Tip speed is tip speed
Tip speed is tip speed
"It's the firstest, not always the fastest that wins the race." ( O.F Christner, Quincy Welding Co.).Quote:
Originally Posted by Mark75H
I had a square nose Bunky ASH, 8'3" long, A Mercury KG4H and an old B Anzani 1-1 wheel a bit bigger than 6x9. Set up level and somewhere higher than 18". In the 70's you shimmed it until it wouldn't pump water and then went down an eigth. That boat was very competitive, ran 63mph and could get through a three pin turn without backing off, putting the fin in the water or moving out of the back of the boat. The 15ss was a Hot Rod A ( probably Swanson). There was a pressure to have them run as A stocks but they were a bit faster than an A stock and were given their own class. 15ci, they are probably todays B stockers. If I remember correctly the props were 7x12 or 13. The 15SSH's had a lot of speed from the middle of the corner out. Everyone said a KG4 would turn 7300 rpm but I don't know what a 20H turned. Mk75H: I know you see Mercury reedcages as the main restrictions. Why am I wrong to think that if they can feed 60hp they can't be very restrictive in a stock AorB? Thanks: John
They feed 60 hp thru 3 ... 20hp per
In Stock (A or B, it doesn't matter) everyone is using the same motor, so any physical limit of the motor applies to all competitors equally ... as equally as the rain that cancelled this year's finals at the Nationals
Nothing to do with prop tip speedQuote:
Originally Posted by champ20B
Quote:
Originally Posted by Mark75H
Not to change the subject, But I need info on a coil set-up for a Mark 20 Bendix Scintilla ignition delimna. This is a weird situation on what I,m working with. I bought a scintilla ignition plate recently to build up a ignition using what I thought was bendix coils from an old military generator I have. Well, here is where it gets wierd...The coils are IDENTICAL to the bendix coils. But there appears to be NO POINTS OR CONDENSERS. They are also stamped with the name,"REPCO". They use the same snap-clips and one wire is just wired to ground, and the other, a on-off switch. They do fit perfectly though. Anyone know about these coils? The center rotor magnet is identical also, with no breaker cam in sight.
REPCO is Robert E Phelon Company ... Merc's other ignition supplier
Nevermind my question, I think the points ect, are in the motor (referring to the parts doner generator) behind its ignition area. It must have been designed by Germans. It seems like some of their design characteristics. Anyway, I'm giong to check into finding some points later on to finish the Mark 20 ignition. These coils are direct replacements for Scintilla coils though. I did not even know that Repco made those kind.Quote:
Originally Posted by champ20B
Sam, I sent you a photo of the 20-H Toilet bowl mock up some years ago. Can't find it now.
Did find the patent
Balance of patent filing
I realize this thread is a bit dated, but I recently found this on a FB page and think it belongs here. Something else I should mention is that in 1969 we (Mercury) had tooled up a replacement cylinder block for the KG4H. A good friend from racing (Charlie Blanchard, now deceased) took it to the Hinton '69 Nationals to talk to the commission about it but at the last moment he was told not to show it and the engine stayed in the trunk of his car and died on the vine, gut feel was price to manufacture and low quantities made it a non profit-Attachment 425097Attachment 425098