Box Stock

CC for Non Hemi and Hemi

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briggscrazy

Member
At our track we do a CC check for one of the techs. It is not done very often but they have used the 26.5 which is the clone cc check. Now they are going to make a new cc rule for the predators. I am wanting to know what the cc check is for the head on for the hemi.
 
They have to establish the rule set, hemi, non hemi, head and decking milling yes/no, head gasket thickness etc. then take an engine do everything to the max or min then measure the chamber.
 
They say stock configuration which is a broad term in my opinion. But no matching or mixing of parts from each. I know the Hemi sits about .020 in the home, and the non hemi is about .010 to.015 in the hole. Also for every .010 shaved off the block or the head, it is a cc. So the non hemi comes with in some like the 69730 which has the rtc-8 head' the .009 head gasket, but the hemi has the .045 head gasket. So they will have to cc according to the model of the predator, which is I think is really stupid and hard to police and tech. I had a Hemi but now am building the 69730 which will make a better motor for what I want to run on our track. By the way no milling or decking.
 
That 1cc per .010" milled is too vague, it worked for the block on a 196cc but the bore is larger for Predator. The head is a rough guess that did not work after the first .010" the head shape is much different so that rule of thumb is not valid. Someone needs to cc two new engines out of the box to get a baseline, you cannot take a stab at it.
 
This is one reason why I think the predators should not run with the 196cc class or make rules that allow both to be competitive in the same class, carb, cam, springs, porting, etc:
 
It was the same for the clones, there are so many variations on the market, to arrive at the stock dimensions is a moving target.
 
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