240 Z Head

[Guest Anonymous]

I have been told that a warped 72 Z head is unrepairable by a Datsun dealer years ago. In a book by Tom Monroe on rebuilding Datsuns there are references to milling the head top and bottom and using shims on the cam towers.

I also have been told by a local machine shop that a head may be straightened by heating which restores it to the original condition. I am a little suspicious about this last method. What are your thoughts on this subject. I am attempting to get my Z back running after years of storage and neglect.

Thanks

[spotfitz]

In reference to your last choice. I was told by someone in our club that heating up the head to 400* and then bolting it onto a good flat block will fix the warping. I have yet to try it, but I plan to with a warped head I had planned to rebuild. I will be posting my results in the next week or so.

[Mike C]

Buy the book "How to hotrod and race your Datsun" or "How to build and modify your NIssan/Datsun OHC" They both talk about "bending" a head and then surfacing it to restore its use. If you are building a driver, I wouldn't worry about it and would get another E88 head or even better, and N42 with the larger valves.

[speeder]

I've had at least 2 heads straightened most of the way by heating, then made perfectly straight by milling the rest required from both top and bottom.

The heating was done by the machine shop in a big industrial oven they had, with the head bolted to a heavy steel plate. Seems like they said that they left it in for a long time - overnight - at something like 400Deg, checking it periodically.

This is a pretty common head reconditioning process.

[johnc]

THe trick is that you have to maintain that 400 degree temperature for an extended period. Heating it to 400 and then bolting it on a block will have the head around 200 by the time the last head bolt is torqued.

[Mudge]

Using a rose bud tip on a cutting torch, and "bending" the head, which is detailed in the said book