L28 Short Motor

[T8834D]

hi guys

i have a l20et and i have just found a rebilt l28 short motor from a 83 patrol (it has a 240mm clutch)

is this block suitable 4 turbo ? or are they week compared to a 280zx bolck?

i am also wondering what head i should use? ihave the l20turbo one is this the best head?

any advice on what combo's work well would be much appriciated.

[66yostagea]

hi guys

i have a l20et and i have just found a rebilt l28 short motor from a 83 patrol (it has a 240mm clutch)

is this block suitable 4 turbo ? or are they week compared to a 280zx bolck?

i am also wondering what head i should use? ihave the l20turbo one is this the best head?

any advice on what combo's work well would be much appriciated.

PM Ghostrider. He is the MAN.

[stagefumer11]

Perfect for turboing.

8:5.1 compression if its a early l28e or carby. It should have n42 head i think.. which should have the injector notches already in it.

Do not use the l20et head. the vavles are tiny, and will not be able to flow the same. You can use the l20et intake manifold, this will produce huge amounts of torqe but run out of steam around 5500rpm. (small runners = lots of torque less revs)

You should install your l20et oil pump and dizzy drive. Get some vg30et injectors. 279cc. they are the same as l28et injectors. Swap the l20et sump over and oil pick up. Redrill the dipstick hole. Youi will see a notch in the block where it goes.

the factory turbo on a l20et will be limited to only low boost, it will not be able to flow enough to feed the l28et over 10psi. Maybe not even that. YOu can use the factory l20et wiring and ecu with the l20et dizzy. This will give your proper Timing retard controll for boost aplications.

im about to do the same., but i got my l28 from a 139k 280zx. This is what i reseached. l28e's are perfect for turboing with the same crank and rods as the eruo and american l28et's Pistons have been roumerd to be diffrent. But actaully are the same... Ring lands ect same width as turbo ones. Means the heat is kept away from the rings better. The compression ratio is the same as a rb20det. And lower than a rb25det. Either way id doubt you will have much problems. In the long run id recomend a good aftermarket ecu system.

Anything else just ask..

[T8834D]

cheers 4 the reply buddy

the block is from a patrol and has .025 over size pistons and new bearings the only thing that concurns me is the bore thickness.

i have no previous experiance with lseries 6es but when i look at number 6 down threw the main water port the bore has no (spelling) siamizing (crosshtach or ridges) so it would tend to crack or split easy,

does the turbo or the inj block have thicker liners?

i have a set of vg30et injectors coinsedsley.

what should i get a head from? i know of a 280zx one.

what inlet mani apart from a 28et is the best to use?l20et?

i also discovered somthing usefull about the patrol l28,

it uses a 240mm clutch (like a rb) as apposed to the 225mm on the l20turbo.

what head gasket should i use?

what cam should i use l20et or l28?

thanks and sorry about all the questions.

[SteveL]

One thing you need to be aware of before going further....L6's from Patrol's use a rear bowl sump + oil pick-up. OTOH I suspect your L20ET has a front bowl sump. If that is the case, it is not a simple matter to swap th sumps because the block's are drilled diffently for the oil pick-up gallery. The swap can and has been done, but it's not 'bolt on'.

As to your other Q's:

- Block will be either an F54 or N42 (look for one of these ID's cast into the exhaust side, low down near the sump line). F54 is theoretically the strongest block, but the difference is marginal, if any. Nissan experimented with siamesed bore liners in the early L6 turbo blocks, but found little difference in strength.

- The turbo 280ZX racecars used by the likes of Paul Newman reputedly had 600HP at the flywheel with a stock block (but with a crank girdle and modified cranks).

- P90 is the turbo head and the one to get if your going for big boost.

- head gasket depends on boost levels.

- from memory there isn't much difference between those cams.

- VG30ET has about the same output as RB30ET (ie 150kw at the flywheel, stock), so they won't be much good unless this will be a relatively mild engine....in which case you won't need to worry about the block.

[66 skyline gt]

only catch... if ya trying to cahse either a p79 or p90 head good luck... they are rear as rocking horse poo..... i tried chasing one upnot long ago with no luck..... that y i ended up going an rb conversion......

[T8834D]

cheers 4 all the info

i have a spare fj20et with loom and crossmamber in WA the car is in singleton NSW at the mo so i am not looking at huge power outputs, the car has to be nice to drive home.

the reason ihave the motor out is that the front was wiped out and i have fitted a new front end from the fire wall forward.

i have also fitted a complete set of seats from a r34 skyline.

keeping this in mind would the n42 head from a l24 work ok with the patrol block and l20et inlet to make and nice driving donk.

or should i just wack the l20et back in it (the motor is in good cond) and when i get home wack the effjay in it?

[T8834D]

i just looked at my l24 head and its a n47is this as good as the n42?

the l20et head is a 05L is this orig.

[BensDR30]

The N47 _may_ have exhaust liners, which will slightly reduce your exhaust flow. But more importantly, if they're loose, there's a chance that the turbine could get foreign object damage.

Regarding the L20ET snail, it will be far too small for an L28, I'm running a VG30 turbo on my L28ET, and am looking to modify the wastegate as it is unable to hold boost above 12psi - even bleeding off masses of air from the actuator. Having said that the VG30ET/RB30ET size units are about right for a 'spritely' setup as they are designed for a 3 litre engine.

I'm using 380cc injectors in my car, and without the ability to run sequential, or change the injector phasing, the idle is very hard to keep smooth. So I'd recommend something a little smaller for ease of use. I happen to have 6 E15T injectors (sometwere...) that I used to be running. I don't know the CC rating, but they were able to give me about 120rwkW @ 7psi before I upgraded the whole fuel system.

The best thing about using the L28 turbo in an R30 (or Z) is the torque. RPM's aren't so forthcoming, but when you can have 6psi @ 2000rpm it's a fairly fun ride. I like spinning my FJ20 to 6500rpm, but the L28ET has grunt.

I'm aiming for around 160rwkW once upgrade the Haltech E6A to a MoTec M48 Clubman at less than 15psi (currently ~140@11psi). This is a stock 'development' engine that one day (and Steve knows that I've working on this for years...) will be replaced with a fully prepped F54/P90 setup, which is aiming for 300+kW. The head for the new engine has been heavily modifed and is able to flow lots of CFM.

But installing a tailshaft loop, Z31 1/2-shafts & an R200 LSD are first on the agenda. I've already popped the spiders in one R180, and I don't do burnouts... Even with new uni-joints in the stock shafts, I know I'm pushing my luck with the amount of power the car has got.

[paulmac]

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.

[stagefumer11]

The N47 _may_ have exhaust liners, which will slightly reduce your exhaust flow. But more importantly, if they're loose, there's a chance that the turbine could get foreign object damage.

Regarding the L20ET snail, it will be far too small for an L28, I'm running a VG30 turbo on my L28ET, and am looking to modify the wastegate as it is unable to hold boost above 12psi - even bleeding off masses of air from the actuator. Having said that the VG30ET/RB30ET size units are about right for a 'spritely' setup as they are designed for a 3 litre engine.

I'm using 380cc injectors in my car, and without the ability to run sequential, or change the injector phasing, the idle is very hard to keep smooth. So I'd recommend something a little smaller for ease of use. I happen to have 6 E15T injectors (sometwere...) that I used to be running. I don't know the CC rating, but they were able to give me about 120rwkW @ 7psi before I upgraded the whole fuel system.

The best thing about using the L28 turbo in an R30 (or Z) is the torque. RPM's aren't so forthcoming, but when you can have 6psi @ 2000rpm it's a fairly fun ride. I like spinning my FJ20 to 6500rpm, but the L28ET has grunt.

I'm aiming for around 160rwkW once upgrade the Haltech E6A to a MoTec M48 Clubman at less than 15psi (currently ~140@11psi). This is a stock 'development' engine that one day (and Steve knows that I've working on this for years...) will be replaced with a fully prepped F54/P90 setup, which is aiming for 300+kW. The head for the new engine has been heavily modifed and is able to flow lots of CFM.

But installing a tailshaft loop, Z31 1/2-shafts & an R200 LSD are first on the agenda. I've already popped the spiders in one R180, and I don't do burnouts... Even with new uni-joints in the stock shafts, I know I'm pushing my luck with the amount of power the car has got.

Shouldnt you be able to adjust your injector pulse width by adjusting the AFM pre tension and Contact point ? Ive done this when i upgraded my injectors on the l20et. Intresting how you only got 120rwkw.

What do people know about the not so bolt up sump swap on the l28e ? Im getting alot of mixed messages about this.

[T8834D]

any of you guys swaped the steering box front end 4 a rack seutp?

i am nearley ready to put my front end back and i am having no luck findoing out what is the go.

i think r31 skyline must be close but the rack may be wrong 4 the r30 and make her bump steer.

[stagefumer11]

any of you guys swaped the steering box front end 4 a rack seutp?

i am nearley ready to put my front end back and i am having no luck findoing out what is the go.

i think r31 skyline must be close but the rack may be wrong 4 the r30 and make her bump steer.

Looked at a 280zx rack ? I think they have a box tho

[BensDR30]

Shouldnt you be able to adjust your injector pulse width by adjusting the AFM pre tension and Contact point ? Ive done this when i upgraded my injectors on the l20et. Intresting how you only got 120rwkw.

What do people know about the not so bolt up sump swap on the l28e ? Im getting alot of mixed messages about this.

Yes, the mixtures are altered by the AFM tension, but it's a fairly crude method of tuning, especially considering the ECU is a 1st generation digital system, that is far from optimal. I've heard of fairly significant ouput gains on the FJ20ET fitting a decent aftermarket ECU (15-20kW).

The 120kW is relative to drivetrain - and my drivetrain is automatic, so the parasitic losses were significantly higher than if it was manual. To put it into perspective, the stock L24E was 62rwkW & the L28E (Haltech E6A, non-turbo) was 68rwkW. So we're looking at basically double the stock L24E output, and more than 2.5x the torque...

120rwKW in an early Z chassis is quite a bit, remember that it only weighs about 1050kg without a driver.

The sumps will bolt up, no problem.

The oil pickups might not.

There are 2 locations that the pickup could be bolted to, and the blocks are drilled to suit the bowl location of the sump to be fitted. What this means is that you may have to extend the oil pickup, and re-mount the dipstick. I've fitted an external dipstick to L6's in the past. The current engine in the Z doesn't have one at all, and the pickup is extended with a supporting brace to the #4 main bearing cap centre-bolt.

The turbo pump doesn't seem to have any issues dealing with this, or the external cooler.

[stagefumer11]

Yes, the mixtures are altered by the AFM tension, but it's a fairly crude method of tuning, especially considering the ECU is a 1st generation digital system, that is far from optimal. I've heard of fairly significant ouput gains on the FJ20ET fitting a decent aftermarket ECU (15-20kW).

The 120kW is relative to drivetrain - and my drivetrain is automatic, so the parasitic losses were significantly higher than if it was manual. To put it into perspective, the stock L24E was 62rwkW & the L28E (Haltech E6A, non-turbo) was 68rwkW. So we're looking at basically double the stock L24E output, and more than 2.5x the torque...

120rwKW in an early Z chassis is quite a bit, remember that it only weighs about 1050kg without a driver.

The sumps will bolt up, no problem.

The oil pickups might not.

There are 2 locations that the pickup could be bolted to, and the blocks are drilled to suit the bowl location of the sump to be fitted. What this means is that you may have to extend the oil pickup, and re-mount the dipstick. I've fitted an external dipstick to L6's in the past. The current engine in the Z doesn't have one at all, and the pickup is extended with a supporting brace to the #4 main bearing cap centre-bolt.

The turbo pump doesn't seem to have any issues dealing with this, or the external cooler.

Thanks, I needed some confumerd information on this. Im fitting my to my hr30 coupe. So ill be getting another l20et. My plan as is follows.

Swap over to the l20et oil pan. Oil pump and dizzy shaft drive. Refit the L20et oil pickup. Or Cut 30mm away from L28e oil pump mount flange, and adapt the l20et pickup to that. Could be possible ? From what i understand the l28 does have a node (lump) from where the FRont mounted dipstick will mount to. Needs to be drilled tho.

I auctally just got the 280zx here tonight. After a very stressfull night .

[Ghostrider]

What do people know about the not so bolt up sump swap on the l28e ? Im getting alot of mixed messages about this.

What SteveL says is correct, the conversion to front sump isn't merely a bolt on and re-drill affair.

There is an oil gallery right where the front sump dipstick hole has to be drilled in L28 blocks.

The easiest way is a bit agricultural, but it works very well. see attached pic. (SteveL had an F54 block once, supposed to be converted to front sump, if he will sell it) If you want to stay perfectly stock looking an L24E block is your only option, failing bore and sleeve the L20ET block.

The considered opinion for bore, is that an L28 block should take 2.0mm o/size with ease, if your going 3.0mm to 89.0mm the block should be sonic tested first to be sure, as some will and some wont take the 89mm bore.

As for inlet manifolds, it is my belief that both L28ET & L20ET are the same, as I have both and I can't see any difference, same with exhaust turbo manifolds.

I'm building an L28ET at the moment, F54 block, P90 head, stock L28ET cam (ex USA) both L28ET AFM & ECU's (ex USA) 1.0mm o/size, flat top pistons (8.7:1) 460 injectors, VG30 turbo and I'm expecting about 300rwhp @ 14psi with an electronic boost controller.

What you can consider is that our HR30 coupes are a lot lighter than a similar Zed car and we don't need masses of power to be as quick.

Cheers, D

[Ghostrider]

- VG30ET has about the same output as RB30ET (ie 150kw at the flywheel, stock), so they won't be much good unless this will be a relatively mild engine....in which case you won't need to worry about the block.

This, in my opinion is dependent on which model VG30ET we're talking about.

The first series that came to Oz in the Z31 was only twin cam 12V, yet later models 24V's.

The RB30ET turbo is exactly the same as the US spec L28ET turbo, a conventional bearing T03, where the VG30 Z31 turbo was ball bearing (ceramic) and was a much better performer and flows a lot more air for the same psi of boost.

Cheers, D

[stagefumer11]

Far out, big pic indeed.

So. id have to adapt the dipstick to a external feed..

What about this oil pump pick up ? Id presume making a custom one will work fine for me. As i hear i cannot just swap over my l20et one on to it.

And there is a oil gallery in the side of the block ? BIt of a weird place isnt it ? Again i get a lot of mixed messages about this

[BensDR30]

This, in my opinion is dependent on which model VG30ET we're talking about.

The first series that came to Oz in the Z31 was only twin cam 12V, yet later models 24V's.

The RB30ET turbo is exactly the same as the US spec L28ET turbo, a conventional bearing T03, where the VG30 Z31 turbo was ball bearing (ceramic) and was a much better performer and flows a lot more air for the same psi of boost.

Cheers, D

True, but hence the reference to the VG30ET rather than the DET (which I believe was also available with a composite compressor when fitted to Gloria's etc - not good for high boost).

The VG30ET unit wasn't ball bearing - not back in the mid 80's when the Z31 was made.

The VG30ET turbo is a nice cheap well-sized unit for an L6, the turbine is a bit small & fragile for high flow & boost though (my next hurdle...).

Another option is either a stock, or upgrade RB25DET turbo. 180kW in standard trim, quick response, probably more plentiful than the VG30ET & a ball-bearing core.

There are 2 galleries in that side of the block - pickup & main. It's best to be cautious & go the external route, it's not hard to do & is mechanically sound (when braced).

You will soon see the pickup situation once you pull the sumps - a short length of tubing & another brace soon solve that issue. Try not to cause a fire when welding though!