Engines for Eric Henning

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Scraping Paint
Oct 23, 2007

Moving this engine thread over to where it belongs.* Now here is what I consider to be a boat engine.* If you're going to build a power boat you need power, right?* Otherwise what's the point?**

This is my all-time favorite marine engine.* Two or three of these things will do the trick nicely in a recreational*trawler-sized boat.* Relatively compact size for the power,*1200 to 1500 horsepower each.* Most amazing sound on the planet (I've ridden in a boat with three of them).* When you push the throttle up on one of these, something HAPPENS.

Even just one of these in your boat is guaranteed to eliminate all problems with wake-throwing Bayliners, Sea Rays, etc.* Just the ticket for getting through all those boring straight stretches of the ICW.* And in the PNW, currents?* What currents?

So you need to stop messing around with trying to figure out how to put engines into boats*that are even less powerful than the ones that are in there now.* You need to start looking at this power business from the right perspective.* The object is to put more power in, not take power out.

The guys who build hot rods don't sit around trying to figure out how to put a Ford Pinto engine into their cars, they try to figure out how to fit a 427 into it.* You don't want to emulate the Yugo with your marine re-powering schemes, you want to emulate the AC Cobra.

When you come up with a repowering scheme that enhances performance, not eliminates it, let me know.


-- Edited by Marin on Thursday 11th of June 2009 08:12:43 PM


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*** You can dream. I think we learned that when we were little kids. Some guys grow up and stop dreamin* ..* not you and I. Must be a V12 Packard gas engine w twin overhead cams and blower fwd. Yup** .. I'd love to hear that puppy working. There's a boat in*Lake Tahoe*w three V12s** .. aircraft, 1100hp each.*55' and w bright topsides. I think I saw it in Wooden Boat magazine. No in Sea. The Thunderbird* .. designed by John Hacker. Almost 60mph. Sounds like and looks like a boat for Marin Faure!
*** Eric Henning

Basic specs for the Packard 4M engine (from my copy of the manual)---

Models-- 3M-2500 (1939), 4M-2500 (1940-1944), 5M-2500 (1944-1945)
12 cylinders, 60-degree Vee
Displacement-- 2,490 cubic inches
Compression ratio--- 6.3 to 1 (3M, 4M versions) 6.4 to 1 (5M versions)
Carburetor--- downdraft, floatless, located on the inlet side of the gear driven supercharger
Valves--- two intake and two exhaust valves per cylinder actuated by a single camshaft on each cylinder bank.
Ignition-- Single magneto feeding two camshaft driven distributors. Two spark plugs per cylinder.
Normal power rating-- (3M, 4M)--1,200 hp @2400 rpm. (5M)-- 1,500 hp @2,500 rpm
Emergency power rating--- (3M, 4M)-- 1,350 hp @2500 rpm. (5M)-- 1,800 hp @2,800 rpm
Engine weight-- (3M, 4M)-- 2,950 lbs, (5M)--3,100 lbs.

The Packard 4M was not an aircraft engine, although it did require 100 octane aviation fuel. It had its roots in an aircraft engine, however, the Liberty V-12 designed in 1917 and used in several WWI and post-war aircraft. The Liberty was a joint design by Packard and Hall-Scott and it was produced in huge numbers by most of the major US auto companies under wartime contracts. In the 1920s, Packard produced a marinized racing engine based on the Liberty that was used in the speed-record hydroplanes of the day, the most notable being Gar Wood's 38' "Miss America X," which used four of them. It was this marine racing engine that was the basis for the Packard 3M, 4M, and 5M engines that were used in PT and crash boats of WWII.

-- Edited by Marin on Friday 12th of June 2009 01:16:58 AM


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