1952 Cub Valve Seat Question

[jakescubs]

He did not offer compensation, but I will talk to him about it next time I go to his shop.

[Glen]

Hi,
I don't see how one of the inserts could back out, if all you did was screw the head bolts into the holes and tighten them.
If the threads on the inserts are right hand, like the head bolts, the inserts would be turning down into the block, turning them clockwise.

[jakescubs]

Hi,
I don't see how one of the inserts could back out, if all you did was screw the head bolts into the holes and tighten them.
If the threads on the inserts are right hand, like the head bolts, the inserts would be turning down into the block, turning them clockwise.

That confused me too, I don't see how the insert could have backed out.

[Crimson Tim]

Hi,
I don't see how one of the inserts could back out, if all you did was screw the head bolts into the holes and tighten them.
If the threads on the inserts are right hand, like the head bolts, the inserts would be turning down into the block, turning them clockwise.

That confused me too, I don't see how the insert could have backed out.

The only part about that that makes sense to me is if it backed out *as you were removing the head bolt*.

Got any pics of that area, showing the crack?

[jakescubs]

I don’t have any pics of it right now, but I will take some when I get home. The crack runs from the insert to a cooling passage and on the outside of the block next to the breather tube hole.

[Jim Becker]

Yes, he said the crack was most likely caused by the threaded head bolt hole insert backing out of the block.

That explanation doesn't make sense to me. If he said PULLED out of the block, maybe. But BACKING out suggests it unscrewed. I don't see how that could happen.

[jakescubs]

I am gonna go take a closer look at the insert tomorrow. I’ll also get some pictures of the crack too.

[jakescubs]

Heres the picture of the insert and the two cracks.

[tst]

that is a freeze crack on the outside of the block

[Bob McCarty]

Was the block magnafluxed before the rebuild?

[jakescubs]

Was the block magnafluxed before the rebuild?

I checked my invoice from the machine shop, and no where did it mention that he magnafluxed the block. But, I did do a thorough check of the block before I sent it off and I do not remember seeing a crack in that area. This tractor also came from an area where it rarely, if never gets below freezing during the winter. Maybe the insert was too close to the edge of the block, and the casting around it was too thin so it cracked. What do you think?

[tst]

to install the insert the hole is drilled to size, tapped and new insert threaded in, do not see how that could break the casting, I have seen several with the same crack in that area of the block due to freezing

[jakescubs]

to install the insert the hole is drilled to size, tapped and new insert threaded in, do not see how that could break the casting, I have seen several with the same crack in that area of the block due to freezing

You’re right, I must have just never noticed the crack.

[Jim Becker]

Looks like a freeze crack to me and not a new one. It doesn't look that bad either. Given all you already have invested in the block, I'd check the top for flatness, correct that if needed, then use it.

[tst]

I think the inside crack would give you grief, when the engine gets hot it will expand