Tech Pictures of the HDT engine

[Stuart]

Anyone else find these interesting? Some good exploded views I thought.
http://dieselmotorcycles.com/technology.html

[espe]

Nice! Are these motorcycles made available to the general public anytime soon?

[Kristof]

^Unfortunately no. Maybe if the military decides to sell their HDTs. Has anyone seen one for sale? Any idea on when they will start selling them?

I have seen these pictures before. I always like to go back and admire the engineering.

What I want to know is the inside of the high speed injection pump. I want to understand how they were capable of producing such a high speed pump.

Does anyone know if there are any car injection pumps that come close to the quality and speed of the HDT pump?

[pietenpol2002]

Their history page suggests they've not built anything beyond their initial production run in 2010 of 214 bikes (not counting the earlier test prototypes). Not exactly mass production. And I might guess parts support for any that might hit the civilian market would be non-existent. I wonder also if they are incapable of meeting EPA standard for the civilian market.

[BertTrack]

@ Kristof. What do you mean by highspeed pump? It's rpm?

[Rhynri]

VW's TDI engines have revs north of 5k, so I imagine theirs can handle the speed, not to mention any injection pump for a two-cycle diesel running 3k rpm or higher.

[espe]

I guess it wil be quite simmular to a common rail dieselpump. I think that's the way to go. A high pressure pump and a piezo injector on a one-cilinder. That would get the performance up and over gasoline levels.

[Kristof]

I am sure the fuel pump must have been custom made/engineered for the high speed of the engine.

[bean juice]

Better late then never. The largest determining factor in the rev limit to performance diesel engines is not the mass of the reciprocating parts or the fueling system or anything else mechanical. It is determined solely by the speed at of the flame front or the speed at which the air fuel charge can combust. diesel burns slowly. Even the TDI leMans cars are only spinning at a max of 4.5K to 4.7K RPM. Anything above that and you are making smoke not power. To make a diesel engine that could develop effective power and spin faster than that it would have to have an impractically small bore. FWIW my 2010 VW TDI has an indicated red line of 5K RPM but at 4.5K the power drops off noticeably.

[Stuart]

Perhaps the construction/action of the high speed injector pump is such that it has little or no built in guvnor? Perhaps the engine is constructed, in part, to rev higher, not all for more power but also as a safeguard against valve damaged on (abusive) engine overruns?
It wouldn't be the first time something like this had been built in to military equipment to protect it from the operator but sold, instead, as something else? Maybe it's a 50/50 thing? But given you had that flexibility built in, and being human, you'd wanna push it for all it's worth anyway, wouldn't you?

[pietenpol2002]

I do wonder how the tractor pullers achieve 7,000 RPMs? Most are using original equipment injection pumps, albeit highly modified. Below is a quote from a builder of puller engines.

"We do some injector pump work for these engines as well," continues Menke. "We laser out injector kits, put bigger plungers in the pumps, cut the flyweights or take some weights out to make them go faster. Once you do that you have to modify the rest of the pump, including the delivery valve, lines and camshaft. Once they get going, customers can easily spend $5,000 on a pump.

[Rhynri]

I'd imagine a lot of it has to do with the other things they inject along with the diesel (water and whatnot). That, and they don't give two shits about smoking and probably are running abusive boost levels and injection timings. Much of what they do at pulls would make an unusable road engine.