Port & Polish Gains, N/A

geo3@earthlink.net geo3@earthlink.net
Wed, 19 Dec 2001 15:47:46 -0500


Jorge R. jorge181@coqui.net wrote:

>I was just reading in the se-r.net the article of the 200sx where they had
>DPR do the head job (no jokes please). What stage was that? Does anybody
>have an idea of how much that would cost? They also said they raised the CR
>to 10:1.

I'm not sure which article you were reading.  Mike had the work done in two
steps.  The first was the Stage V head (non-modified combustion chambers).  I
don't remember for certain the price, but IIRC it was $900 3 years ago.  The
Stage VI head with the cloverleafed combustion chambers was $1,500 3 years
ago.  When I had my Stage VI head done then, it cost $2,200 delivered, but
that included coated valve stems (so they could hone the worn valve guides -
the coating was just thick enough to give enough room to do this) and DPR's HD
valve springs.

>But that they could also raise it to 11:1, could they raise the CR
>to 11:1 with stock pistons?

I don't see why not.  It would involve more modification of the head to reduce
the volume.  I'm not sure it would be all that effective though.

>Would one be able to run an SE-R with 11:1 CR on pump gas?

Yep.  A lot of people are doing it (or have done it in my case).  It requies a
special JWT program.  The tuning is pretty close to the edge.  Mike Pahls and
I experienced a bit of detonation.  Mike Kojima and Clark worked on this
problem and finally solved it however.  But 11:1 is probably the functional
limit on pump gas, *maybe* a bit higher.

George Roffe
91 SE-R paperweight (but not for long)

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