Precup Materiel.

[JosieGallows]

To clear things up, the precups are NOT Inconel. They are an alloy called Nimocast or Nimonic. It is similar to Inconel and often confused with Inconel. It is not hard at all, it's pretty soft, softer than the head itself. Can scratched using a knife. Apparently designed for heat resistance and not strength.

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[JosieGallows]

Info on Nimonic and the different alloys. http://www.specialmetalswiggin.co.uk/products/by-alloy/nimonic

It is very likely the precups are Nimonic Alloy 81.

 

[icanfixall]

Thanks for this information. Where did you "find" this info?? I found it interesting to read. Mt precups are not listed in any of your information. On the face they have the cast in stamp in the depressed circle this number....88
Mine must be special but I have seen plenty with this number code. I'm not doubting you and there is not need to run off and drink the koolaid or the bong water but. I would like more information if you can "find it". Research is what I have time for.

 

[JosieGallows]

Thanks for this information. Where did you "find" this info?? I found it interesting to read. Mt precups are not listed in any of your information. On the face they have the cast in stamp in the depressed circle this number....88
Mine must be special but I have seen plenty with this number code. I'm not doubting you and there is not need to run off and drink the koolaid or the bong water but. I would like more information if you can "find it". Research is what I have time for.

http://www.thedieselfiles.com/Ford/69lupdatepart4.pdf

The 88 cups are also Nimocast/Nimonic. It seems that machining the heads with the cups in place is no worry anymore. They're softer than the heads themselves. The precups are easier to dent and scratch than the heads, all my NOS cups were dented to hell. But for $7 a piece I couldn't complain.