L28 NA Project

2

240_Z

Well-Known Forum User
Hi

Just acquired a280zx 2+2 auto 83. Looking to put the engine into a 240.
So I need to know apart from the engine is anything else of use on this car.
It has a P90A head , is this any use or should I go with the 240 head.
Is it best to go for a 280zx box or will the 240 one be ok.
I know the diff is no use on the 280.Again will the 240 one be strong enough or
do I look for a 280 manual diff.I am guessing clutch wise things would be straight forward.
The 240z is stock btw. All help appreciated
 
If the 280zx engine runs fine, I would put the whole unit in inc. the cylinder head. Some P90A have hydraulic lifters (you will likely being a 1983), but as it seems like the car/engine is stock there is no point. Have to rejet/change the size of the stock 240z carbs to suit your 280zx engineI can't remember what diff ratio that auto has (do a search as the info is here somewhere) As for gearboxes, I would go with the manual 240z over the auto....otherwise you would have to swap the 240z manual out and put in all the relavent parts auto bits in....

Hope that helps
 
Ok thanks for the advice. Re the gearbox - I meant do I leave the 240 one in or do I search for a 280 manual. No way would I put the auto in. That will be sold or scrapped if no one wants it - although its a good box. From reading up I think I need an R200 diff and an FS5W71B box if I want to beef things up. Ive also got a set of Webers that I thought I would try.Wasnt sure If I was going the right route using the P90A.
 
You have a R200 diff in the 280zx (yes?), but I don't know what the ratio is. Will have to change the back plate, which is a finned one for a smooth R200 back plate. (you can fit a finned R200 diff, but you have to remove and replace the bar behind the diff with an aftermarket bracket) From another post on here, (from someone more knowledgeable than me) the P90A was never a Uk imported head....I stand corrected.

As for the 240z 'box, if it drives fine with the standard engine, I would leave it alone, as youe 280zx engine is not producing more than standard power, so my understanding, the 240z 'box will cope. Hopefully someone who knows more about 240z than I do pipes up (as I only concentrate on 260z, as I have them!)
 
Ian Patmore said:
You have a R200 diff in the 280zx (yes?), but I don't know what the ratio is. Will have to change the back plate, which is a finned one for a smooth R200 back plate. (you can fit a finned R200 diff, but you have to remove and replace the bar behind the diff with an aftermarket bracket) From another post on here, (from someone more knowledgeable than me) the P90A was never a Uk imported head....I stand corrected.

As for the 240z 'box, if it drives fine with the standard engine, I would leave it alone, as youe 280zx engine is not producing more than standard power, so my understanding, the 240z 'box will cope. Hopefully someone who knows more about 240z than I do pipes up (as I only concentrate on 260z, as I have them!)
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Hi Ian I think I have a an R180 in the 280zx - which I believe is the wrong ratio - reading other posts. Re the head - as far as I know the engine and head are bog standard.P90A - I am guessing the A refers to auto - but I could be wrong. As for the box - I will probably do what you suggest for now - until I come across later 280 manual box - quite scarce now by all accounts. Should be a write up somewhere for how to do this - I have lots to learn and find out.
 
Hi, the A of the P90A doesn't refer to Auto its just a seemingly strange head designation that appeared on the last L28's, probably to do with the turbo cars or something? Some of them do have hydraulic lifters but apparently the true UK cars shouldn't have for some reason? I have 2 83 280ZX's, an auto and a manual. One of them has a P90 head and the other a P90A (the manual) :conf2:.

Unless you plan to tune the 2.8 significantly, fit very sticky tyres and some form of LSD (in which case you'd probably go R200 anyway) it would be very unlikely if not extremely unlucky to break the diff and even if you did they are not hard or expensive to replace plus it may be a more sensible point to fit the R200 then if you wanted it. I would equally see no reason why the gearbox wouldn't hold up either as the same L28 was used in the US 280Z and although these used 4 speed boxes predominantly, 5 speed upgrades are not rare in the US.

For my two pence, from a man who fully understands biting off more than he can chew and effectively trying to upgrade just about everything on a Z in one go (which is still in progress some 2-3 years after he started) If you can, keep it simple, put the engine in, get it running as is, drive it, decide whether it performs in the way you want and then replace or upgrade whatever else you want in chunks after that, or as you can find the parts at the right price.

However I would suggest upgrading the brakes sooner rather than later though!:eek:

Cheers
 
zeeman1972 said:
Hi, the A of the P90A doesn't refer to Auto its just a seemingly strange head designation that appeared on the last L28's, probably to do with the turbo cars or something? Some of them do have hydraulic lifters but apparently the true UK cars shouldn't have for some reason? I have 2 83 280ZX's, an auto and a manual. One of them has a P90 head and the other a P90A (the manual) :conf2:.

Unless you plan to tune the 2.8 significantly, fit very sticky tyres and some form of LSD (in which case you'd probably go R200 anyway) it would be very unlikely if not extremely unlucky to break the diff and even if you did they are not hard or expensive to replace plus it may be a more sensible point to fit the R200 then if you wanted it. I would equally see no reason why the gearbox wouldn't hold up either as the same L28 was used in the US 280Z and although these used 4 speed boxes predominantly, 5 speed upgrades are not rare in the US.

For my two pence, from a man who fully understands biting off more than he can chew and effectively trying to upgrade just about everything on a Z in one go (which is still in progress some 2-3 years after he started) If you can, keep it simple, put the engine in, get it running as is, drive it, decide whether it performs in the way you want and then replace or upgrade whatever else you want in chunks after that, or as you can find the parts at the right price.

However I would suggest upgrading the brakes sooner rather than later though!:eek:

Cheers
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Hi Zeeman

Seems like good advice. I didnt realise the 280z had the same earlier box. With that in mind I will go that route for now and see how it goes. Ive got the triple webers I want to experiment with. Should I try the electric fuel pump from the 280zx. I will try and swap the zx brakes and see how that goes. Thanks for the help.
 
best use a Facet red top fuel pump to use with webers with a pressure regulator
 
Agree with Moggy when it comes to the pump, but to be honest you would be wasting your time with the webbers. Unless you build an engine that requires them, ie more compression bigger cam etc there is no benefit. All you will do is lower your fuel consumption from low 20's to mid to high teens. The 2.8 you have will be fine as it is (Assuming it's in good nick) on the standard carbs. It won't set the world alight in standard trim, but it sould be a nice torquey engine. I have run a 2.8 with standard carbs before with no problems with very small carb adjustment. To give the motor more compression you could use your 240 head(depending on wich one you have) on the 2.8 bottom end. Talk to some one like Dave Jarman (DJ road and race) about clearences/cams etc.
As Zeeman says, if your diffs ok then leave it as it is. I'ts got the right 3.9 ratio. If you change to an R200 later it must come from a late 280zx Manual. The early r200's had a 3.7 ratio wich would spoil your accelaration.
 
Seems to all make sense. Will try the L28 for now with 240 carbs and see how that goes. L28 seems good and strong so will give it a try. As was said before I will try one step at a time before I start to look at heads. And I imagine late R200 and boxes are quite rare now.
Thanks for the advice guys.
 
Just to confirm - auto 280ZX in the UK has the R180 diff; only manuals have the R200. 3.7:1 from '79 to '81 and 3.9:1 in the later manual cars (late '81 to '83).
 
Mr.F said:
Just to confirm - auto 280ZX in the UK has the R180 diff; only manuals have the R200. 3.7:1 from '79 to '81 and 3.9:1 in the later manual cars (late '81 to '83).
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Ok Mike - so I need an early zx box then - is that right?
The later one is the wrong ratios.
Cheers.
 
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