Installing Cam

When you install a cam. Does the lobs go up or down???

they will end up being down. you want the piston at tdc. there are alignment marks on the sprocket. when the sprocket is mounted on the cam, the marks should align with the top surface of the head. i would recommend buying a service manual if you don't have one. the manual will explain this in detail.

I have installed cams before. I am working on my Husky and i put the lobs down, but it just doesn't look right. Just wondering if the lobs down is a standard thing?

A service manual will tell you exactly how to do it.

the lobes down is probably standard. with the lobes down, at least on the xr, all valves are closed. the piston must be at tdc.

It depends on how the valves operate on your Husky. The Honda rockers are mounted above the cam so lobes down will be TDC on compression stroke. My BMW F650 thumper has no lifters, the cam rubs directly on some jugs on top of the valve stem. In this case lobes up is TDC on compression. Look at how your Husky valves are operated before installing the cam.


manual does not explain the process too well. I replaced mine and the manual doesn't tell you up or down. The worst part about it is that I can't remember how I did mine!!! 80% sure that it was down.

Always ALWAYS lobes down - piston at TDC - cam sprocket lines flush with the head.

Does it matter? I didn't think it did.

When you install the cam one way you've just installed it with the piston at TDC on the compression stroke. Install the cam the other way and you've just installed it with the piston at TDC on the exhaust stroke. Either way the engine won't know the difference. Just make sure to rotate the crank 180deg if you've installed the cam in the way that locates the piston at the TDC on the exhaust stroke before you install/adjust the rockers.

That's why the service manual doesn't specify whether to orient the cam 180deg this way or 180deg the other way. Remember that when you line up the "T" mark on the flywheel to find TDC during a valve adjust you've got a 50/50 chance of being on the right stroke.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now