Honda CB350 Fat Cam specs / measurements?
- Thread starter plyzo
- Start date
Just take a look at it. If the lobes and bearing surfaces are smooth without pitting, scoring or flat spotting, it is fine and good to go. Same with the rocker arm pads. If that is not true, then replace the components which are scored, pitted or not smooth. If a fingernail catches on an imperfection, then it is, as a general rule (guideline if you prefer), due for replacement. Also pay attention to the other wear surface if you spot trouble on one, i.e. worn bearing surface on the cam means you should also inspect the aluminum bearing surfaces where the cam rides.
My point here being, it doesn't matter what the specs are, just make sure it has smooth surfaces.
My point here being, it doesn't matter what the specs are, just make sure it has smooth surfaces.
what ex119 says holds much water if the lobes are not pitted flacking or scored they are almost assuredly ok because they always get looking rough when worn outplyzo said:
the lobes are what wear (not the base circle)and it is measured at the largest possible diameter lobe tip to base circle
the main thing to check if those rubbing surfaces(lobes/followers) look cherry however is the running clearance of the cam journals
you can free download the fsm over at hondatwins
from memory the service limit is .005" that is looking at the specs and the 2 service limits of the cam journal and the end cap bushings from those service l;oimits can be deduced max running clearance
setting the endplay is important for maximum oiling set it as close the lower limit as is possible .008" endplay i have run as little as .006 no issues
i have 2 nos fat cams although they are the later ones on the skinny blank the fat blank was prone to breakage, however rare,and the skinny blank was used on the last ones
if you want i can mike them at the lobes
the only accurate way to measure the end cap bushings is with micrometer reading the size garnered using a telescoping snap gauge and measured in a few locations
the cam has deeper hardening than the followers and can be smoothed up with an oilstone but needs to be done carefully to maintain a surface paralell to the cam axis
the followers are only a shallow hardening and should not be resurfaced
the most important thing is to also make sure the pump is up to spec including the eccentric drive
a good modification same and what i have done with the motor i am building now is the cb450 clutch basket ,pump arm and primary drive gear
the 450 eccentric is more durable being larger diameter and primary ratio is 10% higher,it spins the input shaft 10% faster more volume of oil at all rpm's
it also slightly closes up the gear ratio gaps and opens up the final drive for better choices of sprockets
another bonus is less load on all the transnmission components and less load on the clutch frictions
the other thing to check is the rocker arm tips that contacts valve stem
i have seen them rust pitted when the follower is cherry i believe it is from damp long term storage and the tip in contact with stem
some scoring of the cam surface journals is ok if clearance is within limits
the cam endplay is best set with only the cam,end cap journals and fresh gaskets assembled dry on the bench in an otherwise empty rocker box, it can and is best observed with a dial indicator contacting cam end at the advancer shaft/spud
you need to use the factory service manual only .it is free
it has all the service limit checks,illistrated and explained. i dont think it has the fat cam lobe major diameter but the journal specs are the same for all 3 different cams.
post up pictures,yesterday allready .
on the cam journals you have to measure it you cannot tell by looking at them.unless it obvious is roached
it has all the service limit checks,illistrated and explained. i dont think it has the fat cam lobe major diameter but the journal specs are the same for all 3 different cams.
post up pictures,yesterday allready .
on the cam journals you have to measure it you cannot tell by looking at them.unless it obvious is roached
