The OEM cylinder head maybe machined or strengthened for longevity. Portingof the cylinder head including intake matching is NOT ALLOWED. Machining, grinding, sanding, or etching of the intake
and/or exhaust ports are STRICTLY PROHIBITED. Camshafts, valve springs, valve spring retainers, keepers, and fowler maybe replaced with aftermarket products. All timing components such as cam gears, sprockets, timing chains, and timing belts maybe replaced with aftermarket products. Titanium products are NOT allowed
Given the fact that porting of heads is not permitted, does the Ecotec really have the CFM to make 300+ Horsepower?? Maybe the Honda does??
From what I understand the difference between DII and BMARA is mostly in the use of aftermarket bolt on parts. Cams, valves, pistons etc. Both have opted for stock blocks, cranks and heads allowing only minor changes to these parts.
It is great to see so much interest in the class and so much interest in keeping the cost down for all the classes of cars. I think we should wait to see the DII rules posted to compare the two. I really don't expect to see a big difference and probably a good DII car could compete with the BMARA racers. I really don't think a lot of guys realize how good of a motor the Ecotec is right out of the car and on to the race track. Many of these aftermarket parts I would classify as Glittering Bull $^it.
Horsepower is directly proportional to how much air you can cram into the cylinder on each stroke and then how much can you compress it until it is time to fire it off. Cams help a little but port design and valve area are paramount and both set of rules take these variables out of the equation.
Honest Dad himself

