How To Hold This Part In Lathe?

WesPete66 said:
Thanks for the good suggestions! This is from a hit & miss gas engine using an igniter (battery & coil ignition). and it is cast iron.
Would concrete anchors be acceptable? I would put the anchor end into the head's thru-hole, and bolt it to the face plate?
Thanks again & keep em coming!
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Concrete anchors is a great idea. I bet you could make that work.
 
water cooled Bo, that's what caused the rust erosion.. the cooling water directly contacts the cast iron of the head through slots in the gasket.
 
Is that an Associated or United head ? looks like it, I have a spare one i think, send me some info on the engine. I would be careful with the concrete anchors, it could expand enough to possibly crack that cast iron.

Tom
 
Gotcha , if the bulk of the pitting is where the gasket relief is I would ignore that pitting and look strictly at the sealing surface .
You might be surprised at how rough it can be and still seal up on a low compression engine.

Another thing to consider before getting to crazy with re surfacing the head is what you will need to do to correct the valve train afterwards. Removing .040 -.060 doesn't seem like a whole lot but depending on rocker set up and the amount of adjustment if any you might be looking at lenghening or shortening your push rods to corrdct the geometry
 
My idea would be to thread the bolt holes and use bolts on the back side to secure it to the faceplate---having the bolt holes threaded shouldn't be a problem when reassembling -----may only need to thread two opposite holes, but doing all four may be easier on mounting and shim adjusting to faceplate for accuracy---Dave
 
Dave Smith said:
My idea would be to thread the bolt holes and use bolts on the back side to secure it to the faceplate---having the bolt holes threaded shouldn't be a problem when reassembling -----may only need to thread two opposite holes, but doing all four may be easier on mounting and shim adjusting to faceplate for accuracy---Dave
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Like this idea!! Seems to solve a lot concerns.
 
One thing I thought of is potting the back end of it in polyester resin or epoxy, then holding it by the face end in the lathe chuck and truing up the potted end, turning it around and facing the surface while holding it with the potted end. You could then just bake the potting compound off. For a part that size, it might be kind of an expensive one time use jig, but might save a lot of time over some other methods.
 
Uglydog said:
Is it cast iron?
If so, she might be scraped in.
I've heard of high compression automotive race engine heads being scraped in so precisely that the need for head gaskets is avoided, and thus no gasket failure.

Steel can also be scraped, but it's difficult due to hardness.

Daryl
MN
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I think laminated copper head gaskets can be used for high compression performance engines, and now a lot of import guys actually use O-rings for special forced induction applications.

Steel is awful to scrape....those rolls of metal stick in you and by the time you're done stoning burrs off you've ground a hole to china.

To hold the cylinder head, I wonder if you could put a cardboard sleeve over it, fill the whole thing with plaster, then chuck up the plaster in the 4 jaw and use the tailstock to keep the head in place. Basically making a negative of the head, similar to a chamber cast in gunsmithing.
 
I think you are thinking too complicated for less than a one hour simple facing-----5 minutes to thread the bolt through holes--then using threaded rods and nuts to carefully secure it to the faceplate accurately may take 45 minutes---then facing the surface shouldn't take more than 10 minutes---and 5 minutes to remove finished part from the faceplate----think simple---Dave
 
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