Real world opinions on a basic L28 & P90 EFI set-up

[grndfx]

Currently a friend is running a standard '79 280ZX EFI with automatic trans.

 

He has recently acquired an old '76 280Z that someone had put a turbo motor in but without the turbo - F54 block and P90 head. The P90 head needs rebuilding, but is it worth using it on the 280ZX ?

 

Has anyone just put the P90 on a L28 with EFI and was it worth it. With an auto trans would you see any real benefit. At this point in time they're not looking to a load of major engine building work with the 280ZX, and the 280Z needs a fair amount of general work before its ready to drive. So at this point in time is it worth swapping the P90 to the ZX while the Z is worked upon.

 

I know there's lots of opinion on how best to use the P90 - turbo, triples, SU's, etc; but as a straight swap does it realize any drivable gain? And with the auto trans would it just be a waste of effort. Done some searching on the forum and read the various post about using the P90 head, which was very informative, but would like to hear from anyone that has actually done this and whether they saw any real difference.

 

Thanks for your time, and I look forward to peoples input.

 

Steve.

[johnc]

Currently a friend is running a standard '79 280ZX EFI with automatic trans.

 

He has recently acquired an old '76 280Z that someone had put a turbo motor in but without the turbo - F54 block and P90 head. The P90 head needs rebuilding, but is it worth using it on the 280ZX ?

 

Has anyone just put the P90 on a L28 with EFI and was it worth it. With an auto trans would you see any real benefit. At this point in time they're not looking to a load of major engine building work with the 280ZX, and the 280Z needs a fair amount of general work before its ready to drive. So at this point in time is it worth swapping the P90 to the ZX while the Z is worked upon.

 

I know there's lots of opinion on how best to use the P90 - turbo, triples, SU's, etc; but as a straight swap does it realize any drivable gain? And with the auto trans would it just be a waste of effort. Done some searching on the forum and read the various post about using the P90 head, which was very informative, but would like to hear from anyone that has actually done this and whether they saw any real difference.

 

Thanks for your time, and I look forward to peoples input.

 

Steve.

 

The P90 head, used as is on a NA application, will most likely lose power (compared to an equally good condition N42, E31, etc.) due to the larger combustion chamber size and the resulting drop in compression. Please search, this has been discussed dozens of times over the decade this site has existed.

[grndfx]

Thanks for the response. I understand that as a long term member of the site you must see the same questions being asked over and over, but you help is appreciated and your input was useful.

 

Although I had searched the topic before I posted the thread, I had not come across the relevant info I needed. Your reference to combustion chamber size gave me the direction to find what I needed.

 

I now know that the N42 head uses the same valves as the P90 head but has a combustion chamber of 53.6cc compared to 44.6cc on the N42. I had previously thought that the lower compression in the turbo motor came from the dished pistons, but I now see why the P90 head would not be a suitable swap for the N42.

 

This link was very helpful in acquiring the various specs for the L series engines ... Z Engine Specs

 

Maybe this thread will be read in a future search by someone, and the answer will not need to be asked again.