Hello all,

I have been reading for a while now older posts on different forums regarding the adjustable cam sprockets. I cam across the topic while looking for possible issues that could cause a camshaft to be out of timing.
From what I read people are on the fence about them . Some fear the bolts loosening over time , but some people do feel that they were able to zone in more on a cams sweet spot. I mean I understand the concept and I could see how it could help with a more aggressive camshaft, but what about for street cams like the newman ph2?
Can the same thing be done by retarding/ advancing the stock sprocket by a tooth or is the adjustable sprocket able to do more precise and incremental adjusting.
seems like the posts i have read on the topic are all older, so just wondering what the opinions are from some of you that have used it in the past and if u felt it was worth it with your setup?

 

A good aftermarket cam will sometimes have a slight advance/retard in the timing already built into the profile of the cam lobes. It really depends on what the cam maker was trying to accomplish.
An adjustable sprocket will let you fine tune the timing to get your desired hp/torque curve out of the engine, and will be much more precise than jumping a tooth on the sprocket. Keep in mind, this is less about hp/torque gains, and more about where the engine is making power wrt RPMs

 

Adjusting by one tooth will not really work, it's not precise enough.

And yes, as mentioned above, if you get the proper Cam for your driving style or needs, it will really only give you minimal benefits, esp for street use.

That being said, I personally am in the Thumbs Up camp on them.

I've had excellent results with one, esp on the OEM Cam, but....
They need "a lot" of experimentation and testing to get them right if your doing it yourself.

All of mine have been from Thumper, and while adjustable, they were actually sold as "Adjusted"... tested and set by him.
I've never loosened the set screws (bolts) or made any attempt to change them.
But I've also never had one loosen up either, even with my higher rev limit.

Hope this helps.

 

Thank you mrbean and blwnaway for your responses,

it seems to be a great addon to be able to dial in to the sweet spot for the correct power . From All the posts I was reading it seemed that thumper tested it quite a bit and found that the adjustable sprockets did dial in the stock cam quite a bit and it did add some power . The only thing in the older posts i had come across is that he did state that he didn't think it would be beneficial for the newman as something to do with the center line of the camshaft. Unfortunately some cam makers don't like to disclose all cam specs so.it seems to be a complicated to do properly without proper cam cards

Seems that quite tooth jump on the ctock cam sprocket is over 15 degrees , so u are correct 1 tooth jump will be too.much . The adjustable goes up to 10 retard/advance i think. Not 100 percent on these specs, just trying to pass on some info i found.

I have contacted thumper for some info . He still suggests some degree on the newman ph2 . I did notice when checking timing that once cylinder 1 is at tdc there is quite a bit of movement on crank rotation where the piston stays at tdc before moving , so that could explain how the adjustable sprocket could help in dialing it in . I am surprised I have not seen more people suggest this mod in their more advanced builds? Is it because more new cam grinds take that offset into consideration now compared to before?