Ka22det

[blackmarkit]

I think with a t3/t4 .57 trim turbo at 20 psi I should be at roughly 450 whp. Turbo should hit full boost around 4000 rpms and pull to 8500.

[datzenmike]

Perhaps a tad optimistic? Keith Law has an L20B turbo that makes a reliable 250RWHP that twists to 8K. Does around 140 with a 4.625 diff.

A turbo doesn't need much cam and overlap should be minimal. Think about it. 20 PSI boost and the intake valve opens air blows in across the piston and right out the open (although closing) exhaust.

[blackmarkit]

Well as they say the proof is in the pudding. I have a the crank and the head. 89.mm pistons. I need a z22 block. I now have a milling machine so I was going to install piston squirters from the ka24de block. I will be posting pictures as I go. I can Oder the rods from summit but I would really like to have the block and machine work done first. I hope nobody is disappointed.

[datzenmike]

I'm interested in how you will plumb the squirters.

 

I found this locally. It's an RB20something something...

 

 

 

The DE has two squirters with a Y to shoot two cylinders each.

.

[blackmarkit]

My ka24de has one per cylinder. Like the rb20.

[blackmarkit]

I guess I could try machining the oil squirters in the l20b block this weekend for practic.

[fo0manchu]

just read through this thread. I had this idea back in like 2004ish! And actually did a bunch of research back then. I still have the l20 crank in a ka24e block sitting in the garage. Everything seemed to fit fine including the front cover. I forget which rod, but one of the Ford rods and piston combos seemed to work out well. It was a really nice long rod combo. Man, I got to find out what car it came out of. It was a v8 motor. I even had a list of the specs or rods and pistons for many cars. Anyways, it seems like a fun project. Who knows if it will make as much power as other options. It will be fun none the less and something nobody else has. It will be torque monster with the long rod for sure and have a great stroke to rod ratio. You can also bore out the ka24 block a bit as well. I'm a fan and want to see this happen!

[TFM1066]

Dude, don't spend $$ on rods (stock rods are forged and are good for @ 175 per cyl with and thats with no bronze bushing), invest in pistons (and thats all). I run 290 HP, Z24 lower end Ka12 valve head all N/A. don't worry about piston squirters you don't need them when tuned. Keep your rod/stroke ratio down (high rod/stroke ratio are old school) that why honda is big on HP these days.

I've been racing this set up for years. Now moving to the Z22 block, Z24 crank, and the 6 inch Z20 rods.

 

Oh and I do rebuilds every 30-40 races (not ten like "datsun mike" says) 5th championship in 6 years.

 

The best money you can spend is on PISTON,

[EricJB]

Dude, don't spend $$ on rods (stock rods are forged and are good for @ 175 per cyl with and thats with no bronze bushing), invest in pistons (and thats all). I run 290 HP, Z24 lower end Ka12 valve head all N/A. don't worry about piston squirters you don't need them when tuned. Keep your rod/stroke ratio down (high rod/stroke ratio are old school) that why honda is big on HP these days.

I've been racing this set up for years. Now moving to the Z22 block, Z24 crank, and the 6 inch Z20 rods.

 

Oh and I do rebuilds every 30-40 races (not ten like "datsun mike" says) 5th championship in 6 years.

 

The best money you can spend is on PISTON,

 

Being a strictly N/A guy myself, I am curious about your set up. Carbs of FI? what size? Also header specs. What is your redline with a stock Z24 crank? Also what pistons are you using on your new setup?

 

I dont run bronze bushed rods or bore squirters either, and my block is filled with grout, leaving the oil to do all the cooling. (L20 block bored to 89mm) But I just run 1/4 mile. And I only spin it to 7000 (Z22 crank).

[datsundash]

please explain how the Ka valvetrain is "better" than the sr20. They both work dont they?

[datzenmike]

The rebuild every 10 races was for effect, indicating that the race motor was built more on the edge and didn't have the restrictions placed on a motor that must be reliable and last for hundreds of thousand miles.

 

..... It will be torque monster with the long rod for sure and have a great stroke to rod ratio.

 

Rod length alone does not make torque, but stroke does.

 

 

. don't worry about piston squirters you don't need them when tuned. Keep your rod/stroke ratio down (high rod/stroke ratio are old school) that why honda is big on HP these days.

 

The best money you can spend is on PISTON,

 

Honda motors are 40 years newer with EFI, computers engine management systems. These are old school motors and old school ideas may still apply. If the motor is managed I guess oil squirters may not be needed. They are a great way to cool a boosted piston. Agree on spend money on piston.

[blackmarkit]

Well the sr20 uses hydrolic lash adjusters and has rocker arms. At high rpms the rocker arms pop off or break. The ka 24 has shim over bucket. This has proven to be the safest valve train. It's used on motorcycles that hit 20,000 rpms safety. Also the less moving parts isn't only safer but is lighter which allows for higher revs.

 

[blackmarkit]

As for oil squiters, I believe most new car use them to help reduce detonation. In a n/a motor I wouldn't sweat over it. But boosted ill take all the cooling I can. More timing - more power.

[blackmarkit]

Also Datzenmike I'm having a hard time finding flow numbers for a race ported L head. I thought I saw one that flowed 190cfm. The ka24de flows 243 cfm intake at .500 and exhaust is 183 cfm. Pretty good numbers for stock.

[datzenmike]

Except the KA doesn't have a 0.50" lift. Doesn't need to with two valves.

[ggzilla]

Yes, long rod alone can make more torque.

 

Take two 5.7 liter engines

* Standard rod version: 392 ft lb

* Long-rod version: 393 ft lb

 

In racing every little bit helps.

[blackmarkit]

Well it looks like I might have found a couple blocks a couple hours away. Ill try to pick one up this weekend.

[fo0manchu]

Yes i agree that stroke makes a bigger difference in torque. However, if we were to compare 2 motors with the l20 crank i would think that a significantly larger rod would produce more torque. I would think that a longer lever = more force to turn the crank. If we are comparing the ka crank with the l20, well then of course the 2.4 crank will produce more torque.

Is my thinking just to old school now? haha

[datzenmike]

Yes i agree that stroke makes a bigger difference in torque. However, if we were to compare 2 motors with the l20 crank i would think that a significantly larger rod would produce more torque. I would think that a longer lever = more force to turn the crank. If we are comparing the ka crank with the l20, well then of course the 2.4 crank will produce more torque.

Is my thinking just to old school now? haha

 

Or do you mean stroke here?

 

 

 

Two L20Bs, one with the stock 145.9mm long rod and the other with the 152.5mm rod. They are both 85mm bore X 86mm stroke. The stroke remains the same 86mm and the rod length does not change this.

 

A longer rod will cause the piston to reach it's maximum speed lower down the cylinder and decelerate more slowly as it approaches TDC and then moves away from TDC more slowly and again reaching it's top speed further down the cylinder. A case could be made that a piston moving more slowly down the bore (at least initially) after TDC will absorb more force from the expanding fuel air explosion. A shorter rod reaches maximum speed higher in the cylinder and it decelerates and accelerates the piston much faster and closer to TDC than a long rod. A short rod is moving away from TDC faster and reaches maximum piston speed closer to TDC than a long rod so it has less time to absorb power from the expanding gasses.

 

One more thing. A long rod will exert less side loading on the piston than a shorter one. A short rod will pull sideways more and the piston will loose power due to friction with the cylinder wall.

 

New or old school... a long rod is a rev happy rod.

[ggzilla]

That's old school. Smokey was the first to popularize that theory decades ago.

[datzenmike]

Theory? You can show the geometry of this with a pen paper ruler and compass. Both rod/stroke ratios are within 1.85 to 1.65 recommended bu Racer Brown for Datsun L series motors.

[EricJB]

To add to Mike's explanation, If the longer rod creates more dwell at tdc and bdc, the motor will not require as much flow from the head with the longer rod. In a forced induction setup ( or even a head that flows well), rod ratio is probably not a big deal.

In a N/A setup, a short rod would require more air sooner, would probably have better bottom end, where a longer rod would rev higher with the same head.

 

We will probably never all agree on this subject.

 

I never read Smokey's book. Wanted to, but the book is way too spendy these days.

[datzenmike]

There are some really funny stories about his trickery getting around the rule book. One was to remove the starter ring on a flywheel and drill 64 holes to lighten it and then put the ring back on to hide them. He said "it's not what the rule books says... it's what it doesn't say"

[flatcat19]

Cheating? No.

Job security. Yes!

 

Officials need work too, right?

[blackmarkit]

Well after tiging a fuel tank and building a center link for my steering to get rid of the bump steer i had to go fix a turbo 280z. I didn't get a chance to get the block but I will tomorrow.