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SuzukiSavage.com
/cgi-bin/YaBB.pl General Category >> Rubber Side Down! >> Cam timing? /cgi-bin/YaBB.pl?num=1475876720 Message started by Armen on 10/07/16 at 14:45:20 |
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Title: Cam timing? Post by Armen on 10/07/16 at 14:45:20 Anyone try playing with the cam timing? On a stock bumpstick or one of the aftermarket ones? Webcam has a decent section in their catalog on the voodoo, but that is assuming one can just play with things like offset Woodruff keys. Just a quick look tells me it'd be a real PITA to alter. But then again, happy cam timing makes for a happy motor. thanks, -Armen |
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Title: Re: Cam timing? Post by Dave on 10/07/16 at 17:23:45 So far nobody has fooled with the cam timing.....although we all see how far behind that timing notch becomes as the cam chain wears/stretches. There isn't anyone that has created a way to alter the timing....there is a pin that locks the gear in place on the cam....and no options to adjust that (yet). |
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Title: Re: Cam timing? Post by verslagen1 on 10/07/16 at 18:17:53 4F5C4B4A55585E5C5708390 wrote:
The forward side of the cam chain run is straight. As an alternate method to taking up slack in the cam chain, OF proposed this... 17343C3E3D34343D2A580 wrote:
http://www.hunt101.com/data/500/medium/Installed3.JPG This is probably overkill taking up the slack and nets 3° advance cam timing. But there's the idea. |
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Title: Re: Cam timing? Post by Ruttly on 10/07/16 at 19:38:18 Really ! You would run your engine with a wooden dowel in it , just for 3 degrees of cam timing ! |
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Title: Re: Cam timing? Post by Ruttly on 10/07/16 at 19:47:30 Armen , Why not machine off a fin or two on forward side of cylinder at cam chain galley to create a flat area drill & tap fab up a adjuster with copper washer & locknut ! Very simple for someone with your skills |
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Title: Re: Cam timing? Post by Armen on 10/08/16 at 04:03:49 Hmm... Interesting. Have to sit in front of the motor and scratch my head a bit. I was hung up looking at the cam sprocket. Drilling new holes in that would be high on the 'no fun' list. thanks, -Armen |
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Title: Re: Cam timing? Post by Armen on 10/08/16 at 05:13:51 Another thought: Verslagen stated that a totally stretched out cam chain would retard the timing by 7 degrees. Not so stretched means fewer degrees. The cam sprocket has 38 teeth, so each tooth is about 9.47 degrees of timing at the cam, which is 4.735 at the crank (cam moves at 1/2 of crank speed). So, if someone is running a stretched out cam chain with the extended cam chain tensioner, probably moving the chain one tooth on the cam sprocket would bring the cam timing pretty close to stock. Thinking out loud here... -Armen |
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Title: Re: Cam timing? Post by verslagen1 on 10/08/16 at 10:08:40 has been done... accidentally. and it doesn't work. common complaint is won't go past 50. and you're comparing .070" of chain stretch vs. 1 tooth at .250" in pitch. I say .01 is ~1°, you say 1 tooth is ~10°... I don't think so. |
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Title: Re: Cam timing? Post by Armen on 10/08/16 at 16:17:38 Verslagen, You had said a stretched chain would retard the timing about 7 degrees. There are 38 teeth on a cam sprocket. If there were 36, each tooth would represent 10 degrees on the cam. There are 38, so each tooth is 9.4737 degrees of the cam circle. A cam rotates at 1/2 of crank speed. Two turns on a crank make one turn on the cam. So, 1/2 of 9.4737 is 4.737. That is the number of degrees of crank rotation for one tooth on the camshaft. If the cam timing (as you said) is retarded 7 degrees for a slapped out chain, then advancing the cam timing 1 tooth would result in correcting the cam timing 4.737 degrees in the right direction. With said clapped out chain, the timing would still be a bit retarded. If the chain wasn't so clapped out, it might bring the timing back to stock. I mention this because so many folks seem to have clapped out cam chains and use the longer cam chain tensioner. Unless I'm missing something obvious. -Armen |
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Title: Re: Cam timing? Post by verslagen1 on 10/08/16 at 16:53:50 That's great, you can type out all those digits. I'm not going to. I'll have to see if I can find the file I used to calculate the numbers. |
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Title: Re: Cam timing? Post by batman on 10/08/16 at 17:06:47 I wonder how far the valves move down when fully open,if you do place a shim behind the front guide is there a chance of the valves strikeing the piston,how much is too much? |
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Title: Re: Cam timing? Post by Armen on 10/08/16 at 18:58:26 Good question Batman. When I change cams, I usually dummy up the motor with a real soft spring, set the valve clearance, rotate the motor and push down on the valves periodically to see how much piston-to-valve clearance I have. |
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Title: Re: Cam timing? Post by Dave on 10/09/16 at 04:03:12 I wonder how accurate the notch on the cam is placed by Suzuki? If it is only to allow the cam to be set on the correct tooth - it might not be accurate enough to used for precise cam timing. If you are going to the trouble of "timing" the cam....then it would be time for a degree wheel and dial indicator......and some advanced motor and math skills! (I am not saying the results wouldn't be worthwhile....it is however more advanced than most of us have done). |
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Title: Re: Cam timing? Post by Armen on 10/09/16 at 04:52:27 Dave, Exactly. If/when I do the timing, I'll def drag out my whole cam timing voodoo kit (degree wheel, piston stop, dial indicator, etc). Just wanted to be able to do something if I found the timing to be off. FWIW, I've never seen a stock motor where the cam timing was within 2 degrees of what the factory said it should be. Sometimes you are lucky and the cam timing can be altered with offset cam keys. I have those for Ducs and Airhead BMWs. But with these scooters, not so easy. To add to the entertainment value, when I do the big motor, I'll measure up combustion chamber volume and measure squish clearance. If i end up skimming a bit off the top of the barrel to tighten up the squish clearance, that'll retard the cam timing a tiny bit. In my abundant spare time ::) |
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Title: Re: Cam timing? Post by Steve H on 10/09/16 at 09:24:30 One problem with your figuring of degrees of crank rotation. The cam turns at half the speed of the crank. The deg of rotation on the crank will be twice, not half, of cam rotation. |
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Title: Re: Cam timing? Post by norm92de on 10/09/16 at 11:36:20 9.47 degrees at the cam, is 18.9 degrees at the crank. Quite a bit. Correct me if I have it wrong. |
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Title: Re: Cam timing? Post by norm92de on 10/09/16 at 12:54:47 Come to think of it, has anybody got a valve timing diagram for the s40? I've seen them on many engines but not this one. |
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Title: Re: Cam timing? Post by norm92de on 10/09/16 at 13:06:32 Retract that last posting. I found the valve timing diagram in Zukis' manual. :) |
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Title: Re: Cam timing? Post by Armen on 10/09/16 at 13:32:01 Steve, You nailed it. Brain fart here. Thinking backwards. Back to the thinking room... |
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Title: Re: Cam timing? Post by Ruttly on 10/09/16 at 15:20:21 One of my Yamaha SR500s that was super fast , had a 540 big bore,ported head,cam,etc . Well anyways one day it ate a exhaust valve while chasing a friends Harley XR1000 at the end of a long straight at about 105 mph. As I was coasting to a stop I let the clutch out to see if engine was locked up, it was ! When I tore the engine down valve head stuck on piston,damaged head,bent con rod! Noticed that the cam sprocket was adjustable, can't remember but cam & sprocket came from the same company,might have been White Bros. Engine was from a half miler flat tracker, wow it was fast |
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Title: Re: Cam timing? Post by justin_o_guy2 on 10/09/16 at 16:19:35 No disrespect intended, Rut, but let's just Look at what you said. wow it was fast I have the Wow, and the FAST, but, I'd like to point out that WUZZZ part... Glad you got shut down without Goin down... You keep the clutch covered? |
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Title: Re: Cam timing? Post by Armen on 10/09/16 at 17:11:16 Rutt, We had one of those sprockets on our SR500 racer. Sure made cam timing changes easy. Put it on about 20 years ago. Can't remember who made it. Wish a similar piece existed for the Savage. |
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Title: Re: Cam timing? Post by Ruttly on 10/09/16 at 18:10:26 JOG , It was a engine I bought for 200 bucks, compression was good , adjusted valves & cam chain & oil change, pulled out another engine that burnt a valve cause header split open on the freeway and didn't make it home, tossed that engine in just to ride it for the summer,that bike went everywhere for 3 years before it gave up under some severe conditions, my buddy with the xr1000 was always amazed that the faster he rode,he always expected to look back and see me still looking for a window to open to pass his asss,but that day he looked back and I wasn't there ! Was a great engine for 200 bucks , yes I said wuzz I heard it back fire when I backed off wot and yanked the clutch in just as rear wheel started to lock up, that back fire saved my asss that day ! Armen, It had three bolts holding sprocket to inner hub. Back then I knew what it did but had no idea how to adjust it. Possible that you could machine one from 2 cam sprockets,making inner hub out of one and sprocket out of the other,three threaded holes and three elongated holes. |
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Title: Re: Cam timing? Post by Armen on 10/09/16 at 18:13:51 Hey Ruttly, I have a spare cam sprocket and will take it to work tomorrow and see what kind of trouble I can get myself into ::) Part of the problem with cam sprockets is that they tend to be hardened and a PITA to machine. |
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Title: Re: Cam timing? Post by Ruttly on 10/09/16 at 18:26:52 Armen ,I always thought they just hardened the area where the chain runs. Just another one of my crazy ideas. I think thats how the one for the SR was made the sprocket side looked stock and hub looked to be faced up ! |
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Title: Re: Cam timing? Post by justin_o_guy2 on 10/09/16 at 18:46:48 GDid you grab clutch because it backfired? |
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Title: Re: Cam timing? Post by Ruttly on 10/09/16 at 19:10:53 Yes, I always cover the clutch when riding stupid fast,that split second it takes to move your finger over the lever and pull it is too long when things begin to go wrong. Engine failures at speed can kill you , it's not like a regular crash ,skidding or loosing traction , it's a violent slam on the ground when rear wheel locks throwing your weight forward. Weight transfer to front wheel sometime causes the death wobble , real hard to recover control. Yes backfire at speed yank the clutch in,something has gone wrong ! I know our bikes backfire,but mine doesn't with that 36vm mikuni,not at all. Took a riding skills course for off road,teacher made us ride the motor cross course and thru the woods with one hand,your clutch hand had to stay tucked in your belt !!! That was tough. |
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Title: Re: Cam timing? Post by justin_o_guy2 on 10/09/16 at 19:16:59 Took a riding skills course for off road,teacher made us ride the motor cross course and thru the woods with one hand,your clutch hand had to stay tucked in your belt !!! That was tough. Nooo, that was sadistic.. I'll change the way I handle it when I'm running hard, thanks. |
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Title: Re: Cam timing? Post by Kris01 on 10/09/16 at 19:34:24 43425F40141F49482D0 wrote:
Post it (or provide a link), please. |
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Title: Re: Cam timing? Post by Kris01 on 10/09/16 at 19:37:16 6360756C606F3539010 wrote:
Valve lift is supposedly 8.5 mm. |
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Title: Re: Cam timing? Post by Ruttly on 10/09/16 at 19:58:54 JOG , It teaches increased balance,no clutch shifting and ability to feel like you are always going to crash but able to save the crash using throttle & brakes but no clutch. If you own a dirt bike try it on a familiar riding grounds you will find yourself going faster & faster,its challenging & fun when you become ok with it. Then when you pull your hand out of your belt and ride normally all fear is gone and your find yourself attacking the track and/or any obstacles,it's amazing how it changes your mindset & skills. When I ride in the dirt which isn't very often any more it's the first thing I do for about half hour,brings back skills and more important brings back confidence!!! |
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Title: Re: Cam timing? Post by justin_o_guy2 on 10/09/16 at 22:29:03 Then when you pull your now stained and foul smelling hand out of your belt and ride norm.. Uhhh, naw man,, I'm gonna pass, The ends of the pegs on my 05were cut way low from dragging through the corners.. I touched a heel, incidentally, scared me. I don't hustle any more,, |
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Title: Re: Cam timing? Post by Ruttly on 10/10/16 at 06:37:56 JOG , I said hand in belt , not finger in butt ! I'm trying to slow myself down too , it's hard to do sometimes ! |
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Title: Re: Cam timing? Post by LANCER on 10/10/16 at 06:42:01 Ya'll getting bad now ! :o |
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Title: Re: Cam timing? Post by justin_o_guy2 on 10/10/16 at 10:41:53 Take my clutch hand away, stuff it in my drawers, and I think a ride through the woods would get just dang near all of that hand. Provided that I didn't hafta grab the handle bars.. Naaah, sounds like a great exercise, good for training, but, I'm just gonna pass ,, |
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Title: Re: Cam timing? Post by justin_o_guy2 on 10/10/16 at 10:51:06 684F4E4E56433A0 wrote:
FWIW, I knew before that what I was doing was foolish and certainly unnecessary, but WHO I Was, in my heart, drove me to Be the risk taker, even while I Knew it was All risk, no reward. It's not until we Are Changed that we change. The people who don't understand that I can't explain it to. Ray will know. |
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Title: Re: Cam timing? Post by norm92de on 10/10/16 at 12:07:17 C:\Users\norman\Pictures\2016-10-10 001\DSC00377.JPG Kris01, I have the cam timing diagram in my computer but I have been unable to attach it? What am I doing wrong? Thanks, Norman. :'( |
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Title: Re: Cam timing? Post by norm92de on 10/10/16 at 12:18:04 kris01 |
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Title: Re: Cam timing? Post by Ruttly on 10/10/16 at 12:23:05 Agreed , It is time , in this world of adrenaline junkies & fools , to let others take the risks and receive nothing in return ! Except maybe on Saturday's & Sunday's I no longer need to prove myself to anyone But after 40 years of riding I don't like not practicing my skills , most skills not used are lost ! |
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Title: Re: Cam timing? Post by Kris01 on 10/10/16 at 18:14:12 Norm, what book is that from? |
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Title: Re: Cam timing? Post by norm92de on 10/10/16 at 20:02:45 Kris, It is from the Suzuki manual. Expensive but fairly comprehensive. |
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Title: Re: Cam timing? Post by Kris01 on 10/10/16 at 21:13:46 I've got a couple of Savage manuals but nothing that detailed. I like the useless facts that won't help me do anything (like cam specs)! ;D Judging by those specs, we have a VERY tame cam. 261° intake / 258° exhaust Valve lift 0.3346" (8.5 mm) IVO 22 BTDC IVC 59 ABDC EVO 64 BBDC EVC 14 ATDC Overlap 36 |
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