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  • 2 weeks later...

This is from a couple of American books I have by Frank Honzowetz .

L24 with single 2 Bbl Carburettor 38mm intake 33mm exhaust valves .

L24 up to 7/73 42 and 33mm .

L24 after 8/76 42 and 35mm .

I'm told that the best L24 head in Australia was the one from the 1981 only build Skyline MR30 2.4E . I can't remember which casting number it has but someone in here will quote . Im opretty sure it used the larger 35mm exhaust valves and has closed heart shaped chambers like the 1600 SSS had .

If you can find one in good nick its the one to use . Basically most L heads need help in the exhaust side and the best available combustion chamber shape is a huge bonus .

Cheers A .

  discopotato03 said:
This is from a couple of American books I have by Frank Honzowetz .

L24 with single 2 Bbl Carburettor 38mm intake 33mm exhaust valves .

L24 up to 7/73 42 and 33mm .

L24 after 8/76 42 and 35mm .

I'm told that the best L24 head in Australia was the one from the 1981 only build Skyline MR30 2.4E . I can't remember which casting number it has but someone in here will quote . Im opretty sure it used the larger 35mm exhaust valves and has closed heart shaped chambers like the 1600 SSS had .

If you can find one in good nick its the one to use . Basically most L heads need help in the exhaust side and the best available combustion chamber shape is a huge bonus .

Cheers A .

are you talking about the N47 head???

  paulmac said:
are you talking about the N47 head???

No, he's talking about the E88 head fitted to local spec R30 Skylines. The N47 is a round exhaust port, US spec head (shudder). The R30 type E88 has a 'small' combustion chamber similar to the early 240Z E31, but with 42mm inlet and 35mm exhaust valves. It's an easy matter to fit the bigger 44mm inlet valve used in L28 heads (eg N42) and it's a bolt-on compression increase for an L28 engine, even with dished pistons.

For the OP, what you have is an E30 head...there's no such thing as an L6 'E80' head. The E30 is fitted to stock, L24S (single carb) engines used in 240K and C210 Skyline. It uses very small valves and inlet ports, but has the one redeeming feature of a 'small' combustion chamber, similar to the E31 head. So it also gives a bolt-on CR increase for an L28, but is otherwise a good boat anchor. In the early days of Z performance builds when E31 heads were scarce and expensive (still are...), we used to port E30 heads and fit bigger valves, but it was a LOT of work.

  SteveL said:
No, he's talking about the E88 head fitted to local spec R30 Skylines. The N47 is a round exhaust port, US spec head (shudder). The R30 type E88 has a 'small' combustion chamber similar to the early 240Z E31, but with 42mm inlet and 35mm exhaust valves. It's an easy matter to fit the bigger 44mm inlet valve used in L28 heads (eg N42) and it's a bolt-on compression increase for an L28 engine, even with dished pistons.

For the OP, what you have is an E30 head...there's no such thing as an L6 'E80' head. The E30 is fitted to stock, L24S (single carb) engines used in 240K and C210 Skyline. It uses very small valves and inlet ports, but has the one redeeming feature of a 'small' combustion chamber, similar to the E31 head. So it also gives a bolt-on CR increase for an L28, but is otherwise a good boat anchor. In the early days of Z performance builds when E31 heads were scarce and expensive (still are...), we used to port E30 heads and fit bigger valves, but it was a LOT of work.

You are right, it is a "E30" Head, thats what you get when looking in the dark with a torch..

You mentioned a N42 head, (I have one of these, with the injector cut into the intake port, on an old tired L28) will this fit on my L24 and Is it worth putting on it if it does fit ?

post-13098-1153902353.jpg

  paulmac said:
so the n47 is a US spec head :happy: i got one on my car but its an aussie ti hatch, so its not meant to be there or is it?? Paul.

Other than yours, I've never seen or heard of one fitted to an Oz spec car. The N47 uses stainless steel liners in the exhaust ports designed to 'glow' and burn-off any un-burnt fuel. This was required to meet more stringent emission specs in the US.

  noddle said:
Is it worth putting on it if it does fit ?

No...it will drop the CR on your L24 and performance (already not great) will suffer.....

If you want to improve performance with the L24, get a good E88 head from an R30 Skyline and bolt that on. With a cam (nothing wild) and upgraded fuel system (240Z carbs are a good option, but can be hard to find), plus extractors and a reasonable exhaust system, the car will be transformed. But at the end of the day, go L28 if you can as that's the ideal upgrade for these cars.

  SteveL said:
No...it will drop the CR on your L24 and performance (already not great) will suffer.....

If you want to improve performance with the L24, get a good E88 head from an R30 Skyline and bolt that on. With a cam (nothing wild) and upgraded fuel system (240Z carbs are a good option, but can be hard to find), plus extractors and a reasonable exhaust system, the car will be transformed. But at the end of the day, go L28 if you can as that's the ideal upgrade for these cars.

If I got my hands on a L24E (R30 engine ?) and put the Electronic Injection on a L28, would this be a better option than a straight L24E ?

I鈥檓 after a little more power but not wanting to reduce my fuel economy by to much.

  • 3 weeks later...

Hi,

I'm building an L28 at the moment. This website is the most informative and simple I've come across.

The cylinder head section gives comp ratios, combustion chamber cc's, valve sizes, describes ports for every L series head. A must read.

http://www.geocities.com/zgarage2001/z.html

  • 2 weeks later...

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