Who to approach with a radically new engine design?

this may not be the proper StackExchange site (flag if you think it should be moved elsewhere; I did not find a mechanical eng site) but I have an engineering-related question. My dad created a design of an engine that is unlike any other engine in production today. He has been an engine engineer for over 40 years and really knows what he's doing. This is not some "I have created a magic machine" design. He's been working on it on paper for over 3 years and believes it does work and is far more efficient than any other engine out there. Now, the problem is that he has no capital to build a prototype to document the engine's characteristic (basically a document that states its qualities and efficiency). He does not have the design patented as that costs a lot as well and takes for ever. Who should he turn to with his design? He doesn't want to go to any car manufacturer as they will likely take the design and not let him be a part of the prototype building phase. Finding an investor is very hard as everyone likes to see at least a prototype and that it works before funding it. Any suggestions are appreciated.

"He does not have the design patented as that costs a lot as well and takes for ever" "they will likely take the design and not let him be a part of the prototype building phase." That's what patents are for. If the discovery is important enough, at a minimum you should learn how to protect your/his interests with a provisional application patent. Read up on how to do it - Nolo has great guides. And a micro entity can submit a provisional application for a utility patent for under $200 (USPTO fees here )

Once prepared / armed with information, you can meet with a patent attorney and have 1 year to come up with a cost effective way to file a patent.

While a provisional application (and even a patent) cannot stop other entities from stealing your idea, it does provide a legal record with a timestamp of your submission from which you can mount a defense if you believe your idea was stolen.

Once you feel your idea is protected enough (likely post your patent attorney discussion), engaging with local universities / crowdfunding / hackerspaces to go from paper to working prototype will be easier.

It has to be patented first, you can't trust anyone else or anything else to protect your invention.

Patenting doesn't cost that much, a $750 or so, depending on the country and the options. Some European countries even offer special letters that can be used to prove that some information (like an invention) existed at a certain date. When you later fill a patent with their office you can use the date they received your letter as the date the invention was made. It costs $25 or so.

You must not go public (or share it confidentially) before your patent is pending or it will become public domain.

Once it's patent pending, you can use a crowdfunding service like kickstarter.com to fund a prototype. A prototype shouldn't cost so much either if you resort to rapid prototyping. Contact nearby fablabs to see what's possible.

Once you have a prototype and if you intend to mass produce it, you can either ask again for crowdfunding and start your own company, or contact a manufacturer that would need your engine. In this second case I recommend contacting a small manufacturer in a niche, like lawnmowers or chainsaws, not giant automobile corporations as they will swallow you like a pea.

Be fully aware that if your motor uses a fuel that cannot be profitable to the oil, biosomething or electricity industries, they will make sure your project never sees the light of day, whether by buying you or burning your house.

Patents are very good to have, but they are worthy if you have enough money to sue somebody who had stolen your design. If the company Ford/Cadillac, etc. builds your fathers design, most probably you won't have money to protect your patent... It's a cruel world...

About prototyping:
I would definitelly go for making a prototype of it. Without a prototype nobody would "buy it".
To reduce costs, I would build a much smaller motor (10-20 times smaller). It needs much less materials, it is easier to build, etc. .
If the costs are still high I would go for a non-working small model made from plastik, maybe 3D-printed by local Fablab. If you feel unsafe, ask several 3D-print service for printing the different parts of it. Showing a non-working prototype is still much better than nothing. If you show it to an engineer he/she will probably see the idea behind it.
If it cost still a lot, or as an "add-on" to the non-working protoype I would create a 3D-model in a free CAD-tool ( for example: http://www.designspark.com/eng/page/mechanical ) and make an animation, showing how would it work.

Good luck!