[T3] There will be a 4th build

[Jim Adney]

On 27 Jun 2020 at 11:51, Keith Park wrote:

> I was a bit worried about boring out the 94mm to 96, but Jake recommended it
> and he KNOWS those OEM cylinders

How about going the direction mentioned in the "How to Hot Rod the VW 
Engine" by Bill Fisher: Consider a non-metric piston. 94 mm comes to 
3.7008". Might there be something just above that size in an inch dimension, 
like 3.750"? There are also places which will make custom pistons, but that's 
$$$. VW used to show oversize (0.5 mm, 1.0 mm) pistons in their parts lists, 
but I don't know if they were ever available for Type 4 sizes. RIMCO used to 
offer boring oversize and provided pistons, but that was a long time ago.

Going 2 mm oversize just sounds too extreme.

> I have a local shop here that looked at one and had no issues with doing the
> boring, they have been around for a long time and Ive never heard anything
> bad about them, Ill probably have them do the boring and fitting for me.

The key to boring VW cylinders is that they need to be held just like they are 
in the engine, clamped between rings around each end. You'd need to find 
someone who had already made those rings, or was willing to make them for 
not so much money. Or you could try to make them yourself....

Setting them up in someone's normal jig is likely to end up clamping them 
side to side, which will end you up with oval bores.

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Jim Adney, jadney at vwtype3.org
Madison, Wisconsin, USA
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