N42 Versus F54 The differences! The truth! turbo and overboring

Nigel, your L26 block is not a N42, I think it is an E88. Yes, the thread was to do about what block to overbore, but since (as far as I know, be happily proved otherwise[on any of this]) we did not get a N42, and there has been a couple of L28 blocks off the discussion list, can't have too much of a discussion until the others are considered...for all we know the others are "better/worse"... Also if siamesed is discussed, what about the P90 and the P75...? It could even be that Nissan kept using the F54, but called it the P90 without any physical changes....I don't know it all.

The differences between the blocks could be significant, or very minor.... its like having a discussion on what S30 is best, without considering the full range (rather than just the 240/260 that the UK got.

I have observations/thoughts/research on overboring on this non definative subject, but its a load of typing, we have been here before and I have other things to fit into my lunch break (like food!)
 
twoforty said:
:conf2: looks like an Arizona Z pan like mine....mine only takes about 6 litres to max, must be small french litres :)
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We aint got the same block, pipework (or oil rad ?) ! All I know is that it takes a lot of expensive 10/60 100% synthetique to fill it up !
 
My old engine was an N42block N42 head....I was told it came from a 280zx auto 1983 UK car .
 
UK market cars, data taken from Nissan microfiche for the 280zx:

L28 P75 Oct-'78 to June '81
L28 F54 May-'80 to June'81
L28 P90 July -'81 to end and if you wanted to buy a new L28 from Nissan, then and any time after, it would be a P90. I doubt if they would be new from Nissan now....
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There is no P75 L28 block for any market, Nissan never made one.
I double checked with a very knowledgeable source, and he has never heard of the P75 block
(This source, who has lived in Japan and worked extensively with Nissan L-series engines).
There is however a P75 intake manifold that came on some non-USDM cars (i.e. Fairlady 280Z, etc.),
so that must be what it is talking about.

I suspect that the head gasket problems had nothing to do with the block.
Nissan quality control was very good on the blocks. And since there is no P75 block, there are only
TWO L28 BLOCKS.

And coupled to that, it is not as straight forward for you in the US (from Nissan microfiche:

L28 N42 Dec-'74 until the end of S30 period (not in 280zx)
L28 P75 1978 to 1981 (280zx)
L28 F54 May '80 to June '81
L28 P90 Dec. '80 standard fit (inc. turbo). Same if buying new from Nissan after the run of the 280zx, would be sold a P90 (and now if available)
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Again, there is no P75 block anywhere. Nissan seems to have listed the P75 manifold as a "version" of the L28 on an N42 block (look at the dates of the block)
And obviously the P90 is the F54 with the turbo pistons. NOT a different block.

If it were me, I would not leap to conclusions based on microfiche
or what others had "told me", and not doing real research. Making statements without doing
RESEARCH and FACT CHECKING is the real "dangerous ground".
 
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Well this thread got me wondering which L28 block head combos I have, results as follows

UK cars

79 280ZX (auto) N42 block N42 head
83 280ZX (auto) F54 block P90 head
83 280ZX (Man) F54 block P90A head

US car

77 280Z (Cali spec Man) N42 block N47 head

I don't know what this proves apart from for a guy doing a V8 conversion I have a lot of the wrong engines;), but thought I'd just chuck this data up.

Steve

PS L28 engine and transmission sale coming soon;)
 
Thank you for your input. I did not say I was right and happily shown otherwise, as I don't know it all. Bold type seems to say you are shouting....

When we call a cylinder head a P90, this is taken from the Nissan part number, that Nissan gave it. And thus this is what the N42 or the F54 is numbered from..so if a block is called another thing from its part number, why can't it called that to? Are you saying Nissan was wrong on its parts microfiche (and your "told you" source is correct), the firm that produced the product and the microfiche? I agree that it could be the fact that Nissan produced only 2 physical blocks, but the part numbers indicate Nissan called them something else, (beacuse they could be different), why can't we (we do for other Nissan parts)?

You are missing the point on the head gasket front. It is not about the quailty of the block, it is just when adding a new head gasket, there has been some issues that the holes don't always line up (water passage holes missing or holes where there should be), not just here, but also on the American z forums. This may point to there being different part numbers, as the blocks were slightly different (as pointed by the water passage holes), but this could be minor differences on the blocks...and Nissan called them something else probably for a reason....


Based on your info (which you neglected to mention and which was the main point of my original post), tell me when the N42 and F54 were produced/available for the UK market please (with some documentation)? All I am trying to do, with some level of documentation (rather than hearsay), is did we get the N42 in the UK? Because if we did we can discuss the merits of the blocks we can use here (in the UK), if not it is much more difficult to talk about "which block is best" if we in the UK only got the F54.... Obviously, my first port of call for any documentation query, is Nissan and its microfiche....

More than happy to be shown what is what..

Regards
Ian
 
And obviously the P90 is the F54 with the turbo pistons. NOT a different block.
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I'd like to clarify that, despite what the casting on the block says, there are four distinct part numbers for L28 blocks that I can see - and I do mean blocks, not short engines as you imply.

The only part number which includes the N42 designation is 11010-N4200-SV as fitted to all USA 280Z 12/74 to '78. The L28 block carries the N42 casting number, but for the inception of the 280ZX, the N4200 part number does not appear. Instead there are two blocks 11010-P7585 designated "Type A" on the parts fiche and 11010-F5480 (the "F54" block) designated Type B on the parts fiche which run concurrently. I have two UK 280ZXs here, both from '79/'81 series, one with F54 block the other with N42 casting on the block. I can guarantee that the N42 casting is the original engine for the car (matching numbers and known history etc.). I would suggest, therefore, that although Nissan regarded the block as being sufficiently different in some way to give it a new part number, this was done without significantly changing the casting moulds and the casting number. This could be differences in casting bosses for items not found on the 280Z (power steering?) or something more fundamental. The external casting may remain the same, but details of internal structure altered...? I can't say as I've never had the opportunity (or desire) to cut up and analyse alternate blocks. Suffice to say, as far as I'm concerned there is an N42 N42 and a P75 N42 version which probably have shared desirable characteristics but come from different sources and periods of time within the foundary facilities of Nissan. It is likely that there are detail but non-significant differences between them.

With the inception of the USA turbo, the part number for the block changes again to 11010-P9080. Nissan would regard this as an unconditional replacement for the previous two 280ZX part numbers, so there is no change in the block waterways in theory. If however, you put a P90 head onto any block using the earlier gasket, two waterways become uncovered on the underside of the head and water pours out. Now Nissan have superceded to the later gasket for all L28 ZX applications, although there is currently some concern that this obscures waterways elsewhere on the early combination with N42 head. I don't have a late 280ZX to look at to see what casting number is on the block - anyone confirm with a late UK 280ZX with known matching numbers? This later part number would have been offered as a replacement part to all potential purchasers of new blocks from 07/81 onwards. Is this the P90 N42 or a P90 F54...?:)
 
Just been out to check the pair of 280zx I recently bought to get a few bits to upgrade my 240 and then break for parts (if anyone needs anything:D).

The May 83Y manual has N42/N42 but engine number does not match log book.

The August 82Y auto has F54/P90.
 
On the engine block/head debate... my 78 260 is fitted with an engine i removed from a 79 280zx. This engine is stamped N42 on both block and head. I also have another 79 280zx which i know is totally original and it is fitted with the N42 block/head combo. They are both original uk imports:conf2: :S30::Z31:
 
Mr.F said:
The only part number which includes the N42 designation is 11010-N4200-SV as fitted to all USA 280Z 12/74 to '78. The L28 block carries the N42 casting number, but for the inception of the 280ZX, the N4200 part number does not appear. Instead there are two blocks 11010-P7585 designated "Type A" on the parts fiche and 11010-F5480 (the "F54" block) designated Type B on the parts fiche which run concurrently. I have two UK 280ZXs here, both from '79/'81 series, one with F54 block the other with N42 casting on the block. I can guarantee that the N42 casting is the original engine for the car (matching numbers and known history etc.). I would suggest, therefore, that although Nissan regarded the block as being sufficiently different in some way to give it a new part number, this was done without significantly changing the casting moulds and the casting number. This could be differences in casting bosses for items not found on the 280Z (power steering?) or something more fundamental. The external casting may remain the same, but details of internal structure altered...? I can't say as I've never had the opportunity (or desire) to cut up and analyse alternate blocks. Suffice to say, as far as I'm concerned there is an N42 N42 and a P75 N42 version which probably have shared desirable characteristics but come from different sources and periods of time within the foundary facilities of Nissan. It is likely that there are detail but non-significant differences between them.
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Great information! Blimey, is nothing bloody easy eh?
 
For what it's worth I have an L28 'spare' engine. Just had a look and it's an N42 block.

Am I sitting on a fortune:)
 
Mr.F, I was deliberate in not considering every possible minor casting change, such as bolt holes, mounts, other minor external or internal changes etc. For instance, the F54 NA block would obviously be different from the F54 Turbo block; the NA block would have provisions for a spin-on type oil filter and no provision for the bolt that goes above oil filter/cooler adapter as would the F54 Turbo block. This really is not a major difference, but would have different designations/part numbers obviously.

In terms of major distinctions, there are only two L28 blocks, N42 and F54.
 
the F54 NA block would obviously be different from the F54 Turbo block
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I don't say this to be provocative, but the part number for the NA block and the turbo block is actually the same from 07/81 onwards - 11010-P9080 - introduced as the "turbo" block, but common usage with later NA and the supercession part for the NA F54 block.

I'm in agreement with the fact that there are two L28 casting numbers, but it should be apparent that there will be minor variations. From the UK point of view it is important to understand that we didn't have the "favoured" N42 block which was used in the USA 280Z.
 
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