So I've embarked on the project to make a '81 510 live. I got a couple years out of the first one (2-door)- just had to change the clutch- then it wouldn't pass smog and I sold it to The620Kid who promptly wrecked it.

A few years later I picked up a beautifully maintained '81 Wagon, which had a warped head, fixed it and 9 months later it was totalled after I got rear-ended on the freeway.

So, hopefully 3rd times a charm.

I picked up this one up in South Everett back in October. The PLAN was to maybe just get it running (had been sitting over 2 years) and have an Automatic car to either sell to my Mom (who would lend it to my Sister whenever her oft-broke Jeep conks out) or keep it so I'd have an emergency Automatic tranny car.



Anyhow, the prior owner had parked it and tried to sell it a couple months prior but it wouldn't start- wouldn't even turn over. I was HOPING maybe just a starter, but the engine really felt locked up. No problem- I have the nice fresh Z20 out of my wrecked '81, swap the flywheel for the flex plate and add a few vacuum lines, right?

But, having nothing to lose, I figured I might as well see WHY it's locked up. Wouldn't budge a bit with a breaker bar, so I pulled the spark plugs. Green liquid ran out of the first 2. The rear ones looked fine. Uh, oh. Engine turned over fine after that- though I did get antifreeze 15 feet up the side of the house. I spun the starter over and blew all the water out- can't really hurt it much anyway- then cleaned the plugs, reinstalled, and it actually fired up. But didn't have enough power to even put in drive, let alone move.

Unfortunately December came, bringing cold, wet, snow, wind, more wet, January, more wind, more snow, more wet, February, still really wet, plus 2 weekends in a row making parts runs for other projects.

So, February 10th the weather is actually half decent (basically, NOT RAINING) so I start disaasembly to get the bad engine out. Manage to get the thing out in a day- though I did leave the transmission in place since automatics have a lot of excess tubing that really gets in the way. Sunday the 11th dawned nice and WET out, #@$#. BUT- Mike (Mklotz) posted an ad for a pair of Z24 engines for $50- I had just spent the PRIOR weekend getting another Z24 to replace the now dead one in my '83 720, but for $50 sounded like a deal. I started thinking- how cool would it be to not only replace the blown Z20 in the car, but put a Z24 in instead? Never seen a Z24-equipped HLA10-type 510. So I packed up then and there and headed for Gresham, OR.

A tank of gas later, plus keeping Mike up past his bedtime, I had 2 Z24's in the bed of my beater KC...



So then started the saga of making a Z24 truck engine into a car engine.

A few differences:

The 720 uses a rear sump. The '81 510 uses a front sump. Not a front sump like the old PL510- a REAL front sump. So far up front the dipstick has to be moved.

The Z24 was a manual tranny engine, so I had to change out the flywheel for a flexplate and spacer setup.

The 720 used a completely different exhaust manifold- different outlet flange, and a different set of breather tubes.

I started pulling stuff apart, but of course it wouldn't quit raining. I finally got fed up throwing tarps over 2 engines and managed to get BOTH engines (by now on matching $29.95 Harbor Freight engine stands- it's sad- I have 4 of the damn things) into the garage via the man door (the garage, as anyone who has seen it, is a complete disaster area. But I did clear enough space for 2 engines on stands, the solvent tank, and I used my chest freezer as a table). This involved getting the engine up a couple steps, which was interesting. Oh, and rolling a Harbor Freight engine stand and an old 1970s era hoist through mud.

In there I swapped oil pans, pickup tubes, exhaust manifolds, drilled out a new dipstick hole, and plugged the old dipstick hole. I plugged that with a small length of brass tubing and a steel drift pin. I also cleaned many, many parts. That solvent tank is great. No more rubbermaid tubs of acetone.

The 720 Z24 used a different intake too- this would prove to be a problem. Since Stage 1 of the project means "Change as little as possible" from the original '81 stuff, I needed to keep the '81 piping, which meant using the '81 Z20 intake. The Z24 already HAD a Z20 intake on it, but it had a couple wrong parts that I couldn't break loose. SO I ended up pulling the intakes of both engines and swapping them. I did find the reason for the water problem in the original Z20 though...



Check out the RTV job. I didn't find a complete gasket here. SOMEONE pulled the intake, and rather than getting a new gasket just RTV'd the hell out of it and slapped it together. See the water passage on the left side? That's right next to #1 intake, and the gasket was completely blown out there. So it filled the #1-#2 runner with water, which ran past the valves... and filled the cylinders. And yes, I pulled the intake without removing any of the parts attached, including carb and upper radiator hose.

Problem though- the Z24 used SQUARE intake ports. The Z20 uses ROUND ones. Well, it was already wrong... the bolts and water passages line up... Oh well, just go with it.

Once I had the engine assembled (everything but the flexplate and the fan) then I had to get out back OUT of the garage. Via the man door. Plus steps. Engine was a lot heavier, too- all the parts were on, whereas it was partially stripped going in.

Word to the wise- don't try to pick an engine and stand up via the stand's rotating assembly. While the lock pin stayed in place (how I don't know) the engine was somewhat top heavy and managed to invert itself- stand and all- when I rolled the hoist off the bottom step (had 2 wheels up the step). Good thing I hadn't put oil in the engine yet.

Anyhow, I did manage to get the engine and stand back upright, well, kind of...


The world is askew, but at least the stand is wheels down. No, I didn't get a pic of the stand/engine hanging from the hoist upside down.
     
The next step was to get the engine off the stand so I could install the flexplate. After careful measurements I decided the pilot bushing (used only on manual tranny engines) wasn't going to be in the way- the TQ converter pilot doesn't go in that far, so I just left it there. That done, I tried to get the engine in the engine bay.

Of course, the engine won't lean the right way- it's unbalanced due to the heavier intake, so it won't line up. Ugh.

Then it started raining. Again. Yep. It's nice and sunny ALL WEEK then come Saturday/Sunday Rain... You know the saying- what do you call 2 days of rain? A weekend. 3 days? A holiday weekend.

I tried again the next weekend- this time I re-set the hoist and used the tilting device. But got distracted from a potential 200SX buyer, so got nowhere. Still couldn't get it to line up with the tranny. Just needed a couple degrees clockwise... Left it hanging in the bay, and threw a tarp over it all.

Sunday, rain. Stayed inside, watched NASCAR.

TODAY... It wasn't raining, so went out and tried again.

Small adjust, up, tilt, back, twist, THUNK. The THUNK was the TQ pilot slipping in where it belonged- and I managed to get the bolts in. Cinched up the tranny, put the motor mounts on, and snapped a shot



Yeah, yeah, doesn't LOOK any different. An fact, even someone who knows '80-81 510s would be hard pressed to tell the engine isn't stock. There's only 2 real clues- one is obvious- the engine ID/serial tag says "Z24". The other is the Z24 uses a stamped-steel valve cover, where the Z20 (and Z22) used a cast aluminum one.

Then it started raining again, but it's almost done. I did get the starter and the flexplate-Torque converter bolts installed and a couple vacuum lines reattached before a real downpour. I went to the licensing office to get current tabs, since they've been expired since 2004, so HOPEFULLY the engine will RUN. I still have to wire everything up, install the fan, install the radiator, attach the ATF coolant line brackets (they bolt to the oil pan), fill the coolant and oil, and install an electric fuel pump. The Z24 didn't have a place for the mechanical fuel pump, so I'll have to go electric. I installed the Z24 fuel-return system so no regulator will be needed.

MAYBE tomorrow it'll run.

Rain, rain go away

All the Z20 and Z22 heads I've seen had the injector notches already in them- the notches were cast in.

Well, finished and screwed up big time. The starter won't properly engage, and makes a bunch of clunking.

I think I put the flexplate on backwards...

Oh yes, both spacers are on. Well, only one is a spacer, the other is a reinforcing plate. I think I overthought which way it went on- the plate is welded to the ring gear offset to one side, but what I really did was looked where the TQ converter bolts had left indentations on the plate, then put those facing OUT instead of IN. I'll know for sure when I pull the starter (again) tomorrow, since there's a bevel on the ring gear that is obvious (now) which way the starter is supposed to mesh.   

Well, crud, I'm gonna have to take the whole thing apart. I can't get the transmission to go into gear- it's acting like no fluid is being circulated at all. Fluid level is "High" but that's because nothing appears to be circulating. It was working BEFORE I pulled the engine, I have no clue why it doesn't work now. All selections are Neutral except Park which engages the parking pawl.

I haven't tried pulling the cooler lines to see if it's actually circulating. The cooler runs on "Torque converter pressure" so that would at least tell me if the pump is working a little. I suppose it's possible the cooler is plugged- I used the radiator out of the wrecked '81 since it was a new radiator 9 months before the wreck.

I suppose it's a good thing I have a spare, though it's a L-series A/T vs a NAPS-Z A/T. It's just a pain in the rear pulling everything apart again.

It might be, but the noise and hard starting and clunking was the fan smacking the crank pulley. Since the tranny appears to be shot I'll have to take it apart anyway.

Or is it possible that the 2-3mm difference in TQ position (if the flexplate was backwards) would cause it to get no pressure? I just don't know Automatics that well. They usually don't just up and quit like that. It's like the fluid pump isn't pumping. I mean, you shift from neutral to Drive or reverse and NOTHING happens- like you never moved the lever. The reverse lights come on in "R" so the internal lever is being changed. But it's like it has "Park" and 5 neutral positions (except one turns on the Reverse lights).

OK, it rained rats and frogs yesterday so I got nowhere (well, other than have the ceiling in my dining room cave in, I was waiting for DRY weather to fix that too) but today it was dry so I worked on it. Pulled the starter and yep, the flexplate was definately backwards.

So, spent 3 hours disconnecting everything. I only assembled it a week ago, but the downpipe bolts were locked up solid. Broke one, and a second stud came out with the nut.

Anyhow, got it out- Automatics are so damn heavy, snaking that mess out was harder than normal but I got the engine back out with the transmission and got the engine/tranny assembly apart.

Upon examination, the backwards flexplate was probably near a half inch offset, which wasn't engaging the tranny pump. So I reassembled everything the correct way. Hopefully that will solve the no go situation. It got dark so I didn't get the engine back in, but I did some remedial work such as hooking up the tranny cooler line brackets correct (had 2 in the wrong place).

Be another week until I get the engine back in. Still have to get the broken exhaust stud out. This time I'll antisieze them, which I should have doen in the first place. I also have a problem with the engine itself- it is burning a LOT of oil on cold starts. The longer it sits, the more smoke it puts out. Clears up quickly, so I think the valve stem seals are shot. I have several sets of stem seals so I'll fix that once I get the engine back in and verify the tranny is OK.

It's awesome to hear that it's moving and running!!!!!!!!!  I'd love to take a ride! :)

Whew......I still had a shade of doubt that it was a good motor since I never ran it, but that's gone now.  Sounds like it was worth all the effort!!!  Makes me seriously consider putting that KA in my wagon! :)  If I could trade a 5spd for a good 4spd auto to go behind it, I just might do it! :) 

You might have a vac leak that is causing the rough idle.

Try the Bearin' Seal by Gunk....if it doesn't help, I'll pay for it :)

hhmm....could have hooked you up on the batt...I've got several extras :)