Another LZ23- With R1

[oldschool90]

Hey all, decided to start a project thread for my R1 powered LZ23 powered 720. There's not much to show right now besides a few parts, I plan on getting all the parts together first, then get the machine work done, then take some time off work and get it all put together. My plan is to get it running/broken in with a stock carb then figure out the R1 part so I'm not trying to break in the motor while figuring out carbs. I have most of the parts (head, cover etc.)purchased and waiting to be shipped, but I'm still waiting on a few big parts, mainly KA pistons, exhaust mani or header, and a matchbox dizzy. My original plan was to get it running, then swap it into a 4X4, but I think I'm just gonna leave it there and do something else for a 4X4. I don't have much to show just yet, but here's what I got:

 

ARP head studs

 

Some leds for the dash

 

A "muffler"  ;)

 

And some Z car gauges that I'm redoing that I'm either going to fit in my truck somewhere, or sell them and use money toward the truck

 

And the beast that this is all going into

 

[jvb5577]

Is this going to be a baja truck?  .Really diggin' the look  B)

 

Under the engine section there is a lot of great information on the R1 carbs.  I was going to go this route too but decided to go with the SUs instead.  Mostly because it is going to be my DD.  Keep us updated!

[oldschool90]

I don't know, I haven't really thought of what to do with it yet. I'm gonna get it running first, then I'll decide what I want to do with looks. I'll definitely keep updating, but it's going to be a bit slow for now. Once I get ready to get it back together it'll start to pick up. I've read a few R1 threads and it seems like no one can get it tuned quite right which is why I want to break it in first then mess with the carbs. I think I'll make it a semi-DD, I have an eclipse I'm still paying off so I suppose I still need to drive it some  :P

[datzenmike]

So this is an '81, Z22 with KA pistons and R1 carbs.

 

I assume an open chamber L head? I would suggest a U67... and then you could run an L16 4 into 2 manifold.

[oldschool90]

Yes and yes, U67. I was hoping I could maybe borrow a working intake setup from someone until the motor is broken in, in the meantime have a custom intake made up for the R1 carbs. Or something like that. Just so I don't screw up the break in process trying to mess with the carbs at the same time.

[datzenmike]

Don't forget it will be tilted down to the driver's side by about 20 degrees.

[oldschool90]

I'll figure something out when I get close to that point. Right now I'm just trying to get all the parts I need. 

[datzenmike]

I imagine the Hitachi will just think you are driving on a side hill. It'll work just keep in mind is all. :lol:

 

When you make the R1 manifold it will take care of itself.

[oldschool90]

Yeah, I figured. So what piston options do I have? I know pistons from a KA D21 will work, giving me a CR of about 9.7-9.9, are there any other options, with higher CRs? I don't mind running premium, I already do it with my other car, just not so high that I need race fuel  :) Also, is there a difference with L20B rods and the Z22s? I keep reading it says to use L20B rods, but it'll cause vibrations and lower the redline.

[datzenmike]

All L20B and 720 truck Z22s use the same 12100-U6000 connecting rods. Exactly the same part. The only other Z22 was used in the '82-'83 S110 200sx. It also used the same connecting rod for 6 months. From Jan '81 through '82 a different piston and rod was used.

 

That said the connecting rods may be the same but balanced at a different weight because the crank and pistons on a Z22 are different. That's a good point. Shit, I already have the L20B pistons off. Well I can cut a Z22 off and weigh the rod at work. If they are different I can grind them down if heavy, and switch to Z22 rods still if lighter.

[oldschool90]

Update:

 

I pretty much have everything ready to pull the trans and the block, now I just need someone to help me do it. 

 

 

I also got my pistons in today

 

 

Most of the other big stuff should be on it's way soon, and I'm hoping to have the machine work done within the next month.

[datzenmike]

I compared 4 L20B to 4 Z22 rods.

 

All are within 7 grams or 1/4 ounce.

[oldschool90]

Small update: Trans is pulled, block is ready to be pulled, just waiting on the main parts and the funds to go and get the machine work done. Went to the junkyard today to see if I could find a part I lost while rebuilding my trans, but didn't see anything that had the 71B trans in it. But I did happen to score some exhaust tips that I like, and seem to fit quite nicely on the truck:

 

 

 

I compared 4 L20B to 4 Z22 rods.

 

All are within 7 grams or 1/4 ounce.

 

Thanks Mike, I might have them balanced anyways because I've got either the L rods on the Z crank, or the Z rods which are all sorts of mix n match. 

[oldschool90]

Small update

 

Scored some stuff at Ecology's sale yesterday:

 

(The holes are plugged because I was cleaning them.)

 

$30 for both (and an hour wait in line), which isn't bad. They seem to be in pretty good condition, and the fluid didn't smell burnt at all and the fluid looked good. Didn't find a 3-bolt P/S gear though, I was really hoping to get one while I was there.

 

Also got some stuff to delete the A/C on my truck.

 

Still waiting on all my big stuff to get this going, also getting close to be able to do block work.

[oldschool90]

Got the block pulled the other day, found a broken ring in #1, and found a nice sized groove in the last main bearing.

 

 

Cyl #2 had some odd etching in it, boring should get it out.

 

 

Have a pit on the fire ring area on the block on #1, will have to have it machined off.

 

 

Also found numbers marked on deck surface #1&2 are marked 2, and #3&4 are marked 3.

 

 

Crank looked fine, despite a slight knock I had from air being constantly being sucked in with the oil from somwhere.

 

 

Also took some pics comparing my truck clutch with the new z clutch it'll be replacing

 

[Z-train]

Have that bore checked first-it may NOT clean up.The mark in the fire ring area looks like an impression from a mason's hammer.I don't see it being a BFD.Machining might change the timing situation.

[datzenmike]

, and found a nice sized groove in the last main bearing.

Check crank in this area... something did this. Bearings are made very soft to allow particles to embed rather than score the crank.

 

Have a pit on the fire ring area on the block on #1, will have to have it machined off.

 

Check # piston top. If dinged then something got in there. Looks like the block took a hit from something.

 

Also found numbers marked on deck surface #1&2 are marked 2, and #3&4 are marked 3.

This is normal. Mass production isn't perfect and to reduce waste the bore diameter is measured and given a 'grade' 1 to 4. Pistons also can't be perfectly machined either and they are measured and graded also. For example an 85mm L20B piston can be anywhere from 84.985mm to 85.035mm and the block 85.000mm to 85.050mm. Piston to bore clearance is between 0.025mm to 0.045mm so by grading the pistons and bores you can quickly select a 'slightly' larger piston to fit a 'slightly' over size bore.

 

 

Also took some pics comparing my truck clutch with the new z clutch it'll be replacing

 

 

Hope you got a new release collar or sleeve to match the height of the new clutch.

[oldschool90]

Have that bore checked first-it may NOT clean up.The mark in the fire ring area looks like an impression from a mason's hammer.I don't see it being a BFD.Maching might change the timing situation.

 

Will do.

 

 

 

This is normal. Mass production isn't perfect and to reduce waste the bore diameter is measured and given a 'grade' 1 to 4. Pistons also can't be perfectly machined either and they are measured and graded also. For example an 85mm L20B piston can be anywhere from 84.985mm to 85.035mm and the block 85.000mm to 85.050mm. Piston to bore clearance is between 0.025mm to 0.045mm so by grading the pistons and bores you can quickly select a 'slightly' larger piston to fit a 'slightly' over size bore.

 

Thats cool.

 

 

Hope you got a new release collar or sleeve to match the height of the new clutch.

 

Of course I did.

[datzenmike]

Easier to ask than to pull it out later. :lol:

[Dirttrack510]

I  really dig your truck, it looks a lot like the 1980 that I just got. I love my 720 already. These are pretty nice driving little trucks. I'll be watching your build. Good Luck :thumbup:

[oldschool90]

Easier to ask than to pull it out later. :lol:

 

I know, especially in these trucks.

 

 

I  really dig your truck, it looks a lot like the 1980 that I just got. I love my 720 already. These are pretty nice driving little trucks. I'll be watching your build. Good Luck :thumbup:

 

Thanks, I'm debating on if I want to paint it or not. Kinda like how it looks now, but I have to fix a big ding in the drivers front panel, and then color wouldn't match which I hate. Painting would be at the bottom of the list anyway, I have other goodies and such to stuff into my truck before I spend the time and money on cosmetics.

[oldschool90]

Couldn't get anything done on the truck today, but I did get all my parts in for a project to keep me busy when I can't get out to my truck.

 

Some nice clean uncracked & uncut tail light lenses & buckets

 

 

Work area

 

 

Components installed on proto board

 

 

IT WORKS!!!!!

 

 

Testing

 

[oldschool90]

Got a few things done today.

 

 

 

Small bit of rust to fix

 

 

Noticed this while taking stuff apart, thought it was neat.

 

 

Next steps are to power wash bay and prep for paint. Also need to do some wire cleanup.

[DAT510]

Updates! :D

[Cpl620]

ohhhh, where did you snag the LED sutup?