ok so i want to increase the compression ratio of my engine, and i'm leaning toward different pistons rather than milling the head. if you have replaced youe pistons please post which ones you used, and your results with them(power increase, mileage, u get the idea) keep in mind this is a 200 I6
Depends on your budget and how much work you feel like doing. Milling the heads is the least expensive and least amount of work. I have been "told" that if you remove a lot of material from the heads, you must also mill the intake manifold, or you will have sealing problems with the heads sitting lower on the block and the angle being different. I am sure someone here knows for sure one way or the other. I don't know what compression ratio you have in mind, but if you increase it by too much, it's gonna need high octane fuel and/or backing off the timing by quite a bit. Aluminum heads are more forgiving with high compression than iron heads. My freshly built 302 (308) has 9.5:1 flat-top pistons in it. I didn't want any more than that. They would be 9:1 with 302 heads, but I get an extra 0.5 with the 289 heads that are on it...
http://www.lincolnversailles.com/Granada/Blower1.htm check out the articles on this website a lot of useful info
if it's a V8 I would swap pistons. I've read enough fordsix stuff to know milling the head is the way to go for the ford small block six. deck the block and send the head in for milling (.060"), as the new head gaskets will drop your compression ratio anyway. Swap pistons only if you don't mind buying the 2.3 Liter 4 cylinder pistons for a 200. Or 255 CI v8 pistons for a 250. Or if the head cannot be milled any further. I don't think the 2.3 pistons will bring you up more than .5 compression alone. If you haven't grab the ford six performance handbook, it has the right info for this sort of thing
You guys are answering a post from 2007! Someone voted in the pole, that's why it showed up again.....
I did the math for it years ago and with a stock head(well a 60s 200 head) and using a stock gasket those Lima Flatop pistons would still get you over 10:1 without any milling I'll have to dig up the equations because I don't think I ever uploaded them anywhere.
