I'm probably wrong but I seem to remember the 2V heads at about 58cc. I'm sure someone on here will have the correct info for you.
the 4V has 61 - 64 cc combustion chambers and has 10.3:1 compression. 5) the 2V has 53 - 56 cc combustion chambers and has 9.8:1 compression. ////all this taken from this site. The real answer is who knows. But this gives you an idea. http://www.fomoco.com/forummain/results.asp?Page=1&Max=20&Option=1&Name=on&Email=on&Key=289%20head%20combustion%20chamber%20size Dan
RE: is this a hipo manifold by john 4/15/2001, IP 216.68.15.90the valves on the 302 4v heads are the same size as the 2v heads in 68. the only difference is the combustion chamber size. 53-55cc vs. the regular run of the mill 2v heads at 63-66cc. the smaller chamber bumped advertised compression to 10.5 to 1. the heads are clearly marked with a 4-V cast into the head on the top side. yes, they will wake up a 2v 289/302 rather nicely. The above reply is what I have always thought to be correct. And is the rule I have always gone by. Dan
I have always heard (and even read) that '68-'76 302 heads are 58-60cc chambers (2V). I was just wondering how much smaller (if any) the '66 289 2V chambers were, and how much they'd bump the compression on a 302 from 8:1 with the stock dished pistons. I have 2 sets of these heads. I already know that aftermarket heads will out-flow them. My question right now is strictly concerning compression ratio...
If you have not found out what size they are, you can try using alcohol and a hyperdermic needle and measure how much fluid they hold before the overflow.
All at 54.5 Here is a table that shows all 66's at 54.5. I had previously read differences in CR in 66 were done with pistons. http://home1.gte.net/res03net/faqs/head.htm Don't know how accurate this is but it lists everything by casting number, with valve sizes, including 302's.
Although I did discover that the information for intake valve size was wrong. The '65 and later 289 heads all had the same size valves as the 302 heads. It was the early ones that had the smaller intake valves...
yup. You are right. I didn't check it at all just pulled it off this site:http://www.network54.com/Forum/119417, which is a windsor engine site that is really good.
T.L. I have a set of these, '66 289 4v heads, and I have heard everything from 49cc to 64cc. Don't really know which is which. I think I am going to port these out and use them, but just don't know when. Thinking it might be easier to get a set of late model heads, and get the same results, just cheaper. Good luck!
