[Unknown User]

Hello people. I am in the task of turbocharging my '81 non turbo 280zx. I need a turbo engine with in fair condition. I have heard that is possible to install a '84 300 zxt brain into the 280zx. Do you need the 300zxt e.c.U.wiring too?. or can I use the e.c.U. wiring from the 280zxt?.
What other modifications do I need in order to accomplish my swap?.
Any help will be greately appreciated.
P.S. I live in the Los Angeles area. Anyone who is selling the engine in this area write me a message.thanks.

 

[CarlosZXT]

You dont necessarily have to change the engine, sure there are some differences between the turbo block and the non turbo block.
The differences I would be most woried about is the difference in the landings of the piston rings and the rings themselves.
In the turbo pistons both compression rings are 1mm wide and are less prone to brakage due to temperature (moly treated).
The normally aspirated L28 pistons have on 1mm (upper) and one 0.5 mm (lower) compression ring which are in most cases carbo, not chromed.

Besides that...
the block of the L28ET is supposed to have some wedges to make it stronger. I dont think the L28 n/a is THAT less strong (if so, we would already know)
For example: everybody knows that the rods in the honda (non acura) engines are their weakest point and the same reason most honda racers swap to acura's

In terms of compression, the 81 posed a change in compression ratio for the normally aspirated Z. It was raised from somewhere around 8.0 to 9.something (sorry not sure of the exact amounts)
8.0 is perfectly doable for turbo 9.0's are not that common (you would need 93+ octane to be able to run above 6psi of boost)

you can drop your high compression engine to lower just putting a 2mm head gasket. that gasket can lower you some compression points.
If you are interested I can determine the exact dropof compression due to the swap.

About the '84 ecu...
It is helluva job, and dont think it is worthy.
I am sure the n/a ecu can deal with the turbo injectors with some tuning of the Air flow meter.
tha main difference between the 300 ecu and the 280 is the elimination of the restrictive Air Flow Meter (AFM). That may be the only reason to make the swap.
I forgot to tell you that you need some sort of ignition retard when in boost (in the turbo's it is provided by the ECCS but you can get the same from a MSD BTM which controlls retard related to boost pressure.
If you are going to the 300 thing you DO need the wiring.

Anyway, If you find the engin, and the eccs DO IT!
if not, now you know there are other options.

Hope this helps

CarlosZXT

> Hello people. I am in the task of
> turbocharging my '81 non turbo 280zx. I need
> a turbo engine with in fair condition. I
> have heard that is possible to install a '84
> 300 zxt brain into the 280zx. Do you need
> the 300zxt e.c.U.wiring too?. or can I use
> the e.c.U. wiring from the 280zxt?.
> What other modifications do I need in order
> to accomplish my swap?.
> Any help will be greately appreciated.
> P.S. I live in the Los Angeles area. Anyone
> who is selling the engine in this area write
> me a message.thanks.

 

[Ian]

> You dont necessarily have to change the
> engine, sure there are some differences
> between the turbo block and the non turbo
> block.
> The differences I would be most woried about
> is the difference in the landings of the
> piston rings and the rings themselves.
> In the turbo pistons both compression rings
> are 1mm wide and are less prone to brakage
> due to temperature (moly treated).
> The normally aspirated L28 pistons have on
> 1mm (upper) and one 0.5 mm (lower)
> compression ring which are in most cases
> carbo, not chromed.

> Besides that...
> the block of the L28ET is supposed to have
> some wedges to make it stronger. I dont
> think the L28 n/a is THAT less strong (if
> so, we would already know)
> For example: everybody knows
> that the rods in the honda (non acura)
> engines are their weakest point and the same
> reason most honda racers swap to acura's

> In terms of compression, the 81 posed a
> change in compression ratio for the normally
> aspirated Z. It was raised from somewhere
> around 8.0 to 9.something (sorry not sure of
> the exact amounts)
> 8.0 is perfectly doable for turbo 9.0's are
> not that common (you would need 93+ octane
> to be able to run above 6psi of boost)

> you can drop your high
> compression engine to lower just
> putting a 2mm head gasket. that gasket can
> lower you some compression points.
> If you are interested I can determine the
> exact dropof compression due to the swap.

> About the '84 ecu...
> It is helluva job, and dont think it is
> worthy.
> I am sure the n/a ecu can deal with the
> turbo injectors with some tuning of the Air
> flow meter.
> tha main difference between the 300 ecu and
> the 280 is the elimination of the
> restrictive Air Flow Meter (AFM). That may
> be the only reason to make the swap.
> I forgot to tell you that you need some sort
> of ignition retard when in boost (in the
> turbo's it is provided by the ECCS but you
> can get the same from a MSD BTM which
> controlls retard related to boost pressure.
> If you are going to the 300 thing you DO
> need the wiring.

> Anyway, If you find the engin, and the eccs
> DO IT!
> if not, now you know there are other
> options.

> Hope this helps

> CarlosZXT

I just blew the motor on my 240Z turbo. It was due to the pistons I used. If you decide to turbo the n/a motor, which you can do, make sure that it never detonates. I had a lot of trouble with detonation and I am sure that is what killed the motor. BTY, the c/r of an n/a 81 motor is 8.8:1. This would be as high as I would want to go on a turbo motor. You will have good throttle response, though. BTY, its going to take more than a little tuning of the AFM to get the right air/fuel ratios under boost. I would recomend a rising rate fuel pressure regulator and a really good fuel pump. The can be had from Vortech or Paxton and they can advise you on what rate regulator you need.Good Luck!!!

 

[CarlosZXT]

the pistons are not neccesarily the reason for that. Remember, compression ratio is related to a series of factors. increasing 1 mm of head gasket can lower you compression quite a bit an reduce the chances of blowing your engine.

did you take any precautions against ignition advance?
when in boost (after 6 psi) youp should have retard.

maybe that is another reason for it to blew.
I am not blaming you for blowing your engine just wanna say that it is possible to turbo the n/a w.o having to install the complete turbo engine./

CarlosZXT

> I just blew the motor on my 240Z turbo. It
> was due to the pistons I used. If you decide
> to turbo the n/a motor, which you can do,
> make sure that it never detonates. I had a
> lot of trouble with detonation and I am sure
> that is what killed the motor. BTY, the c/r
> of an n/a 81 motor is 8.8:1. This would be
> as high as I would want to go on a turbo
> motor. You will have good throttle response,
> though. BTY, its going to take more than a
> little tuning of the AFM to get the right
> air/fuel ratios under boost. I would
> recomend a rising rate fuel pressure
> regulator and a really good fuel pump. The
> can be had from Vortech or Paxton and they
> can advise you on what rate regulator you
> need.Good Luck!!!

 

[Ian]

In my case, the pistons, coupled with detonation were the cause of the engine failure. Here is the breakdown of the motor build:
diesel crank
280z rods
1mm over dished 280z pistons
p90 head
stock turbo cam
this comes out to 2967cc motor.same as a 300ZX
Now the reason the pistons failed is because when i built the stroker, i knew nothing about what piston/rod combination to use. Nor could i find the info. At the time, I had a friend who had a motor built by Rebello and they had used 240 rods w/280 dished pistons in an L28 block. The motor was not turboed. in order to compensate for deck height, they machined the tops of the pistons. I don't recall how much they removed for his setup, but the dish was nearly gone. At the time, I had no intention of turboing my car and I decided if it worked for Rebello, It'l work for me. So I cut 2mm off the tops of the 280 dished pistons and the deck height came out to 0. At the time, I had a ported e88 head and Isky race cam and tripple Webers. It ran great and I never had a problem w/it. Then I found a turbo 280ZX and decided it would be fun to turbo my 3.0. It lasted 1 year and let me tell you. This is my daily driver and I am very hard on it. I also drag race it on the weekends. Now, the motor is still running, it just has tons of blowby, and I have not taken it apart yet. I am sure that I will find that the rings are shot. But, this is because they are 2mm closer the the combustion chamber and subjected to some detonation.

As for you inquiry as to my ign. system:
I am using an MSD 6-BTM.
The reason the engine detonated was because I had trouble with getting enough fuel to the injectors. I finally installed a NOS high flow fuel pump, 1/2 feed line from the pump to the Paxton adjustable fuel pressure regulator that I installed on a custom built fuel rail sporting 30lb/hr Ford Motorsport injectors. That alleviated the pinging. However it cost me about a grand! Oh well. If you want to play, you got to pay!

BTW, It is possible to turbo the n/a motor without any internal mods. I don't see anything wrong with that. However, fuel and ign. are a very critical part of how any turbo motor runs and stays together. As long as the motor doesn't detonate, it will be fine. As we all know, the L-series motors are very tough. I also do not see a reason for installing a metal head gasket on the motor in this discussion. The 81 is 8.8:1 and that is fine for turboing. In fact, I am turboing a stock L24 that is 9.0:1. We are using a blow-through setup w/the stock carbs and manifold. So far the whole setup has cost $200.00 (junkyard exhaust manifold and turbo). We'll see if it runs good.
Z-ya L8R!!!

> the pistons are not neccesarily the reason
> for that. Remember, compression ratio is
> related to a series of factors. increasing 1
> mm of head gasket can lower you compression
> quite a bit an reduce the chances of blowing
> your engine.

> did you take any precautions against
> ignition advance?
> when in boost (after 6 psi) youp should have
> retard.

> maybe that is another reason for it to blew.
> I am not blaming you for blowing your engine
> just wanna say that it is possible to turbo
> the n/a w.o having to install the complete
> turbo engine./

> CarlosZXT

 

[CarlosZXT]

Nice info for all those who wanna go turbo

> In my case, the pistons, coupled with
> detonation were the cause of the engine
> failure. Here is the breakdown of the motor
> build:
> diesel crank
> 280z rods
> 1mm over dished 280z pistons
> p90 head
> stock turbo cam
> this comes out to 2967cc motor.same as a
> 300ZX
> Now the reason the pistons failed is because
> when i built the stroker, i knew nothing
> about what piston/rod combination to use.
> Nor could i find the info. At the time, I
> had a friend who had a motor built by
> Rebello and they had used 240 rods w/280
> dished pistons in an L28 block. The motor
> was not turboed. in order to compensate for
> deck height, they machined the tops of the
> pistons. I don't recall how much they
> removed for his setup, but the dish was
> nearly gone. At the time, I had no intention
> of turboing my car and I decided if it
> worked for Rebello, It'l work for me. So I
> cut 2mm off the tops of the 280 dished
> pistons and the deck height came out to 0.
> At the time, I had a ported e88 head and
> Isky race cam and tripple Webers. It ran
> great and I never had a problem w/it. Then I
> found a turbo 280ZX and decided it would be
> fun to turbo my 3.0. It lasted 1 year and
> let me tell you. This is my daily driver and
> I am very hard on it. I also drag race it on
> the weekends. Now, the motor is still
> running, it just has tons of blowby, and I
> have not taken it apart yet. I am sure that
> I will find that the rings are shot. But,
> this is because they are 2mm closer the the
> combustion chamber and subjected to some
> detonation.

> As for you inquiry as to my ign. system:
> I am using an MSD 6-BTM.
> The reason the engine detonated was because
> I had trouble with getting enough fuel to
> the injectors. I finally installed a NOS
> high flow fuel pump, 1/2 feed line
> from the pump to the Paxton adjustable fuel
> pressure regulator that I installed on a
> custom built fuel rail sporting 30lb/hr Ford
> Motorsport injectors. That alleviated the
> pinging. However it cost me about a grand!
> Oh well. If you want to play, you got to
> pay!

> BTW, It is possible to turbo the n/a motor
> without any internal mods. I don't see
> anything wrong with that. However, fuel and
> ign. are a very critical part of how any
> turbo motor runs and stays together. As long
> as the motor doesn't detonate, it will be
> fine. As we all know, the L-series motors
> are very tough. I also do not see a reason
> for installing a metal head gasket on the
> motor in this discussion. The 81 is 8.8:1
> and that is fine for turboing. In fact, I am
> turboing a stock L24 that is 9.0:1. We are
> using a blow-through setup w/the stock carbs
> and manifold. So far the whole setup has
> cost $200.00 (junkyard exhaust manifold and
> turbo). We'll see if it runs good.
> Z-ya L8R!!!