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kenikh kenikh is offline
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Join Date: Feb 2005
Location: North of Exit 17
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Compression and 2.0S MFI

I wonder what the realistic maximum CR is for a 2.0S w/ MFI on pump gas. When reading Wayne's book, I noticed that (on p. 112) that a 2.4L w/ 2.2 pistons makes compression of about 10:1. It also says this motor will run on pump gas with single plug. From that, the question has arisen: WHY?

I realize that the 2.4 heads don't have piston dome interference problems like the 2.0, thus aiding flame propagation and increasing knock resistance, but they are larger, increasing flame travel distance. It is thus reasonable to assume you could run a 2 liter engine with even higher comrpession in single plug form and even HIGHER compression in twin plug.

The problem with the stock 2 liter is the heads. Can a 2.2 or 2.4 head be run on a 2 liter to increase flame travel efficiency and compression when coupled with custom pistons? For comparison, the 2.0L HSR motor runs 11:1 compression and needs race gas (again from Wayne's book), but does not mention plug configuration. I will assume single plugs.

In a nutshell, here are my big questions:
What CR could you get on pump gas with single plugs in a stock 2.0? I assume the stock 9.8:1 is near the limit.
What CR could you get on pump gas with dual plugs in a stock 2.0?
What CR could you get on pump gas with single plugs in a stock 2.0 w/ 2.2 or 2.4 heads?
What CR could you get on pump gas with dual plugs in a stock 2.0 w/ 2.2 or 2.4 heads?


Any expert insights will be greatly appreciated.

(edit) What are the squish band repercussions of using larger diameter heads on smaller pistons and cylinders?
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Last edited by kenikh; 08-18-2005 at 02:57 PM..
Old 08-18-2005, 01:55 PM
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