Topic: Degreeing a cam with no data: comments?

[MCRider]

So I get this WebCam grind #41 (not 41a) from APE. I get a card with lash. lift, and duration, but nothing else.

So i call WebCam and they say just throw it in as is and go, they don't provide any more data than that. called APE and essentially the same.

Though I'll have an adjustable sprocket from APE and I can do what i want.

I actually have no problem dropping it in and going. Done it many times before. But I've always been intrigued with the idea of making it better.

So any engine builders have a comment?  Remember the 41 is the puniest of thier offerings, and WebCam says they don't change the lobe centers, so its good to go as is.

Jeff at APE (not Big Jay) suggested, after I did, this idea of "squaring it up" and then trial and error to find the sweet spot.

[scondon]

Ah yes, the infamous Webcam timing card dilemma 

KB02 posted the specs for the 41a recently.

http://forums.sohc4.net/index.php?topic=55839.0

When I did my Webcam I squared it up as recommended. Then I turned the engine until the "open" number matched the timing card, and noted what the lift was ( about .038 if memory serves ). Then I spun around to close and measured at this same lift. I got the #'s to very nearly match the card, just not at the .050" lift spec'd on the card.

Hope that made sense

[MCRider]

Ah yes, the infamous Webcam timing card dilemma 

KB02 posted the specs for the 41a recently.

http://forums.sohc4.net/index.php?topic=55839.0

When I did my Webcam I squared it up as recommended. Then I turned the engine until the "open" number matched the timing card, and noted what the lift was ( about .038 if memory serves ). Then I spun around to close and measured at this same lift. I got the #'s to very nearly match the card, just not at the .050" lift spec'd on the card.

Hope that made sense

I followed most of KB02's travails. I have the 41 not the 41a. The advertised duration of mine is less than his. What I don't have is any open or close data.

It'll be a while before I'm installing the cam. I'll collect your comments and raise the question again then. THanks!

[scondon]

I followed most of KB02's travails. I have the 41 not the 41a. The advertised duration of mine is less than his. What I don't have is any open or close data.

It'll be a while before I'm installing the cam. I'll collect your comments and raise the question again then. THanks!

 Funny how I read your well written post and didn't grasp this bit. I wonder if I should be twirling wrenches today  
 

[MRieck]

I followed most of KB02's travails. I have the 41 not the 41a. The advertised duration of mine is less than his. What I don't have is any open or close data.

It'll be a while before I'm installing the cam. I'll collect your comments and raise the question again then. THanks!

 Funny how I read your well written post and didn't grasp this bit. I wonder if I should be twirling wrenches today  
 

Basically a stock cam.

[MCRider]

I followed most of KB02's travails. I have the 41 not the 41a. The advertised duration of mine is less than his. What I don't have is any open or close data.

It'll be a while before I'm installing the cam. I'll collect your comments and raise the question again then. THanks!

 Funny how I read your well written post and didn't grasp this bit. I wonder if I should be twirling wrenches today  
 

Basically a stock cam.

That's really what I needed to know. There is a visible difference between it and a stocker, likely all I need or want.

Bigger bumps, maybe later.

I'd had big bump cams before, in my Triumph and my CB750 racer. While sexy and all, and necessary if HP is the goal, on a street bike, one must think twice.

Thanks.

[wrenchmuch]

I installed the same cam in my 836 . Given what I saw on this site I set the centers as close to equal as possible using the instructions on Webcams site . I put Kibblewhite valves ,springs ,and guides in with a mild port job ,and stock carbs . Carbs still need some work . It runs well to about 4000 RPM then the power comes on nice right up to 8500. Thats about how far I've pushed it so far . I might re-degree for more mid if I do it again . Hope this helps .
Mike

[MCRider]

I installed the same cam in my 836 . Given what I saw on this site I set the centers as close to equal as possible using the instructions on Webcams site . I put Kibblewhite valves ,springs ,and guides in with a mild port job ,and stock carbs . Carbs still need some work . It runs well to about 4000 RPM then the power comes on nice right up to 8500. Thats about how far I've pushed it so far . I might re-degree for more mid if I do it again . Hope this helps .
Mike

Sounds good, I can do all that. I'll be using 29mm Mikunis, used them before with good results. I don't lug it, but I won't be looking for 8500+ either. Guts in the upper middle is the goal.

Thanks!

[754]

The middle upper for most cams is 7-9K..

 As for only revving an 836 to 8500, you can do that with stock cam.

 I find the extra rpms available with the hotter cams, give you greater choices of gearing (added benefit)

[MCRider]

The middle upper for most cams is 7-9K..

 As for only revving an 836 to 8500, you can do that with stock cam.

 I find the extra rpms available with the hotter cams, give you greater choices of gearing (added benefit)

Many of you have much more current impressions, experience to work with than i do. So if 7k+ is comfortable, I can do it as I have rods, springs, Ti retainers, etc.  I'd even pop for a hotter cam, could probably resell the 41.

If I need to detune to my liking, I have 2 stock cams, with obvious different grinds.

So I look forward to the experience.

[NitroHunter]

You could use the lobe center method, this will tell you what the cam is ground at.
Most aftermarket SOHC cams are around 103-106 lobe centers.
 
To find lobe center:
(opening + 180 + closing) / 2 = XXX
XXX minus the opening # = Lobe center when measuring intake valve.
XXX minus the closing # = Lobe center when measuring exhaust valve.

[MCRider]

You could use the lobe center method, this will tell you what the cam is ground at.
Most aftermarket SOHC cams are around 103-106 lobe centers.
 
To find lobe center:
(opening + 180 + closing) / 2 = XXX
XXX minus the opening # = Lobe center when measuring intake valve.
XXX minus the closing # = Lobe center when measuring exhaust valve.

I think that is the method described on the webcam site

http://www.webcamshafts.com/

Click on the "Degreeing your CamShaft" link on the left.

I haven't been thru it completely yet.

I've no doubt I'll get her to run as good as she can. Good help and a reasonable skill level.

Thanks!

[paulages]

i agree with NH- find your lobe center if you want to dial it in perfectly. 104-105 degrees should do it.

[MCRider]

OK, will do, thanks.

[Bill/BentON Racing]

Great help and well above reasonable skill level!!!!!!!!!!,Bill

[MCRider]

Great help and well above reasonable skill level!!!!!!!!!!,Bill

Thanks... we'll see.