I thought it would be good to archive some of the high performance four strokes that were promoted in the US around 2008 ish but never seemed to have much adoption. I think most of these came from the FIA’s proposal to move to four stroke from the super high performance 100cc classes.
The information I have from these is from the US importer, engines4racing.com which is long gone, but I was able to find the info on waybackmachine…
Here’s a summary, just keep scrolling to see details and pics.
Incidentally they also imported the Rubig 600cc two stroke. It was demoed at the Supernats one year and it was claimed that it was faster than shifters by a good margin. (Going from memory here so specifics are vague but it was something like two seconds!)
I went back and forth on the XR because a lot of people would agree with what you’re saying. On the other hand some will say two stoke because it has ports and needs oil mixed with fuel.
Technically, Wankels are zero stroke engines. They have stages\chambers yes, but so do gas turbine engines.
They were all production motors that were imported to the US by engines4racing. The Biland for karting dates back to 1997 I think. I drove one in 98 ish. Fun engine for sure.
Either the Vampire or the Swiss Auto did get a bit of traction in the UK.
It’s a great reminder that a good (or even great) product is not enough to make a successfully adopted class.
It’s definitely semantics, but you did say “technically” so it’s natural that we’ll end up here
The four stages of ICE often get conflated with the number of strokes. These four stages (Induction, compression, combustion and exhaust) just happen to line up with each of the strokes in the most commonly understood engine: Four stroke.
Turbine engines are also ICE and have the same four stages, but are not considered a four stroke. Same with Wankel and two stroke. Same four stages, but each stage is not a stroke.
Sounds like you might be referring to the likes of the Detroit diesels, screaming jimmy etc…. Those are also two strokes. They still fire every second stroke. They just happen to have poppet valves for exhaust. The cam gear turns at at 1:1 ratio with crank. At 5:20 in this video there’s a good explanation of how poppet valve two stokes work.
Don’t get me wrong, I understand that most people associate valves as being a four stroke only thing and that two strokes can’t have a separate crankcase oil system. However the two stroke diesels have both of these.
I can’t recall honestly. But I’m sure the TCO over say, three seasons would be lower with the four strokes compared to the Leopard, Sonik, Rok GP and sealed Rotax etc at the time. Even considering the extra hardware that might be needed at service time.
Then again I don’t think TCO is a big consideration for most of us. It probably should be though.
(TCO is Total Cost of Ownership in case anyone reading is wondering what the heck I’m talking about.)
