Adjustable/Correct! Cam Timing

[Dool]

Us with Scram/Himalayans (LS410) have been duped, the New J platform has adjustable cam timing as it should.
If you dont see this as important then best you do some reading, start at the beginning with the Otto Cycle
The Ignition Timing is important as is the correct Fuel to Air Ratio we agree, so it stands to reason that we want our Valve opening and closing to be perfectly Timed which it is not currently
To achieve just average results we need adjustment of some sort yet all we have is a Tensioner that pulls the Timing back as takes up the Slack.
Numerous times I have fitted Cams and been left with this compromise resulting in Retarded Timing,
How many people have installed their New Cams and not been overly impressed with the results? they all set the Timing or so they think because on a Himalayan/Scram it is hit or miss!

Solution, an Adjustable Cam Chain gear for LS410, this will prolong the Life of Cam Chains and maintain Engine performance on stock Bikes and more importantly enable me to Dial in My Camshafts without being overly Retarded or overly Advanced.

I do not know the Price but a Good Cam is worth Less without adjustment or is that worthless?
Have been told this is a month away so some time this year

 

[thony]

This is a thread to look forward to.

 

[RCruiser]

Peter regarding your rhetorical question: I think, 'worth less' (not worthless). I've often felt a nagging feeling with the 3-4 CAMS that I've put in, with 1 exception I've always kinda felt that it just wasn't 'there', and I've just put this into the category parking lot of 'things to figure out'. Or maybe the category of 'it is what it is'? Sure would like to give the adjustable sprocket a whirl though...

 

[Dool]

I have never been able to get the Timing exact, the Engine was not that well designed when compared to the new 350 "J"
That has a Physical Lock on the Crankshaft ( so you gotta believe it is TDC ) then a Tool to Position the Cam.
We have a line on the Flywheel that we can only get "close" to because of the Eye and the Angle ( and because some people look at the "T" and not the Line!) its close but exact.
Then have Zero adjustment at the Cam and settle for where the Tensioner pulls the Timing back to where it takes up the Slack so we end up with this!



I did remember to put the Bolts in

 

[Dool]

So here is the "update" on the adjustable Cam sprocket,
Should be ready next month!
Consistent delays are a part of this process it seems.
To say it is not necessary is perhaps giving up on a percentage of horsepower, this video shows the potential even though it's not a Himalayan.
Dyno Chart shows increase with adjustable sprockets, we only have 1.

 

[sam2019]

Flashy colors, I can see the importance LOL
I assume this video is just an example for the principle and the the real thing. So YOUR solution is made how and by whom?

 

[Dool]

Pity the Cam Cover is not Perspex, I would like a Gold one.
As yet it appears I have no solution to offer, the Himalayan/Scram is not that popular that these accessories would be made by the mainstream companies that cover Japanese brands.
I was under the impression that ONX was onto it but as the months go by my confidence lessens
Being that the Sprocket and Hub would be Hardened, it's is not just a simple matter of drilling some extra holes. ( not that I haven't contemplated it)
Something has to be done as we fit the pre requisites ( of needing adjustment) because of the modifications we are doing, modifications we do for increased power at present without an option to adjust the Cam Timing.

 

[sam2019]

Something has to be done as we fit the pre requisites ( of needing adjustment) because of the modifications we are doing, modifications we do for increased power at present without an option to adjust the Cam Timing.

in not so many words: situation is hopeless?

 

[Dool]

Well not hopeless but not a priority to those that can achieve it.
Part of the problem is that there is low( very low?) interest in this Design Flaw, if this motorcycle was being raced it would become important and be overcome.
Of course for the " average" owner who is comfortable not knowing what 5 % more power could feel like this is not required.
I know that my Cam Timing has been sub optimal so the results from the Dyno testing are doubtful at best.
Nobody likes to be told they have an ugly baby But it is what it is! ( not my Quotes)

 

[sam2019]

If I get this entire idea right you are talking about a modified part that is depicted here with no. 10 - right?
Make it adjustable instead of a fixed hole for the screw so you can play with the chain movement and take slack out of it when re-fitting it.
Did I get it right so far?

 

[Dool]

yes, but not so much for taking up the slack, more for timing.

 

[sam2019]

ok, how hard can it be to modify this part accordingly?

 

[beemerboff]

 

[sam2019]

Looks good! Source?

 

[sam2019]

Is modifying the oem part an option?

 

[Dool]

I dont think so , but could be wrong.
The Hub that holds the sprocket is pressed on to the OEM Cams and The new High lift that comes with a decomp, that perhaps can be pressed off and modified, I think the sprocket would require grinding to make the elongated holes.
The other Cams on the Market have the Hub as part of the Cam.

 

[sam2019]

The other Cams on the Market have the Hub as part of the Cam.

glue is not an option I figure?

 

[Dool]

Not with the Glues I have seen

 

[beemerboff]

Source is my local engineer , MDA Engineering, run by Martyn Adams.
At one time he was making two piece sprockets for hot shot jap motocrossers, that one is for a old Brit bike.
But his website is gone, now only facebook,

 

[wdgld]

I've fitted adjustable cams to several Yamaha XS650 motors over the years.
When I first saw the cams I was sceptical that two M6 bolts would be man enough to hold the sprocket/cam timing securely, but I have ran re-phased XS650's north of 8500 rpm using these slotted cam sprockets with no issues. As you can see in the picture, the cam sprocket comes with the sprocket through bolt holes in the 'correct' position for immediate fitment, but can be swapped over to the slotted holes and timed with a degree wheel and dial gauge for optimum performance.
Like Dool states, the difference in performance can be significant.