It had been brought to my attention that there is a special reason why the ST
displacement limit was raised from 2.4 L in its original form to the 3.1L in its
current form.
There exists a GM 3.1L motor, found in the Sunfire and similar cars, that unlike
all the other rice rocket motors is a _pushrod_ motor, not an OHC motor.
Accordingly, it needs the extra displacement to be able to run with the small
Japanese/Euro motors, as it's valvetrain limits the amount of RPM you can wind
out of it.
I had forgotten that GM still made pushrod motors. :)
This presents an opportunity. Pushrod motors don't make the same power as OHC
motors of the same displacement, even when supercharged/turbocharged like they
would in STU. This means we can allow some more people to play (and cut out some
problem cars) if we differentiate on valvetrain type.
Something like this:
STU displacement limits are as follows:
- for overhead camshaft engines - 2.500 litres
- for pushrod valvetrain engines - 4.000 litres
- for rotory (wankel) engines - 1.5 litres
This would allow the Grand Prix, Regal etc (they _are_ pushrod motors, right?)
but keep out the more expensive/rare Porches, Supras, etc.
Looks like something Tony George would cook up, eh? :)
Take a hard look at this, please. Let me know who we wind up
allowing/disallowing (especially with the rotories) with this layout. Feel free
to suggest better limits.
BTW, how big is the Olds Quad 4 motor?
DG
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