BannedCR500Riders.com

magnetpuller?

ya i think so. it looks exactly like a honda puller but different size threads. i was hoping a honda puller would work but it was a no go

not sure yet if i can make this work but im going to try. honda rod and bearings are much beefier and will add alot of strength. sizing things up to see if i can stuff it in there.


got alittle over .055" now but the honda big end is bigger. maybe trench the cases alittle and machine down the big end. pin will also be 2mm bigger.





need 3mm more width here.






the part in green is pretty thin. im alittle concearned with taking any material out of that area.





where do you guys think the most stress on the rod is ? the big end or small end ?

only place i've ever seen a rod that style fail is about 1 cm under the wristpin area, just pulls the top off and augers the cases out. Hard to say what started it, could have been wedging up with the piston skirt ontop of the crank, under the wristpin that pulled it apart

I like those beefy roller bearings they use! Snap some shots of the ports for us, I'm liking the 3 pairs of transfers, and a big boost port!

from left to right: cr250, ktm 550, cr500


what was ktm thinking when they put this flimsy fuggin bearing in a huge single cylinder . several people told me stories of rod failures, now i see why....... the lower bearing is just as cheesy. im definatly going to have to put the cr500 rod in.

What did you decide to do about a piston?

dannygraves wrote:I like those beefy roller bearings they use! Snap some shots of the ports for us, I'm liking the 3 pairs of transfers, and a big boost port!

i like the roller bearings also. i asked a few motor builders about the 550, they said it can make good power. hopefully the rest of the motor will hold together. im going to iron out the rod issues so that will be plenty strong, and the tranny looks to be plenty strong also. im praying the clutch holds up. i put a magnet on the clutch plates, the fibers AND drive plates are all steel..........the basket might explode though . actually i need a new basket, the steel plates hammered the fuck out of the basket fingers , and theres no rubber cushions in the basket like on the honda

Exnav wrote:What did you decide to do about a piston?

heres the shop thats having wiseco make the pistons.

http://www.seven4racing.com/motoshop.htm

aparently there is some family trouble or something, and thats whats causing the delay.....from what ive been told anyways. im going to wait and get the wiseco piston, honestly i dont care for the mahle design. im sure they are excellent pistons, i just dont like the way they designed the 550 piston. i hope wiseco designs the new piston similar to the cr500 with a solid wristpin boss area, it will make it stronger for when i put the honda rod in there, because the honda rod small end is 7mm wider than the ktm rod.......im going to have to do some machining somewhere to make it fit.

oh and i already tried to put this cylinder on a cr500 bottom end. wont work

how does the rod length work out?
I'm loving that port layout already figuring in my head where I want to remove some material

dannygraves wrote:how does the rod length work out?
I'm loving that port layout already figuring in my head where I want to remove some material

well i have to say, even with the ktm rod, i dont think the 550 had rod angle issues. i believe the cheesy bearings and flimsy rod were the areas causing the failures. the honda rod is 2mm longer, so it will decrease the angle slightly and put the rod ratio alittle closer to what the cr500 has. over all i think the honda rod will work very well in this application, its alittle longer and a shit load beefier, and theyre only like $90

im not sure what the "ideal" rod ratio is for 2strokes, but ive read 1.8 works good in alot of v8 race engines. im definatly no expert on this stuff though, so i could be wrong on some of it.

heres some ratios i calculated. the smaller the number, the more rod angle:

kx500 1.68

cr500 1.82

ktm 550 with honda rod 1.75



what you doing on your head ?

gonna order the honda rod and some other parts probly by the weekend. ill keep this updated when i get it fitted on the crank

found out some info on the piston tonight. i was told by a reputable source the 550 wisecos will be ready with in 4 weeks. i guess they will have some new coating on the dome and skirt. from what i understand, it will also use a "dykes" style ring. i havent read much info yet on that style of ring but i hope its a tried and proven design for hi performance.

I wonder if that is like a total seal ring? I ran total seals in my starion, and for that app I HAD to keep a vacuum on the crankcase for those rings to seal.

not like total seal, like oldschool hemi

the ring is an L shape, fiting the piston lower part in and the tall shelf allows it to "catch" more pressure to hold it down in the ringland.
some sled stuff is the same, mostly single ring applications tho. In some sleds the top of the ring is actually flush or above the outer lip of the pistons crown

a crappy phone picture

aaahhhh, makes sense

1.8 is a good overall rod/stroke ratio but for good life out of a high winding 2 stroke motor 2 is ideal for piston and rod life. For our 500's even getting them reving to 8500 rpms and still making power 1.8 is fine.

other than some sled rods I have seen, you don't get much stouter than a CR 500 rod. I haven't seen another big 500 cc single motorcycle rod that comes really close.

Cool port layout on the KTM, my TRX puma cylinder looks very similar to that design with three smaller transfer ports and the triple exhaust port lay out.

LOVEMYCR500 wrote:1.8 is a good overall rod/stroke ratio but for good life out of a high winding 2 stroke motor 2 is ideal for piston and rod life. For our 500's even getting them reving to 8500 rpms and still making power 1.8 is fine.

other than some sled rods I have seen, you don't get much stouter than a CR 500 rod. I haven't seen another big 500 cc single motorcycle rod that comes really close.

Cool port layout on the KTM, my TRX puma cylinder looks very similar to that design with three smaller transfer ports and the triple exhaust port lay out.

ktm has used almost this same port layout since the early '90's and maybe even the late '80's. im wondering if calvin "borrowed" some of the ktm ideas when he designed the puma, they look real similar. maybe just a coincidence

heres another one i picked up the other day. it gots a pwk, radvalve, and the old style fmf fatty . the previous owner was a total dumbfuck and half assed a few things but otherwise its pretty decent for being 15 years old. im realy stoked about the power these motors have, its just a damn shame theres no reasonable way i could fit it into a AF chassis

It certainly would make a great AF conversion if it didn't cost as much as it will to get it in the frame.
I am sure it would be possible to do it though.
BTW it looks to be in good condition.

very do you mind if I ask... how much did you pay for it?

nice bike, the lil cuz is hunting for one since the weekend, seeing as how he'd break contract on a honda 500