Motor size for Tom Cat

[drjohn71a]

You have to trim the bow up???

Apparently, we need to take into account the differing loading patterns between users. For instance, I have absolutely nothing in the forward storage area, so the bow is almost always "up". If some of you have the bow always "down", I'd be worried a bit and consider shifting loads.

Also, I rarely am in the boat more than a day or so, unlike you cruisers. Cruising demands alot more equipment and supplies, so probably more weight there. Give me a few years of 'losing' things and gradually packing all the remote recesses and maybe I'll have the same problems...

Squidslayer - I don't know about your boat, but most of the TomCat 255s are riding with 1/4 to 1/3 of the cockpit draining scupper outlets under water - even without extra batteries and a full livewell. I don't see how the aft hull could be driven much further into the water without water actively entering the cockpit!

John

[flagold]

[Pat Anderson]

I have to take a little exception with this - assuming we are talking new prices, rigged, with a trailer, a nicely rigged CD25 these day is closer to $90K than $70, and a nicely rigged TC255, well, I wonder how Squidslayer got one for $100K, I'll bet it is $140K or more - how about it, other new TC255 purchasers? How much did you end up spending, ready to cruise? Whether a TC255 is "twice the boat" is also quite debatable - they are DIFFERENT boats, as is the Ranger R25 - all nominal 25 foot boats. The big advantage of the TC255, which we all acknowledge, is its awesome ride and ability to handle rough water at speed. I am quite anxious to see how the new BF15 Les installed two weeks ago pushes Daydream for slow cruising. For a slow cruiser, though, no debate at all - go for the Ranger R25. But look at Wild Blue, Anna Leigh, Daydream, and the other CD25s on this site, how people use them, their satisfaction level...the CD25 is a great all-around cruiser.

[drjohn71a]

Pat - I agree about the TC 255 price levels. That aft steering station demands complete dual sets of electronic controls and the base price is nudging 10 grand just for that setup. I think a total, equipped price level is closer to 140-150 grand. Prob' Squid was comparing base price levels.

The TomCat cockpit seems to have alot more usable space than the CD 25 and that solid Armstrong bracket/Diver's platform is like the back veranda!

John

[journey on]

[thataway]

The price of a TC 255 with trailer and power starts close to $120K. By the time you add electronics, upgrade the charger, wiring, generator, AC etc you are fairly easily at $150K.

We keep the boat in cruising mode, and she rides level--no bow down.

We have not had any significant water in the scuppers even in heavy weather--but again we don't keep a lot of weight. The extra batteries are under the dinette --only item aft may be the generator and inflatable, but we try and keep these foreward in the cockpit.

Putting weight in either end of the boat makes it pitch or hobby horse more.

[onwater4fun]

Thanks for the input, we appreciate your experience and tips. We had demo of 25 Ranger and Tom Cat. First Mate & I fell in love with the Tug but because I have had operations on both my ears diesel sound and I just don't get along. The Tom Cat was everthing we expected in the water but after seeing the beautiful finish and the many extras in the Tug the Cat is tens of thousands too expensive. So like you JimD I guess we will remain Bayliner alreadybe's and C-Dory Wanabe's

[squidslayer]

A Basic TomCat 75k with Twin Outboards 30k basic stove..sink with out any toys ..without trailer (I don't want or have one) good to go costs about 105k+
When you add a trailer 10k..Refrig.1k..windlass1k...rear station3k..dual electronic controls 8k...digital fuel guages1k....electronics15k ect ect
140k+

Dick

[JimD]

OK, so in the old days we learned about hp rating based on that "displacement factor" formula from the USCG. Seeing as that was/is weight based, and that the 175s from Evinrude (and Honda too?) are the same wieght as the 150s, has anyone tried these out? ...disregarding the NMMA and your insurance company I remember we worried about "surge torque" on the transom with very high power obs as much as weight (hehe we just wanted to go fast), but that seems to be a non issue with the Armstrong brackets.


PS I also heard from a "little bird" that initial TC 255 testing was done with twin 200s ..not sure if that is really true,, but I guess I still like fast even though I am in my 50s now

[Sea Wolf]

[thataway]

The intial TC 255 testing is well documented on this list--and it was with Honda 130's or 150's--not 200's.

The Suzuki 150's and 175's are basically the same engines. I would see no real reason why one could not use the 175's--and get a little more top end speed. But I would not do it--because the 150's give adequate speed. The forces on the transom are related to the weight of the engines, as well as the hp, the sea state and characteristics of the hull as it goes thru the water.

[thataway]

Finding the line between planing and displacement speeds are difficult on a TC 255. Many cats are displacement or semidisplacement hulls and do not plane. If the Tom Cat didn't drag the bridge deck it would act more like the "normal" semidisplacement cat.

We spent several hours running the boat at planing down to displacement speeds. We found that trimming the bow down at 20 to25 knots decreased the effeciency by decreasing the speed slightly and requiring more fuel. We noted that as the boat become less effecient, the rooster tail decreased. As we dropped the speed, we could keep the boat semi planing down to about 9 knots. But there was dramatic change in the quarter wave and in the power required to keep the boat at that speed--thus the effeciency dropped to half of what it was at 20 knots.

For a boat to plane, it must climb over its bow wave, and as this occurs the quarter wave (which is "wake" as we normally define it)--decreases.
As we brought the boat down to the lower speeds, the wake (quarter wave) became very large--over 3 feet--vs only a few inch wake at high speeds. Fuel consumption went from 2.3 miles a gallon to less than one mile a gallon. Also at a definative speed of 9 to 10 knots (with the bow trimmed fully down), there was a large amount of water pushed up around the outboards--well half way up the cowlings. When we tried to turn at this ineffecient speed, this wave was actually pushed up on the motor bracket and slopped some of the wake into the cockpit.

My conclusion is that my boat will not plane at 8 knots--and at 8 to 10 knots the boat is running in a displacement mode, not a planing mode, despite being able to keep the bow down. The tunnel was not clear at these speeds.

[JimD]

Very Impressive. That pretty much answers any questions I might ever have about the TC, TNX!

[drjohn71a]

Jim D,

Another thought is that a lightly loaded TomCat can go pretty fast with the 150's, even at below max throttle. We were showing 39 Knots at about 5300 rpm and that feels pretty darned fast in moderate seas in a boat that size. It'd be tough enough to dodge a log at that speed!

John

[JimD]