The company who is helping is a manufacturer of 2T racing engines,
that has over 30 years experience on it.
Their engines are state-of-the-art, in fact, They are constantly successfully competing in various categories up to world championship level.
Their help consist in the fact they:
Gave me access to (part of) their engines' design
Agreed to build my RG-adapted variant of their design
This is done as a personal favour and it is mandatory I respect the NDA (Non Disclosure Agreement) with them. When I say "I can't tell", it means just that, I can't tell. Some people on the Gammalist got offended by this, which makes me really wonder!! It's industrial secret! Should it be my way to thank Them for their help and their trust in me, to publish their reserved information on the Internet??
Also, in case I'd violate the NDA Their collaboration would drop so even if you don't understand correctness and you don't care about my reputation, maybe you could care the availability of the RG parts depending on this.