The Art of Fine tuning the KFL for Lake Tahoe...

[L76]

RE: The "art" on how to get the best performance out of our motors on Lake Tahoe (6,200 ft elevation). Hoping to share results, tricks, and tips here...

BACKGROUND ON MY BOAT/MOTOR for reference:
1948 CC 17' Deluxe Runabout w/ KFL (spec'd at 131 hp at sea level). Dual Zenith downdraft carburetors. Stock ignition w/points.
Estimate I am losing 20-30% at this elevation. Motor tests @ 120psi on each cylinder at elevation of 350ft.
Propeller = 12-RH-12
WOT = 3,700 RPM (CC Engine manual indicates I should be at 3,800 RPM @ WOT)

MY TARGET:
I would like to run on Tahoe at 3,000 RPM cruising speed with 4 people + gear (e.g. 800 lb load)... and be able to reach 3800 RPM @ WOT. Ultimately I wonder if I am headed towards a custom camshaft grind, more compression, and tweaking the prop until its perfect. Goal = 180hp-200hp (@ sea level on 91 octane pump gas) with stock zenith twin carbs.

"ARTIST'S TOOLS" I will be working with:
Fuel/Compression/Camshaft/Head
Spark/Ignition
Propeller

What are you guys running? What performance are you seeing in your boat on Tahoe?

Cheers,
L76

[Johnny V.]

Just a thought-might be time for a V-8 repower. Since the KFL is not stock to the boat, you're not replacing the original engine, so that might be the way to go for the performance you are looking for. You might get incremental increases by playing with the cam, compression etc., but I don't think you'll get 50-60 HP. Chris Craft only got 175 HP from the 336 cu. in. MCL.

[maritimeclassics]

I don't think shoehorning a V8 into a 17-foot boat is the answer, not sure it would fit under the hatches and you’re talking about changing a lot more than just the engine to make it work. I would call Sierra Boats in Carnelian Bay and ask them about the prop which is the biggest difference from running a boat at that elevation. Some owners that travel with their boats have what is called their Tahoe prop. Then you need to make sure you have the engine tuned properly after that you need to adjust the carbs at that elevation and synchronize them to that elevation. We use a vacuum synchronizer like this: https://www.summitracing.com/parts/edl- ... eKEALw_wcB