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| Joined: | 04-01-2008 |
| Location: | Sandefjord, Norway |
| Posts: | 617 |
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The 907's 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.
The cars will not be used for commuting, so that is not much of an issue. From what I can remember from the thermodynamics course I took way back when at university, the thermal efficiency will go up quite a bit with higher compression, so for cruising at highway speed, the upped compression should be good.
Regarding the pistons: to date I have only seen higher than 9.5:1 pistons for the 2.0 from one single source, and I can't help but think there must be a reason why, since 10.9:1 and 11:1 pistons are abundant for the 2.2. According to the source, they are actually lighter than the stock pistons, so weight should not be an issue.
As far as carbs go, I am about to order a set of 45mm Dell'Ortos.
--
Joachim
Last edited on 05-26-2009 09:08 pm by subwoofer