Seeing that CT Racing has been putting the Rotax power valve onto the 250R engine, I was wondering if the same thing can be done for the Banshee?

87 Banshee
99 Banshee

 

Why not jsut find the Cylinders and power valve off of the RZ350 street bike engine. they would bolt up.

 

see my home page for details of the RZ banshee engine, get on down past the raptor stuff.

http://homepages.ihug.co.nz/~crainic/INDEX.htm

Kiwi-Craig

 

i checked that out a while back but i was thinking, what pipes do u use? can u use banshee pipes or would u have to et some specially made pipes? same question for the carbs and manifolds, and what about the head? all banshee parts for this?

 

Ok here we go:

you use the RZ head, it matches the larger water jackets on the RZ cylinders. You need to fabricate short stibs to bolt onto the RZ exhaust ports (easy) then your Banshee pipes bolt straight on. You need the RZ stator, flywheel, CDI, YPVS black box and YPVS servo motor.

Yes your intake manifolds, reeds and carbs will bolt straight on, they are basically identical except that the RZ doesn't have that TORS crap stuck on the top of the carb bodies.

And yes the effort is worth it, an RZ cylinder will produce more midrange torque than any Banshee cylinder based setup AND awesome top end grunt AND a smooth linear electric type power delivery........ all to do with those magic little powervalves...........

Kiwi-Craig

 

My local yamaha shop has a used RZ 350 for sale.
They want 1500 bucks for it. Do you think it would be worht it to buy the bike and use the parts i need off it. Or is the power gain insignificant compared to the cost and hassle.

scotch- 2000 banshee, renthals, razars, holeshots, Pro curcuit pipes and silencers, pro flow kit, shockwears, cascade headlight covers

 

I'm not going to get to indepth here but I would like to offer a few comments. The gains that would be seen would not be worth the 1500$ price tag. If it were every race shop in the country would put the engines on their pro bikes. Second, is the fact that the banshee pipes will not perform properly on the rz engine. The engine rpm range is different. The exhaust valve is used so that the port duration could be increased for more top end while still scafrificing bottom and mid. I know a guy who has experimented with this and the only thing that would come close to matching the power band was drag pipes. In most instances the power valve is used for added torque, but in this case they were used to maintain mid range so that the exhaust port could be opened up more for top end speed. Remember that the rz engine was not designed for MX or XC, but for road racing. The power vlave has a different purpose in this sense.

 

Would modern power valves like Rotaxs be a better sollution than going the RZ direction? I read that CT had great success putting one on the 250R, so thats why I was thinking if the same thing could be done with the Banshee? I'd like to know how something like that would do. Would be interesting.

87 Banshee
99 Banshee

 

Brandon

surprised your buddy had so much problems, just how ported to death where his cylinders. Stock RZ cylinders work great on a Banshee.

I know personally three guys running this setup with exceptional results, all three are full on racers who have been down the fully built banshhee cylinder race engine route and have junked them for the RZ setup. These quads are amazingly rideable.

The RZ powrvalves where used in the production bikes to maintain midrange grunt and allow a decent top end and retain tractibilty for general road use, ie a better mousetrap for run of the mill road users. Serious road racers who port the living daylights out of these engines don't bother with the powervalves, they come in to low at 5500 - 6000 rpm on there 12000rpm screamers.

Ask your average Banshee engine builder if he has ever seen an RZ engine, chances are NO......... ignorance is bliss...............

Stuart Toomey of Toomey racing pipes (think he knows a thing or two about Yamaha 350's) has commented that we can expect between 50 to 60 BHP from the stone stock RZ porting with T5 Banshee pipes. The RZ porting layout, stock, is similair to the Banshee, see my webpage for comparative maps, with one important exception. The exhaust port height is 2.5mm higher, yet the powervalve has 3.5 mm travel, therefore it starts of with 1mm slightly retarded port timing CF the Banshee to plus 2.5mm advanced. The transition through the rev range is smooth as and the top end rush impressive. Porting them just increases the power with the tractibility advantage basically maintained.

We tried my friend Grahames Banshee with the powervalves locked up,ie full open, hell it was gutless,NO midrange, clutch city to get it off the turns, powervalves locked down it was super torquey but reluctant to rev over 6500rpm, a short shift Banshee !!!, working, it's just damn impressive.

I agree that $1500 is too much, the whole setup can be on and running for about $1000 or less if you are resourceful in picking up the parts, just who much did you say your 60HP engine kit costed ??

I find so many doubters out there it's amazing. Big Time racers such as Dean Sundahl who I believe has won more desert races than any other quad pilot, used Tommey built RZ engined Banshees as far back as 88 (again see my webpage article) Also I think either DirtWheels ?? or 3 / 4 wheel atv action did a Banshee RZ engine article about 6 years ago, the ultimate woods Banshee setup they called it I believe............ so it's nothing new, just different.............. and it works.

 

Yea, what he said!! hehe