I’m curious if anybody knows how much these engines differ from the VHPD we run in our cars? Are they not fundamentally the same engine? If there are differences what are they>
Perhaps folks with further knowledge of the build spec can enlighten me. It seems they have a pretty decent longevity thriving on high revs used on track as race engines.
That’s a good question. I don’t know the answer but it looks like Vulcan racing prep some of the engines. They mention a VHPD head or converted vvc, solid followers, cams, forged pistons, rods and crank. That’s pretty much a VHPD. Probably just done properly… and throttle bodies.
If they are race engines, they’re probably being rebuilt fairly frequently? I wonder what the motorsport Elise specs are too, I think they were meant to be around 210bhp?
I’m assuming the idea of a lack of longevity for the Exige/Elise K-series stems from the occurrences of head gasket failure?
Bear in mind the engine was designed for use in front-wheel drive saloons like those used in the MG Championship and there is the basic answer: engine location.
The K-series was never intended to be rear-mounted (even if it was subsequently in the MGF, as well as by Lotus). Thus its cooling system was expected to be in close proximity, not stuck at the opposite end of the car.
HGF tends to occur when a hot engine is hit suddenly with cold coolant. Given its intended application at the front end, coolant runs are short and heat from the engine soaks into the whole system quickly, bringing it to equilibrium.
In a rear location this doesn’t happen so easily - no heat soak, engine and radiator at opposite ends, long coolant pipe runs, etc. So the opportunity for a slug of cold coolant to hit a hot engine is hugely increased.
Result: warping and gasket failure.
With race engines in particular, such as in the 190 Championship, most will be properly warmed up before being put under load so don’t suffer the same potential stresses.
As another example, look at the engine used in the MG-Lola Le Mans cars. Built by AER and turbocharged, these, were capable of 500+ BHP output. Yes they were modified and developed extensively, but the basic architecture is K-series.
Overall, the K-series doesn’t really deserve its label of ‘fragile’ - properly maintained and looked-after, it is perfectly capable of high mileages.
Interesting and I agree race engines will be pampered with maintenance. However Rover/MG engines were bad for hgf even in FWD cars where they don’t get thermal shock. I tend to agree that it’s not a bad engine and if the development has been finished (as Ricardo have done for the Chinese) and manufacturing quality had been managed we would have a very different view of the engine.
I totally agree, it’s a very light engine that, once solved the few shortcomings and setup issues, stands out
to be also powerful and reliable!
Cheers
Excellent info guys and great insights. I find it interesting to hear a good range of perspectives
I had no idea about the MG -Lola Le Mans cars. I shall be checking those out shortly!
Me too, would love to hear more details
Mea culpa…
It would appear that MG’s marketing department (at the time of the MG Lola Le Mans cars) may have over-egged links between the XP20 engine developed by AER and the K-series!
Those myths are still common today, however the link may, in reality, be little more than they are both inline 4-cylinders following the ‘suck-squeeze-bang-blow’ cycle…
…although this still doesn’t detract from my belief the K-series isn’t a bad engine overall 
http://tech-racingcars.wikidot.com/aer-p07#toc3
It looks like that the two engines have little to share.
Cheers
I read that, along with other sources from the time that indicated the Le Mans engine was K-series based (as it states).
However I have now concluded, as per my later posting here, that the engine designated MG XP-20 for the MG-Lola program and otherwise the AER P07, was a clean sheet design by AER themselves.
The power of marketing over reality?