Setting deck height for 9:1 compression Options

[Chad911sc]

I have my short block built and I’m ready to set my deck height. It’s 96mm bore with stock 71mm factory crank. This is a 2.0 2056 build. I have a Web 86a cam calling for approx 9:1 compression. I have 60cc heads with 3cc valve reliefs on my flat top pistons. If I plug all this into the calculator, I get 8.3:1 for my compression ratio if I set the deck height to .040 inch
After I set up the piston on the rod and bolt down the cylinder to the block, I get .053 inch from the piston to the top of the cylinder.
My question is, what is the best way to proceed to get the 9:1 ratio with at least .040 inch total deck height.
I am thinking that if I take off 6 total cc’s from the head, that will leave me with 54cc heads with the 3cc valve pocket = total 57cc’s. Bringing me now to the correct 9:1 compression ratio with the .040 inch deck height.

If I am in the right ballpark, this means I need to have my heads fly cut….correct??
If this is correct, how do I go about calculating how many thousands of an inch do I need to have removed by the machine shop to remove 6cc from the head?

I obviously will need to remove at least .013 inch total deck height get to my .040 goal, and that’s with no shims or head gaskets being used.

Thanks for your time, Chad

[technicalninja]

Will .010 give you the deck height you needed?

I thought you needed .013 from your initial post...

I'd have gone a little bit deeper allowing for shimming.

If your using cast pistons it will probably work fine at .037 but that is getting close in my book.

The above (and the next post from me) is TOTAL BS!

I even sucked Jack Standz in...

I got the math BACKWARDS AGAIN!!!!

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It looks like he didn't remove ENOUGH material.

This would have put the piston DOWN the bore, not up.

He's NOT tight, he's loose!!!!

I'm happy he rechecked his shit and choose the proper amount to remove.

In my book .040 is OPTIMAL and safe enough to release to non-technical folks.

He's as TECHNICAL as I am...

I still suggest checking all of them and (this might be important!) check to verify the jug fins are NOT hitting the head.

The check I did for him on register depth on my stock junk was eye opening!

It looked like either fly cutting head OR cutting top of jugs would require doing something to the fin section of the jug. Without the original compression ring it looked like they ALMOST touched the head in STOCK form!

And I truly believe, on pump gas, the deck height is the MOST important measurement to get right. Something without quench pads, something using fuel that is not prone to detonate, it's not nearly as critical.

But for the crap we can get out of a commercial pump (besides E/85) deck height is stupid important...

Merry Christmas all!
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Edit: Everyone, even brand-new members, can add good info to the forum.
Chad has given me a small Christmas present (and he didn't even try!).
This guy has a functional turbocharged air-cooled VW (the Sun Bug) at 220 hp!
I want to know ALL about that set up!

I VASTLY prefer to force feed engines below 3.5L It's my NORMAL recipe.
I automatically discounted "turbo" due to the limitations of the T4.
Might have been short sighted...

I hope "Nickies" are not part of the equation; blows budget bigtime.

Chad, we will have PM conversations regarding this after the holidays.

And LOTS of folks on here would be interested in turbocharging the T4.

It would make a KILLER thread on its own!