Cam shaft and rocker arm wear?

[AshimotoK0]

I saw a NOS camshaft the other day on EBay, expensive though.

I wrote with an eBay seller who is selling one that is new. He is telling me that the part number is 14101-323-000EH, but he is warning me that the cam shaft is only 27hp. I am not even sure what he means, as I have only been able to find one part number for the cam shaft in an CB550F (for all the CB550 actually), and his part number fits that.

Am I missing something here?

I know with the CX500 in Germany there were two different power options  (perhaps due to some legislation in Germany) so perhaps that was the case in Germany on the 550. Even the 1st CB750 diecasts had German option on the pipes and were marked HMCB750 rather than HM300. Having said that I can find no reference to a lower power cam option in Germany in either parts books I have only on CMSNL

Uli on here (Sgt.Pinback) will probably know. Although the 27PS option is listed for USA ? ? 

[murdock]

compre un arbol de levas usado que este dentro de esta tolerancia , por que gastar tanto dinero en uno nuevo ?
como ya le dije un tornero puede reparar el suyo , ojo ! aqui hay otra errata , en vez de 35.85 son 34.85 


buy a used camshaft that is within this tolerance, why spend so much money on a new one?
as I said a lathe operator can repair yours.  see here is another typo, instead of 35.85 it is 34.85.

[alexdecker]

compre un arbol de levas usado que este dentro de esta tolerancia , por que gastar tanto dinero en uno nuevo ?
como ya le dije un tornero puede reparar el suyo , ojo ! aqui hay otra errata , en vez de 35.85 son 34.85 


buy a used camshaft that is within this tolerance, why spend so much money on a new one?
as I said a lathe operator can repair yours.  see here is another typo, instead of 35.85 it is 34.85.

I have no workshop in my area that provide that service, so that's why Im looking at new ones as well. I live in Denmark…

[philward]

And part of the repair process will involve case hardening after filling/machining - so even more specialist/expensive

[murdock]

a pity, but it would surely cost much less than 1100 euros + taxes.

[Oddjob]

Surely there must be some camshaft repairers in Denmark?

If not send it to a UK firm along with the followers.

[Oddjob]

I've made some enquiries at Newman cams in the UK to see if they can reprofile my current cam, I'll let you know what they say and if they give a price.

[alexdecker]

I've made some enquiries at Newman cams in the UK to see if they can reprofile my current cam, I'll let you know what they say and if they give a price.

I already asked around a bit, but the one I found who could do it was really expensive - just about as much as buying a new one.

Thank you for that enquiry! Looking forward to hearing an answer - really appreciate the help an effort!

[Laverda Dave]

Send it to Newman Cams, they have reprofiled two cams and followers for me in the past. Good price, fast turnaround. Call them and speak to Mike Newman.

[philward]

There you go Alex
http://www.newman-cams.com/

[Oddjob]

Got the reply from them today, they have quoted £100-120 plus VAT plus P&P.

Good price.

[Sesman]

I presume that’s just a regrind and surface heat treatment?

[Oddjob]

That was a price to reprofile the cams, which is essentially the same as repairing the lobes.

I asked for an additional 5 degree overlap and 10 degree duration as per Mark Paris recommendations.

Additional information.

After emailing with Newmans the price for repairing the lobes is the same as reprofiling them, just wanted to confirm that. They are EXCELLENT at responding.

I also asked about journal wear, like scoring etc, these can also be repaired by hard chroming the journal and grinding it back down to size, cost is £40 a journal, even doing all 4 at £160 is cheaper than finding a NOS cam. Plus it would probably last longer so long as the oil problem that caused it in the first place is solved.

He did however say that the cam lobes must not be knackered, I presume by that not blued etc due to oil starvation where the lobe has virtually melted. I'm trying to get some clarity on what or how much damage is knackered. 

Hope that helps those who want a cam repaired.

[Laverda Dave]

Admittedly I am no metallurgist and therefore my knowledge of surface treatments is somewhat limited but, I remember asking a question to a camshaft engineer a few years ago about surface treatments applicable to my Honda 400/4 camshaft as in would they case harden the re-profiled lobes to bring it back to standard. The response I received was Honda camshafts are made from chilled iron and don’t have any surface treatments?

I always thought the lobe of a cam is case hardened to prevent rapid wear or does ‘chilling’ cast iron produce the hardened surface? When I was at school we case hardened metal by heating it and dipping it into a tin of powered carbon (I think, it was a long, long time ago). I also thought a worn cam lobe is built up by ‘welding’ new hard wearing metal (stallite?) to it using a metal spray technique but apparently this isn’t always the case, some lobes are just re-profiled but this is something I just don’t understand, surely re-profiling will make the lobe smaller so how can it therefore provide the specified lift to the valve? This would especially apply to something like a four cylinder ohc, if one lobe is worn and re-profiled I therefore assume the remaining lobes will have to be re-profiled to match even if they are not worn otherwise one lobe will be smaller than the others?

Also, if the cam is chilled iron and therefore has a certain depth of case hardened material on its surface, how deep is the case hardening and will re-profiling the lobe go below the hardened depth?

Is the above the reason why Honda recommend the frequent oil changes they specify, to protect the cams that are not case hardened?

My head hurts now

[Sesman]

Ken.

Can you expand upon the 5 and 10 please.