collapse

www.dimecitycycles.com

https://www.townmoto.com/collections/vanson-leathers


www.restocycle.com

www.CITYLIMITMOTO.com

www.jadusmotorcycleparts.com

www.bisonmotorsports.com

www.speedmotoco.com

www.lostapostlejewelry.com

www.cognitomoto.com

www.sparckmoto.com

www.pistonsociety.com

www.steeltowngarage.com


Author Topic: Dr. Jekyll and Mr. Hyde ( a pair of KZ400s)  (Read 50741 times)

Offline Nebr_Rex

  • DTT SUPPORTER
  • *
  • Posts: 853
Re: Dr. Jekyll and Mr. Hyde ( a pair of KZ400s)
« Reply #210 on: Aug 26, 2018, 22:34:55 »
I worked on getting the engines compression up. Started at 65lbs. on no. 1 and 90 lbs. on no.2.
Reset the valves at .007 in., two were at zero lash. Sprayed PB Blaster and carb cleaner into the
ports and spark plug holes to wash down the valves and seats. Ended up having them test at 140/150
no. 1 and no. 2 respectively. They would probably seal up some more if the engine would be run for a
while. I can't leave well enough alone. I flipped the sprocket like I posted earlier. Ended up with 165/170.
The bore diameter for the 'Cruise Image' head gasket is 66mm. That rules out a 67.5mm piston. But I
do have a set of nos KZ650 66mm big bore pistons. Bad part is it is old enough to have a 1 piece oil ring.
If I can't find a three piece oil ring. 66mm x 2.4mm I will have to use it. Compression works out to 8.9/1
before any head milling. Now to source some engine seals.


.


.

Offline doc_rot

  • DTT BOTM WINNER
  • *
  • DTT SUPPORTER
  • *
  • Posts: 1108
  • Oh the usual... I bowl, I drive around...
Re: Dr. Jekyll and Mr. Hyde ( a pair of KZ400s)
« Reply #211 on: Aug 28, 2018, 03:56:36 »
What do you mean "flip the sprocket" ? Also why are 1 piece oil rings bad? That what I ended up with for my KZ750 pistons. I had never seen a ring like that before.

Offline Nebr_Rex

  • DTT SUPPORTER
  • *
  • Posts: 853
Re: Dr. Jekyll and Mr. Hyde ( a pair of KZ400s)
« Reply #212 on: Aug 28, 2018, 22:37:13 »
The top of page 20 is where I started to explain what can be done to improve
the factory cam timing for the KZ400/440.
One piece oil rings were used in automobiles before the advent of three piece.
Three piece have better oil control and last longer.

Offline doc_rot

  • DTT BOTM WINNER
  • *
  • DTT SUPPORTER
  • *
  • Posts: 1108
  • Oh the usual... I bowl, I drive around...
Re: Dr. Jekyll and Mr. Hyde ( a pair of KZ400s)
« Reply #213 on: Aug 29, 2018, 02:50:03 »
interesting. I will have to look into some new oil rings for my build.

Offline Nebr_Rex

  • DTT SUPPORTER
  • *
  • Posts: 853
Re: Dr. Jekyll and Mr. Hyde ( a pair of KZ400s)
« Reply #214 on: Sep 03, 2018, 22:58:41 »
  Located enough seals in my 'stash' to replace any that need to be.
I have my eye on some rings with a three piece oil ring also. The cam
out of my other 400 is pitted on the nose of the cam lobes. Which
makes it a good candidate to be welded up. Plan is for 66mm pistons,
stock valves with head porting and milling to achieve 9.8/1. As for the
cam I'm looking to just add to the nose and not alter the ramps. The
eccentric valve lash adjustment will not allow much of the base circle
to be removed. To ensure I don't go to far I cut up an extra rocker box.
Going to add 1mm to the lobe to get about .350 lift with valve lash.


.

Offline Nebr_Rex

  • DTT SUPPORTER
  • *
  • Posts: 853
Re: Dr. Jekyll and Mr. Hyde ( a pair of KZ400s)
« Reply #215 on: Sep 09, 2018, 22:45:12 »
 Accomplished a little something this weekend.
Welded up the nose on the KZ400 cam lobes.
The ground them back down on the lathe.
They are roughed in at about .015 in. taller then final size.





.

Offline doc_rot

  • DTT BOTM WINNER
  • *
  • DTT SUPPORTER
  • *
  • Posts: 1108
  • Oh the usual... I bowl, I drive around...
Re: Dr. Jekyll and Mr. Hyde ( a pair of KZ400s)
« Reply #216 on: Sep 10, 2018, 04:02:13 »
cool setup. think you could grind a starter sprocket for me?

Offline Nebr_Rex

  • DTT SUPPORTER
  • *
  • Posts: 853
Re: Dr. Jekyll and Mr. Hyde ( a pair of KZ400s)
« Reply #217 on: Sep 12, 2018, 21:44:42 »
I could do a good job of grinding the teeth off.
PM me if you have something more specific.


.

Offline Nebr_Rex

  • DTT SUPPORTER
  • *
  • Posts: 853
Re: Dr. Jekyll and Mr. Hyde ( a pair of KZ400s)
« Reply #218 on: Oct 03, 2018, 23:12:12 »
Finally found some rings for my pistons.
Nicked a ramp on the cam. Since the plan was to use the stock ramps and just add lift.
I evil bayed another one. All the cams I've seen for the KZ400/440 have been forged steel.
The new one is cast iron. So I'm going to weld up the original cam from the engine and use
the cast iron one for a stock reference. I'll post up some pics this weekend.


.

Offline Nebr_Rex

  • DTT SUPPORTER
  • *
  • Posts: 853
Re: Dr. Jekyll and Mr. Hyde ( a pair of KZ400s)
« Reply #219 on: Oct 07, 2018, 22:03:33 »
Here are some pics of the piston with a KZ440 piston on the left and KZ400 on the right.
My guess is the dome volume is 9-10 cc compared to the stock pistons.
Also the two different cams, hollow forged and cast iron.


.