did I "drop " a valve? need to get to work...

[Poot]

Having messed around enough with my engine today, setting the cam-timing, and clearance, I somehow managed to drop a valve, or I think thats what its called. I cannot rotate the crankshaft any further forward or backward beyond a very limited range (maybe half the full rotation of the crankshaft) , because the piston(s) in either cylinders 2 and 3 (maybe both) come into contact with the valve stem prematurely.

adam said that my valve might have "kissed" the piston?

I havent started it, but just cant turn it over all the way by hand...

how can I go about fixing this? please dont tell me i've got to take it apart.... :?

thanks in advance guys...again



poot

[Anonymous]

If you pull the camshafts the valves will retract. From what I've heard it is a good idea to buy new high grade fasteners for the cam caps instead of using the old ones.

Steve

[Anonymous]

Picking up valves

Just about the only way will be a magnetic pick-up tool, trick is you will have to search far & wide to find one small enough diameter to fit down the guides The magnet wil be sticking onto cylinder walls seemingly all the time.....perhaps you could run it down the plug hole & start working it toward the guide. The plughole size magnets are far more common.
Worth a try......
_________________________________Rick......

[Anonymous]

Yes, removing the cams will close all the valves which will tell you if you have "dropped a valve" or just had a little collision between a valve and a piston. Dropping a valve I think means that the valve got loose and dropped into the cylinder or that the head broke off and is in the cylinder on top of the piston, neather a good thing. I would bet that your cam chain jumped a few cogs while you were messing with the chain adjuster and your valves met your pistons. This alone can bend a valve so even if you retime the cams, you will need to do a compression test to determine if you have bent a valve or not. Do not persist in trying to turn the engine against the new resistance or you will bend things if you have not done so already.

[Poot]

well, this is the thing.....

I dont want to start it, and totally fek things up here....

I dont think the valve completely dropped into the cylinder, but I can see the bottom end of it sticking out through the spark plug hole (just a little bit of the circular part.)

:?

[Anonymous]

If you have retimed the cams and can turn the engine normally now, look at the valve that you can see in the plug hole while you turn the crank and it better disapear and then return. If it stays in view all the time you turn the engine, it is bent and is unable to close. You could also have a look in the ther plug holes and see what happens in there. Make sure that you are actually looking at the valve head and not just the "fly cut" on the top of the piston. The "fly cut" is the notch machined in the top of the piston to make a little room for the valve opening. If the cams are still out and you can see the valve, the valve is unable to close because it is bent. Steep learning curve now.

[Anonymous]

I hope you didn't try to start it and know the engine is binding from turning it by hand. If you didn't try to start it, then you probably don't have any major problems. If you did (without checking the rotation several times) then you screwed up big time.

If you didn't try to start it, here is what you do. You are going to have to start all over. I'm of the mind you didn't screw anything up bad, you just have the cams installed wrong.

Remove both camshafts. If you have a dropped valve you will know it right away - I won't describe it as it's just that obvious. If everything is still in place, you are probably ok in the valve area.

Important to note at this time - do not let the cam chain fall into the motor! I put a spanner across the valve area to prevent this screw up. Do something to prevent it.

Now pull the cam chain up as far as jou can and try to rotate the engine. You need to see if the cam chain is binding somewhere. (Don't ask how I know). If the engine binds a bit rotate backwards and pull the chain more. Once you get to the point where you can rotate the engine you can install the cams again.

Follow the procedure. It's tedious work, but you must follow the procedure exactly. Keep the chain from getting loose when you put the cams in. You don't want it to bind again.

[Poot]

hey swanny.


no , i didnt start the engine. didnt figure things would get too far if i couldn't do anything by hand.


I had done what you said, but i guess i didnt do it enough to completely work out the stoppage...fek....this sucks now, cuz i just put back on all the camshaf covers ............. :x

all of the shims and stuff were right on top when I had it off, but i dont think i worked a blockage in the chain out completely.



oh well, i got less than an hour to get it all together....heres hoping it works.

[Anonymous]

hey swanny.


no , i didnt start the engine. didnt figure things would get too far if i couldn't do anything by hand.


I had done what you said, but i guess i didnt do it enough to completely work out the stoppage...fek....this sucks now, cuz i just put back on all the camshaf covers ............. :x

all of the shims and stuff were right on top when I had it off, but i dont think i worked a blockage in the chain out completely.



oh well, i got less than an hour to get it all together....heres hoping it works.

The cam chain can bind in the area where it passes under the crank. It is a light chain with links close together. Make sure that you can rotate the crank fully before installing the cams. It's a bit tricky, but hold the chain up all the way with no slack and make sure you can rotate the crank. If you don't ensure free rotation everyting you do after than if for nothing.

The good thing is there probably isn't any damage. It would take some real ham-handedness to bend a valve by rotating the engine manually.

Look at it this way, you can now be one of the resident experts on installing cams!

[Sandy]

If you remove the exhaust system you might be able to look in the exhaust port and get some idea of what's going on in there.