KZ650 Sleeper Build (KZ1000 engine transplant)

Discovered these RC cams don't have a M6 thread on them like the Yosh 650 cams have in them.





Will need to make up a slip collar for those cam ends to be able to use the degree wheel. Will get it turned on the lathe.

I made up this degree wheel years ago to bench test those Pop Y stage 2 cams because I could not find a timing card for them. I wanted to know the duration so it was a solution to do it off the bike. At that time I did not want to tear into a engine to do it but had did have plenty of spare heads sitting about.

Are you sure that cam timing with the degree wheel on the cam shaft instead on the crank shaft gives you accurat readings?
 

Scirocco wrote:

Are you sure that cam timing with the degree wheel on the cam shaft instead on the crank shaft gives you accurat readings?

 

This was only to find the duration of the cam lobe with no cam card specs available using the bare cylinder head on the bench.

Now that I am retired if I get a few things accomplished during the day it keeps me out of trouble. Got a 50KM bicycle ride done around noon then got out on the lathe and finished the cam end mount to fit the tiny degree wheel on these cams.



I made that adapter out of some UHMW engineering plastic scrap I had in my bin.

Mounted it on the cam then put it on the head, fits better than I though and the wheel just clears the head.

 

 

 

Again this is just to bench test with, it will make it easier to find the duration of unknown cams that I don't have specs on.

I also greased up and installed some valves and a spark plug to check the combustion chamber volume and piston dome volume so I could find out the static compression ratio. I was in a bit of a rush so I never took pics, but I got it done and found out my head is at 38 CC and my piston come is at 12 CC. I input all the variables into a online calculator and the results were 10.45:1 which is just about where I wanted to be for a street engine.

 

Glad I was able to get that put to bed.

I will try to get back on this tomorrow as there is not much going on, I still have some more things to check as far as the head goes. I also need to take two valves back to my engine guy to grind some off the tips.

I found my cam timing equipment but could not find my valve shims.



Moved onto the installed height valve spring (seat) pressure with new APE .440" street springs.





Cycled them all 10 times to coil bind then based lined them at 1.300"



Was able to set intake side at 82 PSI with one .010" valve shim and exhaust side at 86-90 PSI with two .010" shims (copper sheet)
Good thing I did not need thicker shims, will run across them somewhere around here. 

At full lift I can get a .070" feeler in between the coils so lots of room. 

Happy to get that done now I just have to find out how wild these cams are.
 

I was able to use that tiny cam end degree wheel to find total duration on these cams at .050" lift with .006" lash.



Here is the missing timing card based on the actual measurements recorded using the dial indicator and degree wheel.



This was generated thru the WebCam online cam timing calculator.

The cams end up being very similar to the cams I am running on my 831cc street bike, which has a nice lumpy idle.

Found a unusual thing on this cylinder head that I all but forgot about.

The #4 exhaust guide has been replaced with a aftermarket bronze guide that uses a cir clip at the base of the tappet bore. Odd thing about it is the PO had not ground the spring cup to make it sit flat (clip was raised up by .075")

I looked to see if any of the spring cups were modified and they were not, so I needed to grind a "thru" slot with my Dremel tool to clear the cir clip "ears".

First time I have ever done this modification and the first time I have seen a guide like that.

Hard to get a picture of it installed, this is the best I could do. Forgot to take a pic of the ground spring cup.





Only the "ears" are showing as the rest of the clip just fits where the radius on the spring cup is. It is sitting flush on the bottom of that bore instead of rocking on top of the clip like the PO had it. The ears are still .035" proud of the spring cup but the spring ID is bigger so there will be no interference.

Got all the valve spring shims installed under the spring cups and the valve seals installed on the guides. All ready to fully assemble the valves and springs the next time I am out there.
 

I have been busy with other projects around the house but I should be getting back on this one soon.

I got some valves tipped and got all the shims sorted so the next step will be assembling the head. After that I need to get a back tire put on it, and a front brake seal on the one side fixed as it started to leak mid summer just sitting there.

I decided not to assembly the top end till I can start and ride it. The plan is to fire it up in March or April depending on the weather.

In the mean time I can sand and polish these last two covers in my basement at my leisure.



No rush getting these done and fitted.
 

Had some time today so I assembled the valves onto the head.



Stainless steel oversize Manley valves with APE oil seals, 650 style retainers, and APE valve springs.

The combustion chambers measure 38cc, and I measured my piston dome to be 12cc. I was able to input those numbers into a online calculator to arrive at a 10.45 static compression ratio. My pistons are sitting .006" below the top of the barrel.

Nice!

I was unsure about the old MTC pistons I am using and what they give as far as compression, given the fact that my valves have been sunk back.

Years ago when I was in the planning stages of building this engine it was going to be supercharged, so I opted to buy some new Wiseco 1200 pistons. I then ran into these cheap old MTC's at a fraction of the price. I ended up returning the piston kit in exchange for the porting and valve job... pistons have since doubled in price!

This engine was originally going into a vintage laydown drag bike frame but I scrapped that idea because I found out I could not run the supercharger properly without going up to 1500cc and using a massive carb. I just ran out of time and money since I bought the frame and engine back in 2014.





I ended up selling the frame and supercharger in the Summer of 2020. I held onto those pieces for so long I ended up making money

The Wiseco 76mm next to the MTC 76mm - Notice the "shoulder" and slightly deeper valve pockets on the MTC piston.



The Wiseco's have numbers etched so very easy to ID them, the MTC's which could be from the 1980's or 1990's have no numbers on them.

I did find out that the MTC's are pretty old because they use the older style ring set with the weird oil scraper wire. They don't sell those rings any more but MTC will machine the pistons to accept the new ring sets. Ended up cutting the grooves on my own as it would have doubled up the price of getting them refurbished.

I think I still made out pretty good swapping the new Wiseco's for the porting/big valving on the head. This engine is going to be plenty strong.

Checked my carbs over today to make sure I have the correct jets installed and made sure the sync adapters cleared the float bowls. PO had drilled and tapped for M5 thread but the adapters you can buy are M6.



I fixed those holes to accept M6 and have SS Allen head plug screws Loctited in place for first start.



Carb ID number signifies a later series, probably 1992 just about when they fell out of favor for the RS flat slides.

I have a Sudco catalogue from 1988 where they were selling #33A-14 (Kawasaki) so counting back that seems correct, but just a guess. I do have a 1992 performance catalogue where they dropped advertising them and compared that to the same companies 1990 catalogue showing they were still available.

Also checked to see that the CV rubber ducts fit, perfectly smooth transition onto the carb mouth.



This was just to confirm my plan to use the 650CV air box. Need to clean the rubbers as they are a lightly used set (still supple) may replace them with new units in the future.