Lee new style mold problems

[LuckyDog]

As soon as I saw the post that it is now run by the "third" generation, that was all I needed to know.

I really expect them to tank now. Unfortunate.

Second gen watched father struggle and work. They have an appreciation for the gift.

Third generation grew up always having money. It was always there, and they think they are smart enough to wring even more out of it.



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[Edward]

Guess I must be the exception as most of my Lees (17 at present ) sometimes need a little help , but get the job done at a reasonable cost and have created heaps of accurate boolits ! I do own some accurate moulds ,more Noe but without Lee molds my casting would be limited/boring and no way varied ! There service might suck but if I cant fix it I can toss it and replace it at their price point without crying about it . For somebody starting out its the only way to learn casting and dealing with fixing the little things without breaking the bank !!!!

[racepres]

You cats throwing them away....Just send 'em to me...I'll pay shipping!!!

[No Blue]

This is a problem that goes back at least 80 years. It was airplane engines, made of aluminum for light weight, that had valve seats installed in the aluminum head.

The aluminum will expand 3 times what steel will at the same temperature. To deal with this, they machined a bore in the head that was .006" smaller than the OD of the seat. Then they had a .006" crush on the insert. That would make it stay in the head.


So the fix was to freeze the seat in liquid nitrogen at 320 degrees below zero, heat the head up to 250 and drop the seat into the head. When everything got back to room temperature, the seat was 'probably' there to stay.

Unless the engine got really hot; then the seat would expand, crush the aluminum, and the seat would fall out. B-29 engines were infamous for this; seat would drop out, that cylinder would start munching parts, break up, catch fire, set the wing on fire and crash in the ocean.

If you were into air cooled Vw's or Porsches, they had the same problem with dropped valve seats. Aluminum engines like aircraft.

But even water cooled engines had it. First job out of tech school was at the Ferrari dealer in Dearborn. First job was pulling the heads off a V-12 Jag that they suspected had dropped a seat. That's what it was. Out to the machine shop, came back with all the seats 'peened' into place. They had used a pointed tool to upset the metal around the seat to trap it in place. Since then they also use a Loctite glue to keep the seat in place; on top of the press fit and peening. This can kill a $20,000 engine in a few seconds, so they do everything they can to stop it.

Lee is advising to not run the mould over 450 degrees. They're aware of what happens to aluminum and steel inserts. Probably good idea to get an IR thermometer with a laser and monitor the mold temp. My guess is they start a peening operation to keep the steel insert in place.

[Echo]

Re valve seats on Al heads - I drove Corvairs many years, and always had the valve seats peened. A chum who worked on them saw a fellow that had an old diesel valve the right size trimmed and undercut so he could set it down, stem in the hole, and give it a whack, and upset the material around the seat to hold it in.
I will check my Lee's- I have several, and will do some preventive maintenance...