Flat tops plus Aussie heads
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Joined: Mar 2001
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Flat tops plus Aussie heads
Ok, I have read alot of post on the flat top pistons and the Aussie heads. What would be the compression ratio with both? I have seen posts that say 10.1 to 1 with just the heads. I have seen ones that say the heads raise it 1 to 1.6 points which puts it at about 9.5 to 1. The flat top pistons are 9.5 to 1. So, if I put this combo together, is it like 11 to 1 or higher? Would this combo be streetable for a daily driver on 93 octane? Hate to build something then not be able to drive it.
Thanks
Chad
Thanks
Chad
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Joined: Sep 2001
Posts: 30,255
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Flat tops plus Aussie heads
You can use the compression ratio calculator in the back of the Ford race parts book, in Desktop Dyno, or a variety of downloads. There may even be a tech article about it here.
With a carbureted engine you may want to play it safe and stay around 9:1, with fuel injection you may go a little higher 10:1 on 90-92 octane. It is better to error on the minus side and have a vehicle that you can drive somewhere without hauling your own fuel or additives. Remember the compression ratio goes higher with a build up of deposits in the chamber. These deposits can also flake and have hot spots that cause preignition.
over!
With a carbureted engine you may want to play it safe and stay around 9:1, with fuel injection you may go a little higher 10:1 on 90-92 octane. It is better to error on the minus side and have a vehicle that you can drive somewhere without hauling your own fuel or additives. Remember the compression ratio goes higher with a build up of deposits in the chamber. These deposits can also flake and have hot spots that cause preignition.
over!
Flat tops plus Aussie heads
