Alternative rods and pistons

[crazypj22]

The only modification is to make bushings to make the small end fit the piston pin. The CR500 has a 25mm small end so you can bush it any size you want.
The new big end pins are too long for the Yam flywheels so they have to be shortened as well but its a pretty easy job. You can probably use Suzuki 1200 Bandit pistons as well (79mm) This is a relativley cheap way to get a high speed motor, use used pistons and liners
PJ

[flash]

does any one have a running motor whith CR500 rods? I have read a lot abaut this but never have read that any one had one running motor whith this rods. if it is so good why dosen't any one as a motor like this? maybe it is all just talk!!!

[crazypj22]

I have two cranks built with CR500 rods, a standard 360 and a 277 rephase. I have no rush in fitting them into engines as I always intended them to be long term projects. The 800 is almost complete, engine is in the frame as its the easiest place o store it ;D and the 860 still needs some work on cases to fit the 86mm pistons (or rather the spigots for cylinder) then its getting the rephased crank. The cam is done.

I've also bought another pair of CR500 rods, pic is of 447 and CR500 for comparison.
Other pic is rephased crank with CR500 rods, the 447 rod is balanced in position but you get the idea of lower rod angle with short rod.
PJ

[flash]

Ok, you have the crank ready but the engine has never worked, are you thinking in dynamik balancing the crank and pistons? Because if you dont it will vibrate alot?

[crazypj22]

Hi Flash,
I read some of your earlier posts as I wondered what you are trying to achieve with your line of questions/statements.
My motors are not finished so have not been run, and your point is??
I have no information or experience of the 533 rods so I cant comment. I am working at my own pace and have provided information for anyone else who wants to do the same or similar conversions. It would probably be cheaper and easier to have pistons made to fit the rods you already have. When I'm finished I'll run the engines and provide whatever data I'm able to, if I can get a dyno run I'll let you know what is happening..
So far, I probably have less money tied up in the numerous projects than some people would pay for a single carbon fiber/titanium golf club/fishing rod or whatever.
This is my hobby, when its done I'll start another bike, which is already in progress (and I have another 5 or 6 with further plans)
Sorry I'm not fast enough for you, but if you want to spend a couple of hundred dollars ( or pounds I guess in your case) you can get a motor built and tell us how well or otherwise it runs
PJ

[650motorcyclescom]

Hi! PJ,
In the second image your crank is rephased incorrectly. The right hand cylinder needs to lead the left by 3 splines to be a 277° rephase. You said you have the camshaft ground for a 277° rephase so it will not work. Hope you correct this.
www.650motorcycles.com/XS277kit.html

[650motorcyclescom]

Here is a view with your crankshaft:
www.650motorcycles.com/RephasedCranks.jpg

[crazypj22]

Hi Bob,
the cam matches the crank phasing. I had 800 motor mostly built with re-phased crank, etc. but decided to put re-phase into 860 and have all the original numbers match in the 79, so it got stripped down. The 800 now has 360 crank with 'long' rods It is going into the 79 frame for testing but is going to live in the 78 when its all done. ( its actually in the frame but I dont have time/inclination to finish it off/work on it at present, too much other stuff going on)
PJ

[jerry57g]

Do the sleeves from a XV750 work? Are they long enough? If too long they can be shortened easily. Also www.DennisKirk.com has Hot rod Kits for CR500 for around 90.00.

[crazypj22]

I have a pair of liners from XV, bit rusty in bore, so I havnt fitted them to anything (looking for pistons about 1mm over, without paying much) They actually need shortening to 14mm less than 650liners (the amount the rod is longer than stock 447). The piston skirts are about the same length from pin centre to bottom edge on all the pistons mentioned (to within a mm or two)
Handy to know about Dennis Kirk, I had a friend look up CR500 rods, Parts Unlimited only had 19 in the entire USA (they have 17 now ;D) You can see date in pic above, the 'new' ones I got were made 07-01 so I guess they are 5 yrs old already
PJ

[crazypj22]

Fitted oil pump back into clutch cover, clutch assembled and tight cover fitted. Fitted kickstart and checked compression ( no oil in engine yet, except 'film' that's in there during assembly) 180psi left & right cyls. Should be enough to get it running ;D. Need new sump strainer and oiul line (I'm fitting cooler/external filter)
All for now,
PJ

[crazypj22]

Just read this entire thread, I'm about on track for my original time frame but a year behind what I thought I'd be doing.Not much progress. Had to make some new oil fittings/unions as the nice looking ones I had made previously wanted to be in same place as either exhaust or frame tube, working on bench was so much easier, even if wrong Made a blanking plug for rev counter drive going to make an exhaust system soon, getting to use most of the stuff I've been accumulating the last several years
PJ

[jerry57g]

Picked up a pair of XV750 cyl's and good pistons for .99 each, plus shipping total was 9.99 each. Starting the motor now to miss the winter rush

[crazypj22]

Thats an excellent price, I want some more to play with ;D ;D
Thought I'd reply here to move this thread back to top and make it easier to find for people looking for the info.
PJ

[otto]

BUMP!
I might be looking at going this route. Too bad Bigmatt disappeared. I'd say this is a bit over my head, but what the heck.
Hey PJ, hope you notice, how'd those 400cm pistons look? Might be a good option, as then I could save the cost of boring the jugs for now and focus on the bottom end. Do they look like they need milling for clearance at the top like the xv750 pistons do? What kind of CRs you looking at with them you think?
Of all the big bore options, the xv750 looks best. Was that extra head shim really necessary? (ie, is there another option?) Maybe enough meat to cut more off the top of the piston since it needs milling anyways, deeper flycutts for the valves, etc.
Anyways any more experience from anyone in this matter would be appreciated. CHEERS!