In an installment of learn from my stupid mistakes:  As I was preparing to install our heads today, I noticed through the hole where the distributor would go that the gear for the distributor drive appears chewed up. If I stick my finger in there, I find gold colored flakes. Nothing that sticks to […]

I suspect this will be the final installment in the trials and tribulations for this head and associated cc’ing, clearance checking, deck height measuring, and compression calculating. Not only am I exhausted from doing this four times, I think we’re at the limit of what can be accomplished with this head. Our deck height is

Inspecting my heads today I noticed that the valves, which had been stamped long ago, no longer match the number next to the chamber the head. The machinist is telling me they are confident they’re in the right spot. Got me a little worried.

With the heads reworked a second time, I’m back to the single 1.0 mm cylinder base gasket and more measuring for deck height and compression ratio. Compression is low for this big bore kit. Deck height is high at average of 1.91. Looks like we’re back to removing the cylinders to try a different gasket

Doing things the first time, it’s not always obvious why things are the way they are. When it comes to Porsche engines, there certainly seems a reason for everything. Case and point, the head bolts It would appear at first glance that I can use any of the head bolts in any position to secure

After a trip through the mail, our heads returned home. They got very similar measurements of the head angles as I did. They also mentioned that my original machinist may have surfaced the head, but did not adjust for decking off the top. Which I believe would explain my issue with getting 1 – 1.5

I had removed the pistons from the engine, thinking my machinist might be reworking them. Having abandoned that idea, the pistons were put back on the connecting rods today. Ring gaps reset. I’m back to the single 1mm copper cylinder base gasket.

After a lot of consternation, I shipped the head off to a well known Porsche machine shop for a second machinist opinion if you will. Unlike my original machinist, they indicated they wouldn’t consider machining the pistons. They did think they could improve the head squish angle. They might get into the valve seat, but

The results of measuring my heads, clearances, and compression has given me a lot of anxiety. In consulting with my machinist, his advice has been to use thick shims to avoid interference and run with it. Uncomfortable with some conflicting info and not knowing how to proceed, I used a metal contour gauge to try

I guess measuring the squish angles in the head was not something our machinist normally does. After much hand wringing, and some emails with our him, I took the head back to him for review. In short he wasn’t comfortable modding the combustion chamber any more, for fear of getting into the valve seats. The

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