The basic problem with the T&L situation from the perspective of a disgruntled consumer is that the consumer is struggling to get some leverage over the guy. If you don't have some leverage then it doesn't really matter how many letters you write to him or phone calls you make - his lack of response actually is a response, specifically, he's not going to do anything to honor the inducements to purchase (such as delivery timing).
So how do you get leverage? Well, obviously, you can sue the guy. However, nobody wants to throw good money after bad and lose another $10,000 in litigation costs for a potentially unenforceable judgment. Remember, a judgment is of no benefit unless you can actually enforce it through a garnishment or a lien, and even then you're stuck with a less-than-ideal outcome (garnishment=trickle of money, lien=no immediate cash).
So, what do you do? Start with things like contacting the Attorney General in T&L's home state. If everyone who has been screwed by T&L wrote a nice fact-based letter to the Attorney General then T&L wouldn't be in business today. The AG has the authority and resources to very easily shut down a business w/in the state where the business is demonstrably engaging in repetitive fraudulent practices. And, they can, and will, draw in the criminal law authorities if the fraud rises to the criminal level. Here's the link the North Carolina AG:
File a Complaint
You can also draw in Federal authorities to try to gain some leverage. Because T&L sells via the internet then they are engaging in interstate commerce and thus all the Federal consumer fraud legislation applies. The FTC is a good starting poing and has a consumer protection mandate with an online portal for collecting data relating to consumer fraud here (just like the NC AG's office):
https://www.ftccomplaintassistant.gov/
And, at the local level, as Jack suggested above, contacting the local police and making a formal statement could prove helpful. If nothing else, the local police might go by and interview the owner. Being interviewed by the local police tends to make people take notice.
The above is just a few suggestions - there are more. But the point is to get some leverage on him and put some pain in his backyard rather than wasting your time writing/phoning a guy who is obviously blowing you off. Again, his lack of response actually is a response. Don't kid yourself and think that he's just forgetful or a poor business man (that's probably true as well....). He's not responding because he has no intention of shipping you your engine on time, or perhaps not at all and he doesn't have the backbone to tell you this directly.
I once bought an f-car via ebay from some dirt-bag auto dealer in NJ (should have known better). Litigation would have been fruitless, but through a combination of contacting local authorities, the AG and the FTC enough pressure was exerted that they returned the money (the car was never delivered). I later learned (when their bank called me after they defaulted on their line of credit) that they sold all of the inventory several times over in rapid fire and then trucked it all to another state and started again with fraudulent sales. The bank told me that their investigator determined I was the only one to get a refund of monies paid out of several hundred defrauded buyers - they obviously didn't want their cover blown until they could run the whole scam process across a large number of deceived buyers taking many weeks.
So, the point is, forget about writing more letters/emails to T&L, go get some leverage first!
That said, T&L probably does deliver a bunch of decent engines to people who have placed orders, but likely on a high delayed time schedule. So I'm not suggesting T&L is running a similar scam. But, their business practices aren't right and they should have to answer to parties with authority (local police, AG, FTC) to either make them change their ways, or deny them the right to do business at all.