rebuilding z24

[720driver97]

ok im going to rebuild my z24 engine how dose this sound for a build

1. R1 carbs

2. ka24e head

3. some how make  a turbo set up

4. different cam, what would work?

5. stainless headers

 

how dose this sound any other things i should do? also would shaving the head or block help? I dont have any experiance with turbos do i need to modify anything else to make this work?

[datzenmike]

The E head has a much larger combustion chamber and put onto a Z24 block will drop the compression from 8.4 down to 7.47.

 

The E head also has an oil drain back hole to the block that if put on a Z series block will open into the cooling system.

 

How will headers fit if you have a turbo on there?

[720driver97]

Can u weld the hole shut? Dont the headers lead into the turbo? This is my first time building a engine like this so any advice is good

[datzenmike]

Yes you could fill it with JB weld, a two part epoxy.

 

A 'header' is usually individual exhaust pipes from each cylinder of equal length and as few bends as possible, joined at a collector into one. It's purpose is to be more efficient at removing the exhaust from the head to the exhaust system than the stock manifolds which are usually restrictive but cheaper to make.

 

The pipes between the head and a turbo would be better described as a turbo manifold. They are unlikely to be equal length or straight. They can also be welded individual pipes or a cast manifold. The KA24E has lots of turbo support and turbo manifolds are made for them.

 

 

You are still left with a 7.5 compression....

[Lockleaf]

If doing a basic turbo system, low boost, just build the z24 as is. That head will offer fair performance as the boost helps overcome any flow deficiencies in the head. R1s take boost well according to the sled guys, so they should be fine.

Who cares what your manifold is made out of when you're building your first system. Save money by buying a kae cheap turbo manifold so you can learn the ropes and have extra money for when things break, and running boost they probably will. If you want a more hard core turbo build, your money will go farther on a kae than on a z engine. More aftermarket support equals less cost per part usually

[720driver97]

OK but if I shave the head or block then I get my compression back right?

[720driver97]

by the way im in collage now for machine tool just moved in today so this is my progect while im up here so i plan on building every thing my self

[datzenmike]

Can't say no th shaving as that's what I'm doing.

 

As the Z24 and the KA head were never made together, and for this you will have to make your own timing chain, I don't think it matters much is you shave the head or the block. You need to eliminate about 10ccs of combustion chamber volume. By my calculation 2mm (0.080") shaved will remove 12.4cc of volume. The Z24 has 15cc dished pistons and the KA were 2.8cc so I think there will still be lots of valve/piston clearance.

[720driver97]

OK so what would be a better piston for this the z24 or the ka

[datzenmike]

Didn't say there was any problem with the Z24 piston but switching to a KA pistons would save you shaving the head. KA pistons in a Z24 with a KA head should give around 8.4 compression. Congrats... you've basically built a KA24E using a Z24 block.

 

Use the Z24 distributor and remove every other spark plug wire as the KA only has 4 plugs.

[nis720]

KA24E and Z24 share the same bolt pattern for the exhaust flange. The KA ports are round and the Z ports are square and colser together. When I did the KA swap in my 720 I resued the Z headers and it worked fine. There is a little interference between the ports but it works.

[720driver97]

OK thanks so the ka pistons will fit on z24 rods or what do I have to do there

[datzenmike]

Short answer.... yes. There are S13 car and D-21 Hardbody truck pistons and while either should work for you there are differences.

 

Truck rod/pistons are the normal press in type just like the Z24

.

Car rod/pistons are fully floating and the pins are not pressed onto the rods ends but have grooves in the piston on either side of the pin that contain C clips to keep the pin in place. Floating means the piston pin is free to rotate in the piston AND the rod end. That said the Z24 rod with the pressed in pin will still work on the 'floating' piston. It just won't be floating. Just in case you get car pistons and wonder what the C clip grooves are for. Otherwise, car and truck pistons have the same piston dish. 

 

The KA small rod end is 0.988" wide, while the Z24 rod end is narrower at 0.850". Narrow Z24 rods will fit KA pistons but unlikely the wider KA rods will fit Z24 pistons.

[720driver97]

how much boost can i run with out breaking somthing with this setup 

[Lockleaf]

8 lbs easy, 10 lbs if careful, 12-15lbs short term fun.

[datzenmike]

This :thumbup:  above.

 

Assuming you don't detonate on a regular basis.

 

run premium gas

ANY pinging reduce the timing

Intake air for the turbo should come from in front of the rad

an oil cooler would be nice

swap in a KA oil pump

[720driver97]

What gas is best 91-93, how hard is a oil cooler to hook up

[720driver97]

I just found a ka24 out of a 240z with transmission for sale near me http://minneapolis.craigslist.org/wsh/pts/5156737968.html. Heres the link how much do u guys think it's worth

[datzenmike]

Too bad it was pulled. Now there is no way to verify any claims made about it. Assume the worst... it needs a rebuild.

[720driver97]

OK thanks dose anyone know of a oil cooler that will fit

[Lockleaf]

Oil coolers can be purchased in a variety of sizes at your local auto parts store for pretty cheaply. They are simple to attach as well. Just buy whatever size suits you.

[720driver97]

Do they just screw on before the oil filter?

[720driver97]

I just found out my cousin is selling a Mazda 12a rotary engine what do u guys think about a swap it puts out 130hp stock

[datzenmike]

Well you need a transmission and nothing about the Mazda fits a 720. They make good power... when revved up but are not cheap to rebuild. It's a car engine and won't pull a heavy 720 like the Z24 will.

[Lockleaf]

12a makes no torque. Terrible truck engine. Like Mike said, they need revs to move things. And Mike is also right about the rebuild. They run $800 for a basic re gasket and it goes up from there. Fun in a 510. Terrible in a 720.