N42 on a L24?

[RA64]

I have a l24 and a n42 head, what is needed to run this set up? I was reading that I might have to notch the block out for the valves to clear the bore, but I was also thinkin, Do I have to run a diffrent head gasket like from a l28 becuse of the notch?

Does any one have pics of this stuff?

Thanks>

[JMortensen]

Why bother? Should be easy enough to find a L24 head, then you don't need to hassle with notching the block and all that.

 

I think the advantage from the bigger valves will be offset by the lower compression and the fact that on the sides the valves will be right next to the cylinder walls, even if you notch the cylinder walls.

[Guest norm[T12SDSUD]]

When I broke my 280 crank back in 1998 I installed my .070" shaved N42 head onto my WORN OUT L24 Block which yeilded a 10.7:1 CR. I notched the block but the valves were still barely hitting the cylinder walls so I had to back my valve adjustment up to .013" from the ideal .008" to shut it up.Thankfully no damage was suffered to the valves.

Anyway, since it was temporary motor while I built my stroker motor I didn't worry about it. I put about 7000 miles on the combo and it was a great performer!!

 

I turned a 13.6 @ 99 mph on street tires with this setup.

 

It PULLED LIKE CRAZY above 5000 rpm and althogh it lacked the low end torque of the bigger motors it was smoother and more powerful above 6000 rpm than the bigger motors.

 

Anyway, I would suggest you shave the head at least .040" to bump the compression up to nearly 10:1 .With only a .040" head shave you won't be forced to use cam tower shims as long as your chain is fairly new you can adjust the chain guides and tensioner to take up the slack.

 

Get a mild cam and go tear up some roads!!

[RA64]

Well I already have the n42 head + hear in vegas you cant find sh!t for the 240z. All the cars at pick a part are 280z & zx all the heads that Iv seen are the p79.+ people that I know (in town) want hella $$$ for the 2.4 heads. So this is what I got to use, I dont have a lot of money to play with too.

 

Well what head gasket do I need?

Tell me more about notching the block an stuff?

Thanks

[JMortensen]

You really need to pull the crank and rods to notch the block. I suppose you could try and catch all the shavings, but I wouldn't do it on my engine. It's kind of like porting the head with the head still bolted to the block. BAD IDEA. So disassemble the short block first. Then you can start to notch the block.

 

What you want to do is get an L28 gasket, lay it on the block with the dowels in the block. Use a pick or a scribe to scratch a line in the block that represents where the headgasket ends. Use a die grinder with a carbide burr and you grind away the metal so that you push the edge back to the line that you scribed. Don't go too far into the cylinder, because you don't want to affect the top piston ring. I would not go more than 2/3 of the way down to the top ring. You'll be able to tell where that is because the top of the cylinder will be discolored above where the rings stop. That's pretty much it.

 

Oh then remember to have results like Norm you'll need to shave the head .070 and shim the cam towers up, then redo the lash pads. All more labor intensive stuff.

 

Or you could buy an L24 head. Matman has about 10 heads, I'm sure he'd sell you an E88 or an E31 for a reasonable price. You might want to PM him or email him before you get into all this other BS.