Deck height

1930 said

See above as to where I am at with the heads and give your opinion.

I am not going to use a cam that large.

At this point do we have enough info to say how much has to be removed from the head to get to the compression I am after?

What order am I too approach this.

My plan is

1- Have the head re-conditioned replacing any valve guides that need replacing and installing the over-sized valves.

2- porting the head to increase flow

3- shaving the appropriate amount from the head to get to a 9.1 9.5 to 1 compression ratio. Amount still un-known at this point. Dont know how to calculate that. Must be something more specific than 6 thou = 1 cc so figure 48 cc to get to 9.1 ......just off the top of my head

What would be next in other words?

Click to expand...

We need to know where your pistons are. How far below the head deck is the top of the piston at TDC? Are they flat tops? Any eyebrows/valve reliefs?

Put the piston at TDC and measure the volume above the piston to the head deck with the cover plate as described in the compression check thread. With that info, we can start figuring out where you are and need to go and how to do it.

I would not recommend trying to mill the head and block to get compression. If you do too much milling, you may now have issues with push rod length. It may be better to see if there are any affordable pistons that will get you close, then do the milling.


I gotta go for a bit. The kid wants to do some work on the cars for a while. I will check back in when we take a break....