5 replies to this topic

[Chris Ashcraft]

?
FROM


January, 2013 – Version 2013.2
NASA Spec Miata® Challenge


.11.2. Balancing and Lightening: Lightening of engine parts and engine components is not
permitted. Balancing of Crankshaft and Flywheel is permitted; minimum weights listed in
these rules must be maintained.

12.1.4. Crankshaft: The stock Mazda Miata crankshaft must be used with no modifications
allowed, as shown in the following table, which also displays minimum weights (not
including pilot bearing or hardware).

is it just me being a newbie or is this a contradiction?

Chris

[Caveman-kwebb99]

it is really simple... you can read rules till your blue in the face. I and others gave you some good advice in your other threads. Send your engine to someone that specializes in SM engine building. They know the rules, they know what will and wont pass tech, theyknow what is and isnt inforcable so forth and so on... Those engine builders reputation rides on building engines that will pass the teardown...

Rules often seem contadictary at least to me, that is why knowledge and experience is KING.

here is a list I know of:

East Street (obviously my builder of choice)
Stewart Indianapolis (have had many friends with great stewart power)
Race Engineering ( Bob is a good guy)
Ti-Speed (Dan is another good guy)
Nelson Engines (Skip Crockobile sure has a good engine from there)
Rosini ( Danny's guy)
Autotechnik ( Jeff normaly only builds for those who race under his tent)
I am sure there are others I have missed...

[Bench Racer]

"Could" be an offical from NASA could answer your question.

I "could" read the two rules and answer your question, but I "could" be wrong

[Mike Collins]

While I am not a NASA official, I have have been the NASA SM Chief of Tech for the last few years.

What that says, as I read it. The Crankshaft and the Flywheel have to meet minimum weights as posted. However you can balance the assembly the same way the factory did SO LONG AS your parts do not fall below the minimum posted weight. The factory did balance these parts. You may choose to balance it to a tighter tolerance within the weight limits allowed.

[john mueller]

While I am not a NASA official, I have have been the NASA SM Chief of Tech for the last few years.

What that says, as I read it. The Crankshaft and the Flywheel have to meet minimum weights as posted. However you can balance the assembly the same way the factory did SO LONG AS your parts do not fall below the minimum posted weight. The factory did balance these parts. You may choose to balance it to a tighter tolerance within the weight limits allowed.

I like where Mike is headed with this thinking... Regardless, I'll get it cleaned-up soon along with the NA Diff.

[Chris Ashcraft]

Mike,
Thanks for the explanation..very well put!
Chris