pics of my tri z powervavle cyl all snazzied up

[TRI Z Racer]

here are some pics of my powervavle cylinder after i had it bored honed and bead blasted. i spent tonight polishing the exhast port and cleaning up the transfers a bit. They looked HORRID!! they are nice and pointed and smoothed out now. i just have a little more work left on them until they are finished. take a look at the pics and let me know what you think

[TRI Z Racer]

couple more

[TriZGuy]

What exactly is a powervalved cylinder??? Hear it mentioned alot, but never knew exactly what it was. Can anyone explain it to me??

[MO350X]

That cylinder is breath-taking, Tri ZRacer.
It ought to flow like crazy.
I'd love to ride a powervalved Z....heck, a powervalved ANYTHING.
I've read lots of good about them.

Be sure to give us a full report when that beast is back together and wheelying in 5th gear. :D :eek:

[twgranger]

It would look better on the Z not your desk. ;)

[Jeb]

What exactly is a powervalved cylinder??? Hear it mentioned alot, but never knew exactly what it was. Can anyone explain it to me??

It's an engine that has a mechanism to raise and lower the exhaust port height based on engine RPM. Allows for top end power while retaining some of the low-end power.

I guess the 86/87 Tecate and 87/88 Tecate-4 were the only powervalved ATVs, stock. Maybe the Suzuki Quad Racers were too, can't remember for sure. Most MX bikes have been since the early 80s.

[MTS]

What year of cylinder did you use? i plan on pickin up a 86 top end here quick...but i noticed a 82 top end too and it has a straight intake n im wondrin if that would work too...?

[RCGUY]

the 87-92 250 quadracers were powervalved and all the 500 quadrecers were powervalved

[Derrick Adams]

83 to 87 cylinders will work for sure, the rest are unconfirmed.

[MO350X]

83 to 87 cylinders will work for sure, the rest are unconfirmed.

Remember guys, you're dealing with a Tri-Z newbie. ;)
Maybe these are stupid questions but I HAVE to know:
"83-87 cylinder" meaning from WHICH '83-87 did the cylinder come from?
It's a bolt-on swap?
If not a bolt-on what mods are required?

Thanks for the clarification.

[MTS]

Remember guys, you're dealing with a Tri-Z newbie. ;)
Maybe these are stupid questions but I HAVE to know:
"83-87 cylinder" meaning from WHICH '83-87 did the cylinder come from?
It's a bolt-on swap?
If not a bolt-on what mods are required?

Thanks for the clarification.
Yz250 cylinder, its basicly a bolt on, you need the PV linkages n set up..just do a serch and you will find a few threds on it...derrick adams did a great step by step for it..

[TRI Z Racer]

yeah, his step by step was really good. I still have a lot of things to work out in mine to get it to the point where its running correctly and making the power it should. if you need any help or advice, dont hesitate to pm me

[hondatrikesrule22]

Sorry for bringing this back up, but I have a question.When you had the cylinder bead blasted, did you have it bored before, or after the media blasting? What media did they use? Does it hurt the bore? How much did it cost to have it blasted? Did you have the head blasted too?

[TRI Z Racer]

it was blasted prior to boring, i am not sure of the glass bead media size, i believe it was the finer stuff. it was like $50 for blasting, boring and recutting the powervalve due to the bore size.

[diggerzmound]

There are some things that you will run into putting the PV cylinder on.. You will have to get a spacer for the exhaust, and you will have to do something with the intake, it points to the side YZ and straight Tri-Z..

Looks smooth Tri-zRacer. Should run good!! :beer

[atctim]

Most MX bikes have been since the early 80s.

Correct me if I'm wrong, but Honda CR's did not power valve until 1992. I have a 92 CR 250 and the 91's are not power valved. Not sure about other Japanese manufacturers, but Honda was pretty much ahead of the pack back then. Possibly Kawasaki powervalved in the late 80's since the tecate had it, but for sure not Yami and Suzi

[hrc85250r]

they started to powervalve cr's in 81 or 82 i think....