[lord]

I don't know my compression, i asked in another thread and i'll ask again here. 64 cc chamber, flat top pistons with little grooves for valves, the piston tdc is about 1/4 inch below deck. 350 block bored .030 over. anything else you need to help me figure comp?

Anyways, i tore the motor down to replace the piston rings, and was wondering what kind would be best to buy. the motor is 350 with double hump heads, mild cam, I want power.

[BOBCRMAN@aol.com]

Use plain cast iron rings such as Hastings 139 on a used bore, if there is no taper or wear you can use a moly ring, do not use a chrome ring on a used bore.

[roys63]

[QUOTE]Originally posted by lord
[B]I don't know my compression, i asked in another thread and i'll ask again here. 64 cc chamber, flat top pistons with little grooves for valves, the piston tdc is about 1/4 inch below deck.


Are you saying that your pistons are a 1/4" below the deck of the block? If so you have the wrong rods or pistons or both in this motor!! This must be changed !!

[lord]

maybe its more like an 8th, what should it be?

[roys63]

The deck height can be at 0 or.010,20 depends on the heads and head gasket to work out your compression ratio, if you want power the piston needs to be a bit closer to the head . What is the casting # of your crank and block? You need to measure your deck height better to be sure. Someone else may ring in on this.

[lord]

yeah, i was wrong, i was looking at the marking on the cylinder wall and I figured that was where the piston topped out. But that is just where the piston ring tops out so the deck heigth should be normal.