E30 radiator

[Brighouse-gti]

Shamelessly stolen from another forum;

2E ADY 10.1 AGG 9.6:1 All rod lengths the same at 159mm.
2Es have the same head casting as an Audi 80's 3A 037103351H. This was touched in an earlier thread where a 2E inlet was used on my complete 3A motor installing in a MK2.
AGG and ADYs have the same head casting 0481033351D The only difference is the camshafts used so still does not explain the compression difference.
2E, ADY can use 0481033383B head gasket (fibre)
ADY,AGG use 048103383D (metal) stll does not explain compression drop.
The only non universal set explaination would come from the pistons.
2E and ADY carry the same pistons 048107065R
But the newer AGG carried 048107065S
If I was to go by common sense and the above infomation I would say that your CR difference is down the piston dish/deck height differences. A burette or dial indicator and some patience can always confirm.

Going of subject a bit here I know, but after doing a bit more searching, the spec for this turbo setup I've got was originally for the 1.8 GTi which has the 10:1 ratio, and was dropped to 8:5:1. How do I calculate how much 'thickness" of a gasket or spacer I would need in relation to the 9:6:1 ratio of the 2.0, to get it to the equilavent of how much of a compression reduction there was for the 1.8GTi.
(I think that makes sense?¿?)

[gazareth]

if the gasket diameter is 83.5mm you would do .7854 x 8.35 x 8.35 = 54.7600515 which would be the surface area of the cylinder ring in the gasket in cm2. so if you change that to cm3. as in from a flat surface area to 3D. you would divide 54.7600515 by 10 which would give you the volume ccs of a 1mm thick gasket which would be 5.47600515 cc. hopefully i explained that right

[Brighouse-gti]

Yeah that makes sense! Sooooo, if the ratio percentage of a 10:1 is 9.09 and it drops to 8:5:1 giving a percentage of 7.14 then the percentage drop would be 1.95. So if the cubic capacity of said cylinder is pi x radius squared x height bla bla bla would give a 661.33cc per cylinder which would need reducing by said 1.95 ratio percentage which would be equal to a 12.896cc increase which goin back to your calculations would equate to roughly a 2.5mm gasket. If that makes sense!! Hhhmmmmmmm?

[Waspy]

Pretty sure some maths need checking there...

However I'm only doing it in my head, needs some pen and paper work

Never seen so much maths on a car forum. Be discussing aerodynamic drag coefficients next 

[lemski]

Makes a change to the no point doing it.
Started of as what rad people use