Engine swap

[CCC77]

I have a 77 280z that has some bad rings in it. I just took the motor out of my 82 280zx that I am having scrapped. That motor was in perfect shape the body was just a wreck. I was thinking of using the motor and head out of the 280zx for my 280z. The 82 has the flat top pistons and a little extra compression couldn’t hurt. Does the exhaust head and intake manifold fit from the 77? What is better to use? From what I have read I don’t think I can use the head off of the 77 on the 82 motor. Anyone have any suggestions? Or should I just redo the rings on the original motor?

Thanks in advance

Curtis

[hls30.com]

Drop the complete ZX engine right in, the whole efi setup to if you want, and you are done! Everything will bolt right up!

Will

[JEFF]

Get a 240 block and go thruogh the lower end.... install the 280 head (ether one) on the 240 block and you will have a very fast revving engine with higher than stock compression! I did it.. It's the best thing I've done to it in 8 years of restoration!

- Jeff

[Ed]

You should be able to use either head on the F54 block from the 82. If memory serves me tonight you should have a N42 head on your 77. The N42 has square exhaust ports. I can't remember what head is on the 82:stupid: (P79?) but I'm sure it has the round exhaust ports. So you should keep the exhaust manifold of whatever head your going to use. Another difference is the combustion chamber size. The N42 will give you a higher compression about 10.3:1. If you keep the original head I think you will be around 8.5:1.

Personally I would do what Will suggested and drop the whole thing in, EFI, intake and exhaust manifold, distributor, the whole ball of wax. Alot less work for about the same performance.

Ed

[texasz]

Or if the '77 head happens to be an N42 put it on the 280ZX block. With the flat-top pistons this combination will yeild aprox 10:1 compression ratio.

As for your manifold question, the intakes should be the same. The exhaust on the other hand may be different. If your '77 head is an N47 they are both the same, round exhaust ports but if your '77 head is an N42 these will be square ports and the 280ZX which has a P79 head are round ports. The issue here is pretty simple, if your '77 head is an N47 then just drop in your entire 280ZX engine and you're good to go just as hls30.com said...if your '77 head is an N42 do as I said above and you will still not have to change the manifolds. Easy solution either way!

[CCC77]

I was going to use the intake manifold from the 77 because it seems to have a lot less crap attached to it. Don’t know if that really matters. When I took the motor out of the 82 I did it rather hastily and may have left some of the associated wiring behind. I will have to check to see if the head on the 77 is a N42 but I think its probable a N47. According to this web page: http://www.geocities.com/zgarage2001/heads.html either of those two heads should give me high compression with that block. I just don’t know if that high compression is going to do that much for me? I do want to get more power out of it. I was also thinking of putting a hotter cam in. If I do, do I really need the all the extra compression from the older head?

[Ed]

Originally posted by CCC77

I do want to get more power out of it. I was also thinking of putting a hotter cam in. If I do, do I really need the all the extra compression from the older head?

Depending on what grind cam you get, and your car's application (street or autocross) the higher compression would be better.

[texasz]

Originally posted by CCC77

I was going to use the intake manifold from the 77 because it seems to have a lot less crap attached to it. Don’t know if that really matters. When I took the motor out of the 82 I did it rather hastily and may have left some of the associated wiring behind. I will have to check to see if the head on the 77 is a N42 but I think its probable a N47. According to this web page: http://www.geocities.com/zgarage2001/heads.html either of those two heads should give me high compression with that block. I just don’t know if that high compression is going to do that much for me? I do want to get more power out of it. I was also thinking of putting a hotter cam in. If I do, do I really need the all the extra compression from the older head?

I didn't mention that the N42 and the N47 are exactly the same except for the exhaust ports. So if you do have the N47 you could still put it on your '82 block and get the same 10:1 compression. Only reason I said just drop the entire '82 engine in if you had the N47 head was for ease.

[CCC77]

Thanks I appreciate all your advice. One more question. Would I need to run premium gas at that compression level? I am thinking detonation would definitely start to be an issue.

Curtis

[hls30.com]

I think that would depend on your tuning(spark advance), the ambient temp and humidity. The finer your state of tune, the more high octane becomes a priority.

When you put a fine point on it, you actually tune to the gas you use.

Will

[texasz]

Originally posted by CCC77

Thanks I appreciate all your advice. One more question. Would I need to run premium gas at that compression level? I am thinking detonation would definitely start to be an issue.

Curtis

From what I understand basically, yes you would need to run premium if you have a 10:1 CR.