George.....If you are using low tension rings and your getting blow-by,
then it stands to reason some power is getting into the sump.Any blow-by
is a waste of compressible power(work) that you've just got the fuel/air
to do. If, to make the power you are running, 14 or 15 to 1 compressions
then pumping losses are also eating HP.
It's been proved that above 15 to 1 that gains are too small to justify
the increased pumping losses and the added stress on
components....Presuming the gas can stand it too .
I ran a VW 1300cc Formula Vee a while ago and I made it 14 to 1 because
the small carbs restricted the breathing so much.If I could have used
the right size carbs it would have made more power from lower CR's
The blow-by on this engine was nearly zero and a leak down showed
1.5%.It made about 102hp.
As you probalbly know the highest loss from parasitic drag is the ring
sets but also a pumping loss from moving the crankcase air around in the
motor eats power, so, it's a good case for very low pressure in there
and a scavenge pump will still suck out the oil 'cos the vac is behind
the pump as well as in front.
Wot u think?.................DK.
(Scrap-Iron Racin')
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George Mitchell wrote:
>
> Don,
> Just going by whats works for me in the past on big
> motors ( over 600 Cubic inches ) with a low tension
> rings and compression close to diesel status....
> Everybody must go with what works for them.
>
> George in DC
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