582 rotary valve

[asra]

Just had a little problem with my engine, in that the brass cog that runs off the crank to drive rotary valve/water pump shaft chewed out and then things stopped turning,[!] the worst part is that i cant find a reason for it [?], both the bearings FEEL alright, the water pump was free same with the valve, is there any one who may be able to shed a bit of light on what has happened ?????Orr and i just thought that i should mention that i wasnt flying at the time this happened, so i dont need to lodge an iccident report, do i???Mark

[Tim]

First thought Mark is was it full of oil? - I had to ask. Does the shaft spin true? (not bent)Are there any witness marks on the engine case to suggest something caught in the rotary valve?Incident report not required but if you find the reason, it would be a good idea to inform others.Tim McClure

[asra]

Tim that is a fair call, yes as best i can tell it should have bleed all the air out and should have been full of oil, on closer inspection of one of the bearings there is a very small rough spot in it, so at 6250 rpm that would be magnified alot i would think, the shaft i would think it would be straight, no lathe at the moment to check but i will, i'll order a new valve disk as well as the cog, maybe the disk is a fraction out of flat, if the disk was draging abit could that have been enough to chew the cog up do you think Tim?Mark

[Tim]

I dont think so.There is another possibility and that is that the brass gear is spring loadedto allow it to "float" and absorb the engine pulses at low RPM's. If it was assembled the wrong way around it could damage the gear.Are the teeth on the drive gear on the crankshaft in good condition?Tim McClure

[asra]

Tim, Just got the other bearing out of the motor this morn, and it is rougher than the other, the spring is completely u/s dont know if this happened before the cog chewed out or not, thinking it may have just been a combination of things to add up, the hardest bit is going to be makin sure to get all the brass of the crank cog before it goes back together.New bits on the way so guess i'll find out soonDid you mean the cog or the spring assembled the wronge way around, please explain which way is correct, this may turn out to be a really dumb question to ask upon looking at the new bits, but there arnt much left in one piece to look at now.Mark

[asra]

Tim or others would like some help please, the book shows how to hook up the oil tank for the rotary valve easy enough how ever the book shows the motor with plugs up, i have the plugs down do the hoses have to be reversed or not?The way it is at the moment the feed from the tank goes into the top of the valve and the return out the bottom(remmember the motor is mounted plugs down, worried that it may be wrong and since just rebuilt, wanted to know for sure?????ThanksMark

[Tim]

G'day Mark. The oil only thermo-circulates so no matter which way the engine is up, the oil must come out of the highest pipe on the engine and travel up hill to the pipe in the tank that has the internal riser. The outlet from the bottom of the oil tank then returns to lowest pipe on the engine. I guess that means that the flow would be opposite to an engine "right way up".Tim McClure

[asra]

Thanks Tim will reverse them then, didnt seem right and couldnt remember how they were.Mark