Valve gear not moving

[jack350]

Engine been out for 'too' many years, have been turning over from the crankshaft pulley. Today felt resistance when rotating (no plugs in) but rather a 'crack' sound, resistance got greater and foolishly used force to overcome, resulting in larger cracking sound. Now engine still moves freely but no movement of the valves. Any ideas? If the chain had broken surely I would hear a rattle from the casing as I rotate the pulley?

[Jack Valiant]

Assume RV8? Not necessarily as it could have snapped the chain and dropped nicely to the bottom of the case and to the side and off the gear...Time for a new chain, oil pump and gear me thinks

[jack350]

Yes it is RV8 but what do you think my have caused the resistance to rotation to cause the chain to break?

[njhucker]

Sheared woodruff key??

[adam quantrill]

The camshaft would be rather dry after all this time increasing friction but I wouldn't have thought this would be nearly enough to cause either the chain or the key to break.

Either would explain lack of rotation (I expect the dizzy isn't rotating either?)

If you are doing this for a while maybe it's a good idea to remove a rocker cover to oil the camshaft from time to time before rotation.

You'll have to remove the timing cover to investigate. Also the camshaft will be misaligned so you'll have to re-time it to the crank.

The question is what is your piston/CR arrangement and will any valves foul the pistons? You will need to check the one that's currently the most depressed. If it isn't the whole way down then you're probably OK.

[jack350]

Removed crankcase cover - timing chain and crankshaft sprocket in pieces, just unsure as to how this would have occurred by turning the engine by hand?

[350zwelgje]

jack350 said:

Removed crankcase cover - timing chain and crankshaft sprocket in pieces, just unsure as to how this would have occurred by turning the engine by hand?

Rover used plastic timing gears...
Now you know why an upgrade is to use metal gears and a double chain.

Rob

[adam quantrill]

Hmm that is a worry! Can you post up any pics of the bits?

Do you means the chain itself was broken too? This sounds really unlikely to be caused by turning over by hand. Surely real running would be far more stressful.

If our nylon gearwheels are breaking up, we need to know.

[Wedg1e]

adam quantrill said:

Hmm that is a worry! Can you post up any pics of the bits?

Do you means the chain itself was broken too? This sounds really unlikely to be caused by turning over by hand. Surely real running would be far more stressful.

If our nylon gearwheels are breaking up, we need to know.

Some previous owner of my car pushed the boat out at cam change time and went for duplex chain and vernier timing gear.

I'd be surprised to find the cam had corroded into its bearings however it wouldn't be unheard of for the rocker arms to seize on the shaft... so the cam lobes wouldn't be able to move the pushrods.

[jack350]

Sorry no pics. Sprocket teeth were metal not nylon. If I was to replace the timing chain as a set including both sprockets any recommendations . Not wanting to go to the expense of vernier

[V8 Fettler]

Can RV8s be rotated backwards? As I recall, some 4 stroke engines don't like being rotated backwards. Is that a possibility with this one?

[adam quantrill]

I can't see it doing any harm - all the backlash for the dizzy timing etc would be wrong but of course you aren't running it so that's irrelevant.

Didn't get too much detail from the OP but sounds like the teeth were broken rather than the wheel itself. Maybe the chain then just fell off.

[njhucker]

Don't think an rv8 ever used nylon. Ford v6 used tufnol and nylon gears instead of sprocket and chain. Believe standard rv8 is sintered steel which can crack. You can get a machined steel set with duplex chain from RPI.

[adam quantrill]

e.g. http://www.v8tuner.co.uk/product.php?id=676

But yes it's worth putting in an adjustable steel one.

[Jack Valiant]

Was going to say the same.... I put billet gears and 'gold chain' in the 500 Gredge along with new oil pump as a matter of course. Did you take a long bar to the crank to turn it as it would need a bit of force the break it. I have seen dry stuck lifters make the engine stick before.

[Wedg1e]

njhucker said:

Don't think an rv8 ever used nylon. Ford v6 used tufnol and nylon gears instead of sprocket and chain. Believe standard rv8 is sintered steel which can crack. You can get a machined steel set with duplex chain from RPI.

Aye, as mine has an RPI cam I assume that's where the vernier gear and chain came from.
ISTR the Ford Cologne had a big brown gear on the cam, that would look right for Tufnol. I think it was used to keep the noise down otherwise it'd whine like the primary gear on an A-series - not what you want on your executive saloon.

[adam quantrill]

Yeah there was a warning on noise with the metal ones but when I replaced the nylon one on my 350i with metal, I couldn't hear any different over the exhaust. Probably more of an issue on the Rover P5 which was whisper-quiet.