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Z24 Turbo????


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#1 84Datsun720

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Posted 17 October 2011 - 08:04 PM

I have a Z24 and wanted to add a small Turbo, but I can not find any out there that are made for this engine. I really dont want to do a complete engine swap because my engine just has 92,000 and I have had it since 78,000 and it is running great. Does anyone know where i could find a turbo or a kit for my z24

#2 datzenmike

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Posted 17 October 2011 - 08:11 PM

You would have to build or have a custom turbo manifold made for it. A KA24E has similar exhaust port shape and placement on it. If there is a KA24E turbo manifold maybe it could be modified?

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#3 84Datsun720

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Posted 17 October 2011 - 09:10 PM

You would have to build or have a custom turbo manifold made for it. A KA24E has similar exhaust port shape and placement on it. If there is a KA24E turbo manifold maybe it could be modified?

I kinda expected that about the manifold, but I did not know that the KA24E might fit if one exists, might give me a starting spot...Thank you

#4 84Datsun720

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Posted 17 October 2011 - 09:20 PM

I kinda expected that about the manifold, but I did not know that the KA24E might fit if one exists, might give me a starting spot...Thank you


I may still just make myself a custom manifold, I have access to a 1.8T VW turbo, its small, but Im looking for just a small upgrade in power, will use the vacuum most of the time to suck better gas mileage and just use the power to play some.

#5 datzenmike

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Posted 17 October 2011 - 09:26 PM

I kinda expected that about the manifold, but I did not know that the KA24E might fit if one exists, might give me a starting spot...Thank you


Oh it won't fit but it is close.

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#6 nis720

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Posted 17 October 2011 - 10:26 PM

I kinda expected that about the manifold, but I did not know that the KA24E might fit if one exists, might give me a starting spot...Thank you


It will bolt on for sure... but the ports are different shape. I ran Z24 headers on my KA for a while with no issues.
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#7 84Datsun720

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Posted 18 October 2011 - 07:18 AM

It will bolt on for sure... but the ports are different shape. I ran Z24 headers on my KA for a while with no issues.



If the ports are different shape, then how will effect the engine?



#8 sinner720st

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Posted 30 October 2011 - 04:35 PM

it will slow down flow, just take a gasket or paper template from your head and transfer to the exhaust manifold, then grind material off until both are the same...

what are you going to do about fuel delivery, blow through carb. or draw through, or fuel injection?

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#9 Zombro

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Posted 02 November 2011 - 05:11 AM

if you could find an MPFI setup off an old z20e then turbo it, shizz would be fun.
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#10 datzenmike

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Posted 02 November 2011 - 05:20 AM

if you could find an MPFI setup off an old z20e then turbo it, shizz would be fun.


Don't forget it was a very primitive system and was not programed to accept a turbo. It may only adjust for a few pounds of boost.

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#11 84Datsun720

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Posted 09 November 2011 - 10:59 PM

Probably a dumb question, but wont the standard fuel delivery work for a small turbo?

#12 datzenmike

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Posted 10 November 2011 - 07:46 AM

On a suck through probably. Say 7-8 pounds would be about 50% more air so 50% more gas. You do not want the carb to run out and go lean on a turbo.

On a blow through, the carb is pressurized and this means the stock pump has to push with 3 PSI against a force of 7-8 PSI so you can see there will be a problem here. You would need a pump with a higher output pressure and a regulator that increases the pressure so you always have a pressure differential of about 3 PSI above what ever the manifold is.

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#13 84Datsun720

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Posted 10 November 2011 - 02:43 PM

On a suck through probably. Say 7-8 pounds would be about 50% more air so 50% more gas. You do not want the carb to run out and go lean on a turbo.

On a blow through, the carb is pressurized and this means the stock pump has to push with 3 PSI against a force of 7-8 PSI so you can see there will be a problem here. You would need a pump with a higher output pressure and a regulator that increases the pressure so you always have a pressure differential of about 3 PSI above what ever the manifold is.


So if I did a suck through, how would I increase the fuel...larger fuel pump or what? I wanted to use the turbo more for the vacuum during normal driving and use the power only occasionally.

#14 datzenmike

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Posted 10 November 2011 - 03:22 PM

So if I did a suck through, how would I increase the fuel...larger fuel pump or what? I wanted to use the turbo more for the vacuum during normal driving and use the power only occasionally.


:lol: Yeah, like that ever happens. :lol:

Seriously that stock one will probably be fine for 7-8 PSI. More boost than that and you really should start thinking about forged pistons. I know, I know,... someone has a friend who boosts to 12 all the time and they are fine. Yes they can take a quick punch to 12 or more but this overheats them and detonation is inevitable... the hyper-eutectic stock pistons are hard and brittle as glass and won't survive that in the long run.

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#15 84Datsun720

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Posted 10 November 2011 - 04:20 PM

:lol: Yeah, like that ever happens. :lol:

Seriously that stock one will probably be fine for 7-8 PSI. More boost than that and you really should start thinking about forged pistons. I know, I know,... someone has a friend who boosts to 12 all the time and they are fine. Yes they can take a quick punch to 12 or more but this overheats them and detonation is inevitable... the hyper-eutectic stock pistons are hard and brittle as glass and won't survive that in the long run.




Thank you so much for your help, I really think I am going to turbo it, I will definitely post up pics and create a build post.

#16 datzenmike

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Posted 10 November 2011 - 04:49 PM

I think it an excellent idea. There are several things that make the Z series a good candidate for a turbo.

Cross flow head... exhaust ports are not near the intake ports so they stay cooler.
Dual plugs... shorter burn time so less advance needed. Hot gasses inside the combustion chamber for a shorter time less heat absorbed.
Rods are thicker/stronger than the KA motor. Will handle more power.
Main bearings are much larger/wider than the KA motor. Will handle more power.
2.4 liters so will make more power for the same boost as a smaller displacement motor.
The Z24 head has larger intake ports than the earlier Z20/22 head.

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#17 Dean720Ada

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Posted 20 October 2013 - 04:09 PM

As far as the turbo manifold, could you use the plates from like Doug Thorley headers or pacesetter headers and make your manifold?

#18 datzenmike

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Posted 20 October 2013 - 04:26 PM

Probably both cheaper and way faster to make your own.


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#19 DaveZilla

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Posted 21 October 2013 - 11:55 PM

The single cam KA exaust manifold bolts right up but the KA port holes are round and the Z ports are squared, you can easily match port a KA manifold so the ports match up to the Z head.

The easiest way to go is to do a draw thru system and you can use a variety of carbs for draw thru, but you'll be limited on how much boost you can run... about 5 to 7 psi... no problem, but after that it's tricky to keep your AFR good for everyday driving and while under boost.

The better way to do it is with a blow thru system using a Holley 350 2 barrel, You'll need to get a fuel pump that can push more psi than the amount of boost you're running and you'll need a boost sensative fuel pressure regulator set to the carb's needs at no boost and set it to add 1 psi per pound of boost to the base pressure as the boost comes up... This will always keep the fuel in the bowl 3 to 5 psi above the boost pressure as the boost goes up. This page will show how to set up a HOLLEY carb for running under boost http://www.hangar18f...m/blowthru.html by keeping the jetting in the normal range for normal driving and using the power valve circuit to enrich the mixture as the boost comes up. The page I posted pertains to a 4 barrel Holley, but with the 2 barrel, the mods are exactly the same. There are other articles out there to show how to make a boost sensative power valve as well so there are plenty of reliable and effective ways to set a Holley carb to add the right amount of fuel under boost without killing the gas milage for normal driving. You'll also need to use the nitrophyl floats in the carb because the boost pressure will crush the brass ones. Other carbs you can run blow thru will need other mods to keep the air fuel ratio correct both under normal driving and under boost, but i've seen Harley carbs work really well without modifying them on smaller engines like the Suzuki 1.3 that's in the Swift and the Samurai, but you'd need to run dual Harley carbs (Keihin CV40) for a 2.4 liter engine to feed it properly. the Harley carbs just need the fuel pressure to be 1 psi above the boost pressure, and the bowl vent is at the intake side of the carb to pressurize the bowl and raise the amount of fuel delivered according to the boost pressure, it's that easy (properly jetted under no boost ) with these carbs. The Weber side draft and down draft carbs have been used successfully as well as the Edelbrock/Carter 4 barrel carbs, but I know Holley and Harley best.

 

Now the easy way out is EFI... (also the best way, but blow thru can be just as accurate if you know how to set up the carbs) like getting a system off a Z20E and megasquirting it or having a factory ECU programmed to run under boost. Basically, with EFI, you can set the fuel curve right on the money regardless of boost pressure or driving conditions if you have a laptop and the right software. It's not uncommon to have a friend drive the car with you in the passenger's seat setting up the fuel curves on a Megasquirt... It can be made that easy to deal with.

 

You'll also need to upgrade your exhaust system as well... back pressure on a turbo setup is a huge no no now that you have 50 to 75% more (or a lot more depending on boost) exhaust coming out of the engine and it needs to go somewhere... For low boost (under 8 psi), you can get away with a 2 1/4" system along with a very non restrictive muffler. A glass pack will work, but not the ones with the louvers sticking into the stream, or you can use a magnaflow or cherry bomb.

 

I'm currently working on a turbo setup for my Z24 powered 720 4x4 and my setup so far consists of a T3/T4 hybred turbo, a KA turbo manifold (240sx top mount) that's been ported to match the Z exhaust ports, a Holley 350 2 barrel carb with the power circuit modified (from the Hangar 18 website), a front mount intercooler that I'm still trying to figure out how to conceal behind/under the front bumper, an external wastegate with a 4 psi spring installed (for now), a blow off valve, and I ran a full 2 1/2" exhaust system using a Cherry Bomb Vortex single inlet/dual outlet muffler so I'll have dual tailpipes (mainly for looks). I chose the Cherry Bomb Vortex because it's a straight thru design with no restrictions, and splitting it off into 2 outlets will also help reduce back pressure and let the rest of the system run cooler. for fuel delivery I'll be using a Ford EFI fuel pump and a boost sensative pressure rgulator to keep the fuel pressure a constant 4 psi above the boost pressure, running this pump at low pressure vai a return line and the regulator will also help keep this pump alive for a long time. The stock distributer will work by locking out the total advance, but I'll most likely get a MSD6 BTM to keep the timing from running too high under boost.

 

I've probably missed a few things in my grocery list, but that's the basics you'll need to get started... Options are to make your own manifold, bigger or smaller turbo (depending on how you want your engine to perform), converting to EFI or sticking with a carb, and whether or not to use an intercooler... it's not really needed in a blow thru but it will help, you can NOT intercool a draw thru setup, and with EFI, run one if you can.

 

Here's some stuff you'll need to own or have access to in order for your build to go as smooth as possible...

Lots of garage space

All the basic hand tools (wrenches, sockets, pliers, etc, etc, etc... the more the better)

Air tools... air ratchet, impact wrench, die grinders, etc, etc

Welding equipment (mig/Tig preferred)

Plasma cutter (Not mandatory, but VERY nice to have)

A metal cutting chop saw for the exhaust system fab work and for the turbo/intercooler piping

A band saw (optional) same function as the chop saw, also great for cutting smaller parts if needed.

A die grinder and a compressor that can keep up with it

Carbide rotary files for match porting

Sanding rolls for porting the aluminum stuff

LOTS of shop rags

 

This is just a small list of stuff to have that helps BIG Time, if you are lacking stuff from the list it won't kill your build, but it will take much longer. Most people jump into these projects without the tools needed and end up not finishing or taking much longer than planned, a turbo build can't be done in a weekend, but can be done in a few weekends so plan for it and don't take your daily driver apart friday night if you need it monday morning... have some backup transportation Before you start just in case Mr. Murphy pays you a visit to enforce his law...

 

Hope this helps get ya started....