Bruce, Thanks for the "very logical" explanation. I thought you might like to know that the PRV-6 is a modified version of an earlier PRV-8. Don't ask me for details though, I learned this years ago from a PRV publication that disappeared some time ago. "We're here to help you" DMC Joe / De Lorean Services / <dmcjoe@xxxx> Web Site: <www.deloreanservices.com> . ----- Original Message ----- From: BRUCE BENSON <delornut@xxxx> To: <dmcnews@xxxxxxxxxxx> Sent: Sunday, June 25, 2000 6:29 PM Subject: Re: [DML] PRV6 Variations > Chris, > > I was a bit hasty in my response. If cost is no object, and the Venturi was > quite expensive considering it didn't look all that exotic, a crankshaft > with a separate journal for each cylinder would make an even firing engine. > 99% of the worlds 90 degree V-6's are odd firing because of the simplicity, > cost , and reliability of making a crankshaft that has three journals with > every two cylinders sharing one. Many modern V-6's now have their cylinder > banks at 60 degrees which makes an even firing engine when six cylinders are > involved. Many early V-6's were derived from 90 degree V-8's which are even > firing when cylinders share crank shaft journals. Lopping off two cylinders > makes the math come out different and the result is odd firing. My wife's > Taurus SHO with a 60 degree V-8 is just the opposite. It was derived from a > 60 degree V-6 and it now is an odd firing engine with a balance shaft > installed to smooth things out. That shaft rotates opposite of engine > rotation and offsets any engine shake associated with the odd firing > scenario. It's very smooth and pretty high in performance. A couple of > months back I wrote a description of what odd firing actually is in the > mailing list and that should be in the archives. > BRUCE BENSON