Topic: What aftermarket camshafts work with stock rockers?

[gschuld]

FWIW, I brought back an older thread “what aftermarket camshafts work with stock rockers?” from the sohc4 bikes area since it already had a few good posts in it: 

http://forums.sohc4.net/index.php/topic,162745.0.html

George

[PeWe]

I have seen that thread too and suddenly I have to do something about it since I have a welded cam that like the upper part of the tacho scale.
There are other discussions where hardwelded cams should have hardwelded rocker arms.
CMSNL sale complete set of new stock rockers.
https://www.cmsnl.com/honda-cb750-four-1973-cb750k3-usa_model481/rockerarm_00000kit0005/#.WpfBw2rOX0M

Racing applications using high lift/short duration cams and high rev using harder springs must be tough for the stock rockers.

I saw marks on the chromed surfaces after the CX7 cam rather shortly, almost like dents, not really chrome damage but not same smooth prints as seen before with a milder cam with max lift of 0.360" after long time use. ("The cam for those who are worried about "hot" cams".) The extra lift might compress the race springs, probably Action Fours, much more.  RC295 has high

I noticed that the oil quality is important too. (No real lab tests)
Some zddp additives have slippery moly in the mix which I noticed after I had added it and reading the label on the bottle. My quickest oil change ever. Castrol ActEvo 10W-40/20W-50 minerals I used for break-in did not feel very lubricative in a good way for the rockers as 20W-50 Semi and full synth I used later. All oils with short milage. (Finger feeling and thin scratches on cam lobes)

[gschuld]

Yes, I noticed the new rockers listing as well. 

So in my situation, an NOS 1970s CWC blank RC327 cam, would I be better off with new OEM tipped rockers or hardweld rocker?  Basically, would hardweld rockers cause premature wear on an NOS 70s performance cam?  Seems a fair question since a hardweld cam seems to be an issue with non hardwelded rockers(wearing the rockers). 

George

[Old Scrambler]

I run 'like-new' rockers in my C.B.R. motor and have no wear evidence after about 80-miles of running hard. I would run the NOS and weld later when or if wear is evident. Hopefully I will get to inspect my rockers and +4-size cam lobes in August

[bwaller]

I would say that with a non welded cam, use stock rocker arms, NOS if the cam is unused.

Twice I've seen welded cam lobes destroy non welded rockers, not only a SOHC4. It does happen often enough.

[gschuld]

I’m not an expert by any means regarding surface hardness of metals.  I am curious to where the old CWC aftermarket blank cams land in reference to hardness of cam lobe when compared to a factory cam, newer generation billet cams, and hardweld cams.

In rough terms, from what I understand:

Factory cams are considered the softest
Hardweld cams are the hardest

The aftermarket billet blank cams are somewhere in between?

Are the lobes on the older CWC blank cams softer than the newer now extinct billet cams?

George

[MessnerMoto]

Stock rockers chrome measured to around 55-57 RC by company that did hardwelding of rockers for me....

After hardwelding around 65 RC...

[gschuld]

Thx.

So going from 55-57 RC (OEM) to around 65 RC (hardweld) is a jump for sure.  I’m wondering if matching an NOS 70s billet blank cam with hardweld rockers would cause premature wear on the cam.  Or would I be better off with NOS OEM rockers?

George.

[PeWe]

I found interesting threads were welded cam and rockers are discussed. It is very important that the rockers are perfectly shaped when welded and grinded. My own question: Higher priced welded rockers are made more accurate?
https://thumpertalk.com/forums/topic/753369-hardfacing-rockers/

Really? More clearance save the cam and rockers? Is this why RC315 should have double clearance?
http://www.teryxhq.com/forums/kawasaki-teryx-performance-discussions/4824-welded-cams-myths-busters.html

A good oil and clearance will not be the way?
Hard surface save it when oil film is not strong enough and does not lube under the rocker pad and/or clearance is too tight?

I'll search more...

[gschuld]

Yup, it’s easy to get confused when you’re already over your head on a subject.  I see me do it all the time🙄.

George

[PeWe]

One more interesting cam thread
http://www.motorcycleproject.com/text/v4_cams_what.html

Now dive deep into the subject, at least more...

[POPS 911]

65RC