3.2 (930.20) FORCED INDUCTION - REDUCING COMPRESSION RATIO
Discussion
Hello gents,
I am in the process of rebuilding my motor and looking to supercharge it initially and turbocharge it later (or Turbocharge it from the beginning).
My cylinders are in mint condition and my pistons are in very very good condition too.
Since I have a 3.2 (930.20 Euro spec motor) the compression ratio is 10.3/1, which needs to be decreased especially since the climate in Greece can get really hot.
You have any suggestions for dropping the compression ratio using my pistons?
Maybe thicker gaskets or that doesn't work on the aircooled motors?
My mechanic told me that at the base of the cylinder there are copper rings that can be found in 0.25 or 0.50?
Fitting 0.50 could lower the compression ratio? Any idea? If so by how much?
Maybe another solution would be to machine the pistons or this is not a good idea as we will weaken the pistons? Anyone done it?
If the option above (maintaining both my pistons and cylinders) is not possible, What about buying a new set of pistons (in which case I will go twin-plug) with lower compression ratio whilst maintaining my cylinders? What pistons would you suggest?
Lastly would it be a solution to buy 3.0 Turbo pistons since they have the same bore ie 95mm? What other parts would need to be bought ?
Most importantly what would you guys do to have a cost effective but correct engine build to accommodate forced induction, trying to at least keep the cylinders that I have (replacements are not cheap!! and I find it a pity to change them since mine were found in top condition).
All the best,
Alexis
I am in the process of rebuilding my motor and looking to supercharge it initially and turbocharge it later (or Turbocharge it from the beginning).
My cylinders are in mint condition and my pistons are in very very good condition too.
Since I have a 3.2 (930.20 Euro spec motor) the compression ratio is 10.3/1, which needs to be decreased especially since the climate in Greece can get really hot.
You have any suggestions for dropping the compression ratio using my pistons?
Maybe thicker gaskets or that doesn't work on the aircooled motors?
My mechanic told me that at the base of the cylinder there are copper rings that can be found in 0.25 or 0.50?
Fitting 0.50 could lower the compression ratio? Any idea? If so by how much?
Maybe another solution would be to machine the pistons or this is not a good idea as we will weaken the pistons? Anyone done it?
If the option above (maintaining both my pistons and cylinders) is not possible, What about buying a new set of pistons (in which case I will go twin-plug) with lower compression ratio whilst maintaining my cylinders? What pistons would you suggest?
Lastly would it be a solution to buy 3.0 Turbo pistons since they have the same bore ie 95mm? What other parts would need to be bought ?
Most importantly what would you guys do to have a cost effective but correct engine build to accommodate forced induction, trying to at least keep the cylinders that I have (replacements are not cheap!! and I find it a pity to change them since mine were found in top condition).
All the best,
Alexis
the turbo heads are different , they are made of a different material that can properly handle the heat that comes from turbocharging oilcooled engines ( high temps).
The Material is Rolls Royce 350 ( RR350) . I have a complete set of heads in Cambridge if you are interested.
best,
Axel
The Material is Rolls Royce 350 ( RR350) . I have a complete set of heads in Cambridge if you are interested.
best,
Axel
People have milled the tops of normal pistons,look on pelican parts forum.
Not to leaky depends what bhp you are trying to-tease out of the engine,lemans rings work well.My gt2 engine i used to run at 550bhp,had good head seals but thats using proper gt2 cylinder heads,gt1 spec engines head the heads welded for 650 plus.
I have been using JE pistons for 15 years In competition engines,great product for the price.
Sound advice could come from contacting ctr developments nr huntingdon,hope this helps.
Not to leaky depends what bhp you are trying to-tease out of the engine,lemans rings work well.My gt2 engine i used to run at 550bhp,had good head seals but thats using proper gt2 cylinder heads,gt1 spec engines head the heads welded for 650 plus.
I have been using JE pistons for 15 years In competition engines,great product for the price.
Sound advice could come from contacting ctr developments nr huntingdon,hope this helps.
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