View single post by Esprit2
 Posted: 05-26-2009 08:50 pm
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Esprit2

 

Joined: 05-01-2005
Location: Minneapolis, Minnesota USA
Posts: 289
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subwoofer wrote: (Snip)... do you have any experience with upping the compression for the 2.0? SJ Sportscars can provide 11:1 pistons for the 2.0, which (I guess) would be good in concert with a pair of 104 cams.

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Joachim


Joachim,

The 907's semi-hemi combustion chamber is very tolerant of higher compression on pump gas.   11:1 isn't a problem on the pump gas available in the USA.   Of course, a lot will depend upon the gas where you are.

If you're considering 104 cams or hotter,  then raise the compression to at least 10:1.   11:1 would be good if you wish to drive in a spriited manner,  but a waste of high octane fuel if you'll be trundling along in traffic most of the time.   Be sure you know what you want,  because it's not a simple change later.

I have a pair of 104 cams in a low compression 907,  and it works well.   I just know that it could work much better with higher compression...  the cam's true potential isn't realized when matched with the low compression.

If you're thinking 104 cams and Hi compression,  then also consider a pair of Dellorto DHLA45E's with 36 or 37mm chokes.   The 37's are more in keeping with the 104s and hi-compression fun mentallity.   But if you think the majority of your driving will be trundling around town,  then go with 36mm chokes.   They give up some top end, but the engine will be more commute-friendly.

Last edited on 12-10-2016 07:22 pm by Esprit2