Cylinder head problems (1 Viewer)

[Flying40guy]

Pulled the head off of my '77 2F due to a blown HG. Took the head into the shop to have it cleaned up and valves done. They said the casting has some cracks in it. Pretty small but cracks none the less. Is this something that can be repaired? Guessing I"ll need to find a cylinder head that's in better shape. I'll be posting a "wanted" ad on the classifieds section but any other ideas would be greatly appreciated. I'm in the Twin Cities area if that helps. Thanks.

 

[fjc-man]

Cracks in the mating surface side of the head, right? Didn’t he tell you it’s not useable, go get another one?

 

[Malleus]

Yes, a cast head can be repaired, but the folks you need do this for industrial engines, and it's not cheap. Large industrial castings, like the ones used in marine diesels and power generation diesels and turbines are routinely repaired this way.

You're better off using a sound head, if you can. Of course, that may be a big IF...

 

[1969FJ]

These guys are good.

Metal Stitching & Thread Repair Inserts. - Turlock , CA - LOCK-N-STITCH, Inc

LOCK-N-STITCH Inc. provides cast iron repair services such as metal stitching, emergency thread repair, fusion welding, & machining services for industries in power generation, gas compression, shipping, and pumps.

www.locknstitch.com

 

[sggoat]

in my experience, cast iron is essentially non-repairable-for the long run. Even with new and exotic repair techniques, the original cast cannot be duplicated--you get it hot enough to repair, and the surrounding metal will fail--Even if you stuck the whole head into the furnace at 2500 deg F to fix a crack, the rest of the casting will be compromised--plus you would need to duplicate the exact same metal composition that the original casting was made from--unlikely. Best option is to find a replacement head free of cracks/blemishes--certainly not cheap--but way cheaper than recasting the whole head--which is very likely not possible---as Malleus said---

 

[Flying40guy]

Thanks for the replies. First time for this type of repair. Currently looking for a new head.

 

[Malleus]

FWIW, getting cast material hot isn't what the main problem with welding, although it is for aluminum. Cast iron has to be heated to remove enough carbon to be weldable and then cooled properly afterwards. This is a permanent, as good as as-cast solution, when performed properly. Industrial engines and turbines are not thrown out when the develop cracks, they're repaired. These are components that keep modern society functioning; the repairs have to be reliable. The casting processes used for those parts are the same as those used for engine castings in vehicles, it's just the material that differs.

 

[1969FJ]

in my experience, cast iron is essentially non-repairable-for the long run. Even with new and exotic repair techniques, the original cast cannot be duplicated--you get it hot enough to repair, and the surrounding metal will fail--Even if you stuck the whole head into the furnace at 2500 deg F to fix a crack, the rest of the casting will be compromised--plus you would need to duplicate the exact same metal composition that the original casting was made from--unlikely. Best option is to find a replacement head free of cracks/blemishes--certainly not cheap--but way cheaper than recasting the whole head--which is very likely not possible---as Malleus said---

A new one is best. But, Lock and stitch has repaired a lot more cast iron items that are a lot more valuable than an FJ40 head. They know their business. Their reputation is well documented. So, to me if something cannot be easily replaced I would certainly consult them. If cast iron is essentially non repairable , then how are they in business ? Please read as you might see details of cast iron.

http://www.locknstitch.com/pdf/gmrc_white_paper.pdf

 

[middlecalf]

Wow, cool stuff. Wish I’d had a bit more Mechanics of Materials learnin‘ back in my school days a few centuries ago. So what’s the ballpark cost for a 1F/2F head repair? A few hundred, a few thousand?

 

[sogncab]

I'm in the Twin Cities area if that helps.

Minnesota?

@Poser might have something?

 

[1969FJ]

Wow, cool stuff. Wish I’d had a bit more Mechanics of Materials learnin‘ back in my school days a few centuries ago. So what’s the ballpark cost for a 1F/2F head repair? A few hundred, a few thousand?

It depends on how bad the cast iron is. A few years ago I had a block repaired by them , (crack about 2 inches), and the cost was ~ 300.00. The shipping cost was even more.

 

[joestewart]

What is the casting number on your cracked head?

 

[Flying40guy]

FWIW, getting cast material hot isn't what the main problem with welding, although it is for aluminum. Cast iron has to be heated to remove enough carbon to be weldable and then cooled properly afterwards. This is a permanent, as good as as-cast solution, when performed properly. Industrial engines and turbines are not thrown out when the develop cracks, they're repaired. These are components that keep modern society functioning; the repairs have to be reliable. The casting processes used for those parts are the same as those used for engine castings in vehicles, it's just the material that

What is the casting number on your cracked head?

 

[Flying40guy]

Shop sent me these pics. Red marks are around the cracks I think. Not sure what the casting number is. I’m currently out of town so can’t check.

 

[B y r o n]

If the cracks are in the seats it should be an easy fix. Seats can be replaced.