Megacycle Cam clearance....

Status
Not open for further replies.
That’s what it says. It’s taken from their current online catalogue. If in doubt, perhaps drop them an email?
 
I had Jim Mosher of Performance Indian rebuild my 850 motor
he installed a MegaCycle 5600 cam specified .009 valve
clearances both inlet and exhaust
 
Hi , for, example the Johnson 360 same lift (.360) BUT duration with 272° at .040 , want 0.008 lash .........
 
Megacycle has specified .013"/.013" clearance for their 560-NR cam (the one manx850 has) for at least 30 years now, and probably more like 40+ . If you have one of their seven other 560 grinds (560-00, 560-20, etc.), you would clearly want to run the clearances recommended for them.

Ken
 
I BELIEVE (but you would have to ask) that Megacycles recommendation "assumes" standard head, barrels, and pushrods.

Tell Barbara what all equipment you are running, and she'll get back to you with alternate settings if appropriate.

She did that for me when I told her I was using a VR880 cylinder with White Bros. pushrods & JE pistons on my bike that got a 560-00, I believe it was .010". Oh, yes, they radiused the lifters for me. I forget who she said she asked, and he gave her the setting for me to use.
 
The subject of lash has been discussed in previous threads on this forum. In one such thread,
https://www.accessnorton.com/NortonCommando/all-about-cams.20413/page-5#post-304501 ,
I posted images of opening ramp details for CDO and 2S cams, but because the images were based in Photo Bucket they are no longer available for viewing. I just reposted the original images there.

I bring this to your attention here to possibly provide some insight into opening/closing ramps and why a vendor might specify a particular range of lash. In general the vendor recommended lash setting provides appropriate clearance to assure that the opening event occurs on the opening ramp regardless of engine temperature. In the CDO plot you can see that the factory specified opening event occurs somewhere near the midpoint of the opening ramp, thus unless a material substitution has been made in the design, e.g., aluminum pushrods, Al cylinder, etc, you would lash any cam with a similar ramp at a similar setting. For the OCD crowd (me) you’d also want to check the lash hot and cold to see how it changes with temp and assure that it hasn’t grown or shrunk unreasonably at temperature extremes.
 
Status
Not open for further replies.
Back
Top