KTM cylinder...

[jcs003]

has a KTM 300, 360 or 380 ever been mated to a trx bottom end?

of course, the PV would need blocked off. just taking a cheap glance, the bolt pattern looks like a promising match.

[troybilt]

Originally posted by jcs003
has a KTM 300, 360 or 380 ever been mated to a trx bottom end?

of course, the PV would need blocked off. just taking a cheap glance, the bolt pattern looks like a promising match.

How's the PV operated on those cylinders? Could control it with a small servo. Would be a fun project. I was working on my Master a few years ago for a couple of semesters, on Servo motion controls... then decided a paycheck was more important.

[jcs003]

Originally posted by troybilt
How's the PV operated on those cylinders? Could control it with a small servo. Would be a fun project. I was working on my Master a few years ago for a couple of semesters, on Servo motion controls... then decided a paycheck was more important.

this idea just popped into my head yesterday when i was considering getting a roller and putting in a KTM big bore.

im not sure how the PV works. my assumption is that its like a rotax design.

another thing. the gasgas has a counterbalanced bottom end. i would say, some BIG BORE motors could be built from this. 500cc and more.

[troybilt]

Originally posted by jcs003
this idea just popped into my head yesterday when i was considering getting a roller and putting in a KTM big bore.

im not sure how the PV works. my assumption is that its like a rotax design.

another thing. the gasgas has a counterbalanced bottom end. i would say, some BIG BORE motors could be built from this. 500cc and more.

Yes and the cylinders could be compatible or close to being anyway with 250r aftermarket cylinders...

If the KTM PV is like a Rotax, then the PV is operated by the exhaust pressure right and not a linkage like the older CR cylinders??? correct?

Didn't KTM build a 500+ cc big bore 2 stroke, I forgot what it was... I even looked at buying one back when I was heavy into dirt bikes in the early 90's... It was 510 or 525 or something...

[Jerry Prokop]

the big ktm was a 550 and I've had quite a few 2000 and newer 2 stroke ktm's and they all had the power valve run off the crank but that servo idea could work

[jcs003]

Originally posted by Jerry Prokop
the big ktm was a 550 and I've had quite a few 2000 and newer 2 stroke ktm's and they all had the power valve run off the crank but that servo idea could work

from what i have read. the ktm big bores have great useable power. also, the info i gathered lead me to believe the 360 and 380 are built tame and have the potential to put up big numbers with minimal modification.

[bsmith106]

All the ktm top ends, 300,360,380 are case reed intake and the powervalves are run by a centrifugal govenor. their may be some older models, early90s that are cylinder reed. The 380 top end bolts to the 300 bottom end with minor or no mods. all the bolts line up powervalve links up etc. Theirs a guy on ktm talk who just did this at built it to about 440ccs. If someone would cast a new set of ktm cases to accept a balance shaft it would bring alot of possibilities with it. Right now theres sx, xc, and xcw all built of the same cases. 5spd close ratio 6spd semi close ratio and 6spd wide ratio traany options, as well dual map ignitions with changeable cdis sx=hard hitting xcw ignition=heavier flywheel and the ability to run lights, and all these parts are available from your local dealer. on a side note is why hasnt anyone adapted a 02 and up cr250 ignition to the trx. It has a servo run powervalve that should b adaptable to pro-x and esr style powervalves. If you buy a vortex ecu it gives you control over valve opening so it could be tuned to a riders liking and should be less headaches than the diaphram style, just have to check cable slack once in awhile. Most new sleds still have the blade style powervalve but abandoned the exhaust activation in favor of servos about ten years ago.

[jcs003]

great info bsmith106. i know the KTM rod has been used with the trx crank. this im assuming they have the same stroke??? or evidently have the same length connecting rod.

another thing i would like to know is if the KTM bigbores are all using the same bottom end(same crank assembly and such)