Tom Cat Power

[tomconley]

I own a 1999 24' Tom Cat with the original 90 Honda's and really enjoy the boat. We fish offshore in Florida and have considered re-powering with a little more horsepower to help make the boat a little faster.
I have a DF140 Suzuki on a smaller boat and wander if anyone has any information such as speed and fuel consumption on a pair of 140's on a 24' Tom Cat.
Thanks,
Captn. T

[thataway]

There is at least one Tom Cat 255 with dual 140's. The 140 and the 115 were the same block--so I don't see a problem there. I think you will have a very fast (light over 50 mph) well handling boat, which will still get over 2.5 miles a gallon--maybe slightly more--if you keep the boat light.

[helm]

We are repowering our CD-25 with a Suzuki 200 and will have a Suzuki DF 140 available, 260 hours, balance of Suzuki 6 year warranty which began in March 2008. The Suzuki 140 has been a great engine just not quite enough HP for us when fully loaded.
Eric

[T.R. Bauer]

[helm]

Nope, its the 100 gallons of fuel, 20 of water, couple of kids and all that goes along with spending a few weeks on the boat at a time. The DF 140 is great if the boat is light.
Eric

[Captains Cat]

I've got twin 115 Suzis on Captain's Cat and it's plenty for me. It'll do about 40 knots lightly loaded. No need to go faster than that! I don't have any hair for the wind to blow through anyway!

Charlie

[drjohn71a]

I think the most important thing to watch in the TC 24 is the weight of the engines. I'd go with the lightest ones possible, whatever brand - maybe even the Evinrudes.

Good luck!

John

[garyk]

Is there a possibility of hanging Armstrong Bracket on the 24?
Other than the cabin design, the hulls look simular to the 225. I'm going by photos, I've not been close to a 24. It seem to me this would make a hell of a boat if someone wanted to up grade the earlier model.

[drjohn71a]

The TC 24's major problem was that it was designed for light outboard engines. While all TomCats could benefit from it, I think it's critical to think of the TomCat 24 as an airplane. Lightly loaded, it should perform well and economical. However, it's weakness is aft weight, which should be minimized. Consideration of the pounds added for more horsepower is important.

I think the main reason for the Armstrong Brackets on the TC 255 was to remedy (at least to a moderate degree) this aft weight Achille's tendon.

The TC 24's hull is not designed for Armstrong brackets and it would be costly to reinforce the hull and add the brackets. You'd have to install new engine and steering controls as well.

The best move might be to keep the weight down, both in engines and carry ons.

John

[Captains Cat]

[drjohn71a]

Well, I am definitely NOT a marine engineer, but...

The Armstrong Brackets provide flotation - they are sealed, hollow aluminum "pontoon sections" - when the boat is at rest.

The Armstrong Brackets raise and set aft the engines which seems to provide more lift than had they been deeper and up against the hull turbulence - which is considerable in that stern area.

Maybe Dr. Bob or someone from the factory could explain it all better.

John

[Captains Cat]

[drjohn71a]

Charlie,

Well, when I first asked about them putting the pilothouse on the TC24 hull, several conversations were had about the engine weight problem over time. At that time, the factory sold direct to customers in areas with no dealers.

If I am remembering correctly, they were saying that the TC24 was designed for 2 cycle engines which were prevalent and lighter at that time. This was from a saleman, so I don't know what the engineers' position was on that.

As for adding the Armstrong Brackets on a TC 24, I don't know how much you'd gain in the cockpit unless you cut out the exiting motorwell and built a beefed up transom to engage the Armstrong brackets.

John

[thataway]

The 140 Suzuki weight is 410 lbs and the 150 is 474 lbs. That is 128 lbs more for two of the 150's. The Yahama 115 weight is 402 lbs, little different than the Suzuki 140, so the boat should be able to handle the weight. I don't know if the boat is engineered for the HP of the 140, but my best guess is it is. There is a suggestion in one article that the boat had been run with 150 E tecs.

The Armstrong bracket only gives a small amount of extra floatation at low speeds or at rest. I believe that the running surface of the hulls on the 255 is longer (the hull is extended) by about 1.5 feet--but I have not measured this. The 255 has the full solid transom--the 24 has motor wells which are on the sponsoons, but do intrude into the usable cockpit area--so that the cockpit is larger on the 255. The longer running surface gives more support aft (It is not at all unusual to extend molds--many 30 foot boats have been stretched to as much as 38 feet) Basically the 255 is a slightly larger boat, with the same beam and some hull extension, as well as the bracket.

My understanding is that an outboard bracket will give better performance, with slightly better speed and fuel economy--it puts the engine in cleaner water and allows the engine to sit several inches higher, decreasing lower unit drag. There is some floatation of the bracket when the boat is not at a plane.
It also allows a solid transom of full height

I don't see any advantage to bracket/brackets on a 24--you cannot really increase the cockpit size easily. I had considered a bracket on my 25, and If I had more time I probably would have done it--in that case I would have eliminated the spashwell, and extended the cockpit, with a full transom (and put in different cockpit floor hatches!) I would have had to do some re-engineering of the entire transom, but at that stage it would have been fairly easy. Often brackets are used to convert I/O boats to outboard boats--and this is a very good conversion.

[Sea Wolf]

I'll just bet that while the engines are moved aft and the additional flotation somewhat compensates for this at rest and displacement speeds, the real advantages are to:

1. effectively lengthen the boat at planing speeds (enhanced even more with Permatrims). Rides like a boat 2-3 feet longer with the motors further aft on the long lever arms. The Permatrims amplify this effect with their additional planing area. This all helps greatly with the ride through chop since we now effectively have a longer boat.

2. move the engines out and away from the turbulence from the hull.

3. raises the engines to reduce drag and enhance speed.

4. engine / boat trim control is enhanced with the further aft placement.

5. this whole arrangement allows the use of more horsepower, and perhaps even a higher horsepower to weight ratio, enhancing potential performance.

There's probably even more to it than this, and some of the above effects overlap and may have other facets to them as well.

Just a bunch of 2¢ guesses from a CD-22 owner! Total cost 5 x 2¢ = 10¢ (I'm saving up for a deepening recession!)

Joe.