N42 fit my....

[ZD44TT]

Hi guys, just a quick one.

 

My motor currently has a E88 head..........what do I have to do to fit on a N42 head?

 

I read somewhere that I had to do something to the N42 head.

 

Which is better btw?

 

thanks.

[gav240z]

That question is kinda like "how long is a piece of string". There is no hard and fast simple rule.

 

Do you have an L26 block? There were two types of E88 head that I'm aware of. The earlier 240z's had a closed chamber design more like the earlier E31 head.

 

The later 260z E88 was an open chamber design (less compression for emission control reasons).

 

To fit an N42 head to an L26 block you may need to notch the cylinder bores to accommodate for the larger valves.

 

To do this would be more effort than sourcing an L28 block with an L28 head already. The performance gains from such a swap are quite minimal really except for perhaps the extra displacement and more compression.

 

I think while you have it running ok, leave engine heads where they are. If you want acquire an L28 block and head. Do some work to it while it's out of the car and then slot it in for more fun!

[ZD44TT]

That question is kinda like "how long is a piece of string". There is no hard and fast simple rule.

 

Do you have an L26 block? There were two types of E88 head that I'm aware of. The earlier 240z's had a closed chamber design more like the earlier E31 head.

 

The later 260z E88 was an open chamber design (less compression for emission control reasons).

 

To fit an N42 head to an L26 block you may need to notch the cylinder bores to accommodate for the larger valves.

 

To do this would be more effort than sourcing an L28 block with an L28 head already. The performance gains from such a swap are quite minimal really except for perhaps the extra displacement and more compression.

 

I think while you have it running ok' date=' leave engine heads where they are. If you want acquire an L28 block and head. Do some work to it while it's out of the car and then slot it in for more fun![/quote']

 

 

thanks that does answer my q........my motor is running super sweet....... I wanted to put a cam in it soon and though a cheap ported and bigger valve head might help for additional power.

 

but if it's too much hassel then i can't be bothered.....

 

thanks again.

[nat0_240_chevZ]

the n42 goes straight on an l24!!!! yes it does i have done it.

 

but the n42 over the 'later' e88 head is not much of an improvement in the sense of static CRatio. it IS however a better breathing head due to its larger vlaves than any s30 based motor.

 

i went from (with dished pistons)L24 with a p30 (or e88, cant remember)head i think it was, blew the head gasket and went out through my bonnet vents glowing red, out left side of the block, no oil or water breach just compression out the side of the engine, had an n42 on the l26 i just pulled due to it dropping a rod bolt and stopping on the highway, no leg out of bed though (breakthrough the block).

 

went and got the N42 faced, faced and then faced some more about 2.25mm off the face (couldent get my existing head refaced as it was flat along the cyl side but a bannana across the cam side so the engine builder said throw it away).

 

Anyways just to show that you can put it straight on, only time you need to notch the block is when you run bigger valves than the N42 on an l24 bore. My block as you may be asking was actually a worked 240k motor which is basically identical to the 240z l24 but had dished pistons instead of the flat tops. The N42 starts to look like the u67 head sought after by the 4 cyl lseries buys like a kidney bean. excellent for high quench without much detonation, and i was running heaps of advance.

 

Also a note to remember is that the p90 and n42 have the same combustion chamber shape, (ah before you start get them side by side) The difference is the depth of the combustion chamber shape, p90 is deeper for the reduced chamber/dish in the piston (flatop), also the valve lengths vary by about 1.4mm from the top of my head, due to this depth of the combustion chamber difference.

 

nato