[T3] Heads

[Jim Adney]

On 14 Jan 2012 at 19:59, Keith Park wrote:

> Original 72-3 heads have a step that the cylinder sits on, it moves the head
> out slightly farther and gives the lower compression ratio of 7.2:1 on the
> 72 and 7.3:1 on the 73 if I recall right, (the 72 had dished pistons).  The
> engines run a bit cooler, can run on 87 octane and are less stressed with
> the same HP.

I have owner's manuals from '72 and '73 that both say 7.3 to 1. I 
know that '72 engine had dished pistons, but I don't think I've ever 
pulled an original '73 engine apart. I always assumed they were the 
same.

There were actually 3 different FI engines supplied in those years:

U 0 xxx xxx, U 5 xxx xxx, and X 0 xxx xxx

I THOUGHT the  only differences were external: things like EGR, 
dashpot, and vacuum retard, but I can't be sure.

One booklet I've got shows all U engines to have 7.7 to 1, but we 
know that's wrong.

The parts list shows the same pistons for all 3 engines, but that 
could have changed if older parts were superceeded.

Does anyone have a '72 owner's manual that shows a compression ratio 
of 7.2 to 1?

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