View Single Post
Old 05-06-2019, 07:58 AM   #24
educator monkey
740atl's Avatar
Join Date: Apr 2010
Location: USA

Originally Posted by 2turbotoys View Post
Fred Gwynne, ya gotta start your own thread for those questions, we don't do threadjacking here.
or just answer his questions.

Originally Posted by Fred Gwynne View Post
I have a few real beginner questions for you folks. Is there a difference between shaving, skimming and decking? Is one for the head while the other is for the block?

Also, if you remove material from the head that means that the valves will now be closer to each piston. If you use a high lift cam such as a "k" cam then the valves may collide with the pistons if too much metal is taken off of the head. Is that correct?

What exactly does shimming mean? Are the valves or is the cam shimmed? Is the idea there to keep the valves from hitting the piston?

Thanks for your help.
You can shave the head. Take a bit off. Yes to the valve q. It also raises cr or is just used to correct a warped head.

You can deck a block... similar concept. This brings the pistons closer to the head. Used to correct a block surface or decrease squish clearance. There are some performance benefits to this.

You can also get the pistons closer to the head by using a thinner headgasket.

In a Volvo application shimming refers to changing the distance between the camshaft and the lifters. Typically by adding or removing shims of a specific thickness.

To keep a valve away from the piston typically you cut a valve relief into the piston top.
740atl is offline   Reply With Quote