99summitx
Active VIP Member
I am having my 670x bored 1mm over std, has anyone done this? As I need to know if rave valves need to be shaved down to clear larger pistons. Takes 670 up to 686CC Thanks
Boring and rave valves
- Thread starter 99summitx
- Start date
maxwell
Active VIP Member
i know i did my 600 1mm over standard and i didnt have to do anything. im now going 2mm i think the machine shop said and they said they might have to adjust, i dont think you would need to shave them as they are adjustable
Paininthe#$%
Active member
You can't shave reed valves. The read valve is situated quite far from the piston its self.
saint_nick3
Active member
How did the overbore turn out?
- Thread starter
- #5
99summitx
Active VIP Member
Got talked out of it, Guy suggested as the cylinders are in such nice shape to stay stock as long as possible. go the 1mm over thats all there is, no more if you gouge a cylinder. Should have it all back together next week.
- Admin
- #6
- Joined
- Oct 20, 2006
- Messages
- 39,540
- Reaction score
- 14,738
- Location
- Edmonton Alberta, Canada
- Website
- www.sledbunnyracing.com
Did the same thing on my 98 when the motor was rebuilt, oversize as required and kept it pretty much stock. Extremely reliable and did exactly what I wanted it too in the snow.
I think it's a good call.
I think it's a good call.
- Thread starter
- #7
99summitx
Active VIP Member
That's what Trevor was saying "reliable" staying stock. I'll just stop eating ice cream for the next 6 months and make up the extra little bit of power with weight loss. LOL
- Admin
- #8
- Joined
- Oct 20, 2006
- Messages
- 39,540
- Reaction score
- 14,738
- Location
- Edmonton Alberta, Canada
- Website
- www.sledbunnyracing.com
Here is a cookie to help you with the weight loss...lol....
Attachments
neddacsac
Active VIP Member
Paininthe#$%
Active member
I have a stupid question. What is a rave valve?
- Thread starter
- #11
99summitx
Active VIP Member
It,s not a stupid question, the rave valve is on the skidoo exhaust ports, they open and close depending on exhaust pressure. When their closed( low pressure, light throttle) making a smaller exhaust opening it gives you more torque and better fuel economy while idling and just cruising when open ( high pressure, heavy throttle) making larger exhaust opening it will give you more power for speed and climbing. I think that's it, I'm sure someone will correct me if i'm wrong.
Attachments
Paininthe#$%
Active member
I have only ever herd the exhaust vavles reffered to as "variable exhaust valves" or "Power Valves" I have never herd anyone refer to them as RAVE valves before.... It must be a term one sled manufactures uses.
Now it makes sense why the guys were talking about shaving them! I was thinking to my self these guys should be doing engine work if they don't realize you can't shave reed valves. My mistake sorry for the confusion.
Now it makes sense why the guys were talking about shaving them! I was thinking to my self these guys should be doing engine work if they don't realize you can't shave reed valves. My mistake sorry for the confusion.
R= Rotax
A= Adjustable
V= Variable
E= Exhaust
Bombardier was the first to develope this exhaust valve and as time went on the rest followed. It aids mostly in the bottom and midrange power curve of the engine.
A= Adjustable
V= Variable
E= Exhaust
Bombardier was the first to develope this exhaust valve and as time went on the rest followed. It aids mostly in the bottom and midrange power curve of the engine.
Paininthe#$%
Active member
Are you sure Bombarier was the first to develop this? Honda and Yamaha started putting variable exhaust valves on 2-stroke engines in moto-cross bikes back in the late 80's...
maxwell
Active VIP Member
hmm i wonder why yamaha didnt carry the technology onto there early 2stroke sled motors
Well ya caught me off guard there Mr. I'll find out forsure. And maxwell yamaha did carry the technology the 700srx has powervalves controlled just like cats with a servo. Not 100% sure if they used it on any other models.
- Admin
- #18
I had an RZ350 Motor cycle and it had YPVS Yamaha Power Valve System.
briguy99
Active VIP Member
hi all and good day...not to hi-jack this thread or anything....but i have noticed that 99summitx has a 144 track with the 8 tooth drivers...did you convert this yourself from a 136???? i have a chance to pickup a 144 x 2 track for my 98 summit x. i have read abit about movin the skid which changes the track attack angle givin much more positive results in the deeper powder than just extending the rails or puttin 144 rails on.....does anyone have the proceedure to do this????? pics??? any input???? time to do this...i smell snow...any and all info appreciated....happy postin....Bri
Attachments
Similar threads
