Switching from High Compression L20 to a LZ22

[Gensaiken]

I currently have a High Compression L20b with a shaved 219 head and SU's. (I assume flat top L18 pistons in the L20b block)

 

Would moving to a LZ22 block with the 219 head and SU's be an upgrade? or a down grade? Is it enough of a gain to be worth the swap? :mellow:

[sssr20det510]

Turbo the lz22 then it wont

[Gensaiken]

Turbo the lz22 then it wont

 

Not doing a turbo. :no:

[hang_510]

no replacement for displacement! :D

 

not that its huge :cool:

 

 

 

if you already have the Z22, do it!

[banzai510(hainz)]

just run whats in the car already.

 

loweer compression its ezer to run regular. otherwise I dont think youll know that much of a difference

[datzenmike]

I currently have a High Compression L20b with a shaved 219 head and SU's. (I assume flat top L18 pistons in the L20b block)

 

Would moving to a LZ22 block with the 219 head and SU's be an upgrade? or a down grade? Is it enough of a gain to be worth the swap?

 

 

Two things.

 

You are cramming an extra 50cc into the same combustion chamber by going to a 2,2 liter block, so the compression will only go up.

edit: not exactly, see post #12

 

The open chamber L head is about 12 cc smaller than the stock Z22 head.... you're using a peanut head which is even smaller! The comp will be through the roof.

[hang_510]

i was thinking Z22 bottom , swapping his current top end over.

 

only a small CR increase.

[hang_510]

http://www.ozdat.com...e/enginedesign/

 

 

i like this program. :cool: mike hates it!!! :fu:

[Gensaiken]

Two things.

 

You are cramming an extra 50cc into the same combustion chamber by going to a 2,2 liter block, so the compression will only go up.

 

 

The open chamber L head is about 12 cc smaller than the stock Z22 head.... you're using a peanut head which is even smaller! The comp will be through the roof.

 

 

i was thinking Z22 bottom , swapping his current top end over.

 

only a small CR increase.

 

 

So what you guys are saying is i'd be pretty much building a race motor. Maybe i'll pass good to know tho. :lol:

[HRH]

You can do that, but yeah, compression is ultra high. Detonation likely, probably will need to use race gas or build an alcohol/water injection setup to quell.

 

But, you could easily find a U67 head and pop it on that Z22. The extra 6mm of crank stroke definitely makes a difference. I would have built a Z22 but at the time, I had more parts to do the L20 high compression.

[datzenmike]

http://www.ozdat.com...e/enginedesign/

 

 

i like this program. :cool: mike hates it!!! :fu:

 

I don't 'hate it' I just couldn't be bothered to try and make it work. Low level for frustration or for my own incompetence I guess. Plus you don't learn anything about how everything interrelates... it's just numbers plugged in.

 

I find working with the numbers yourself as opposed to just typing numbers into a program gives you a feel for small changes that affect the answer. I imagine myself inside the cylinder measuring and comparing things. I have most of these pistons so I've taken a close look at them and can visualize the dish volumes. Same with the heads plus no one I know has cc d the Z heads so I did that myself to answer my own question about them.

 

I have a small HP calculator and pi R 2 the bore X stroke. A little practice and it goes quickly and smoothly. I have done most of the L and Z motors and written down deck, gasket and dish volumes as well as single cylinder volumes. I've also done the same for 1mm and 2mm over sizes too. Combustion chamber volumes are listed for applicable head swaps. If someone asked what the compression on a 1mm over L20B with peanut head is, I just look at my 'spread sheet' and leave out the piston dish to get 9.06 Almost every question involves something more complicated so I resort to pi r squared. If I really had to I could do this with a pencil. I can also work out how much to shave an open head to raise the compression. Does this program do this?

[datzenmike]

I currently have a High Compression L20b with a shaved 219 head and SU's. (I assume flat top L18 pistons in the L20b block)

 

Would moving to a LZ22 block with the 219 head and SU's be an upgrade? or a down grade? Is it enough of a gain to be worth the swap? :mellow:

 

Morning Richard,

 

A stock L20B with flattop pistons and un-shaved 219 head would have a compression of 10.68

 

Placing an un-shaved 219 head on a stock Z22S block would give a compression of 10.48

 

So no meaningful change in compression really because the bigger displacement also includes dished pistons. BUT the engine is 10% larger!!!

 

 

Peanut chamber heads work best with flattop pistons. This gives the maximum 'quench' or 'squish' between piston and head surface. Actually, only the head gasket thickness of 1.2mm. Dished pistons negate this because the distance between head surface and piston top is much wider. A Z22 with a flattop L head may ping more than what you have now. Just sayin' may.

[hang_510]

Low level for frustration or for my own incompetence I guess.

Plus you don't learn anything about how everything interrelates... it's just numbers plugged in.

 

Does this program do this?

:lol: i did learn from changing each parameter. its more of a fitment/compatibility program, AKA step 1.

i learned enough from it to measure twice and spend once! it was harder to stick to the plan!

 

once the data is entered its easy to see compatibility.

its not saved to go back and repeat...

 

you could program my TI-85 to do it. :nerd:

 

mechanical pencils FTW!!!