wrong cam postion

[robsgreen]

Hi Guys
Just put my CBX cams in and in error installed the left hand cams with the cylinder 1 lobes facing the spark plugs, the same as the right hand cams on the 6th cylinder. It turned over OK but I soon realised I should have had the lobes facing away from the spark plugs . Im pretty sure there was no valve to piston contact but will this have done any harm? has anyone else done this or am I out there on my own? Put all correctly now and seems OK.

Regards

Martin

[EMS]

There will be no danger of having piston-to-valve contact as half of a cam rotation means a full crank rotation and the piston would be in the same position as if the cams were installed correctly. The problem is the cam chain. As now twice as many valves are being actuated at the same time, the load on the chain is high and extended operation may break it. If you remedied the situation, you should be fine - if I have this all right..

[robsgreen]

Hi
Thanks for your reply
All seems OK, I've looked at the cam chain very carefully and there appears to be no damage or stretched areas.
Thank you for your help and interpretation of my garbled question
cheers]
martin

[mike209]

I did the same thing, was running motor for quite a while few times but I did not take it for a spin, I was just adjusting carbs and things like that, should cam chain be replaced or if it did not snap it's good ?

[robsgreen]

I only turned it over by hand about 6 or 7 times. Knew something was wrong when I started checking valve clearances and one of my valves was down when it shouldn't have been!

[daves79x]

There's no 'may break' about it - the cam chain WILL break within 20 miles of riding. Many testimonials here to that. Just turning over by hand, as mentioned, won't hurt anything.

Dave

[mike209]

Which chain fails? Short one or long one?

[herdygerdy]

The long A chain is the one that WILL fail. I fell into this trap back in the early 80s when I was a numb nuts with more ambition than skill.

2 broken cam chains, 9 bent valves later and countless strips down to the crankshaft.......I gave up & forked out 2000 Aussie 1980 dollars to the bike shop to 'just fix the damn thing'.

I put it down to the cost of my CBX 'education'.

No issue at all if only turning over by hand. And would also suggest if you ran it and it didn't break, then set the cams correctly, you are still good to go.

Sigh....if only I knew then what I know now....

[EMS]

Now there! Here is your way to fame in the CBX world!
Instead of restoring your CBX to a 100 point concours condition or building a wild custom with everything fabricated and turbo-nitro-oxided, just install your cams the wrong way (use the procedure in the early non-corrected service manual to blame it on Honda) and then drive the bike carefully for 25 miles or so without the cam chain breaking. You will be in the Guiness Book of World Records!

[Mello]

Now there! Here is your way to fame in the CBX world!
Instead of restoring your CBX to a 100 point concours condition or building a wild custom with everything fabricated and turbo-nitro-oxided, just install your cams the wrong way (use the procedure in the early non-corrected service manual to blame it on Honda) and then drive the bike carefully for 25 miles or so without the cam chain breaking. You will be in the Guiness Book of World Records!

I think I may have made the record. The '82 I bought seems to have suffered cam chain failure. The chap I bought the bike from told me it had been running but not well, a "few years ago" when he acquired it. He said he rode it once. I pulled the carbs, stripped and cleaned them, serviced the bike and ran her. Seemed all good except the battery eventually died. Pulled nicely and sounded great (6 into 1 exhaust). There seemed to be a charging issue which I eventually traced to dud coils. Swapped these out and went for a long ride. After about 20 minutes, I accelerated onto the highway and bang, clatter. Quickly pulled in the clutch but too late. I coasted to a stop and found the engine was locked completely. Took the exhaust off on the weekend and metal bits fell out of one of the pipes. Exhaust port on number 2 doesn't look healthy

I'm busy making a bracket to hold the engine so haven't looked further.

I must have covered close to 100 km (60 miles) before the failure. Perhaps another cause?

[EMS]

Probably another cause, Mike. The motor doesn't really run that nice when the cams are installed wrong. It runs more like a 3 cylinder bike.
Maybe it dropped a valve. Could be the reason for the parts coming out of the exhaust port.

[Mello]

Ok, that makes sense then. She seemed to run pretty well. Wondering whether its good news as perhaps only one cylinder is affected. Was picturing lots of bent valves and damaged con rods.

[herdygerdy]

Hi Mello,

There is no way on this earth it would have run even slightly happily if the cams were in the wrong position.

When they are wrong, you end up with two cylinders firing on the exhaust stroke at once, along with twice as many valves being opened and closed when compared to normal. They sound like a munted up old Triumph Trident with the timing way off.

I would think it far more likely yours has dropped the head off a valve. And because you say it happened as you were accelerating onto the highway (ie; rpm North of 4,000 rpm), then suggest there will be colateral damage to other valves that kissed the piston tops before it all came to a halt for its long rest.

And Robsgreen, methinks you should go out and buy yourself a lottery ticket. You, Sir, have definitely dodged a bullet and are one lucky bugger!!

Cheers..Tony