Topic: Cam Bearing Help

[Ksgfx]

Hey all,
I could use the expertise of this forum to decide what I should do for the cam holder on my 75 CB750k build.

Here is the holders that came with the bike which sat for 40 year but only had 8k miles on the clock.
https://photos.app.goo.gl/ddAmySZ5CGN5rYfZ6
The problem with this set is while the cam and holder bottoms are in great shape, the caps all have massive pitting in them from what I assume is poor manufacturing process. Especially the one on the far left.

I also have another set from a donor engine with unknown miles, see here:
https://photos.app.goo.gl/TSB2WNKhHpoFErbd8
The cam and caps here are fine, but there is a bit of scoring on the base journals. Not quite enough to catch a fingernail, but noticeable.

So my question is which one would be better to use on my build? Or should I try to combine the good bases with the good caps.

Appreciate any help. Thanks.

Kevin

[MRieck]

To be honest there is so much clearance I'd just smooth out the cap surface with some 400 paper

[Tom R]

The carriers and caps are matched sets. You’ll see matching stamps on them… don’t mix them up.

[bryanj]

99% of load is on the carrier not the cap and there does not seem to be any problem to me with your orriginals when looked at on my dumphone

[69cb750]

They are in good shape, the caps and base have line bore numbers, make sure they match.

[Ksgfx]

To be honest there is so much clearance I'd just smooth out the cap surface with some 400 paper

I thought about that but some of the holes are quite deep, especially the one of the far left, probably a 1mm hole. So I'm not only scared it will hurt the cam but could also weaken the cap so it cracks.

[Tracksnblades1]

If your state side why not remove your doubt and worry and get a good set….
Just take your old ones out of the equation… someone on here may have a very good set
From a donor…

[bryanj]

I dont see any hole in the pic provided

[willbird]

I dont see any hole in the pic provided

I concur, all of the parts shown in the two pictures look great to me.

[Tracksnblades1]

To be honest there is so much clearance I'd just smooth out the cap surface with some 400 paper

I thought about that but some of the holes are quite deep, especially the one of the far left, probably a 1mm hole. So I'm not only scared it will hurt the cam but could also weaken the cap so it cracks.

Are those holes from the original casting imperfections?  Porosities..?

It looks like the lower left and right journals show sign of scoring or debri….

On an iPad it looks like the journal scoring favors one side. Like the carrier’s journal aren’t square or within the same plane as the camshaft..especially the outside two.. perhaps it’s just the angle of the light and an iPad.?

[bryanj]

We need better pics showing just the journals and caps

[Mark1976]

   Why don't you reassemble the camholders with the cam and plastigauge (measure the bores and journals if you want) to see if you can get a clearance number to start with and check it against the honda #'s. I'm pretty sure its a relatively generous clearance number. Then take some pics a smidge closer to get a better look, but from what you've posted, some minor scoring is not out of the norm. Nothing wrong with asking questions, the more ya know the better off you feel about it.

[Ksgfx]

Thank you all for your support and advice. I do really love how this group helps everyone out.

Here are some close-up pictures of the caps from the first engine:
https://photos.app.goo.gl/oaT3jdTAEr59u6UD6
I do believe these are just from the casting process, but the amount and size of them has me concerned. Perhaps they will be fine but would like the consensus of the group. I didn't take a close-up of the bases because those are all in great shape

Here are some closeups of the other engine that has a bit more wear on the bases:
https://photos.app.goo.gl/6Uy7AV8K9wmMtbK46
Again my biggest concern here is the base on the far right has the deepest groove. It's not deep enough to catch a fingernail but it does create the slightest bit of drag.

Let me know what the group thinks. Again thanks so much for the help and advice.

kev

[69cb750]

I would use them.
They look dirty, clean before using, plastic gauge or test cam spins free.

[bryanj]

All those bits are fine to use for any normal use

[BenelliSEI]

They look just fine to me too!

[newday777]

Just be sure that you put assembly grease on the bearings before spinning the cam

[HondaMan]

Those 'pitted' caps are fine, I've seen many like that. Truth is, unless the cam chain itself has a huge amount of slack in it (because someone is ignoring the slapping noise and it needs adjusting) the caps never touch the cam's journals. I have seen very few caps with any bearing marks even on them, including mine at 131k miles.