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Black Bomber valve clearances.

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royhall:
Your right BryanI should really let Newmans sort it, but if you ever dealt with Ken Newman you would know why I'm buying a new follower instead. I have managed to measure the cam whilst in place in the engine and its fine. Ken Newman mentioned grinding down and welding on a pad if the followers didn't clean up. Looks to me like they may have ground it down and forgot to fit the pad and just sent them out like that. That story would fit as that Ken guy was truly hopeless.

AshimotoK0:

--- Quote from: royhall on July 02, 2019, 07:52:59 AM ---Your right BryanI should really let Newmans sort it, but if you ever dealt with Ken Newman you would know why I'm buying a new follower instead. I have managed to measure the cam whilst in place in the engine and its fine. Ken Newman mentioned grinding down and welding on a pad if the followers didn't clean up. Looks to me like they may have ground it down and forgot to fit the pad and just sent them out like that. That story would fit as that Ken guy was truly hopeless.

--- End quote ---

Wow that's bad Roy .. I have often thought about sending cams and followers away to be repaired and that firm seemed to crop up as being a good service on all counts, so it was always my intention to use them if I couldn't find decent used or NOS parts. I still reckon it's best to try to find original parts in good condition or NOS, as there always seems to be that nagging doubt about whether repaired parts are up to the original Honda standards. I have never risked sending a pressed together Honda crank for repair or inspection for that reason. What's best... a crank with a bit of hardened sludge in the flywheel sludge trap, that may or may not work its way into the lubrication system sometime or a wrongly pressed together crank ..... difficult one that. It's going to be a cracking good Bomber when you get it finished though and your rebuilt thread will be a great record of your attention to detail if you ever come to sell it.

K2-K6:
I feel there's room for mitigation here,  not to make an excuse for a supplier as I have no connection with Newman, but the pure reality of accomplishing something of this type.

For an item that is effectively scrap in its damaged form this gives an approach that may bring back into service a part that may not be readily available in the condition needed. Newman appear to know their trade regarding materials and refinishing of cams etc. The specific details of geometry (this is a very tightly designed and specific engine with highly resolved components)  may not be fully a part of their appreciation of the job given to them. It doesn't mean it can't be completed,  but further discussion prior to event may yeald a very satisfactory outcome. You've really to combine the two elements to succeed.

I've known absolutely impeccable machinists that carry out superb work without need to know further intricacies of the component parts,  but it's not always like that.

The crank assembly Ash,  it would probably serve to blow steam backwards through the oil routes to flush out tarring from oil ways etc as an non invasive method to clear it out.  Followed by engine oil to prevent corrosion in storage.

On that point,  sludge, it's an area where "synthetic" oils seem to easily outperform previous types in tolerating higher temperature location within the engine.  I agree completely with the "Dutch " view on this.

I've worked for a long time on a particular car engine that has much in common, material and temperature wise, with these bike engines. Prior to synthetic type oil they were notorious "sludgers " but are completely absent of those effects now with improved oils.  They were specified and designed in the late 1950s too,  which certainly doesn't tie in with "old engines need old oil " mantra often sung out collectively via the Internet.

royhall:
Sorry but I don't feel Ken Newman has any room for mitigation. After speaking to him on the phone I thought I had better back it up in writing. Attached is a photo of the letter I sent. I'm not sure I could have done any more than this, after all he's the cam expert. The issue is that I didn't pick up the advice from Laverda120 to ask for Mike rather than Ken Newman.

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When I rang him 3 weeks later he had even managed to lose the letter, and the cam and followers were lying around on his desk under a pile of paperwork. I had to resend him the letter via email as he had no idea what he was supposed to be doing with the cam. After two months he finally rushed the (two week) job back to me. That's why I suspect he forgot to weld the pad on the follower.

I shall be stripping it out again tonight so will be able to compare it to the new one (as long as it arrives today). Will post what I find.

Trigger:
Did you send a full spec sheet with all the measurements and service limits ?

I had a run on Corsa 1300 TD heads in for skimming. And the customer coming back and saying, that I had skimmed them too much as, there are no saver shims available for that head. I skimmed the heads until they were flat, which the customer asked for. How am I to know that saver shims are not available at that time.

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