Originally Posted by atec77
have you seen the rule and why ?
what sort of car.
Yes, I have seen the rule... if you mean the rule regarding maximum capacity. There are light vehicle modification factsheets you can download from the RTA website. The one in question is titled "Guidlines for light vehicle modifications." There you'll find the currently applicable formulas to calculate the maximum replacement engine capacity that can be certified for various types of car. I don't know what you mean by "... and why?"
The car in question is a Datsun 240z.
RTA records say the 240z (HS30 chassis) weighs in at 1020kg. The relevant multiplier is the one for vehicles with a tare mass over 1100kg, and/OR with engines having more than 4 cylinders: Original tare mass in kg x .294 = allowable capacity in ci. As I said above, the capacity limit comes to 299.88ci.
Does that info help you help me??
Again, to avoid getting sidetracked, I'm hoping someone can tell me whether 289 blocks are externally distinguishable from 302 blocks, ie, by stamping/codes. I'd really appreciate the help.