2270 Deck Height and CR, Pistons sitting proud of the deck, how many shims is too many shims? Options

[vjb206]

Hey folks! I have the bottom-end of my 2270 assembled and spinning freely. Thanks to all who helped me get to this point!

(IMG:http://www.914world.com/bbs2/uploads_offsite/media.giphy.com-23760-1708984357.1.gif)

To quickly recap: I bought the 2257 kit from AA Pistons (78mm stroke, 5.158" rods, etc.). And when I threw a P&C on for a test-fit last weekend, I immediately noticed the piston sitting proud of the deck height at TDC (negative deck) by about 2mm.

(IMG:http://www.914world.com/bbs2/uploads_offsite/media.giphy.com-23760-1708984358.2.gif)

Before I overreact, or buy the wrong stuff, I thought I'd ping the community...

1. Is this normal for a stroker set-up?
2. Can you stack multiple shims when getting up into the .06 >> .09 range?
3. (If no-stack) What's the best place to have custom shims cut?
4. I recall Jake saying using large shims requires lots of advance, anyone have experience here? What am I looking to adjust for upon start-up?

Once I figure out whether or not this is normal (I.E. verifying that I don't have to backtrack), I'll get into the CR questions (just waiting on clear plastic from Amazon so that I can measure my CC volume this weekend) (IMG:style_emoticons/default/biggrin.gif)

Thanks!

[VaccaRabite]

You are asking the wrong question.
Stop everything else with this build and start here:

What is your target CR? Don't make or buy anything else until you have decided this!

Once you know your target CR, do the calculations (lots of CR calculators online). You will need to know (really know) your head volume in CC for this. Easy to find, but its a little extra work.

At minimum you will need a .123 inch (3.13mm) spacer to give you a .040inch deck height. You MAY need more then that. You won't know until you have done the full CR calculations to figure out your optimal deck to secure the CR you want. If your block is square and cylinders equal all 4 spacers will be the same. Don't count on it though!
You will still need to straight edge the tops of the cylinders to make sure they are aligned flat to each other so they sit right on the head. And don't forget to measure deck on the wrist pin. Otherwise the piston rocks a little on that axis and you will get inconsistent measurements - that get worse the farther you are from the pin axis.

The good news is that once you know, you just call one of the shops above and get base spacers made for your specifications.

I built my first engine just winging it and learning as I built. I learned a LOT. I then rebuilt the engine a few months later when it failed. The second engine ran for years. It was a very expensive lesson. Start with the math and go from there.

What is your CR target. That's the math you need to do right now before going any further. Hopefully you already did the bearing clearance math and fitting!

Good luck!
Zach