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jkelly

Block/Head Combo options

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Hey guys, I"ve been reading around here a bit and have a few questions on what route you think I should go. I have a build thread over in the members rides section too. 

 

What I want:
A streetable/daily driveable turbo car that's also fun on the track and has room for growth. 300 - 350 horsepower to start with.


Budget:
Budget isn't a huge concern, but it's not unlimited.


Block/Head options I have:
Completely rebuilt L28 NA from a 1978 280z 2+2:

  • Rebuilt N47 head with NA Schneider .460 260/260 cam, 300zx springs
  • Rebuilt N42 block with 0.020" overbored flat tops

Non-running L24 from a 1972 240z:

  • E88 stock head
  • P30 stock block

Non-running L28 from a 1975 280z:

  • N42 stock head
  • N42 stock block

Maxima stock MN47 head


Intake/exhaust options:
Non-egr shaved N42 intake manifold with 60mm TB
Turbo (?? something like a Garrett T3/T04E Stage III Turbo 50 Trim 0.63AR??)
BOV (??)
Wastegate (??)
Intercooler (??)
L28ET stock exhaust manifold


Fuel/ignition management:
Megasquirt 3 with MS3x board
COP using LS coils
Full sequential ignition


Fuel delivery:
Stock 240z tank
Walbro 255
Carter low pressure lift pump
1 liter surge tank
5/16" fuel feed line (big enough?)
5/16" fuel return line
440cc or 550cc high impedance injectors


Do you guys have any advice on what head/block combination I should use from above? Should I start looking for a P90 head? 


Should I swap the NA Schneider cam for a turbo cam?


With the N47/N42 and a 2mm head gasket I'm still looking at almost 9:1 CR.  With a P90 and the N42 block with flat tops I'm looking at about 8.5:1 with a stock gasket and less prone to detonation using the higher quench head. 


Any other general advice or suggestions? Once I get this figured out I'm going to start sizing my turbo.


 

Edited by jkelly

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IF you plan on even reaching that 300 hp let alone 500 go dished and save yourself the 2nd rebuild. Matter fact go forged at 300-500 its pushing it and you want to beat on it for awhile reliably. 300-500 is pretty max for the L series I am making  about 400 to the wheel thats with a stroker and gt35r/

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Thanks for the replies guys.

 

On 12/11/2017 at 3:37 PM, softopz said:

IF you plan on even reaching that 300 hp let alone 500 go dished and save yourself the 2nd rebuild. Matter fact go forged at 300-500 its pushing it and you want to beat on it for awhile reliably. 300-500 is pretty max for the L series I am making  about 400 to the wheel thats with a stroker and gt35r/

I get what you're saying. I would hate to destroy some nice forged pistons while learning how to tune the setup, though. I've heard of people doing this and other people recommending learning to tune on cheaper cast pistons then upgrade to forged. Don't some people run up to 300 - 350 whp on cast flat tops + P90 and pump gas if detonation is under control? Maybe not. I'm certainly still learning.

 

I think TonyD ran (runs?) a boosted L28 with flat tops and N42 at 8.5:1 CR. I'm not sure what kind of power he's making.

Edited by jkelly

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I am using a similar setup with a P90/Flat tops.   One of these days i'll toss the turbo charger on it.

 

I had similar plans to you.  Goal of 350rwhp.  If I had known the total cost my rebuild would cost me, I would have tossed forged bits in with it.  I've been tinkering with my FI while running the engine NA and i'm sure I would be missing a ring land or two if I was turbo charged.  Once I bolt it all together I will tune properly on a dyno.  For me, the cost of some forged bits is cheaper then the time and hassle of pulling the engine apart and putting in new pistons every "oops".  You may get a few "oops" with the forged.

Edited by HuD 91gt

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