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Discussion Starter #1
How much difference would there be allowable in cam lobe "height" (measuring with a pair of calipers the lobe at it's tallest point) from a Megacycle cam? I have one that has an exhaust lobe measuring .020 higher than the other one . . . . (This is a 4 cylinder MegaCycle cam 13120)
 

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are you sure the difference is in the lobe height and not in the flat spot/low spot on the other side of the lobe?? im pretty sure you need some pretty special measuring tools and jigs to measure them.

jc

i dont know shit
 

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quote:
are you sure the difference is in the lobe height and not in the flat spot/low spot on the other side of the lobe?? im pretty sure you need some pretty special measuring tools and jigs to measure them.

jc

i dont know shit
I think you hit that one on the head. To get an accurate measurement of the total lift, you have to have the cam centered on the bearings (I think) and just measure the lift from the "closed valve" area to the "full open" area. As Joe says, the total distance of the cam lobe may not mean anything, or it may at least be irrelevant to the concern of lift.
Joe knows shit.
He just don't know Diddly. I do, I met him backstage once.

FR
 

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But I guess we still didn't answer the question, which is how much difference is allowable.
I don't know. If it were me, I send it to Megacycle and be prepared for the worst. They're kind of a pain to deal with, but their work is spot on, and they still make stuff for vintage bikes. So I guess I can deal with sending certified checks etc.


FR
 

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Discussion Starter #6
yes, that is interesting, that if you can measure the lobe, it is irrelevant if the lifting height is the same for both lobes . . . As I stated, this is not the way to be measuring cams. Problem is, this is the lobe that keeps bending valves and kissing (to use a caferacer gay term) the piston. We are already in touch with megacycle, I'll keep ya informed as to what they say . . . then on to blocks and a dial indicator.
 

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Discussion Starter #7
yeah, what I said. And Joe doesn't know shit.
 

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actually, if youre using calipers, youre going to get the height compared to the others. (duh, i should read and understand before spewing misinformation) 02 is a valve clearance on most hondas anyway. that might be enough to do it as the valve seats and tightens and if youre running serious close squish. although if youre setting the gap correctly, the only thing that should rally matter is if its out of balance. and id guess it should be near perfect. hmmmmm......yeah, be sure to repopst the info here. this is interesting.


just my opinion.

i dont know anything about details. i dont know what youe talking about tim. ;)


jc

i dont know shit

Edited by - joe c on Feb 05 2008 9:36:50 PM
 

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Evil...chuck it up in your lathe using centers in both ends, then use a dial indicator to check lobe height. That's what the rocker will see.

Still .020" is a LOT... could be making that rocker bounce causing float etc which would bend valves etc. Being out .020" means the ramp could be different on that lobe too.

Megacycle really needs to get some new equipment, their cams seem to be all over the place. Lucky if you get them with lobes within 4 degrees of each other. And RD springs suck ass too. A fresh set will have random free heights.
JohnnyB
 
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