Franken engine

[Tiger03447]

 I recently saw a pic online of a Ka24 DE head being put onto a a bored out (and sleeved??) L20b block or an L18 block. Churning out about 225 HP. Do L16's and L-18's run a flat plane crank? Are there any flat plane cranks available for  L-16-L18 blocks? Just wondering..thanks..Back to the Ka24DE head.. looks like a neat way to get more breathing into the engine. 16 valve head and DOHC..Interesting concept..Wonder what the cylinder spacing would be on an L18 or L20 block...Short stroke, way oversquare, 11:1 comp and DOHC... Webers or Mikunis Orr..If one wanted to go the FI route with it might be simpler to tune, but way more complex...wowzers...!

 

 

Edited December 16, 2018 by Tiger03447
additional info

[drawks]

1 hour ago, Tiger03447 said:

Do L16's and L-18's run a flat plane crank? Are there any flat plane cranks available for  L-16-L18 blocks?

 

Flat plane is the standard configuration for 4-cylinder engines, I'm not aware of any crossplane Nissan inline 4 design. Are you perhaps thinking of fully counterweighted vs not?

[datzenmike]

All inline 4 cylinder are flat plane cranks.

 

I don't think the L16/18 cranks in cars and trucks were fully counter weighted but the L20B and the Z20 were. (the Z20 uses the L20B crank) They will rev to high heaven smoothly. An L20B crank has larger main bearings that the earlier L16/18 so they won't swap.

 

All L/Z and KA series engines have the same bore spacing so all heads could swap, not that you would want to.

 

If this was the Ozdat KA24DE head on and L20B, block take a look at the insane amount of work and machining that went into doing this.

[Stoffregen Motorsports]

L18 cranks were fully counterweighted, though  there were some "export" engines that came without.

 

I have seen the DE heads on L motors before. I myself have put KA24E heads on L motors before. Lots of pros and only a couple of cons.

[Tiger03447]

I can see lots of pros on this..care to share what the cons would be? Wouldn't one have to bring the bore size up on an L Series block to match the cylinder bore in the head? IE sleeving the L series block?

[drawks]

I'm curious what your ultimate goal is. People have made good power at high revs with the ka24 bottom end, you'd be out in the wilderness for a timing set to get the ka24 head on a short deck l series bottom end. If your goal is a shorter stroke with a good flowing twincam head you'd have a shorter, cheaper and more well tested solution in an sr20det perhaps with the sr20ve or vet head for it's superior flow and whizbang variable valve timing and lift.

 

[datzenmike]

3 hours ago, Tiger03447 said:

I can see lots of pros on this..care to share what the cons would be? Wouldn't one have to bring the bore size up on an L Series block to match the cylinder bore in the head? IE sleeving the L series block?

 

 

 

5 minutes ago, drawks said:

I'm curious what your ultimate goal is. People have made good power at high revs with the ka24 bottom end, you'd be out in the wilderness for a timing set to get the ka24 head on a short deck l series bottom end. If your goal is a shorter stroke with a good flowing twincam head you'd have a shorter, cheaper and more well tested solution in an sr20det perhaps with the sr20ve or vet head for it's superior flow and whizbang variable valve timing and lift.

 

 

The KA24E combustion chamber is about 65cc compared to the L20B's 45.2 so 20cc of combustion chamber and piston dish must be removed just to keep in the 8.5 compression range. Flattop pistons gets rid of 11cc or so still 9 or 10 to go. Domed pistons?

 

The KA24DE combustion chamber is only 47cc (or so) so close enough to the 45.2 of the L series.

 

The L, Z, KA have the same cylinder spacing of 95.2mm and head bolt pattern (correct me if you think it's wrong) The SR is 97mm so if you center the head on the 2/3 gap between cylinders the #1 and #4 will be 3.5mm out or 0.141" . And I seriously doubt the SR bolt pattern is the same and the L, Z or KA.

 

 

Can anyone ID the KA main bearing?

[drawks]

1 hour ago, datzenmike said:

The L, Z, KA have the same cylinder spacing of 95.2mm and head bolt pattern (correct me if you think it's wrong) The SR is 97mm so if you center the head on the 2/3 gap between cylinders the #1 and #4 will be 3.5mm out or 0.141" . And I seriously doubt the SR bolt pattern is the same and the L, Z or KA.

I didn't mean an SR head onto an l bottom end, I just meant an sr20de or possibly and sr20de block with a VE or VET head.

 

I'm still not sure what advantage a franksteined l20 or l18 bottom end with a 16 valve ka head would have over either a well built KA or SR.

 

I mean it is one thing to have a sweet L series build that looks "correct" in a dime, but at the point that you're throwing a KA head on it you go faster with less money and effort by bringing the KA bottom end along too.

[datzenmike]

Well, maybe the pursuit of ultimate power isn't the goal.

 

1/ You can do it the hard way and make something out of nothing and the personal satisfaction of doing it yourself that goes with it. See what a smaller displacement L series will do with  a superior breathing head.

 

2/ Re-invent the wheel and get a KA24DE or buy an import SR and throw it in your dime, like everyone else. Not really a lot to brag about.

[scooter]

it would be a good hobby machinist project. I think the easiest way to make this work is to machine the crank snout down to KADE snout size, so you can run the correct crank gear. coolant holes and oil drains would be just welding up and dealing with accordingly along with some chain guide mods, looking at what the aussie guy did, it doesnt look impossible.

 

also theres no point unless your boring it to at least 89mm

 

the other benefit to this is an L block is alot lighter than a KA block, well at least a car block anyway. if you did it with an L18 (like the oz motor) you would be considerably lighter than a KA swap and still make more power than an L motor. lighter than an SR? probably not. but unless you do the VE swap which has its own issues, you get a cam on bucket motor without the stupid forked piece of shit garbage rocker arms.

 

[Tiger03447]

Thanks guys..just a thought process..nice to know all this....I thought cylinder spacing would be a problem with all this..Great to have guys on board who know what the "real" answers are! An exercise in thought and futility...Thanks for the answers!!

[datzenmike]

Some of the greatest things begin with... "What if I were to....?"