Konig meets OMC snowmobile Engineering
Just a little back ground on this subject. In 1969 OMC introduced a 437 cc opposed cylinder snowmobile engine rated 25 HP. Now we all know (some of us anyway) that both Evinrude and Johnson have built 4 cylinder opposed engines in the past. Sooooooooo, Snowmobile engineering was asked to put two 25 hp together and see about a possible production 50 hp+ sled. Ok, now we have a 874 cc 54 hp prototype is fan cooled engine, and the next question is how does this compare to our competition? But we have no competition, there are no snowmobile 4 cylinder engines. Enter Konig with a claimed HP of 90 HP @8000 RPM.
The following test was run at OMC Resarch in Milwaukee on 11/11/69 by James Danahue.
Konig VC rotary valve 4 cylinder opposed water cooled racing outboard motor. Bore 2.11 in./ 53.5 cm, stroke 2.13 in/54 cm, displacement 29.64 cu/in, 492 ccm.
Port timing - exhaust port opens at 88.5 degrees atdc, back port opens 107.5 degrees atdc and transfer port opens 114.5 degrees atdc. Rotary valve starts opening 126 degrees btdc, full open 75.5 degrees btdc, starts to close 6 degrees atdc, full close 59 degrees atdc.
Now the big one, - 82.5 CBHP @8500 RPM with stock Konig mufflers, no expansion chambers.
port timing difference between cylinders
The comment about several degrees difference in porting between cylinders on the Konig tested by the OMC lab brought to mind something that Harry ZAK used to do first thing when someone brought a Konig to him back in the late 60's/early 70's to rebuild or try to improve performance on.
He was an admirer of Dieter Konig and his engines in a lot of respects, in fact most respects, but the thing he was never able to understand was some of the little things that were either overlooked or not seemingly cared about in assembly of the engines before exporting to the US. One of these was that he would invariably find the porting on each cylinder of a 4 cyl motor different from another in the same engine. Not ever off by a lot but just not that last little bit to make sure all cylinders were given the best chance to work evenly with the rest so as to have the engine develop maximum power. That and finding the cranks out a few thousandths and not firing the cylinders exactly 180 apart. Another problem, especially after the engine had been run a season or two, would be a intermittent misfire that was very difficult to find. This could usually be traced (after exhausting the other more common problems such as ignition, etc.,) to a poor fit between the bottom of the sleeve flange and the cast block on the exhaust port side, allowing water to leak and be drawn into the cylinder. This was very hard to find because except in the worst cases, it did not happen until the engine reached operating temperature and expansion of the block and/or sleeve in that area allowed a passage for the water to go from water jacket to combustion chamber. I did see several in this time frame that were so bad though, that water would pour into the cylinder while the engine was at rest. This could be determined very easily by hooking a hose, at normal city water pressure, to the inlet side of the cooling system and turning it on and then watching that area with the header removed so as to be able to see around the exhaust port. Some folks tried "water glass" and other types of sealer, but the very best method was to remove the sleeves, face the sleeve flange mating surface on the block casting as flat as possible, and then put an 0 ring groove in the bottom of the sleeve flange so as to seal that surface in the best way possible with a high temp 0 ring.
Just these fixes (which should have never been a problem to start with) could really bring a Konig to life, and the best ones usually had been gone thru in this or a similar manner, checking all the little stuff and making the engine the way it should have been before it was inported into the US.
Harry used to get aggravated with the way a lot of the Konigs were when shipped here, as he was, as most know who knew him, a perfectionist, and he just did not understand how someone could not know these problems existed, and if they did, why they were shipped here for sale to US boat racers in that condition..He used to say (only half jokingly) that there must be two big boxes at the factory, one for all the parts that would be used in engines built for European use, and the other for the not so good parts. We got the engines assembled from that box. That was an exaggeration I know, but I also know he used to find a lot not right that should not have been with a brand new engine.
There were also water leakage problems with Flatheads also, just so nobody thinks he was picking on Konigs. I remember Stan Leavendusky Sr. cussing that problem several times with various customer engines.
If you take the dyno figures achieved at OMC, add expansion chambers to the mix, there is probably no doubt that 100HP was achievable with a good 500 CC Konig equipped with them. And that was just with the standard porting at that time, not even the later models that improved on that considerably with more ports and more efficient porting to go along with the increase in intake area, more radical rotary valve disc cuts such as mentioned in another thread and used by Wayne Baldwin, Tim Butts, etc., the motors developed an amazing amount of HP for the time.
As an example of how that engine design, now 40+ years old has held up competitvely, you only have to look at the Konney engine which is almost a duplicate of the basic Konig design, although with the latest porting technology, pipe design, and intake track goodies. That design still does it's very fair share of winning in PRO racing today, and if Dieter were still here it would be very interesting to see where the engines would be today with the competition provided in PRO racing by GRM and VRP. You only have to compare the Kilo record set by McKean recently to the 500CC 127MPH pass by Dan Kirts with a non-capsuled/laydown Schumaker boat way back in the late 70's/early 80's at Moorehaven, Florida, to see that the engines were plenty powerful back then. Who knows what speeds would be "normal" today in the PRO Category.
We might have capsules mandated in 250CC hydro today, if not for a motorized glider/ultralite airplane accident some years back.
