At long last - Merc 666!

[Powerabout]

Nice project Tim
Isnt the crankcase compression ratio going to be quite a bit lower or is there more clever stuff to come?
good luck
Powerabout

[Tim Kurcz]

'Tall order' Good Luck Tim

Unfortunately, the "666" is not legal for 850cc Mod because it's 66 cubic inches (Mark 78), and has 6 carbs (the Mark 75 - 60 cubic inch engine is legal with 3 carbs). Even though it's 66 cubic inches and has a much better breathing intake system, it's still a deflector, and heavier than the 49.9 OMC. Might be close.........

Tim

[Mark75H]

Can be made lighter ... I'm certain

[Tim Kurcz]

Nice project Tim
Isnt the crankcase compression ratio going to be quite a bit lower or is there more clever stuff to come?
good luck
Powerabout

Good question - you betcha there's more coming. The intake casting and reed plate locate pyramid reed block apex within .060" of the rod swing. More importantly, the reed cages are padded top and bottom with .250" thick plates This makes up for some/much of the duct increase.

The 444 project proved dramatic breathing improvement which is expected to benefit the 666 likewise. Though not legal for Mod, I'm building the beast just so I can hear that sweet music and rattle the neighbors occasionally.

That it can be run in 1100cc PRO is a pleasant, unexpected benefit. Might spike the avgas with methanol, not sure if it will ever see pure alky. But, you never know!

Tim

PS Here the duct castings are trimmed to match the carb adapters.

[Tim Kurcz]

Can be made lighter ... I'm certain

Rest assured Sam, I'll make every effort to reduce weight. But the engine will be equipped with a Merc Speedmaster which is no lightweight even after bobbing 5" off the tail. Though the very tall case reduces weight of the tower, it will be in the 45# range combined. Ad a 120#-ish fully dressed powerhead and you get 165-170#.

So it will just have to make brute power to compete. Assuming 2 HP / Cubic Inch at the crank can be achieved (on gasoline & oil), we're looking at 120 HP at the propshaft. Not shabby, but I'm guessing the Koenig, VRP, Rossi, etc. make similar numbers at much less weight. Throw in some alky though.......

Stated before, I'm building this out of a great appreciation for that Mercury six cylinder shriek - six pulses per revolution - like an F1 car at full tilt boogie!

Tim

[Tim Kurcz]

Would be legal in Pro on a runabout (1100 CCR) Would love to see it entered at the nationals.....Bob

Hi Bob,

Jimmy Robb says the class is 2-person runabout, which sounds like fun to me. Was planning on building a big runabout for Top-O this winter that might also work for 1100cc runabout. But, I'll need some help with boat specs. Can you send the basics and post some pics? That would be very helpful.

Tim

[chris3298]

Tim, I sure would like to know how the heck you got into all this? I mean where did you earn to modify all these engines, trial and error??

[Tim Kurcz]

Tim, I sure would like to know how the heck you got into all this? I mean where did you earn to modify all these engines, trial and error??

Rebuilding blown up Merc "green top" twins for a Mini-Max built in my youth, I scrounged local marine dealers for parts annually. As a result, my first real job became apprentice mechanic at Fairlane Boats & Motors in Detroit, a Kiekhaefer Mercury dealer that stocked parts for and serviced all racing outboards. Frequented by local racers, the place became known as "home of the clamp-on kids" under the direction of master mechanic John Carlsen.

Two years later, legendary engine builder Bud Parker cogratulated me for perfect 25SSH starts at Ocoee, an act that began a new path in life. Though he built many stocks, Bud's heart was in Mod and Alky: In 1975 he talked me into a 25Mod. In 1988, I went to the big boats running D, E, and Formula-E Mod, learning machining & pattern making working at Bud's shop evenings and weekends for 10 years to support the habit.

Bud retired after 55 years engine building in 1998, whereupon I acquired his machine tools, jigs, fixures, patterns, and have been building Mods, a few stocks, and even two of Bud's own alky loopers ever since. In total, I've been swinging marine wrenches and machine handles for 40 years - yikes!

Yes, there was a lot of trial and error. A substantial "box-o-shame" was generated in the process. Over the years I've come to know many fine racers, enthusiasts, and mentors that inspired my work. The 666 photo series is a gift for all to see the inner workings, an inspiration for the next generation of engine builders. With the machine tools and information available today by the web: If you can dream it, you can build it!

Tim

[chris3298]

Rebuilding blown up Merc "green top" twins for a Mini-Max built in my youth, I scrounged local marine dealers for parts annually. As a result, my first real job became apprentice mechanic at Fairlane Boats & Motors in Detroit, a Kiekhaefer Mercury dealer that stocked parts for and serviced all racing outboards. Frequented by local racers, the place became known as "home of the clamp-on kids" under the direction of master mechanic John Carlsen.

Two years later, legendary engine builder Bud Parker cogratulated me for perfect 25SSH starts at Ocoee, an act that began a new path in life. Though he built many stocks, Bud's heart was in Mod and Alky: In 1975 he talked me into a 25Mod. In 1988, I went to the big boats running D, E, and Formula-E Mod, learning machining & pattern making working at Bud's shop evenings and weekends for 10 years to support the habit.

Bud retired after 55 years engine building in 1998, whereupon I acquired his machine tools, jigs, fixures, patterns, and have been building Mods, a few stocks, and even two of Bud's own alky loopers ever since. In total, I've been swinging marine wrenches and machine handles for 40 years - yikes!

Yes, there was a lot of trial and error. A substantial "box-o-shame" was generated in the process. Over the years I've come to know many fine racers, enthusiasts, and mentors that inspired my work. The 666 photo series is a gift for all to see the inner workings, an inspiration for the next generation of engine builders. With the machine tools and information available today by the web: If you can dream it, you can build it!

Tim

Thank you for that and I agree I have learned to fix many things from the web. Please continue on with this thread i'm enjoying every post of it.

[Tim Weber]

Are you planning on running an overdrive like Lon Stevens did?

Tim