4AGZE Piston and 20V Head Volume

[Bazooka]

Does anyome know the volume of the dish in the 4AGZE pistons? I'm looking for both the 8.0 and 8.9:1 figures so I can work out compression ratios for my 20V head conversion.
Also can anyone confirm a combustion chamber volume of 37.8cc for the Blacktop 20V head?
The other thing would be deck height clearance but I am not as concerned about this at the moment.

[Sam_Q]

you dont need to know the dish in the pistons to work that out.

which 20v head do you want to use with 4agze pistons, I will work it out for you

[KARNAGE]

I would like to know the compression to as i have just bolted my blacktop head on to gze block. Thanks sam

[Bazooka]

And why would I not need to know the dish of the pistons? This will effect the compression ratio will it not?
If I can get all the figures it makes it a lot easier to work things out correctly.
I was going to use this to work it all out
http://www.csgnetwork.com/compcalc.html
and it calls for piston dish/dome volume. I can pretty much work out all the other figures but wanted to confirm the Blacktop 20V head as having 37.8cc. I think this figure was actually posted by you Sam_Q.

[Sam_Q]

9.1:1 with 8.9:1 pistons, more for a silvertop

[Bazooka]

Well thats pretty damn close to what I came up with (9.09:1)
What do you get when you calculate it with the 8.0:1 pistons?

[Sam_Q]

bazooka that figue was indeed measured by myself with a syringe and i am very confident in the accuracy of it. You dont need to know any of that becaue theres a way to cheat, heres how I did it for karnage:

we know a ae92 4agze has 8.9:1 compression and a 39cc heaf (assuming its accurate)

we then plug that into our formular:

CR = (cylender volume + chamber volume [volume of head, gasket, piston dish, etcc] ) / cylender

cylender is 396.7cc, CR = 8.9:1

this gives us a figure of 50.216cc

we take away 1.2cc because thats how much smaller the blacktop head is, work it out again and we get your new compression ratio

am I right?

[Sam_Q]

well yeah I got 9.09:1 I rounded it off!

ok 8:1

56.67cc chamber

so ...

8.17:1

[Bazooka]

Yep thats cool at least we are on the same wavelength and my calculations are pretty accurate (unless we are both horribly wrong haha) This is why I am looking at using the lower comp pistons as they seem to give a pretty good result.

[Sam_Q]

well I think we are right because the ae111 chamber is only slightly smaller so it seems ok

[terryo]

most 16V heads are around 36cc with some down as low as 32cc after several machining cuts. The silver top 20V ones start at 43cc. I have GZE pistons with crown volumes ranging from -17cc to +8cc. The deck height varies wildly. some are down almost 2mm

[Sam_Q]

2mm? thats crazy!

[terryo]

the deck height variation is due to people mixing rods, pistons, blocks, cranks, and the tolerances on each. the block is the largest variable. If you give me all the measurements you have, I can supply a suitable set of pistons