Rebuilding an 80 yr old engine is always a gamble....

[James Rogers]

[QUOTE=gilitos;682343]A pinky finger along with a flashlight confirmed that the valve seat has come loose. Here we go![/quote)
I suspected as much.

[gilitos]

Here's the scene with the head removed (isn't it great how quick these come apart?). The machinist who stitched the crack between the seat & water jacket said it was a good interference fit when he re-inserted it, but obviously something was lacking. The $64 question: how do I re-insert it so that it stays? George Miller, I'm paying close attention to your post. Can you detail a bit more the rolling process?

[Tom Wesenberg]

I've seen the same thing happen to a few Model A engines with inserts. I also do not recommend inserts, unless the valve is sunk too low or the block is cracked in that area.

I used to install inserts at a shop I worked at in S.D. You need to grind a small bevel around the top outer edge of the ring. Then use a locktite product on the ring and drive it into place. Use a small somewhat dull chisel to peen all around the ring to roll the metal over the bevel.

[gilitos]

Tom, your method sounds great. I'm going to try it. Just going to hope that the other undisturbed inserts behave themselves and stay put. Do you have a specific Loctite product in mind? I assume it has to withstand high temperatures.

[George Miller]

Originally Posted by gilitos

Here's the scene with the head removed (isn't it great how quick these come apart?). The machinist who stitched the crack between the seat & water jacket said it was a good interference fit when he re-inserted it, but obviously something was lacking. The $64 question: how do I re-insert it so that it stays? George Miller, I'm paying close attention to your post. Can you detail a bit more the rolling process?

Tom has it right. With my machine I have a tool that goes in place of the cutting tool. It has a radius ground on it. It rolls the metal in on top of bevel. The inserts I use all ready have the bevel on them. If you do not have a tool, the way Tom said works fine also.

If the bore for the insert is to big, you can buy over size inserts.

[James Rogers]

Sponsored Links (Register now to hide all advertisements)

That seat will never stay. With a crack in the deck when it gets hot and expands the seat will always loosen and fall out. I wouldn't have used that block in the first place. If you refused to get another or instead on using it I would have not rebuilt the engine. I have many blocks that are like that in a pile to go to the scrap yard.

[1931 flamingo]

Do all the valves have inserts?? As long as head is off and in doubt I would peen/roll the others unless like James says, it's fruitless. Sorry for your situation.
Paul in CT

[Kohnke Rebabbitting]

The only reason the seat came out, is it started with the crack. After the crack developed that took the original interference fit from the seat and block, when it opened up.

Then the seat was removed, and when put back, no matter if it had interference, it didn't have the same interference as when originaly installed.

It should have had an over size seat, or take the over size seat O.D. down in a lathe grinder to the original O.D., plus what was now gone for size difference, if the hole was still true

With out the original fit, it is guess work that the seat will stay in, just as before with the original fit.

[Kohnke Rebabbitting]

Do all the valves have inserts?? As long as head is off and in doubt I would peen/roll the others unless like James says, it's fruitless. Sorry for your situation.
Paul in CT (END QUOTE)


It wasn't the seat that made it fail Paul, it was the crack.

[gilitos]

I think Herm is right. When the crack was repaired, the insert fit should have been more carefully revisited. I'll post a follow up with the result.

[James Rogers]

With the crack it was destined to fail and will continue to.

[Kohnke Rebabbitting]

I have never seen it that way James, and I know it just wasn't luck, as you always make your own luck.

I have put in hard seats since I was 19, with a K.O.Lee. Then when the newer seat machines came out, about 35 years ago, I have had Vern do it. Probably at least 400 just Model A blocks, not counting Model T, and Model B blocks, and they were not all assembled by us, as they were shipped in from all over. Many a time there were 25 blocks setting in line at the align bore. That is when I had 5 employees here.

But what I am getting at, we have never had a seat come loose.

All the modern engines I see into Verns, and that is a lot, all the heads have Hard seats, weather they are cars, or tractors.

It all depends if they were installed right, or some thing in this case it came out after it was taken out, and installed again, not the seats fault

We know that seats come out, sleeves come out, valve guides come out, Valve liners come out, but there is always a reason, and it useally human error.

[Kurt in NJ]

I looked back at the original crack ---my thoughts on a repair then was that the water passage needed to have a piece of metal made to fill it to give the area around the seat support to allow an interference fit ---after the piece was pinned in place water passage holes would be drilled in it ---it could still be fixed that way--