Engine rebuild technical thread (not T25 but very nearly)

[937carrera]

I am following a rebuild thread for a VW 412 over on the Samba, this is the engine that is developed essentially into the CU in the T25, and from there into the WBX.

The latest update covers cold galvanizing the head studs, cc'ing pistons, measuring con rod journal play and trial build to determine deck height.

This is a top quality build,from a guy with loads of experience, and well worth taking the time to read, as the engineering applies to all of our flat 4 engines.

I'll admit I do struggle adapting back to imperial measurements - and there's an interesting bit where the specs in the nearly all the manuals are wrong, the only one that is right is the Porsche 914 spec book. I remember finding a similar type of error in the Bentley manual for the WBX when I was checking my "unknown" engine

Have a read, see what you think

https://www.thesamba.com/vw/forum/viewt ... 32#9006832

[T25Convert]

Thanks for that - I love projects that improve on original build quality...

I'd love to know the variation in performance and longevity of this over a more 'normal' level of build.

[937carrera]

at the risk of banking on about this rebuild, the latest update explains how he found out that the cases were bored off centre at the factory by 0.007" (or 0.18mm), which is what was giving a deck height difference one side compared to the other.

On an air cooled you can simply use different thickness shims, not sure if that is possible on a WBX. He might do something else