At long last - Merc 666!

[Tim Kurcz]

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

Tim

There is no plan to run an overdrive at this time. For show and demos, the 666 will run a 1:1 RH Speedmaster (reminds me a an old pin-drive 8" Dia X 13"P prop must be found). For serious competition, it will run a 1:1 LH OMC 45SS, for which I've got several props.

Tim

[Tim Kurcz]

Here is the latest until next week.

The reed plate and carb adapters have been fitted and some weight relief cut in. Reed cage layout and truncation will come this weekend - sensitive work. There's plenty to go, stay tuned, and keep your questions coming.

Tim

[Powerabout]

whats planned for the exhaust?
Didnt those old engines have a different firing order to later ones that prevented simple 3 and 3 pulse tuning?

[Powerabout]

did anyone ever convert one to rotary valve, seems like its possible on an inline merc

[Mark75H]

Yes, Rich Austin has. Look on his thread about the Looper Beast project.

[Tim Kurcz]

All early (Mark series) Mercs were alternate firing twins, or stacks of them phased evenly around the crank circle. So, pulse tuned exhaust is not possible. As a result, the 666 will run Parker converging stacks. Sam can confirm, but I'm pretty sure the first pulse tuned Merc six was the 1000 in about 1962.

Otherwise, I saw a rotary valve Mark 30H at Ted Millers about 10 years ago. Painted yellow, it was likely built for alky in an attempt to beat the Koenig, the builder unknown. Similar to a Champion Hot Rod, the questions is always; how well did it work? Will take a trip to Dick Austin's thread and check out his work.

For a moment I'd given thought to turbocharging the project, because of the easy to change external pyramid reeds. But then it wouldn't have that beautiful stack of carbs, or fearsome exhaust elbows and megs. Also, deflectors aren't the best choice for forced induction because of the pistons domes. So, it stays the "666".

Tim

[Tim Kurcz]

Whoa! What an incredible piece of artwork!!! Sure wish the thread was open to comment...... A complete crank up design and build of a Merc crank based RV looper complete with billit aluminum block. The historical section and photos are great, would like to see the earlier iterations published. I've gotta see this engine/engines in person. Count on me at Constantine!

Tim

[Fastjeff57]

Tim:

What reeds will you be using?

Jeff

[Tim Kurcz]

Tim:

What reeds will you be using?

Jeff

Boyesen #133 two stage reeds. Images of the reed box mods will be posted next week.

Tim

[Fastjeff57]

Slick! Will you make the reed holders as well?

Jeff