FASTRNU

I know with modifacation to water passages you can use a 2.5 NA head on a 951,can this be done with a 2.7 NA head on a 951 also?I've got ceramic damage in my 51 head.It's spot about the size of a dime worn away in #3.I have a 2.7 head I was saving for a 3.0 motor.What mods would have to be done,just water passages?I know a good 951 head guy who's had nice results with Manley LS1 valves w/5/16" stems and Viper guides,but he wasn't sure about this.Here's some pics of a head he did for a friend of mine.The first two are the big valves with a penny for perspective.the last are stock and my 2.7.What size valves on the 2.7?They look bigger than 951.He's close to $2k for a full worked over head.I'm thinking about offering him my 968 block and crank trade to port,polish,big valve,the works on the 2.7 head.Am I NUTS?Thanks Joel

fast951

The 2.7L head does have larger intake valves. 951:45mm, 2.7:48mm.

The 2.7L head in stock form flows nicely. Unless you are after the last 1hp on a big HP build, minor cleaning and nice seats will get you a long way with the 2.7L head. On a turbo application, I would use the 951 exhaust valves as well as stiffer springs while preparing the 2.7 head.

If you have a 3L block, crank then I would keep the 2.7L head to be used on the 3L. You can modify the 2.7L head to fit a 2.5L block, but why? 2.5L heads are all over the place..

One more item to evaluate. The 2.7L intake ports are oval, the 2.5L are round. So your intake must be modified to match the 2.7L head. One more variable..

gt37vgt

your 2.7 head with only seats done on your 968 bottom end will be a much better engine then anything your likely to do with your 2.5.
just have valve reliefs cut in your forged 968 pistons ot just put dummy it up and hand turn it first .
I like good head work as much as anyone but its not as good as an extra 500cc on en gine that has a big port head anyhow ..