Dear All,
Last time there are some rumours going around in the pullingcircuit about downsizing Pro Stock engines.
With this mail ETPC wants to clarify what is allowed :
-First only two valve heads were alowed on Pro Stock engines. Max. 8364 ccm. No downsizing allowed.
-Later , 2006, the question came to allow newer engines with multivalve heads because those multivalve heads became the standard in newer tractortypes.
Agreed was that this OEM-multivalve head was allowed with a max displacement of 7300 ccm. No downsizing allowed.
-A few years later, 2010, the next question came up to syncronise the multivalve engine displacement with the Farm Stock tractors engine displacement, which was 450 cu. in. is 7374 ccm.
This was agreed with allowing 2 percent downsizing of both type Pro Stock engines.
In other words, the 2 valve engine (max. 8364 ccm. )as wel as the multivalve engine (max.7374 ccm.) downsizing allowed: max. 2 percent.
Hope this makes things clear for everybody.
On behalf of the ETPC tech & safety board,