How do I do this rebuild?

[cruznude]

I know theres much more knowledgable people out here than myself so here it is,  I have a 79kc l20b and its never been built.  Where I live the smog checks are a friggin big issue.  I would like to have the block bored out, replace the smogged out head and replace with a peanut and install a mild cam with a weber.  I have no catlatic converter on exhaust and would like to re-do to 2 inch or 2 1/4.  Any suggestions on where to start. Cost will be an issue so this will take me a bit to get it all and done.

[Guest_kamakazi620]

I know thees much more knowledgable people out here than myself so here it is,  I have a 79kc l20b and its never been built.  Where I live the smog checks are a friggin big issue.  I would like to have the block bored out, replace the smogged out head and replace with a peanut and install a mild cam with a weber.  I have no catlatic converter on exhaust and would like to re-do to 2 inch or 2 1/4.  Any suggestions on where to start. Cost will be an issue so this will take me a bit to get it all and done.

expect 800-1600 at machine shop depending on what needs to be done, unless you do all the assembly, peanut heads use to go for $100 not rebuilt btw , and this is just a start...

[Tucson620]

For start, I say get Monroe's book and do all the disassy/assembly yourself.

 

[datzenmike]

 Where I live the smog checks are a friggin big issue.

.

Then higher compression, cam and no cat is NOT the way to go.

[cruznude]

Okay, the truck is a non california model and has no catalatic converter from the start and what can be done to have a mild running engine w/o going all crazy?  Look, I'm 50 and just want a little bit more performance w/o going all crazy with the speed.  Just a mild build. So, I bore it out .30 over and re-size the pistons etc, and then do some other mild stuff, this really wouldn't be so bad huh?

[Stoffregen Motorsports]

Bore it and stroke it or build a 2.2 or 2.3 bottom end and use your smog head. Not the most awesome way to go, but the extra cubes will definitely help.

 

Why not swap in a KA24 out of a truck? You uoght to be able to find a complete donor truck for $1000. Then it's just labor.

[datzenmike]

0.030" over increases the size by less than 50cc. That's a 2.4% increase is size... nothing really.

 

Find an '81-'82 720 truck Z22 motor. Rebuild the block, rings pistons overbore slightly. (cost the same as doing the L20B) Put your L20B head, timing cover and oil pan on it and you instantly have a 2.2 liter with longer stroke and bigger bore. 10% larger and with 9.8 compression

[cruznude]

Bore it and stroke it or build a 2.2 or 2.3 bottom end and use your smog head. Not the most awesome way to go, but the extra cubes will definitely help.

 

Why not swap in a KA24 out of a truck? You uoght to be able to find a complete donor truck for $1000. Then it's just labor.

alright but just how much work is involved and I'm really not that mechanically inclined.  this seems like a huge project to me and then again, how much welding is going to have to be done and then again if I start something like this and I get to a point where I start having probs then I;m screwed. Theres just no ratsun followers out here just undocumented citizens.

[cruznude]

0.030" over increases the size by less than 50cc. That's a 2.4% increase is size... nothing really.

 

Find an '81-'82 720 truck Z22 motor. Rebuild the block, rings pistons overbore slightly. (cost the same as doing the L20B) Put your L20B head, timing cover and oil pan on it and you instantly have a 2.2 liter with longer stroke and bigger bore. 10% larger and with 9.8 compression

This Z22 motor is this the nap z?  So then,everything on the head stays the same? What changes will have to be made?

[datzenmike]

Find a good Z22 block that can be rebuilt. Over bore to fit over size Z22 pistons... 0.5mm or even 1mm over... might as well go large. All the parts are there, crank and rods... just re build it stock.

 

Your L20B head intake and exhaust will fit the Z22 block if you modify a Z22 head gasket. Use the L20B timing cover, timing chain and distributor, oil pan/pick up tube and engine brackets. All this stuff you have on your L20B now. You are basically converting a Z22 into an L22. 

[Stoffregen Motorsports]

Find a good Z22 block that can be rebuilt. Over bore to fit over size Z22 pistons... 0.5mm or even 1mm over... might as well go large. All the parts are there, crank and rods... just re build it stock.

 

Your L20B head intake and exhaust will fit the Z22 block if you modify a Z22 head gasket. Use the L20B timing cover, timing chain and distributor, oil pan/pick up tube and engine brackets. All this stuff you have on your L20B now. You are basically converting a Z22 into an L22. 

What he said...

 

It really is that easy.

[Stoffregen Motorsports]

alright but just how much work is involved and I'm really not that mechanically inclined.  this seems like a huge project to me and then again, how much welding is going to have to be done and then again if I start something like this and I get to a point where I start having probs then I;m screwed. Theres just no ratsun followers out here just undocumented citizens.

I understand.

 

On the other hand, if you have the whole truck, you can take anything off it that looks like it belongs to the motor or emissions control devices and swap it in - ie, fuel tank with pump, charcoal canister, etc. Heck, you can probably even use the whole wiring harness tip to toe, with little mods. The hardest part would be figuring out how to interface the stock gaegue cluster with the EFI motor. And then when it's all done, you're not screwed, you just tell the mechanic it's a Nissan Hardbody...at least under the hood.

 

But I do get where you're coming from.

[cruznude]

That does really sound like something I might be able to takle so when I pull it I'll see what its gonna cost and call for some help. 

The KA motors sure look tight  once installed and would love to go that way but I dont Know.  Doesn't weber make a smog  carberator?  I know Holley did and had one back in the day.