Collectindust240Z Posted June 17, 2005 Share Posted June 17, 2005 why don't I see any posts about the p90 head. I thought this was the last evolution of the L6 motor and supposedly the best flowing stock head. I'm building a motor using one. Do they have any flaws? Quote Link to comment Share on other sites More sharing options...
JMortensen Posted June 17, 2005 Share Posted June 17, 2005 I just searched "p90" and the search found 421 posts. Quote Link to comment Share on other sites More sharing options...
1 fast z Posted June 17, 2005 Share Posted June 17, 2005 "and supposedly the best flowing stock head" Nope! I have flow tested, ALL L28 heads and the P90 is no different the the N42, or P79. The N47 does not flow as well on the intakes, due to the BULGE in the side of the intake ports. But for the exhuast, ALL L28's Flow the same. Quote Link to comment Share on other sites More sharing options...
randy 77zt Posted June 17, 2005 Share Posted June 17, 2005 some people use the n42 head because of smaller combustion chambers.if you build a turbo engine with dished pistons the n42 head would get the cr up a little over 8 instead of 7.5 . Quote Link to comment Share on other sites More sharing options...
Collectindust240Z Posted June 17, 2005 Author Share Posted June 17, 2005 I've already done the whole thing with having it milled .080, shimming the towers, and using the longer valves. Just in my laziness, I didn't see many posts. I was politely reminded to use the search feature. I feel much better now. Quote Link to comment Share on other sites More sharing options...
AK-Z Posted June 17, 2005 Share Posted June 17, 2005 WHy is the P90 head more sough after then the other heads? Its just impression that it is. I know why a turbo block is (added internal strength than the l28e) but why the head? Is it the compression or is it that almost everybody does a L28et swap and just happen to have the p90 head to work with? Quote Link to comment Share on other sites More sharing options...
JMortensen Posted June 17, 2005 Share Posted June 17, 2005 I bet the answer is in one of those 421 threads... but in one word "quench". It's a big can of worms, search quench p90 and read for yourself. Quote Link to comment Share on other sites More sharing options...
Collectindust240Z Posted June 18, 2005 Author Share Posted June 18, 2005 -JMortensen, I know that I'm new here, but are you rude to everybody here? People ask questions looking for help. Sarcasm is not help. Maybe a little polite direction or redirection is all that is needed. Quote Link to comment Share on other sites More sharing options...
Collectindust240Z Posted June 18, 2005 Author Share Posted June 18, 2005 Maybe I'm being a little over sensitive. My girlfriend doesn't think you're rude at all. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted June 18, 2005 Share Posted June 18, 2005 When was I rude? I wasn't trying to be rude, sorry if it came off that way. I thought I answered two of your questions. This subject has been talked about at length, argued over with many posts on numerous other threads. I was referring you to them. As I see it we have two choices. Rehash the same subjects every time somebody new comes to the site, or tell them to search. I mean no disrespect when I suggested you do the latter. From the READ BEFORE POSTING sticky at the beginning of every forum: 2. Please use the search function before you do anything else. The search button can be found at the top of the page. Use several keywords if you don't find what you need right off the bat. Remember: Just about every possible topic and problem has been posted and answered, in most cases several times. The Members on this board are very helpful and a great crowd of Z enthusiasts, but answering the same questions over and over again gets old. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted June 18, 2005 Share Posted June 18, 2005 One more thing: I did search "quench p90" just to see and nothing came up. Not sure what happened to those old posts, but you can google "quench" to find out what it is and why it is beneficial. There was a couple long dragged out arguments as to the benefit of quench, but the bottom line is that the p90 and p79 have a big quench area, where the N47 and N42 have almost no quench. The E31 and early E88 are in between. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted June 18, 2005 Share Posted June 18, 2005 Bizzarre. I searched again and found all kinds of info. Maybe I misspelled quench or something. Anyway, search "quench p90" and read for a bit. Should answer all your questions. Quote Link to comment Share on other sites More sharing options...
Collectindust240Z Posted June 18, 2005 Author Share Posted June 18, 2005 Sorry for jumping the gun. Maybe I was just having a bad day and was being a little edgy. At risk of sounding stupid, I didn't think the p90 was a common choice. On my last motor, I used the n42. At the time (8 years ago) that seemed to be the hot ticket. I read the Datsun Garage web site and figured that I'd give the p90 a go. Thanks for your help and sorry about sounding like a jerk. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted June 18, 2005 Share Posted June 18, 2005 No harm no foul. Quote Link to comment Share on other sites More sharing options...
Mayolives Posted June 18, 2005 Share Posted June 18, 2005 Here you go...................Lots of head information plus plus plus http://www.geocities.com/zgarage2001/z.html Quote Link to comment Share on other sites More sharing options...
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