You guys are missing the point. The "built" engines still have to be checked by the track and sealed.
The sportsman class is supposed to be an "affordable" division. If you make it so everytime an engine needs something fixed that you have to buy a new $4,000.00 engine then you make the division more expensive.
Lets say a head gasket goes, thats an easy cheap fix, Instead you would have to buy an whole new engine.
Also it only costs $1,500-$2,000 to get the engine refreshed. Instead I would have to buy a new engine for $4k.