suitable tools most common are old screwdrivers and flushing with water. In addition repeated treatments with acids for the block, radiatator, and to some extent the head should be considered if the corrosion is significant.

We also don't know if there is any galling on cylrs and pistons as a result of the head gasket failure and overheating. These are the concerns which must be address by the member if they are to have a satisfactory repair.

Cheers,
GTM