Cam timing... who's had it done ?

[weeksyracing]

on a 620 ?


You had it done or not.

[Monty]

Didn't read the post before voting Steve-I had it done on my ST4S-well worth it.

John

[Ray]

Weeksy,

Every little helps as they say, it should be checked, then its up to you where ya go from there, tune it for the compromise you prefer, top, middle or low range.

Some DD bikes have a distinctive exhaust note that might indicate where they are tuning wise or maybe its just the exhaust set up?

Despite the reasonably tight regs there's scope for making the best of what you've got on the bike before ya start on the rider!!

Ray.

[phil_h]

Actually, I think its the inlet snarl that gives away an advanced cam.
I've run full-race cams on my 450 single, and they had a very early opening as well as longer duration and more lift - they made it very very loud, but especially as far as inlet noise was concerned.
My race 620 certainly has that kind of difference to it compared to my old road 620 (which is now gribs mongster) as it is very noisy on wot, especially compared to the 583.
Certainly the single-can and the twin-can 620s sound quite different, so its difficult to compare them.

[Scooter916]

Steve

I did it to my 583 and it was much better, Had the 620 set up but didnt ride it before or after so couldnt comment, Look at the moto one performance website they show dyno before and after modification.
Glyn

[Grib]

The 583 had it done and she ended up being one of the most powerful out there, so I reckon it's worth it :)

[andys 900ss]

The cam what??

Changed the oil, fitted dynojet kit and.......er, thats it. Must get round to changing the belts and plugs soon!

Andy

[domski]

The cam what??

Changed the oil, fitted dynojet kit and.......er, thats it. Must get round to changing the belts and plugs soon!

Andy

You do all that on your own dude??

I just ride mine ;)

:lol:

[andys 900ss]

I even managed to scratch it too, Dom ;)

Andy

[domski]

Ever considered becoming a Ducati technician?

:D

[Grib]

No pressure then :(

I wouldn't panic, I was rubbish on it so she's not used to going too fast anyway :D

[katana]

What does it entail?

[Chaz]

What does it entail?

A trip to Louigi Moto would be a good start just look how our bike goes.

[DaveB916]

Weeksy, our mate Alan Shirley did my Old Senna with some vernier cam kit and pulled 6 bhp out of it, albeit with a slightly rough tickover but who rides on tickover ????

Worth it ? Certainly on the track but can be a pain in slow slow traffic.

[weeksyracing]

What does it entail?

Techincally speaking from what i can gather, it's about the opening and closing of the valves, and getting them synchronised so they open and close together and at the right times.

Chass,

Already booked in with Louigi after discussions with him and Moto Rapido

[andyb]

Techincally speaking from what i can gather, it's about the opening and closing of the valves, and getting them synchronised so they open and close together and at the right times.

Chass,

Already booked in with Louigi after discussions with him and Moto Rapido


:lol: Sorry Steve, but your technical descriptions make me laugh sometimes ( meant in the style of humour not bitching!)

[andyb]

Heres the valve clearance and cam timing chart from my 999r.........

as the testastretta allready has vernier cam pulleys the timing was easily rectifiable

[weeksyracing]

:lol: Sorry Steve, but your technical descriptions make me laugh sometimes ( meant in the style of humour not bitching!)


what bit is wrong then fella ?

[andyb]

"getting them synchronised so they open and close together"

well this bit..........

In the first instance, you need to ensure valve clearances are within tolerance and as there is a range with tolerance, you want it i would suggest to the lower end of the scale, as once the follower is riding on the opening or closing slope of the cam the less time its taking to close up a clearance gap the more pedantic it can be about at which point it opens or shuts the valve.

Once that is done it is a question of where you want a particular cam, be it for the inlet or exhaust, horizontal or vertical cylinder, in relation to that particular cylinders piston to crank position, generally spoken as degrees before or after TDC, top dead centre.

Moving the cam position can be achieved with either vernier pulleys, pulleys that have a seperate centre to outside parts so their relevent positions to each other can be adjusted, or the use of an offset woodruff key, the semi circular key that locates the pulley to the end of the cam.

Moving the cams around ie altering the timing can have a dramatic effect on where in the rev range the engines power is made. One trick on this is to have VVT variable valve timing, so under certain revs the engine is tuned for economy, and over a certain revs the engine is tuned for peak power.

I think they are looking at introducing this on the R1 at some point?

[katana]

So not really that good for a road bike then.

[andyb]

So not really that good for a road bike then.

yes!

[phil_h]

So not really that good for a road bike then.
It's brilliant for a road bike - its one of the main things that sigma do to make a difference during the full-monty.