If a CR 250 cylinder will fit a TRX 250R bottom, then why don't the PROS run them???? Hmmmmmmmmmmmmm..........

As for a CR 500 cylinder on a TRX 250R bottom, I'm going to have to see it in person to believe it.

 

I'm laughing at you also, my friend. Think about it what do you think would vibrate more.... a little piston, or a huge piston? haha you crack me up, but, ofcourse the counter balancer will get some of it, but I doubt it will get it all, seeing how the piston is twice the size.

 

A pilot cylinder to TRX bottom has been done before.

 

umm...yea I know the CR500 cyl will go on a 250R bottom end because I had the Mac Racing 500 engine in my R for a couple weeks. I have pictures of it on my site if you'd like to see them Here That big piston does vibrate some, but I believe its the 7 mil stroker crank that causes the majority of the vibration..it isn't as bad as a true CR500, but it is enough to cause the plastic around the tank to humm pretty good. The problem is its a 1 way street..convert, and you're forever using a CR500 cyl, vibration or not.

That being said,I ended up going with an MP Racing 440cc Polonda Engine instead. Uses stock stroke and stock cases, no case mods needed. Which is nice in case you blow up the Polonda at the dunes, you just throw your backup 250 on and keep riding.

 

Guys, I guess my title was misleading, but I wasn't really interested in swapping engines for more CC's. The CR500 and the Polanda engine don't really hold any interest to me. I want something that can run in the 250 Pro class, but be a little more efficent. The CR250 motor was my logical choice due to the fact that its a Honda 250cc motor, nicasil coated, and has an electronic powervalve.

 

well, the guys at ESR say the electronic powervalve will eventually come to the TRX cylinders...just not yet. I really doubt a new CR cyl would bolt up without alot of modification, and most shops will go big before they cut up a 250cc cyl to bolt on. I know the older CR cylinders that are nikasiled will work (FTZ has been doing this for years) but they block off the powervalve, as the R has nothing in the bottom end to run them. As for modifying the current CR ignition to fit a 250R quad...well thats just a task nobody has done yet.

 

FTZ RACING makes a complete engine kit that uses the older style CR cylinder. They also make one that uses the 98-01 style CR cylinder. They do not make one that uses the 2002 CR cylinder though. These are stroker kits though. Here is another link Stroker Kits.

I think that you were wanting to use the 2002 type end, since you are talking about the electronic powervalve. The problem with that is that the 02's are case reed induction. This means that the reed cage housing is part of the engine cases, not part of the cylinder. Therefore, the cylinder on the 02's is much shorter, and would require some type of large, custom spacer for it to work. Take a look at this: 2002 CR250R some pics of the new engine and cylinder.

Good luck.

 

aha..case reed induction would make that swap pretty difficult [img]i/expressions/face-icon-small-smile.gif[/img]

 

Well, I wasn't really asking about the 2002, because that motor would be WAY to expensive to build. Dill, you are right.. The case reed induction would be very hard. When I get on a little bit better computer, I will check out FTZ. Have any of you guys ever ran an FTZ motor?

 

Here is a 250R motor with a CR cylinder. Dont know if it is nikasil coated though.