Piston compression questions 4kcsq

[Eric]

I thought about the same thing when I was rebuilding my KH motor
destined for my 4k.  I don't know how the KH compares with the stock JT
motor in the 4k.  I do know that the rod ratio on the KH is quite
different from a VW digifant motor I had appart in my garage.  I didn't
got to the trouble to see what "issues" that may cause as I just kept
the KH setup.

On a VW 1.8 I have I just decked 0.040" off the head and kept the stock
pistons.  It is hard to say what effect that had as I changed to EFI and
head work at the same time.

As others have replied if you are looking to new pistons swaping to a
motor that started with higher compression is probably less $$.

-Eric

Tapparoo at aol.com wrote:

>Howdy howdy.  Interesting question for an uneducated person like myself:  Does anyone have "simple" mathematics for piston compression and relation to power output?  Specifically, a piston exchange between a 1.8 and a 2.22.  Although my engine is running fine, I am thinking of rebuilding another 2.22 block in expectation of mine eventually breaking down.  I noticed that the bore and stroke for a 1.8 piston is the same as a 2.22 and wanted to know 1)Is it a possibility to swap in the 10:1 1.8 pistons for the 8.5:1 in the 2.22  and  2)What kind of increase in power am I looking at if the swap is possible.
>Like I said, I am pretty uneducated when it comes to these things, so any info would be appreciated.
>Mucho thanks in advance.
>
>Dan
>
>86 4kcsq with ~200k (odo broke at 166k)
>
>
>