81SacUti280zx

isnt .070 a lot though. wouldnt .007 be correct? idk to me 7 thousandths seems more correct to me 70 thousandths. just checkin

evandubya

.007" is the thickness of 2 pieces of paper .0625" is 1/16" so .070" is a little over 1/16".
.070" is what you want for compression.

81SacUti280zx

ya i know the sizes but i appologize for questioning lol...i just thought thay .070 would be a lot for a head. i mean i really dont know much about head work but..i know .030 is a lot for a block so..just thought i would ask to make sure. and so is that all i would need to do is shave the head .070 and than get the msa shim kit and than just put new bearings, gaskets, and etc...getting new water pump, timing chain kit, expansion(freeze) plugs, main bearings, rod bearings, and idk what else...

NismoPick

Before you do any machine work, I suggest calculating out all the changes to see what the effects will be. Machining the head .070" will increase the CR by quite a bit (good for a street n/a... too much for a turbo). You may also need to use a thicker head gasket (MLS 2mm is the only one I can think of at $200 when available) to make sure the valves don't hit the pistons. I don't know which HG Shady is using.

So click on this, select your setup, and adjust the numbers to what you want. It will tell you the CR and if there will be problems:

http://www.ozdat.com/ozdatonline/enginedesign/

SHADY280

my setup is a bit odd. when i got my stock overbore pistons installed they stucko out the block by .020". apparently this is common on some setups, so i used a 2mm hg. the other engine i built was a f54 block with stock flat tops, they were a little lower or close to zero deck heght, i used a stock felpro gasket or 1mm equivilent. both yeilded approx 10.8:1 cr. without that 2mm hg on my car, the cr would have been 11.8:1. i drove it a while like that, but the stock ecu just couldnt handle it. once i get ms going i may switch back.

81SacUti280zx

ok so i was reading on a site..(cant remeber) and they said to use early model z valves cause they are longer....i dont know how true that is. im still having a hard time finding a shop. i pm'd braap on hybrid and he hasnt got back to me. im thinking about using orig valvles and such on the circumstances that i cant get a hold of valves, guides keepers, and such...i am getting mixed signals...so far i got gasket kit(head set, bottom end), rod bearings, main bearings, timing set, water pump, freeze plugs, spark plugs, wires, cap, rotor, eng a/f, fuel filter, oil filter, both radiator hoses, fuel and vacuum lines and thats about it...anything else i may need? im trying to still do my head so i know i will need shims from msa..but is that it?

FricFrac

You'd still be way further ahead in price/performance with a stock turbo swap....

hoov100

I haven't gotten any word back from Braap either since I sent him an email about your situation. A stock rebuild with the head decked should be good, I would highly suggest the z31 EFI swap if you plan on having the motor out as well. It's not necessary, but would be well worth it IMHO. If not, adjusting the AFM spring is what they used to do back in the day to give the motor a little more fuel when raising the compression or upping the boost.

SHADY280

+1 with what hoov said. and yes i did the early longer valves in mine. well the machine shop did it. they actually took the time to go on forums and read for me. i paid for it a bit, but well worth the time to have it done correctly. the longer valves make it better so you dont need to get super tall lash pads, but you need new springs as now everything is higher and the spring wont have any pressure up top.

81SacUti280zx

So....would I have to change the.ecu and everything? Or do I just get the fuel rail and injectors or what? And how will the.fuel rail match up

NismoPick

HAVE TO? No... SHOULD... yes. As SHADY previously stated, the stock ecu is a big limiting factor. You use the fuel rail that matches your injectors.

81SacUti280zx

well the z31 is a v6 no? and how would the injector set up work? wouldnt i need a z31 ecu and all the other stuff? would it fit on my l28 and how?

NismoPick

Click: https://www.zdriver.com/forums/240z-280zxt-s30-s130-tech-tips-275/worlds-first-z31-na-ecu-swap-24434/

The Z31 ecu swap is an easy upgrade for the L28ET because the ecu plugs are the same... cut and splice a few wires and done. To do the swap on the n/a, you need to swap in the entire Z31 engine harness. The only issue w/ it being a V6 is running the injector wires in a line of 6 instead of 2 banks of 3. The firing order is the same.

81SacUti280zx

ok..so sounds like quite a bit of work for a n/a engine....although i may have found a turbo donor...82 2+2 turbo. http://reno.craigslist.org/cto/2317662910.html. could use fenders and hood for my 81 2 seater. idk..asking 900. 190k miles. so would still need a rebuild.

NismoPick

You better freaking jump on that... it will be gone in a day or two at that price.

81SacUti280zx

its been posted for a lil while now...trying to come up with the money for it...i was gonna offer him 500-600 and see what he said...i am having a hard time getting money for it. body looks clean he said very litle rust.

NismoPick

You were too slow... sold to another ZDriver member.

https://www.zdriver.com/forums/280zx-performance-technical-79/parts-car-not-32461/

81SacUti280zx

I know he texted.me...who bought it...ima get it lol

81SacUti280zx

Ok sorry im on the mobile.version...dont know how to edit and the link didnt show...i see who got it...i figured so..lol well ill have to give someone a call and work a deal... I need to find a decently priced head set...valves guides etc.. I stripped my head and valves too thin to grind and resurface

81SacUti280zx

ok so i just found out that 5 of my exhaust bolt holes have been helicoiled. i cant find a head set(valves,springs,keepers,etc.) for less than 600. i need money lol. so i still have my 83 280zx 2+2 up for sale. only things missing are the fenders, hood and radiator. Everything else is still there. Engine 5spd trans etc. so i would love for some more input on how i should go about getting a cheaper head set or should i just get a new head from kragens for 580.

SHADY280

put an n47 head on there. its a smaller cc dome, run it for now, ive had them on my car and they worked well. what does the 2+2 have in it for a head, p90? altho that wouldnt help

81SacUti280zx

so where do i find a n47 head? pick and pulls around here are dry on z's and i dont have much money to spend on one. otherwise i would just spend the 580 on the new/rebuilt head from kragens....so i guess what im asking is does anyone have one for sale i could just bolt up and run? would my oem intake and fuel rail work?

NismoPick

Have you verified that you can get an N47 head from Kragens?

Just an FYI, you can get a smokin' N47 for $399 on ebay:

http://cgi.ebay.com/ebaymotors/Datsu...Q5fAccessories

FYI #2... for $580 (what you are willing to spend on a bone stock core rebuild) you could machine a crazy flowing head (doesn't even need to be an N47).

BlueKitsune

I think I might have an N47 on my parts shelf somewhere.... No wait its down at the machinists I think.

81SacUti280zx

so from what i've been reading since i have flat tops in my block its a california z. is this correct? because i've read a couple different forums that have said n47 head is better than the p79 head for cr. im so confused on which is the "best" way to go for the most efficient street daily driver with med. power. i also been told the p79 head has way better flow than a n47 but the n47 will give me a higher cr with the flat tops.