Cam Timing tips

[cannondale27]

xxxxxTOOTH COUNT WILL ALWAYS BE SAME AS STOCK NO MATTER MOVESxxxxx
No Degree wheel?Print this off full size paste it to some cardboard or sheetmetal cut it out,stick it on a socket and mount it to crank and your set.(Mydreamrides idea)
[attachment=7413:Degree_Wheel.jpg]

First off be prepared to spend some time doing this. There is no way to estimate how long it will take to reach the specs you want. Couple times I have hit numbers first try. Other times I have tried nearly 40 combinations on one cam to get what I wanted. Have patience.

Before you start look for wear in the cam drive system. Chain, gears, shafts and bearings. Keep in mind that under load most play will be taken up so a bit isn't critical since you are rotating motor in same direction it runs when doing cam timing. Here is a badly worn chain. If chain has any kinks it is junk.
[attachment=7357:Cam_Timi...tips_010.jpg]

TDC bolt in. Setup your wheel. Use a paperclip under filter cover. Get it as close to wheel matching zero line as possible but not touching. You do this because your eyes can play trick depending on angle you are looking at it. Try to look at it straight on and same each time. 1Deg. matters. [attachment=7358:Cam_Timi...tips_016.jpg]

Confirm TDC with indicator to top of piston. I have never found TDC off more than .5Deg but never know. Then setup your indicator. Notice angle matches angle of bucket as close as possible. Put TDC bolt spacer and cranknut on one of side cover bolts as shown. This guarantees you won't forget to tighten or remove TDC bolt depending on style you have BEFORE cover is on. Cranknut Washer also
[attachment=7359:Cam_Timi...tips_018.jpg]
[attachment=7362:Cam_Timi...tips_017.jpg]

Gear bolts should just be lightly tight when doing cam timing. Loosen them using a vice with softjaws and a breaker bar. Notice alignment with cap before you remove gear. Once you disregard the stock markings on gears this helps. I always remark the gears in same way as factory so you can do your tooth count as normal.
[attachment=7360:Cam_Timi...tips_019.jpg]

Leave bolts out of left timing chain guide it and cranknut will need to be removed if you have to move chain or chain driven gear. Everything else is left intact.
[attachment=7361:Cam_Timi...tips_021.jpg]

Use manual for procedure it is very well written. Following the procedure write down all your results each step doing the math in writing it eliminates errors and gives you records of your work. Congratulations if you accomplish this you will have more power and type of power you want. You also are in a very small club of people who are really serious about thier motor building.
[attachment=7363:Cam_Timi...tips_022.jpg]

Use this order for accomplishing your timing goal:
1)Pin position manipulation with ALL stock gear marks lined up
2)Pin position manipulation disregarding cam gear marks
3)Moving chain driven gear one tooth to left/right of stock mark is 4 deg+ 4 deg-
4)Chain driven gearand pin manipulation.
5)If two or four holecam/gear use a fully adjustable gear on one cam or both as last resort

Remark your gears when you are done ensure your new marks are same amount of teeth apart as stock markings.If only moving pins stock markings will be used for alignment.
xxxxxTOOTH COUNT WILL ALWAYS BE SAME AS STOCK NO MATTER MOVESxxxxx

Here is pic of driven gear and the marking I am talking of.When moving this gear chain will stay in stock position on the crank but be moved one notch on drivengear.Along with leaving the bolts out of left chainguide you can leave the bridge/chain squirter off when doing this also.

[attachment=7410:Rachel_b..._Medium_.jpg]
[attachment=7411:Rachel_b..._Medium_.jpg]
[attachment=7412:Rachel_b..._Medium_.jpg]

Remarked gear.White bright dots are new marks.
[attachment=7414:11_02_08_1253.jpg]

[rayspeed]

See this thread for an excell spread sheet that does the math for you. (you have to have excell to make it work obviously)

http://www.cannondaleriders.com/forums/ind...ic=20726&hl
No excuses for not timing your cams if you want to... these instructins should avoid most of the mistakes and pitfalls that frustrate most people the first time out.


Cannondale timing spread sheet and instructions.
1. Set up your timing marks exactly like the book says and leave the tdc bolt in.
2. Install the degree wheel with the washer and nut and line up the TDC in the middle of the oil filter cover, lock the nut down and fashon a pointer from a long paper clip pointing across the marks on tdc on the wheel right up to but not touching it. You can lightly clamp it with the oil filter cover with the o ring out.
3. Set up dial indicator parallell to way the bucket traveles on intake bucket and zero the indicator. You will need a skinny long probe on the indicator.
4. Back out tdc bolt and rotate crank counter clockwise until the valve starts to open and the indicator reads -1mm or -.0393 if it is sae and if it is a dial that may show as .61 (1mm is .3937008 if you are looking at something that accurate but I doubt it!)
5. Note the degree indication on the wheel
6. Continue to rotate thru until you reach -1mm again or -.039 or .61 again as the valve is almost closed all the way and note your wheel reading

Now go back to tdc and move the indicator to the exhaust.
Repeat the steps above and enter your numbers. Do it again to make sure the results are repeatable.
Tips:
Don????????t overthink it and start adding up degrees of travel of the wheel just put in what shows.
Use a fine pointer right up to but not touching the wheel so you can get it down to .5 degrees.
If you need to change the timing remove the cam and use a soft jaw vise or wood blocks to hold it securly, it will probably be locktited very well so use a breaker bar and steady pressure, some heat may help if it is stubborn. When you make a change keep in mind that your are only changing the position of the pins not rotating the gear in relation to the cam. You are but in a tiny incriment and the gear marks should still line up with the lobes. If you cant get exactly what you want you can change position of the gear and remark if you have to.
Lube up your bearings and seals before you put the cam back in and use plenty of cam break in lube on the cam lobes.
Some people report the cam cap bolt torque may be slightly too high and have reported failed bearings... so you might reduce the cap torque from the 10 the book shows to 6 ft lbs.

It may be a good idea note the timing somewhere on the motor like the valve or side cover for future reference.
106i/106e is factory spec and is strong on the bottom and mid
106i/109e settings are reported to have a smooth power delivery and more on top
107i/108e settings are reported to work well for mx with a strong mid and top
108i/106e settings are reported to have a good top end hit without loosing too much low and mid
108i/108e settings sacrifice some bottom and mid for more top end

Let me know what you think or if you have anything to add.
Ray

[thedeatons]

Spectacular write ups guys..... It should be noted that evidence has shown an increase of ~2hp (peak hp) when going from 106i/106e to 113i/111e. 111i/109e will also provide a great top end hit with slightly more midrange low end than the former timing I mentioned.... Timbo please correct me if I am wrong in my numbers here, I will edit accordingly.

[cannondale27]

I didn't mention numbers but 3 deg seperation with Intake always being higher produces the most power.

[jinx44]

QUOTE (rayspeed @ Oct 27 2008, 04:58 AM) <{POST_SNAPBACK}>

Let me know what you think or if you have anything to add.
Ray

Ray, I have used your spreadsheet a few times, and have also used it for engines other than cannondales, and it definetly simplifies the work. Could I possibly get you to add one more set of calculations to it?

Could you make it so you put in intake and exhaust numbers at the same time? Basically all the same formulas that you currently have in there, just 2 sets of them?

Also, I am trying to find a quick way to see LSA, which would be the average of the 2 centerlines. But with there being 2 possible fields ("if the first number is smallest" and "if second number is smallest"), I can't figure out an easy way to equate that.

[rayspeed]

jinx44,
Here is what you asked for as far as the first request if this posts the file like it should.
As for the other request I am not sure what your are asking... an average of two results?
If so there is probably a way to fix it, there is even probably a way to fix it so that you don't have to do the if one number thing... going to have to consult the excell expert on that (my wife) and if that does not work I will ask a rocket scientist at work... or at least a math major type engineard.
Ray

[jinx44]

QUOTE (rayspeed @ Oct 28 2008, 04:08 AM) <{POST_SNAPBACK}>

jinx44,
Here is what you asked for as far as the first request if this posts the file like it should.
As for the other request I am not sure what your are asking... an average of two results?
If so there is probably a way to fix it, there is even probably a way to fix it so that you dont have to do the if one number thing... going to have to consult the excell expert on that (my wife) and if that does not work I will ask a rocket scientist at work... or at least a math major type engineard.
Ray

Thanks Ray, that is what I was looking for.

The average of the two will give you an idea of valve overlap. But that number is easy enough to do.

If I remember correctly, one cam always uses the smallest number, and the other always uses the largest. I don't remember which is which though. If this is true, then you can make that spreadsheet even simpler by eliminating those fields since you have split up the intake and exhaust calculations.

[cannondale27]

Intake larger or sometimes even. Never less.

[MX Quad Dad]

QUOTE (rayspeed @ Oct 27 2008, 12:58 AM) <{POST_SNAPBACK}>

See this thread for an excell spread sheet that does the math for you. (you have to have excell to make it work obviously)

You PC users jk

Mac users need NUMBERs, just drag the file over the NUMBERS icon and drop it and it will open it

[cannondale27]

Updated the first post in regards to order of manipulation and the Chain driven gear movement.