Topic: Valve cover damage

[Kevnz]

Pulled the pan off my "good" motor a while ago, found the expected sludge, but the screen was clean, and no metallic bits in the sludge.
Did the same to my 2nd motor, had the expected sludge, but the screen was blocked with crap, including metallic aluminium debris. Lifted the breather and found this, presumably the source of the metal. I know I will need to strip the engine now, but is this valve cover still useable? Will oil spray up and out the breather? Thought about repairing with JB Weld, but am concerned that if it came loose and went through the engine, not much good would occur. What about using fibreglass mat and resin?
Thoughts welcome,
Thanks,
Kevin

[bryanj]

I would be wanting to find out what caused the damage before worrying if the cover is useable. It may turn out that other internal damagemay make it uneconomical to rebuild

[Kevnz]

Good thought. Engine turns over freely and has good compression, so I am assuming that whatever happened, was rectified. The cam chain looks ok. I presume it broke at some stage and tried to exit via the valve cover. Does that ever happen? Strangely, the external appearance of the engine is not indicitive of abuse, good screw heads etc. But certainly agree that engine internals need inspecting. Easier to attend to external cosmetics while it's apart too.

[bryanj]

In all the years i have been working on Hondas i have never seen a 500/550 break a cam chain.
If it looks like it has had some new valves when stripped it is a possibility, i wouldbe looking for damage in head and cylinders from loose cam chain.
As to the hole i dont think it would affect running or put oil out of bather as there are breathing holes in that casting anyway

[dave500]

i think oil from the chain whizzing past would swamp that cover,if all the engine needs is that hole fixed id look at getting another cover,a piece of thin alloy could be formed then jb welded(glued)in place.

[caluser2000]

Getting an engineer to tig weld it shouldn't be too hard. Then tidy it up wit  files a grit paper.

[pjlogue]

It looks like the timing chain was loose and jumped a tooth which knocked a hole in the cover.  Debris from that would be caught in the oil filter.  Check the valve timing to make sure it is correct.  Options for fixing the hole are getting it welded or get a replacement cover.  JB weld would be a last resort if it were mine.  If you go the JB weld route be sure to de-oil the exposed metal so the JB has a good bond to the cover.  Acetone soaks and rinses will do a good job of cleaning the repair area before using JB.

-P.

[Kevnz]

Investigated further; good news and bad news. 3 of the 4 bolts adjacent to the cam sprocket required a socket to remove all the way out, suggesting the threads in the head were distorted, as they usually become finger tight once loosened. Fortunately, the threads cleaned up ok. The 4th bolt had been sheared off in the head and further outboard there is a helicoil, so I'm thinking this damage was caused by ham-fisted assembly rather than a failure in use. Not a good sign. Just confirms the engine will need to come apart and undergo serious scrutiny. Will put it aside and concentrate on the other bike; only got sidetracked waiting for chrome plater and upholsterer. Should be able to find little jobs to keep me occupied.
Thanks for the input.
BTW should the breather cover be painted or polished?
Thanks

[dave500]

i just paint em black,they aint really seen,nothing worse than unkempt polished cases.

[bryanj]

Polished when new, corroded months later

[Kevnz]

Thanks guys, doesn't matter whether it is seen, it's what it is supposed to be. Polished it is.

[dave500]

sure not silver paint from factory?with clear?

[caluser2000]

I get rid of any trace or paint and lacquer..  Store properly and has been fine for decades with regular tidying up.I spray CRC5.56 over the engine in winter to form a thin film and clean less until the weather gets better. If cow dung gets splattered on the engine yhough II remove that immediately after the ride with the engine still warm.Respray with crcwhen finished.

[wolf550]

also check which breather cover you have there is one that has a fence or a divider near the opening of the breather tube hose connector.
I think they added this in case that hump/ cam cover got broken somehow (i.e. ham fisted)

[Don R]

 The inside of that cover looks like a tensioner failure, it took a lot of slack to mill out that groove.

[Kevnz]

Hi Team,
I've scored a replacement cover, but it's a bare unit, sans rocker gear. Anyone able to tell me how it comes apart, please? Looks like the rocker shafts have threaded holes, do you insert a puller into them? They move freely in and out, seemingly spring loaded, but don't pull straight out. Some force required, or am I overlooking something?
Thanks in advance

[flatlander]

thread in a bolt and pull them out. there are no springs.
newer covers have pins that hold the shafts in place, that need to be removed first.

[dave500]

they may have a little vacuum from oil inside?

[caluser2000]

The O'rings swell over time. That is all it is. Get correct thread bolt wind the #$%*er in and pull the shaft out.

When fitting those tappets in to the other rocker cover put an Oring at each outer end of the shaft before you fit the two end caps in place. This stops the shafts from rotating and damaging the ali tunnels they are located in.

[Kevnz]

Got them, just needed a good tug. Service manual seems to bypass this procedure.Thanks for the guidance, as always.

[caluser2000]

That's good to see. You can use the craws of a claw hammer as a sliding hammer on the bolt shaft as well if needed.

[flatlander]

this deserves repeating:

When fitting those tappets in to the other rocker cover put an Oring at each outer end of the shaft before you fit the two end caps in place. This stops the shafts from rotating and damaging the ali tunnels they are located in.

it's a common problem with the older covers that the bores wear due to the shafts rotating. then you get so much play that your tappet adjustment doesn't hold any more. the added o-rings are an easy and cheap insurance.

[caluser2000]

this deserves repeating:

When fitting those tappets in to the other rocker cover put an Oring at each outer end of the shaft before you fit the two end caps in place. This stops the shafts from rotating and damaging the ali tunnels they are located in.

it's a common problem with the older covers that the bores wear due to the shafts rotating. then you get so much play that your tappet adjustment doesn't hold any more. the added o-rings are an easy and cheap insurance.

Yip works a treat. The original tappet cover shaft bores were completely knackered when I pulled my '76 CB550s engine appart at around 80.000kms. Got a good second hand CB500 one to replace it from a local m/c wrecker.

80,000kms later on that tappet cover is still fine and dandy.

[Kevnz]

Agreed, good to know.
Bad news and good news. New cover had aftermarket bling tappet covers that had seized in the cover; just would not move, some already rounded off. Tried resizing down to 16mm, but still no go. Resorted to the "in the bbq" trick , which combined with a Stilson wrench did the trick. Fortunately, the aftermarket tappet covers are taller (thicker) than the standard ones,so was able to get good purchase on them. All part of the fun of a restoration! Keeps you on your toes.

[caluser2000]

A good solid wack with a club hammer on the  top of them helps

Filing the flats down so an imperial spanner or socket works also.