[quote=thommo]Well, thanks for that. I can’t say it’s too reassuring!
Andy, don’t worry, pal, we’re both in the same boat. Worrying about it too much will put you in an early grave.Enjoy it while you can. [/quote]
OK, you asked for it… Although banned from this site, what Simnon Erland (who, of course, is a great supporter of the K Series engine) said about VHPD engines is probably not too far wide of the mark…
The VHPD engine was particularly unfortunate, not only in the way it was specified and ran as an engine, but also in the perception of many, even at Lotus, that this was a Rover designed or in some sense approved engine. The history of the VHPD is complicated, but it had its origins in a brief as a competition engine for a one-make series that was proposed by Rover. Initially Tim Seipel at the Performance, Development and Calibration Department within Rover issued a brief specification for head flow rates, inlet manifold design, exhaust manifold design, initial cam profiles and a map, at this stage no work on the bottom end specification was done at all. Some dyno work was done under Tim Seiple on an engine that featured forged two ring pistons but an otherwise standard bottom end and a revised head valve and cam specification, that ran out to 180bhp.
This was done simply to initiate the project and represented the sum total of Rover�s in house involvement. The project was then handed to Janspeed to develop as an engine for the MGF Cup Series. The project was overseen by a Rover engineer, Clive Bagnall, but at no stage was any formal certification done, or any detailed specification formulated, which would have made this a commercially viable project. The commercially available VHPD engine grew out of this original MGF Cup engine, but was entirely done outside the Rover design office, and at this stage without any input from the Rover design engineers. It was a project conceived and executed by Janspeed, Minister and PTP.
The engine emerged in several variations, with differing induction systems, and maps often produced by the companies using them, i.e., Lotus, produced a map for the VHPD in the Exige and the 340 R, initially using a Gems ECU for the handful of motorsport S1 Elises, changing to an ECU from the Esprit for the 340R and Exige. This engine was beset with many problems as a result of this rather convoluted conception, and was described recently by Richard Meaden in EVO magazine as �coughing and farting at low revs, hollering in pain at high revs, with nothing in between�. This is an apposite and accurate description of the so called VHPD engine; unfortunately Meaden did not attribute the engine to PTP and Janspeed, which caused more than a little irritation at the Rover Design office.
Briefly, this engine will not idle or pick up cleanly from low revs because the throttle bodies are a clumsy reworking of parts done to cost by reusing KV6 throttle bodies from a Rover 800 � the butterflies are much too far away from the inlets and the mechanism to balance each inlet is crude. The cams are hopelessly mistimed, more than one degree too much advance on the inlet and the exhaust are retarded by more than one degree too much. The mapping is extremely poor, the engine running far too rich, all of which mean that the engine is well down on both power and torque and exhibits poor emissions and excessive fuel consumption. Added to which, the bottom end build is hopelessly inadequate. In every engine that I�ve knocked down, the stand-proud has stood at zero thou or less! A recipe for gasket failure! The thermostat location is standard! And they have all been built with plastic dowels! The crankshaft is not a Rover crank � it has been made to a Rover drawing by a French company, it has been tuftrided, and it is also very badly balanced as fitted to the engine.
The flywheel is equally badly balanced, but is also mounted to the crank with a dowel hole far too large, which means that any balancing process is entirely wasted because the location of the flywheel to the crank can never be guaranteed. In other words, the engine coughs and farts because the induction system and cams are so badly calibrated, it screams in tortured pain since the engine is so hideously out of balance and there�s nothing in between as the engine is so badly tuned as to be well down on the torque that it should produce. The engine is a total catastrophe and should never have been sold or fitted to any car and is very largely responsible for the reputation that the K suffers. It is absolutely disowned by MG Rover and Powertrain LTD.
However, and whichever way you look at it, 190bhp from a 1.8 road car engine is pretty good and with proper care they last a long time. It may have been poorly executed but the fundamental principles of the engine are fine. Whatever Erland says, the VHPD does come alive in the upper rev range. If and when the head gasket does let go you still have the fundamentals of a very neat and lightweight unit. An emerald helps, apparently, to smooth the bottom and mid range performance. One thing is true though, the need to time the cams perfectly is critical and properly timed cams make the car so much better. All 190 conversions must have the vernier pulley fitted to accommodate this. As he says, a difference of just one degree is very noticeable both in power and driveability terms.
Andy, as Steve says, just enjoy it and don’t abuse it until it is properly warmed through. I’m sure it’s a goodun you’ve got there, but I would say that wouldn’t I!
