p79 head

[stizzyflip611]

hey i got a 78280z, and i want more power out of the engine. im lookin to rebuild the engine maybe bore it, im not sure yet. i was wondering if i would get better compression from a p79 head than my n47. wut model and year z is the p79 head from.

thanx alot

Andrew

[texasz]

P79 head is from '81-'83 280Z non-turbo. Currently I have a complete '82 engine sitting in my garage (complete as it still has FI, alternator, AC compressor, power steering pump, etc attached).

[beandip]

:classic: I just came accross this site last nite , I was looking for information on compression . I am installing a p-79 head that is milled .03 on a 54 flat top block . I figure that it will net about 9.5 to 1 . check out this site . geocities.comrow4navy/head2html see what you think , there is a lot of good info. there. Gary :classic:

[texasz]

beandip, your link does not work. I copy and pasted it into a browser alone, with www in front and with http:// in front and none of the three worked.

[beandip]

I 'll look it up and try it again . must of copied it wrong sorry

[beandip]

http://www.geocities.com/row4navy/head2html sorry I missed the / after com

[ecp48]

Hey Beandip,

There is still something wrong! I am getting "Sorry, the page you requested was not found"

I tried clicking on your link and pasting it into the browser.

Thanks.

ecp48('')

[beandip]

I found it here on the classicZ.org site last nite I will see where and let you know. When I bring it off of my favorites the address I posted comes up , I dont know what gives I ll try again .

[beandip]

all I can do is to send the info as a link . send me your e address and Ill send the link . Sorry:ermm:

[ecp48]

Beandip,

thanks guy,

[email protected]

I may have stumbled over the same thing, going through old threads last night.

thanks again,

Ed Palmer

[beandip]

go the the engine site and scroll down to compression ratio posted by shotmi or something like that . check it out.:classic:

[Gav240z]

http://www.geocities.com/row4navy/head2.html

seeing as some of us can't get url's right or read here it is again.

By the way no offence guys just fooling with you now lets hope mine works or i'll look real stupid.

[ecp48]

Thanks,

Gavin/Beandip, Got It!

Ed Palmer

[z-ya]

Putting a P79 head on your 78' motor will lower the CR to about 7.6:1. Great if you are planning on turbocharging it, not so great for an NA setup. The best, but not the easiest way to increase CR is to change your pistons to flat tops. This will give you about 9.8:1 with the N47 head. No shaving or tower shimming needed.

If you increase the CR, you will also need to add some way to adjust the fuel enrichment. One way is to add an adustable fuel pressure regulator. The older L-Jetronic EFI cannot compenstate automatically for engine changes like modern EFI systems can.

Pete

[stizzyflip611]

thanx z-ya, i was hoping to get the car into the mid or low 14s N/A and suspension work, but if i can get the money of course i will be looking for some turbo ideas.

thanx for the info on the p79 head

Andrew

[ecp48]

Pete,

I was looking at it from three directions. Cutting/shaving the N42 head appx .060 and using with the dished pistons; or shaving the P79 head .080 and using the existing ZX bottom end, as stated in the article; or putting the stock N42 head on the ZX bottom end (flat tops) with the 2MM head gasket, for appx. 9.6-9.8 CR.

The article relieved my mind on one point, and that is the benefits or feasibility of the P79 head with the exhaust inserts. Apparently they work well, if you blend them to the valve seat.

I may try it. Purely going to be a street engine, but I want at least 200 HP and it appears that this will provide it.

I have a clean good running N42 rebuild and a low mileage 83 ZX engine, with an extra head for each. Oh the possibilities! The flow rate for the P79 exhaust was my real question and apparently it works fine.

Ed Palmer