slotting the cam sprockets
Senior Member
Superstock
Joined: May 2012
Posts: 397
From: UK
As you know this is something I have been thinking of doing as I believe it will make a difference even on a standard engine to counteract any chain wear. Plus it gives one a way to individually move each cam a few degrees either way.
Not much as you will only shift things no more than about 4 degrees either way. Adjustable Cam Sprockets/ Falicon Crankshaft Components, Inc. 727.797.2468 I don't think you would be able to make the slots accurately yourself as it wont be keeping the balance so will need to be machined out. Both slots would need to be an exact mirror image.
But you will also need a degree wheel The Machinery Cleanery Universal Timing Disc, Degree Wheel, Downloadable - Goniometro per Messa in Fase dei Motori a 4 Tempi - and dial indicator gauge.
Here an interesting thread on here with some useful info. It goes off topic a bit but go with it and there are some useful snippets.
https://www.superhawkforum.com/forum...stage-i-17262/
And here's a few links for some interesting reading. Which will give you an understanding as to what does what, and what you want to achieve.
Check Your Lobe Centers, Ma'am?
ISKY Racing Cams.
Cam Theory 101
Degree dual overhead camshafts to increase engine performance
(:-})
Not much as you will only shift things no more than about 4 degrees either way. Adjustable Cam Sprockets/ Falicon Crankshaft Components, Inc. 727.797.2468 I don't think you would be able to make the slots accurately yourself as it wont be keeping the balance so will need to be machined out. Both slots would need to be an exact mirror image.
But you will also need a degree wheel The Machinery Cleanery Universal Timing Disc, Degree Wheel, Downloadable - Goniometro per Messa in Fase dei Motori a 4 Tempi - and dial indicator gauge.
Here an interesting thread on here with some useful info. It goes off topic a bit but go with it and there are some useful snippets.
https://www.superhawkforum.com/forum...stage-i-17262/
And here's a few links for some interesting reading. Which will give you an understanding as to what does what, and what you want to achieve.
Check Your Lobe Centers, Ma'am?
ISKY Racing Cams.
Cam Theory 101
Degree dual overhead camshafts to increase engine performance
(:-})
Administrator
MotoGP
Joined: Apr 2006
Posts: 4,402
From: Kempner, TX
IOW slot them so ALL slots allow for the MAX advance you want (say 4deg).. if one slot would allow say 5 deg,, but your only dialing in 4 deg.. it means nothing.. you're not slotting them to allow for an exact degree change.
Yes absolutely,, and the skill to use it.. plus a dial indicator, the ability to make / modify a mount for the degree pointer and the degree wheel to the crank.
If math, observation skills, meticulous methodology are not in your personal skill set... DO NOT TRY to degree cams.
The only time slotting a cam gear at home with less then CNC precision will work, is on designs that actually center and locate the gear on a boss machined onto the cam..
So that the cam gear bolts are ONLY clamping the gear in place.
When the cam gear bolts also locate the gear in relation to the cam... all bets are off. Those slots must have perfect form degree of arc and location to work.
VTR OEM cams use such a locating boss
Last edited by E.Marquez; Aug 24, 2013 at 07:10 AM.
Senior Member
SuperBike
Joined: Dec 2005
Posts: 1,689
From: South Lake Tahoe, CA, USA
I slotted mine by mounting them in a rotary table on a Bridgeport mill. I have also been told of people elongating the holes successfully with a Dremel. As E. Marquez stated, the sprockets locate on the center boss on the cams. The bolts only provide a clamping force.
Senior Member
SuperBike
Joined: Jul 2005
Posts: 1,548
From: MN
I agree with Emarquez - all those skills better be strengths of yours, particularly patience. Doing it with engine in bike is a pain in the ***, particularly getting a good solid mount for both the timing wheel, and then the dial indicator to measure travel - and a good align on the thing. If you enjoy learning then do it - its cool.
I would suggest checking the timing first before removing any of the sprockets/cams etc. If you can reliably get it set up and then get good readings and reasonable numbers that make sense and are completely reproducible - then you should be set to remove gears and slot them. Of course you should be sure valve clearance is correct at that point and do that first if not. On these a dremel works fine. If you know what you are at and what you want to be at then you can slot in just one direction and just the right amount be converting degrees to the circular distance. then you worry less about ever slipping etc.
good luck. its fun and lots of help here.
b
I would suggest checking the timing first before removing any of the sprockets/cams etc. If you can reliably get it set up and then get good readings and reasonable numbers that make sense and are completely reproducible - then you should be set to remove gears and slot them. Of course you should be sure valve clearance is correct at that point and do that first if not. On these a dremel works fine. If you know what you are at and what you want to be at then you can slot in just one direction and just the right amount be converting degrees to the circular distance. then you worry less about ever slipping etc.
good luck. its fun and lots of help here.
b
Rex Kramer-Thrill Seeker
SuperBike
Joined: Jan 2011
Posts: 2,312
From: Brookfield, WI
In a conversation with one of our long time resident VTR guru's (I really hope he doesn't mind me quoting him outside of the forum), I had been looking for any dyno results from swapping out the intake cams for four exhaust cams, and this was his reply:
"I questioned Roger Ditchfield and his reply was, basically, don't bother. There is minuscule difference between the stock intake and exhaust cams (both have 245 degrees duration, and I think the exhaust has 0.1mm more lift). You have more to gain from indexing them (stock is 102.5 and 107.5 LCs, intake and exhust, respectively). You could try setting them at 101 and 106, which would give you about 3 degrees more overlap (slight loss in low-end for slight gain in mids and top)."
I hope this information helps.
"I questioned Roger Ditchfield and his reply was, basically, don't bother. There is minuscule difference between the stock intake and exhaust cams (both have 245 degrees duration, and I think the exhaust has 0.1mm more lift). You have more to gain from indexing them (stock is 102.5 and 107.5 LCs, intake and exhust, respectively). You could try setting them at 101 and 106, which would give you about 3 degrees more overlap (slight loss in low-end for slight gain in mids and top)."
I hope this information helps.
Last edited by CruxGNZ; Aug 24, 2013 at 02:35 PM.
Thread Starter
road racer v2 power
Superstock
Superstock
Joined: Jan 2011
Posts: 265
From: coventry england
thanks guys , im getting the sprockets slotted to moriwaki spec by a very good engineer and hopefully getting a good spanner monkey to set and fit them as i lack the tools and knowledge however im learning . it aint half confusing tho lol.
i am having 4 exhaust cams fitted at the same time all this is to a loose engine .
so by setting them at 101 and 106, which would give me about 3 degrees more overlap and a slight gain in mids and top that sounds good
i am having 4 exhaust cams fitted at the same time all this is to a loose engine .
so by setting them at 101 and 106, which would give me about 3 degrees more overlap and a slight gain in mids and top that sounds good
Senior Member
SuperBike
Joined: Feb 2013
Posts: 1,510
The first time I degreed cams was on a Cannondale ATV engine. We did dyno runs before and after, on similar days (time of day/humidity/etc). Cannondale cams/gears are splined, rather than slotted.
We had a specific setting we were looking for on intake, and exhaust. It took us 14 hours to reach that setting first time around.
Eventually we were able to get the process down to 2-4 hours, depending on where the stock settings were, and how far off they were from the desired setting.
The difference on the dyno was minuscule power-wise, though it did help us shift the power curve exactly where we wanted it. If I remember right we saw 2-3hp difference by doing this, and that was on a 45-55hp engine. So roughly 5% improvement.
We were doing it because it was "neato", and we had some extra time between trips to the dunes. A major plus was that it's free, as long as you have the patience to do it.
If I had to do it over again, I would have spent more time with my family, and left the 2-3hp on the table, though it was a valuable learning experience. For street riders the improvement isn't worth the time/effort. For racers it is a must.
Before anything is slotted I would have someone mark the original location with a "-" (dash) marking, so you can return to stock at any time.
Also - If you are not doing dyno runs before and after, and comparing the hp/torque curves, then you won't really know what you spent all your time on.
James
We had a specific setting we were looking for on intake, and exhaust. It took us 14 hours to reach that setting first time around.
Eventually we were able to get the process down to 2-4 hours, depending on where the stock settings were, and how far off they were from the desired setting.
The difference on the dyno was minuscule power-wise, though it did help us shift the power curve exactly where we wanted it. If I remember right we saw 2-3hp difference by doing this, and that was on a 45-55hp engine. So roughly 5% improvement.
We were doing it because it was "neato", and we had some extra time between trips to the dunes. A major plus was that it's free, as long as you have the patience to do it.
If I had to do it over again, I would have spent more time with my family, and left the 2-3hp on the table, though it was a valuable learning experience. For street riders the improvement isn't worth the time/effort. For racers it is a must.
Before anything is slotted I would have someone mark the original location with a "-" (dash) marking, so you can return to stock at any time.
Also - If you are not doing dyno runs before and after, and comparing the hp/torque curves, then you won't really know what you spent all your time on.
James
Thread Starter
road racer v2 power
Superstock
Superstock
Joined: Jan 2011
Posts: 265
From: coventry england
I have a spare set of sprockets they are the ones being slotted .
I know I won't gain much or if any but compositing for chain where is good and like you said moving the peek power around .
This is for the road bike but I will be doing it on the track bike too .
I still have lots to read and understand . Thanks guys for the head ache lol
I know I won't gain much or if any but compositing for chain where is good and like you said moving the peek power around .
This is for the road bike but I will be doing it on the track bike too .
I still have lots to read and understand . Thanks guys for the head ache lol
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mikstr
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Sep 18, 2012 09:37 AM
