Date:         Sun, 29 Apr 2007 18:58:20 -0700
Reply-To:     Evan Mac Donald <macdonald1987@SBCGLOBAL.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Evan Mac Donald <macdonald1987@SBCGLOBAL.NET>
Subject:      Engine Question...
Content-Type: text/plain; charset=iso-8859-1

Continuing worries...

  If I put 1.9L heads on a 2.1L, (which is being upbored to give 2.2L), then the effective compression ratio is now about 9.5 to 1. This should be within the structural limits of the engine, but what will this mean as a practical matter? This is my daily driver, and compression that high, to me, says "Premium Fuel". At least 91 octane, right? Especially with stock Digijet controls, from 1985 model year.

  I don't want to have to go to new heads, which would, luckily though, be the 2.1L stock type. I don't have an extra ~$1k to put into heads! I doubt doubling up the metal seal rings for the top of the cylinders to increase chamber volume is a good idea. I also doubt I can safely port / remove enough material from the 1.9L chamber area to raise the volume noticably. Or safely.

  Oh, crap. My choices look to be:

  1) Live with Premium. (Expensive, long term.)
  2) Get new/remanned heads. (Expensive, short term.)
  3) Find a used set of usable 2.1L, and hope they aren't cracked too badly to use, also. (Cheaper, over both stretches. Just harder.)

  Any help, anyone?

  Advice always welcome...