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Basic LZ22 Build w/ Flat Top SSS SU


jvb5577

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Today I pulled the L20B out of my '79 620.  Did it by myself, which I will not do again!  :rofl:

 

I am planing on doing a LZ22 or maybe a LZ23 depending on how the cash goes.  Want it to be a street friendly engine with good power.  I have never built a motor before so will have many questions probably.  Anyways what I have is a U95 L20B W2 with a W58 head.  Seems the PO replaced the timing chain as it says "made in USA" it was also a little loose.  Also used water for coolant. :sneaky: Lots of rust.   Took a flashlight to the valves and they are black.  Currently looking for a Z22.  Anyways here are some pictures.  Don't have any on the crazy engine pull.  More to come! B)

 

Will the W58 head work well with a Z22?

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Motor looks good. Exhaust liners are clean. The W58 will work fine on a Z22 block. That said...if I had a U67 head and an earlier L16 exhaust manifold I would run those instead along with the intake you already have.  But if you don't then don;t let that stop you using the W58.

 

So when you find a Z22 you will need everything from the L20B but the steel block and what's in it.

 

Hard to know if the chain is loose as there is a slack side anyway and the tensioner actually uses oil pressure to push out on the chain. You can check it for stretch though and even adjust it so the cam is timed properly.

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My plan was to get a L16 exhaust manifold just so it looks cleaner without all the emissions junk on it.  Will the L16 manifold not work with the W58 head?  Alright will check the chain out a little better. 

 

How much more power is expected with this bare swap, as in, moving the L20B over to the Z22 block?

 

MicroMachinery.  Are you happy with the setup you have?

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Because you are over boring you can use old KA24E pistons, no need to buy new ones. Any KA from a D21 Hardbody '90 through '96 will have them. S13 KA pistons should also work too. 89mm KA pistons in a Z22 block will give a 2288 (2.3 liter) motor with 9,8 compression when used with your W58 head.

 

The L16 (square port) exhaust manifold will work on the W58's round ports. 

 

 

An L20B makes around 96 RWHP hp on a good day so increasing the displacement 10%, an LZ22 should make 105 RWHP or more. This translates to about 112 and 123 net engine hp.

 

An L23 should be 110 RWHP and 129 net. This is conservative I think because it does not take into account the increased compression ratio. If you should add a higher lift longer duration cam and more carb.... say R1 motorcycle carbs. Expect much more.

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LZ22 or LZ23 build?

 

LZ23...

If you can, find a U67 head.

 

Also...it is 'believed' that the Z22 truck blocks have a little more meat to bore to 89mm...relative to the car blocks.

I don't like boring the Z22 blocks to 89mm. There are steam holes between the 1-2 and 3-4 cylinders. You hit them sometimes when boring that big. Z20 blocks are better for 89mm.

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I don't like boring the Z22 blocks to 89mm. There are steam holes between the 1-2 and 3-4 cylinders. You hit them sometimes when boring that big. Z20 blocks are better for 89mm.

what the difference between L & Z 20 blocks? if theyre both 85mm bore cant jvb & i take our existing L20b blocks and bore them out to 89?

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what the difference between L & Z 20 blocks? if theyre both 85mm bore cant jvb & i take our existing L20b blocks and bore them out to 89?

4mm (.160") is a hell of a lot to bore out of any block. The Z22 starts out at 87mm but I dont know if they are thicker to begin with or not. I hope so, since my next one wil be a Z22 block.

 

Summit sells Silvolite 89mm KA pistons with full floater wrist pins (pn 9115 std) for $167.00. Not the greatest pistons, but they took a hell of a beating in my truck.   

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It's round so 4mm is only 2mm off all the way round. 0.80" off the walls.

 

A Z22 only needs 0.040" a spark plug gaps width to get to 89mm.

 

The Z20 and L20B are basically the same and can be interchanged but the Z20 has some changes to the casting.

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I've been reading on other peoples builds it seems that the Z22 has more meat for boring.  But it is also prone to cracking? 

 

Never thought about a Z20 block.  Will have to look into that.

 

Thanks Mike.  So the L16 is a square port.  Got it!

 

Also, what year R1 carbs will work or will all of them?

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Dont know if anyone else has ever ran into this, but after I bored mine to 89mm, I had to turn the block over a take a cut where the cyl walls became bearing saddles, so the hone would clear. 

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Rebello bores Z-22 blocks on a regular basis.

 

This is what you need to watch out for:

DSC01717.jpg

The water jacket needs to be welded up to keep the water jacket from getting into the firering.

 

:o  That is pretty sketchy.  Although if it has been done a lot just got to make sure you have a good machinist.

 

Does anyone have a picture of a bored Z20?

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