Any gearheads here want to talk specifics about valvetrain design?
I am trying to get a understanding of the various ways that valvetrains are designed for adjustment, and the pros/cons of each type. A lot of this is coming from my experience with motorcycles where valve checks/adjusts are common maintenance. Can't say I have ever needed to do any valve work on any cars/trucks I have owned.
1. Locking screw type - I was exposed to this method on an old Honda dirt bike with a single cylinder engine. The cylinder head has "port holes" where you can access the valve clearance adjusters, which consist of a threaded post and some locking nuts. Dead easy to do (if access isn't a problem), but very imprecise.. You would adjust the post for length, and then when you tightened the lock nut, the clearance would change just slightly. I would imagine this design only works for fairly "agricultural" applications at low RPMs.
2. Shim over bucket - This was the first type of valve adjustment I did and it was surprisingly easy. Still requires removal of the valve cover and you have to be careful once inside there, but the shims are easy to access and swap out. I did a little reading and it seems the drawback of this method is increased weight due to the size of the shim and it doesn't seem well suited for high-rpm applications.
3. Shim under bucket - This is my current challenge. Both of my bikes use this method and I don't look forward to removing the camshafts just to change the shims. The shims are tiny, though, so that helps to decrease weight in that area.
I know that cars are using some more advanced methods for adjustment (some automatic).. Can anyone talk about these?
I am trying to get a understanding of the various ways that valvetrains are designed for adjustment, and the pros/cons of each type. A lot of this is coming from my experience with motorcycles where valve checks/adjusts are common maintenance. Can't say I have ever needed to do any valve work on any cars/trucks I have owned.
1. Locking screw type - I was exposed to this method on an old Honda dirt bike with a single cylinder engine. The cylinder head has "port holes" where you can access the valve clearance adjusters, which consist of a threaded post and some locking nuts. Dead easy to do (if access isn't a problem), but very imprecise.. You would adjust the post for length, and then when you tightened the lock nut, the clearance would change just slightly. I would imagine this design only works for fairly "agricultural" applications at low RPMs.
2. Shim over bucket - This was the first type of valve adjustment I did and it was surprisingly easy. Still requires removal of the valve cover and you have to be careful once inside there, but the shims are easy to access and swap out. I did a little reading and it seems the drawback of this method is increased weight due to the size of the shim and it doesn't seem well suited for high-rpm applications.
3. Shim under bucket - This is my current challenge. Both of my bikes use this method and I don't look forward to removing the camshafts just to change the shims. The shims are tiny, though, so that helps to decrease weight in that area.
I know that cars are using some more advanced methods for adjustment (some automatic).. Can anyone talk about these?