Ka dohc head on l20b

[blackmarkit]

Here is what I mocked up last night. After talking to a very reliable sorce it will not work.

 

[dimedriver]

Is it a timing cover issue?  Or chain issue?

 

-Avery

[blackmarkit]

I guess the single row chain is more likely to pop off than a dual ( makes sense). But the way my guide and tensioner are set up it will pop off. Also you must use a billet lower gear. The one in the picture Is a stock ka gear bored. Timing cover fits perfect.

[dimedriver]

So the Crank sprocket is not in the same "Plane" as the Idler sprocket?

I guess that would require a custom made sprocket to fix.  Then some form of modded or maybe the Z series chain guilds.

 

 

-Avery

[blackmarkit]

No the crank sprocket is on the same plane. But a stock ka guide is the tensioner. The whole left guide keeps tension on the chain. The L series tensioner only puts tension in one spot of the chain.

[blackmarkit]

It would be interesting to see if it only pops off at high rpms or all rpms.

[EricJB]

Not trying to be the devils advocate here, and keep in mind I have never seen either KA head in person. While I understand putting a KA head on a 2.3 or larger, (since the Z22/Z24 head is not a performance head ), I don't get why anyone would put one on a 2.0. There is such a thing as too much when it comes to port size and flow. Unless you are road racing, or land speed stuff, with sustained high rpm. With no air speed at low rpm, it will be a turd to drive.

 

While the fully counterweighted L20b crank makes rpm seem limitless, I can assure you, a Z22 crank (partially) is capable of hitting high notes as well. Were not talking about some cast iron slug, they are all decent forgings. And the block is well designed.

 

There are other things to consider. What rods are you going to use north of 8.5k? How long are you going to run between teardown and inspection? How are you going to trigger the ignition?  

 

I never saw the L head as the weak link that was holding an L20 back. An L head can be built, without hogging the ports out to 1.75, to enable an L20 to go north of 8k easily, and still be somewhat drivable. (somewhat) It's the other components that keep it from happening. Rod bolts (at the least) pistons, valve springs, ignition, induction, and exhaust.

 

Again, never seen one. not trying to start a shitstorm. Just theorizing.

 

 

[datzenmike]

It (DE head) could be used where the engine size is limited to 2 liters.

 

I'm currently working on a Z 2.3 with KA24E head. I've since changed it to a KAZ2.3 as realistically there is nothing L series about it now. I see no sense to even running in the L position any more either and will be running in Z/KA alignment and with a Z 5 speed. 

[blackmarkit]

Well ericjb hopefully this helps but when running a 4 valve per cylinder arrangement the ports are relatively small. I will have to measure but I would guess smaller than a stock L. This increases velocity. But sense you have 2 valves for air to enter it doesn't reduce flow. I'll measure after work.

[EricJB]

Ka head on a 2.3 makes sense. The dyno video above is a 2.3. But a 2.3 has a much bigger apatite than a 2.0.

[blackmarkit]

2.0 2.3

1000 rpm= 35 cfm. 40 cfm

2000 rpm=70 81

3000 rpm=105. 121

4000 rpm=141. 162

5000 rpm=176. 202

6000 rpm=211. 243

7000 rpm=247. 283

8000 rpm=282. 324

9000 rpm=317. 364

10000 rpm=353. 405

 

The difference is engine cfm is more of a difference at high rpm. Look at the flow specs on a 4g63.

[blackmarkit]

Ok the way that posted is not the same as I wrote it. The 2.0 cfm is the firsts number after the = sign. The second number after the = sign is for the 2.3

[dimedriver]

Blackmarkit, Here is your chart in a more readable format.

 

|   RPM | CFM of 2.0 | CFM of 2.3 |

|  1000 |         35 |         40 |

|  2000 |         70 |         81 |

|  3000 |        105 |        121 |

|  4000 |        141 |        162 |

|  5000 |        176 |        202 |

|  6000 |        211 |        243 |

|  7000 |        247 |        283 |

|  8000 |        282 |        324 |

|  9000 |        317 |        364 |

| 10000 |        353 |        405 |

[blackmarkit]

Thank you Dimedriver that looks much nicer.

[blackmarkit]

I'm building my LKA turbo for a 1200 coupe but I might through together a LKA on the cheap if I can find parts and just run it with home made parts to see what fails.

[datzenmike]

Yes at some speeds if the port is small enough but not restrictive and the intake and exhaust are 'tuned',  you can get much better than 100% VE.

[blackmarkit]

Yeah those are all 100% VE numbers. For what I understand much of over 100 ve is by using harmonics to improve flow.

[datzenmike]

And inertia. Air has weight and if traveling fast enough, continues to flow into a cylinder even after it is full.

[blackmarkit]

I know peter McDonnell has it already figured out but I still want to know what works, what fails. Why does it fail? I thinking of ways to measure the amount of torque required to turn the cam then put a load on the idler gear and then spin the crank with a electric motor to see if the chain and guides will work. Then I can see what makes the lower gear break. I like when someone else can tell me the answer but I love when I figure it out.

[blackmarkit]

maybe I could make a idler gear that uses the hydraulics to tension. There's a lot to figure out and I'm sure there's more than one way.

[blackmarkit]

If a engine produces 400 ft lbs of torque does that mean the crank is pulling Down on the chain with the same amount of force. I understand there is static and dynamic torque. I am talking about dynamic toque because I'm thinking it would be the same as peak torque from the engine. I'm just try to see if there is some way I can load the chain without running cams or timing chain cover.

[datzenmike]

No. The force pulling down on the chain is only that required to turn the cam and compress the valve springs. You can turn one on a head with a ratchet easily by hand. Cams can be turned by...

 

Gears.... very precice but extremely noisy if metal. Plastic covered are quiet but wear out. On OHC  can be a series of gears that are very complex. Need lubrication and a cover

Chain.... good but require tensioning. need lubrication and a cover.

Belt........ good, quiet. Must be replaced at required intervals before they break and a valve gets bent by a piston. No lubrication or cover required to keep oil in.

 

The above work prety well so stop trying to re-invent the wheel. If not wanting a timing cover use a belt.

[jvb5577]

It would be very interesting to see a belt used with this setup.  Will eliminate a lot of headaches since no oil or cover will be needed.  Will be watching this 

[K_trip]

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[K_trip]

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