

| Subject: | Re: Engine update |
| From: | Erik Soule |
| Date: | Mon, 27 Feb 1995 16:24:25 -0800 |
> Here's another: I CC'ed the combustion chambers, and got them all to within > ..5CC of each other. So I measured the deck height and got .089" and the CR > is 7.7 to one. This is with .040" shims, without them, CR= 8.45 to one. > The jist of it is that the shims must be factory, or else the CR would be > through the roof. The case is a T3, late 70 - 71. I think these had 7.7 to > one CR right? > > Does anyone have an opinion on 7.7 to one or is this still too high for my > bus? > > Chris Bridge Chris, I went through exactly the same process about 5 years ago when rebuilding the motor for my '65 Samba. I'll check my notes when I go home tonight, but I remember choosing a CR of 7.5-7.5. I used an 'AE' prefix case (I think this is about the same vintage as yours). Berg recommends a CR of 6.9 for buses, since they run hotter than bugs with the same motor. *However*, everyone I spoke with felt this number was extremely conservative. As a precaution, I have the stock doghouse oil cooler as well as a full-flow external cooler (with an electric fan mounted inside the engine compartment - I tried to stay German with one from a Rabbit, but the early Civic fan fit poi-fictly!). The motor runs great, if not a little *too* cool sometimes if you can believe it, so I put in a thermostatic bypass valve. I'll get back to you with the CR data, Chris. -Erik. NSC Analog Automotive Systems Tel. (408)721-3476 Fax (408)721-8292 M/S C2480
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