turbo z24

[Mr.Dean_Yates]

I've been bouncing this idea around in my head. Have a blow through set up running a dgv. They make a bunch of stuff for the dgvs so I know THAT won't be a problem. What I'm wondering is, since the z24 and the ka24 are both 2.4 ltr blocks...would I be able to run the ka internals (connecting rods and pistons, maybe crank?) And what about the valves and springs and so on... would they be interchangeable? Just thoughts that run through my head.

 

Any info/experience would be much appreciated

 

Thanks!

[datzenmike]

Rods and pistons will fit and work but sorry the crank won't. KA pistons will give a 9.52 compression. S13 rods are bushed and pistons have floating pins.

[_chiefjt]

Wouldn't it be harder to tune if you do a blow thru turbo. How efficient would the blow thru be? Would you need to custom fab. a turbo manifold or can you use one from a ka?

 

It's been discussed, here's a link:

 

http://community.ratsun.net/topic/21305-turbo-z24/

[Alec 720]

Why not just put a KA24 in and get that blown? 

[datzenmike]

Because sometimes we end up with a basically free motor laying around and build around it rather than going out and buying something else. Turbo KAs are a dime a dozen. Been done. A turbo Z24.... now that's different.

 

We have someone putting a 307 into a 1200 because the motor is simply available.

[_chiefjt]

yes different, but if something ever breaks that's custom, it would cost more to replace it, wouldn't it? I guess that come with the part of being different.

 

How is this "turbo z24"?

 

[datzenmike]

yes different, but if something ever breaks that's custom, it would cost more to replace it, wouldn't it? I guess that come with the part of being different.

 

 

Well as for the turbo KA, there weren't any..... so a KA24ET or DET is all custom anyway. Yes you can buy the parts $$$$ or make your own. If you made it, you probably know how to fix it and have the tools and equipment to do so. 

[Mr.Dean_Yates]

I am more comfortable doing a blow through set up, parts are easy to come by and like i said, there are kits for the weber dgv 32/36. i can have a turbo manifold made for a decent price. i can do this im just wondering if this has been successfully completed. im wondering if i should just do the Ka internals and call it done, but id still really like to slap a turbo on it and have some fun.

[datzenmike]

Which one looks the strongest?

 

[Mr.Dean_Yates]

Right side. No surface rust leads me to believe there is a weakness in the connecting rod on the left. Going off of sight alone...the right side looks stronger

[Mr.Dean_Yates]

Apparently it works...and works well. This is exactly what I'm going for.

 

http://www.theturboforums.com/threads/364622-blowthru-NAPS-Z-Works!!!

[datzenmike]

Right side. No surface rust leads me to believe there is a weakness in the connecting rod on the left. Going off of sight alone...the right side looks stronger

 

Rust isn't the issue.

 

Yes the right is obviously stronger looking. And it's a Z24 rod, the one on the left is from a 240sx KA24E motor. The KA rods seem thinner to me. Could be that the L and Z series are over engineered and when they made the KA they made them weaker, smaller lighter.

 

 

I pulled the KA rod from a KA with a rod through the block. It was sitting outside in the rain and was rusty. I have it just for measuring and luckily comparing to the Z24 rod.

[Mr.Dean_Yates]

Rust isn't the issue.

 

Yes the right is obviously stronger looking. And it's a Z24 rod, the one on the left is from a 240sx KA24E motor. The KA rods seem thinner to me. Could be that the L and Z series are over engineered and when they made the KA they made them weaker, smaller lighter.

 

 

I pulled the KA rod from a KA with a rod through the block. It was sitting outside in the rain and was rusty. I have it just for measuring and luckily comparing to the Z24 rod.

 

That is great information! Thanks for sharing. So if I Dont go turbo but wanna build a high compression motor...use z24 rods with ka pistons right?

[Mr.Dean_Yates]

What pistons would you suggest I use for a z24 turbo build. I may get the head decked by a hair just to make sure I'm getting a good clean seal on the block, but not a lot. I saw something about a u67 head? Not sure if that's right. Anyway, what do you recommend I use for my internal set up? Talk in pistons rods and which can, valves, springs, all that good stuff lol...I have no idea where to start.

[datzenmike]

What pistons would you suggest I use for a z24 turbo build. I may get the head decked by a hair just to make sure I'm getting a good clean seal on the block, but not a lot. I saw something about a u67 head? Not sure if that's right. Anyway, what do you recommend I use for my internal set up? Talk in pistons rods and which can, valves, springs, all that good stuff lol...I have no idea where to start.

 

 

 

 

Well the Z series heads do not breath very well at high RPMs. This is because the motor was designed to produce very little pollution. It was never intende to be revved to extremes, the ports arew low on the head with a somewhat sharp bend into the cylinder. The L heads are much higher and tilted down at an angle with less of a turn at the valves. Z valves are slightly longer than the L series so are heavier. The valve springs are a bit weaker and will float sooner. Some of these things can be corrected but the valve position and the ports cannot.

 

 

Having said that, a turbo changes everything. A turbo makes any head breathe because the engine does not have to work to pull the air in. To make a poor head breath you simply turn the boost up and ram it in. There are some things that make the Z series motors a good candidate for a turbo.

 

For one, it's a cross flow design so intake ports do not absorb heat from exhaust ports close on both sides. Heat is the worst thing for a turbo application. Every effort should be made to reduce the air temp going into a turbo motor. Heat is what causes detonation and exactly how a diesel motor works. 

 

Two, more room for turbo plumbing without and intake in the way. Again the turbo can be mounted where you want it and excess heat does not affect the intake or carb. 

 

Three, this is an ideal set up for plumbing an inter cooler. The turbo feeds forward to the front through the inter cooler to the other side and back to the intake.

 

Four. The NAPS motors have dual plugs. This shortens the burn time, and is like lighting a candle at both ends. Because the fuel burns quicker, you have to light it much later so that it reaches peak pressure just at the right time to push down on the piston. Timing on a NAPS is 3-5 degrees compared to an L's 12 degrees. The shorter time in the combustion chamber means there is less time for heat to soak into the piston top and chamber walls and mor available for pushing the piston. All things equal, a NAPS motor transfers more heat energy into work done. (a short burn time also reduces NOx emissions but we don't care about this only that we can take advantage of a reduced ignition advance.

 

Five. Tha Z series head is almost exactly a HEMI shape. Recognised as probably the most efficient compustion chamber design to reduce detonation causing hot splts.

 

SIX.... the displacement. You can't beat displacement.... ever. A large turbo motor will always beat a small turbo motor.... period. It will be more fun to drive in non boost opperation on the street.  

[datzenmike]

Dam comp. at work won't let me edit.

 

 

Pistons.... custom forged would be best for a turbo but expen$$$ive. If you plan to run 5-7 PSI with very short blasts to 10 PSI the stock will do. Again detonation control is imperative. Oil cooler, inter cooler, perhaps alcohol injection, large rad, cold air ducting.... stuff like that.

 

You can deck the head but in addition have the block O ringed to prevent gasket blow outs. You won't regret this. 

 

Stiffer valve springs.

 

__________________________________________________________________________________________________________

 

U67 head

 

This will convert the NAPS into a 2.4 liter L series motor. It is do able. It will breath better but will suffer from the loss of the advantages of the above listed good points of the NAPS motors such as having the manifolds on the same side. The motor will likely be tilted to the L position and the tranny will need to be changed also.

[Mr.Dean_Yates]

See kids, this is why we ask datzenmike...he's a fuckin guru.

 

Thanks for all the information Mike, you have been beyond helpful here. I will start this project in a month or so (pending new, better paying job) and will do as complete a write up as I can manage!

[Mr.Dean_Yates]

Kinda off topic but this hasn't been answered in its thread...can you bolt the napsz bell housing to the ka gear box? If not, will the ka24de starter work with the napsz flywheel? My gramps (helping me with tranny swap) is worried that it won't work, that it may lock up or not even make full contact with the teeth on the flywheel.

[datzenmike]

The Z24 will bolt to a KA 5 speed no problems. The bolt pattern and engine 'tilt' is identical. The only concern is that the release bearing collar has to match the Z24 clutch you are using  or will be using.

 

 

 

 

See kids, this is why we ask datzenmike...he's a fuckin guru.

Thanks for all the information Mike, you have been beyond helpful here. I will start this project in a month or so (pending new, better paying job) and will do as complete a write up as I can manage!

 

 

Well I don't know. Mostly opinion and some food for thought. Always research research research. Find out all you can about what you plan to do.

 

I think the Z24 would be easier to turbo than swapping an L head on and doing it.

Keep the stock cam if going turbo. Any extra overlap (that's when both intake and exhaust are open at the same time) will simply allow boost pressure to blow right into the combustion chamber and out the exhaust. A waste of boost and gas.

Get a KA or Z24i high volume oil pump from a D21 or S13 and run an oil cooler.

[_chiefjt]

Correct me I I'm wrong but the Weber 38 DGES is a 400cfm carb.

 

Would this carb be good for a blow thru turbo?

 

Would it add anymore performance since the carb is already bigger than stock?

 

What's a good turbo to use? I would be looking for more power (acceleration an top speed).

[Mr.Dean_Yates]

Depends on what you want...if you want snappy instaboost use a small frame turbo, for a decent build up use a mid...and a large frame would be for like distance...also depends on the motor. The napsz realistically would perform better with a small or mid...large turbos are reserved for like 900hp motors and deisle

[_chiefjt]

For small and mid turbos what size would I be looking at?

 

Are there any good stock nissan turbos?

[Mr.Dean_Yates]

Cannot remember off hand...there was an awesome artical in superstreet on turbo applications. Outlined everything you need to know.

[datzenmike]

I think the 32/36 is around 270 cfm so the 38/38 would be higher for sure. If this is the 38 outlaw carb the secondaries are linked directly to the primary so when you step on it they both open. This is fine on a  larger displacement 6 cylinder or small V8 but can often be too much for a 4 cylinder.  You have to learn to 'step into it' slower or there is engine lag. 

 

The Z24 has a 'somewhat' smallish stock carb and usually even a 32/36 will wake it up some.

 

I don't think a larger carb works that much better than a smaller one on a turbo, just my opinion.

 

Too big a turbo means waiting too long for boost to build and then running out of engine RPMs. Rather, a smaller turbo will build boost much sooner at lower RPMs and be running out of breath about the time your motor is. I'm guessing a T25? Others will know.

[Mr.Dean_Yates]

Thanks mike! I'm a little rusty on my turbo stuffs