Terrible motor swap idea kz440

The carbs for the '81 GPz550 are only for the '81; in '82 the 550 had different carbs and IIRC different heads.

The oil cooler appears to be identical to the one on the '81 GPz.

But the big telling point is the shifter: the GPz has the backwards-facing shifter because it has rearset pegs. The KZ550As from '80-'83 had the traditional pointing-forward shift lever.

Basically it looks like someone added GPz parts to a KZ engine.

I figured that someone put the gpz stuff on for fun. If it has an oil cooler i wonder what the engine internals look like... 
The guy updated the description and said that the engine ran before someone laid it down and scrapped it. He also verified that it will rotate freely, also mentioning that he felt compression but didn't verify the amount. For some reason it will not come with the oil cooler. Would I be able to use the one from my zx550? My brother is picking it up today and ill be able to tinker with it this weekend.
Maybe ill finally have a running machine 

The oil cooler worked on the new engine. I ended up shoving the new engine into the gpz and tested for compression while cold. 150-180-180-180. Id say that's not that bad. Then engine cranks surprisingly fast. Way faster than the kz1000 and kz440. I sprayed wd40 into the lower compression cylinder and compression jumped back up to 185.

Im pretty sure the engine will run but we are having carb issues with the 1981 gpz carbs so my brother and I are thinking of swapping the head from the 1985 gpz onto the new engine to use the cv carbs. Do you guys see any problems with this? For now we plan on using the kz cams.

Late in the future we plan on swapping the cases to make sure that everything will function with the gpz as it would, such as the ignition advancer, clutch, oil cooler/pump (not sure about that), and the oil level switch.

I'll try to make sure that this is feasible with stuff like the crankshaft (and advice is welcome) because I dont know how that would work with swapping the crankshaft bearings and whatnot.

As always, PLEASE point something out if you see a problem with what we plan on doing.

Well I've been through a lot in the past couple days. I spent a VERY long time cleaning gasket material off of the cylinder and head mating surfaces then went to fit the gpz head and it went on snug.

I got to the cam timing and then my brother came in so he "helped" me. He bent a valve by moving the crank then blissfully tightening down the cam without any worry of why it was so hard to tighten. 

So today we went in and took a valve off of the kz550 as a last resort and got all that sorted out. This time I did the cam timing all by myself and it went well. 

I got the gpz carbs cleaned and put them on and tried to start it. It won't start but it'll fire over. Im not sure if my plug wiring is good but its trying!

We did a compression test and it came back 120-150-150-120. On the stock motor it was at 180-180-180-150. Im positive valves are to blame but we shot some wd40 into cylinder 1 and it went up to 210.

The service limit for compression readings for the zx550 in my service manual is 119-180psi. Keep in mind i have the lower compression pistons in and I DO have the gpz cams in the motor and there is no interference! Does the different cams affect compression readings? Any ideas to get it started?

Update   IT RUNS!!! The beast lives once more. She runs about as good as she looks but i still have to put makeup on her  . 
The reason it wouldnt start was because im using the kz550 pickup coils paired with the gpz550 igniter which have different wiring. With a little bit of swapping wires she booted up!

There is a high probability of us replacing the rings and doing a valve job on it in the future but I need to get it running good first. It's very rough at idle but if you are able to get it above idle without killing it, it'll smooth out and rev up nicely. This sounds like the pilot circuit is messed up, right?

I have a lot to do to it tomorrow but whats not to love. I also need the tank to be cleaned out and do not look any further if you are afraid of rust!!!  
Some muriatic acid and abrasives should clean that up nicely  ...

it's moving forward
 

Yes it was moving forward! My brother and I have been concerned with the pickup coil because we are skeptical that the kz550 pickup coils wouldn't work with the gpz550 igniter. The cases dont allow the gpz pickup coil to go in and we cant wire in the kz550 igniter so we decided that we want to swap the cases.

I know its a step backward but its in his and my best interest to do that to eliminate the possibility of that being the problem.

With that said, we plan on swapping the crankshaft assembly so would we also want to swap the crankshaft bushings and anything that looks to be in better condition.

I have the cases apart and am getting ready to make sure they're very clean to swap all bushings and other parts. Can I use permatex ultra black to seal the cases? Any precautions I should take?
 

Just out of interest, you started with one "shagged" motor and one that was together with good compression - why are you now trying to build a hybrid of the two given that you have stated you are working within budget constraints ????

I understand your confusion. The reason is that with the kz550 head, the carburetors were junk. we couldn't get the slides to budge and they were completely covered in gas varnish.

To remedy this, we decided to swap the head to the gpz head since that has carburetors that are in a condition that we could work with. Upon doing that, we got it to run by messing with the kz550 pickup coils wiring.

Even after that we still couldn't get it to run well. The bike wouldnt want to rev above 3k and using the choke didn't affect anything. The ignition advancer worked well and the carbs were cleaned thoroughly and adjusted float bowls and mixture screws.

After realizing this, we thought that the pickup coils were the problem since I dont think the kz550 pickup coils will work properly with the gpz550 igniter. We cannot swap the gpz550 pickup coils into the kz550 case so we decided that if we want to move forward with the project, we want a slate that we know is not faulty.

Along with swapping the cases, we will be able to use the gpz550 clutch because the kz550 was a pushrod style and the gpz is not and we dont have a clutch cable for the kz550.

All in all, we have all of the materials to do the swap and it allows us to use all of the gpz550 features so we decided that it is in our best interest.

What we will be swapping over to the gpz case is the crankshaft assembly, clutch basket, transmission, cylinder barrels, and most wear parts like bushings. 

I have the engine ready to put the crankshaft in and slap the cases together. I just had something come up and I'm on a time constraint so I hope I can get the cases together by the end of the day!

I hope all of this writing helps you see my predicament. Thanks for following along though, it really motivates me when I know people are here and invested in this project.