bucket240z Posted October 15, 2007 Share Posted October 15, 2007 so i just picked up my first Z and i LOVE it. it's a 1972 240z. the owner before me swapped a l28 with a n47 head on it. my goal with the engine is to get it to about 220-250 hp. so my question is if the n47 head is good for what i want to do or should i try and get maybe a p90 from the pick and pull? any response would be awesome. thanks Quote Link to comment Share on other sites More sharing options...
z-ya Posted October 16, 2007 Share Posted October 16, 2007 If it has the stock dish pistons, a P90 head will lower the compression ratio to around 7.5:1. Not good for NA power. Check the casting number on the block. If it is an F54 block, it might have flat tops in there. This will get you close to 10:1 with the N47 head. Quote Link to comment Share on other sites More sharing options...
bucket240z Posted October 16, 2007 Author Share Posted October 16, 2007 its an f54. so basically i need a new head NOW so ill change the question i asked. what would be the best head for what i want to do. i also do plan on getting forged pistons really soon. thanks Quote Link to comment Share on other sites More sharing options...
z-ya Posted October 16, 2007 Share Posted October 16, 2007 Shine a flashlight into one of the spark plug holes with the piston at TDC. If it is a flat top piston, then there is nothing you need to do besides maybe a performance cam, header, intake, exhaust. You don't need forged pistons for an NA L6. The N47 head flows almost as good at the N42, and at your HP levels, you are not using all that the N47 can produce. I'm running one on my race motor and it's making 180WHP with a medium cam, header, exhaust, intake, Just intake port matching was done to the head. Drive it, and enjoy it. Quote Link to comment Share on other sites More sharing options...
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