Deck Height, I'm confused could someone help me out here Options

[stephenaki]

OK, first off, this motor is so much more complicated than my MG motors! So, I started looking at the piston assembly to the rod and subsequent assembly of the cylinder to the crankcase. It was then that I remembered reading on the forums about "deck height."

My understanding of this concept is somewhat rudimentary but the basics, as I understand it, is that deck height is the space between the highest part of the piston and the top of the cylinder head combustion chamber. Please correct my understanding if I am mistaken.

I have also read through several threads discussing how to measure deck height in order to shim it properly, change geometry, increase/decrease compression....my head hurts.

Since I want to get this thing put together properly I need to know the following.

1. how do I measure deck height (depth gauge is best from what I read).
2. how do I determine "IF" I need shims.

Now I know a lot depends on what I have so here is what I am working with.

1.7L crankcase
2.0L crank and connecting rods (no, I don't know the measurement of the rods. If needed, can I measure without re-opening the case? How do I measure them?)
standard 94mm bus cylinders and piston set (new set, pistons are dished)
1.7L heads that were machined to fit 2.0L piston and cylinder (I checked, they fit)

Rods and crank were balanced prior to my getting them and then the assembly, cylinders, pistons, rods, crank, etc. were balanced as a unit.

The PO had a 1.7L crank and rods with 2.0L jugs and no shims were present when I disassembled the motor.

I am venturing into a completely foreign area and concept for me and can use all the help I can get. I am not after anything spectacular, I just want the motor to run efficiently so I can drive and enjoy the car. I don't plan on racing it. HELP!

[Dr Evil]

Some good general info here. Its corvair, but relevant.

Deck height is towards the bottom of the page.
http://home.hiwaay.net/~langford/corvair/trial_assy.html

CCing the chamber volumes is towards the middle of this page. Also shown is deack height and there is a link to an Excel spread sheet that will help you calculate CR and shims and stuff.
http://home.hiwaay.net/~langford/corvair/valvejob.html


You can easily CC the dishes on the pistons to help with the chamber volume. This is also provided for on the pages I referenced. If dished and you want a specific CR then I would recommend CCing at least one chamber and dished piston. Be greatful you dont have domed pistons as that is a bit more work. There is a good explanation of deck height and calculation in the second page as well.

AS for putting it close to the top of the cylinder, be careful and research this. Type 1 engines in particular as supposed to have like .060" or something close to keep from getting too close to the valves. (not actual measurements, only meant to be an example of concept)