What happened to Spec Miata?

The spec engine, or crate engine situation is a pretty good idea, but isn't foolproof. We run a GM #604 400hp/400tq 350 in our late model series, and we try really hard to keep it legal and in spec. Any work beyond changing valve springs must be done with a track rep there, and if your blown head gasket turns out to be a warped head, get out your Visa and head for the nearest GM store.

Problem is, most places that run crate motors allow, or even encourage rebuilding. We had a guy show up once this year, with a "guaranteed legal rebuilt crate" that was so obviously wrong it wasn't even funny. It fired instantly with that high compression bark, and made sharper noises than everybody else. I put the whistler on it- all the 604 crates I've tested are 9.5 or 9.6:1. This one was 10.9:1. I didn't bother getting the cam profiler out...

Swank Force One wrote:

HiTempguy wrote: Since these cars are naturally aspirated... have a spec head (stock). Heads should be readily available I'd think. Its easy enough to tell if compression has been changed due to pistons. Boom, piece of cake.

Problem is that 4 different motors are allowed in the series, and none of them have been made in a decade.

Wadunno. They make new flat head cylinders dont they? I honestly dont know what price it would cost to start manufacturing them again. Just throwing out ideas ;)