Piston rings, a subject I could have written a book on at one time. To begin, I would be inclined to agree that the original Twister ran the production 3-ring setup. One of the first races for which we built the original Twister was in Scotland. I recall that the Marketing Dept. was attempting to woo an OMC dealer, known by the name of “Scotty” (he was Renato’s cousin) to switch to Mercury from OMC. Anyway, I was new to all of this crap that was going on between OMC and Mercury but I was told to build two engines and get them boxed so that they could be flown to Scotland. I seem to recall that Scotty built tunnel boats under the “Shakespeare” name but I may be mistaken. Anyway, we built the engines, shipped them and Scotty put the first engine on his boat and went out and set a lap record on the first lap! The word came back that he was delighted and he wanted to run the second engine just to make sure that we hadn’t slipped one by him, so he ran the second engine. The next thing I heard was that both engines failed because after testing them he ran both of them without any oil in the gas and fried them both! Needless to say, we were had by OMC and that was the beginning of a long period of bad feelings I had for OMC.
Back to piston rings – the original Twister I had the production 3 rectangular ring setup and we had lots of scuffing problems, particularly in long races. The pistons would overheat and the rings would coke up and stick in the grooves and then the piston would scuff because the heat wouldn’t transfer into the cylinder wall because the top ring was stuck in the ring groove. At that point we began developing pistons with Keystone rings (trapezoidal shape with a taper on the top and bottom of the ring and, of course, the ring groove. The concept was really quite effective because the rings were constantly moving in and out in the ring groove thereby scrubbing the surface and working the carbon out of the ring groove. The problem was that machining the groove to the correct depth and matching the ring to the groove required some development and some precise machining. I seem to recall that we experimented with a Keystone ring on top and a rectangular ring in the second groove and possibly a third groove. Eventually we most likely settled on two Keystone rings in an attempt to reduce ring drag (two rings instead of three) and I assume that the TII engines built at #38 were most likely that configuration. My recollection is that all of the TII engines were configured with the revised transfer passage cover that facilitated the boost port.
Things get messy when we talk about the TIIX. I do not recall engines built at Plant 38 that were designated with the “X”. Ray Reid and Ron Anderson were working on a turbo charger for the TIII (V-6) and that was such a mess because ...... was insisting that the Speed Master would not handle the power produced by a turbo charged V-6. ....... insisted that we design and build four-shaft gear cases which cost a ton of $$$ and lots of midnight oil. He also insisted that we build and ship turbo V-6’s to the ‘73 (?) Paris race. We were getting ~350 bhp out of the engine but matching a propeller to the torque curve was impossible without a vertical lift on the transom because we couldn’t get the damn thing on plane. Anyway, I disobeyed orders and sent naturally aspirated engines to Paris with the stupid four shaft gear case. We lost the race because no one was strong enough to steer the boat for any length of time and we consequently scrapped the turbo and the four-shaft.
I guess I got off the track regarding the TIIX but my memory is fuzzy with all that was going on at that time. If you built a TIIX at plant 38 I don’t know anything about that. When I talk about the TIIX engines we built at #6 there were two basic areas of effort;
Pistons and rings
Transfer and exhaust ports
I am virtually positive there were less than a half-dozen engines built with rails and I doubt if any of those engines were raced because the pistons were good for about an hour and then they would coke up and stick. We also ran engines with five and seven transfer ports and I think that Merten’s record engine had five transfers and we raised both the transfer and the exhaust ports. That engine worked out very well in terms of matching the propeller with the power curve because we extended the power curve by ~1000 rpm.
I apologize about the later stages of development of the TII(X) because of all the things that were going on with the V-6 development for both racing and production. You may recall that In ‘73 we had an oil embargo and good old Jimmy Carter announced a possible ban on weekend boating. Needless to say, Brunswick reacted as expected - - they ordered me to discontinue development of the V-6 because no one would buy a gas-guzzling big old V-6 outboard! Lucky for them, I paid no attention, although they cut the V-6 budget to zero so we had to improvise.
Nap time.
Dick
p.s. I don’t remember Molly but I do recall Buck Thorton. It is sad that life .......
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