More Tomcat observations/chat

M

matt_unique

New member
I went out for my third cruise yesterday. We had a small craft advisory with seas 4-7' and winds gusting to 25 knots. It was also just a raw New England Spring day...rain...fog...just nasty. I'm still getting a feel for the boat and I actually wanted some rougher conditions.

It was not a comfortable ride, but she handled the sea. I would not normally cruise (for fun) in conditions like this so it was purely a means to get a sense of the comfort threshold. We had some solid 8' swells (close together), most were around 5'. On step she would go off a crest and slam into the trough. Angling off definitely helps, but still not a comfortable ride. I found it was more comfortable to go slower (off step) in these seas.

A few other observations....my fuel gauges are off or the port engine uses a lot more fuel than the starboard. Both tanks were full. My starboard still shows well above Full the line and the port shows just below the Full line. I will eventually get fuel flow meters of some kind. Still trying to figure out if I can take advantage of the NMEA 2000 info from my 2008 engines. So far no one seems to know (from Lowrance to Suzuki to the Suzuki dealers). I have contacted all the above. I would love to use the LMF 200 for all the engine data but I guess there is an adaptor/cable issue and something about not being able to use my analog tachometers if I want to use the NMEA 2000 info from the engines, etc. I may wait until this is sorted out or just go for stand alone fuel flow meters and be done with it.

I did not find any obvious increase in the flex crack where the starboard gunwale meets the cabin. Have we (collectively) figured out any more about that? Clearly it's a flex point, and gelcoat will need to replaced regularly to have a non-cracked exterior, but is it a structural safety issue? I know this is an issue on many of the models not just the Tomcat.

I'm waiting on C-Dory to reply about my open dealer/boat issues post delivery.

So far I love the boat and it's a dream in 3' seas. I still have to get the curtains done, install the (music) radio, speakers, cut/install the finish board above the overhead storage, etc. All small/fun projects to customize her to my liking.
 
Matt-

If the stress cracks in the cabin/gunnel joint continue to be a problem, you might consider having a railmaker make you a 45 degree brace across that area that would transfer part of the load and also serve as a handhold for entering and exiting the boat. Perhaps adding a right-angled section onto the top of the brace to have a vertical and horizontal handhold section would make it more ergonomic.

Just a passing thought!

Joe. :teeth :thup
 
Matt,
Check the "Hull Truth" electronics forum. There are some folks who are successfully getting the fuel data from the engine computer using the LMF 200/400.

I would be leary of putting a brace between the gunnel and aft bulkhead. This would give very localized stress. If there really is a problem, it will be best solved by spreading out the load by building up more glass. I will not have a chance to look further at my TC 255's crack until August.

I agree that somewhere in the high 3's chop (which is really considerable)--is the limit of comfort for the TC 255. Swells are an entirely different story. Again, depending on the peroid of the swell.
 
My experience with handling the Tomcat is increasing with time and use and I wanted to chat about a few things.

I have found the ride comfort to be affected by my loading. If I'm light the boat rides higher and I can handle larger chop with less (or no) pounding. If I'm loaded with dive gear for four, I find I am feeling more pounding. This does not surprise me, it makes sense the boat is sitting lower in the water with the extra weight and thus has a lower tunnel clearance.

I have also found that instead of trimming the nose down in rougher seas, I seem to get a better ride if I trim the bow up. The real slams come when the air tunnel collapses and if I keep the bow a little higher I seem to get less of this in rougher seas. Have others experienced the same?
 
Short answer: Yes.

definately the heavier load, the less tunnel clearance--and the lack of tunnel clearance is one of the short comings of the boat.

As to triming bow down--I only do this when the chop is steep, and I want to plane at a much lower speed.--With the Permatrims, I can plane the boat at about 11 knots (I know that some claim 9 knots) and thus decrease any shock when I do slam in heavier chop. Generally the more chop, the more tunnel clearance you need, and generally if you can tolerate it, a faster speed.
 
Bob also mentioned in past threads that you can't "walk" the stern of a Tomcat as you would with a monohull when docking for example. This has precisely been my experience as well. I approach a dock almost perfectly parallel in the Tomcat and reverse to 0 without the bow moving away. In a monohull this would pull the bow away as you are coming to a stop.
 
Matt, I have been able to get a bit of lateral movement by gently reversing the Port engine to slide to Starboard. If much throttle is used, however, you just go backwards. I think the twin hulls limit the efficiency of that move.

I would think that the larger diameter props that you and Dr. Bob use on those Suzukis would have a more pronounced 'walking' action than the smaller diameter Honda props like mine.

John
 
drjohn71a":euatecd4 said:
Matt, I have been able to get a bit of lateral movement by gently reversing the Port engine to slide to Starboard. If much throttle is used, however, you just go backwards. I think the twin hulls limit the efficiency of that move.

I would think that the larger diameter props that you and Dr. Bob use on those Suzukis would have a more pronounced 'walking' action than the smaller diameter Honda props like mine.

John
Click to expand...

I thought I would find more lateral motion as well. I can get a small amount of movement but nothing close to that of a monohull. I learned I need to approach a dock nearly parallel in order to come to rest parallel with the dock. With a mono mind set I would come in at a 20-30 angle and reverse to rest parallel with the dock, meaning the stern would really walk toward the dock.
 
Under some conditions I have been able to walk the cat sideways--but certainly not to the degree of a monohull (either twin or single engine)--there is a "keel" effect of the hard chines of the two hulls, which limit the amount of side ways motion--also if you want to bring the stern in (and I do bring the boat in at an angle, if there are other boats on each side of where I am going to moor)--just point the engine the way you want to swing the stern in reverse.
 
Hey, Dr. Bob!

While you and Matt are on here, maybe you can shed some light on the strange way the outboards seem to orient themselves on the TomCat.

My two Honda 150's seem to be "toed in" , and turn disproportionately when extreme turning, esp. in reverse.

To clarify, if I turn the helm as sharp as possible to Starboard, the
Starboard engine goes to a more extreme turn than the Port and vice versa on a sharp Port helm.

Is this normal?

John
 
John,

Does your steering system have a liquid tie-bar? From time to time, you may have to adjust for the toe-in or toe-out condition. Teleflex website has the instructions on-line, easy to do. If it goes out of adjustment too frequently, you may have air in the hydraulic system which may require a power bleed machine to get rid of the air.
 
I think mine does the same. Before I depart I always make sure my engines are both parallel, so I know it's not an alignment issue. I think when hard over there is a slight difference in the turn angle on one of engines....one of them seems to go a little farther than the other. When I turn straight they are aligned parallel. I will pay closer attention the next time I'm hard over.

When approaching a dock I too turn the engines and reverse in the direction I want to move the stern. So if I'm approaching a dock on my starboard side, I reverse my starboard engine while turned hard to starboard to pull the stern in.
 
thataway":3nb9wspz said:
. . . if you want to bring the stern in, just point the engine the way you want to swing the stern in reverse.
Click to expand...

It will be a few days, Bob, before I can check in the real world what you're suggesting but can you please clarify the "in reverse" part?

You're approaching a dock on an angle in your twin-engine TomCat, aiming to dock port to. Transmission is in neutral as you coast in.

Are you suggesting that the helm be turned hard to starboard and the engines kicked into reverse momentarily?

--Georgs
 
GxK":3bg0v9o7 said:
thataway":3bg0v9o7 said:
. . . if you want to bring the stern in, just point the engine the way you want to swing the stern in reverse.
Click to expand...

It will be a few days, Bob, before I can check in the real world what you're suggesting but can you please clarify the "in reverse" part?

You're approaching a dock on an angle in your twin-engine TomCat, aiming to dock port to. Transmission is in neutral as you coast in.

Are you suggesting that the helm be turned hard to starboard and the engines kicked into reverse momentarily?

--Georgs
Click to expand...

I will not propose to speak for Bob, but if you were approaching to dock on your port side, you would turn hard to port while reversing engines. Essentially pointing the engines to where you want them to "pull you" in reverse.
 
Hi Georgs,
I hope you got some boating in this "summer"!

Coming to a Starboard side dock, as the boat is in neutral, I turn the engines to Starboard. When the bow is about a foot off the dock, I put an engine in reverse--with my engines set up "opposite" what twins inboards usually are--this would theoretically be the Starboard engine, which would give more "walk"--however, the amount of torque walking is minimal, and so I usually reverse the port engine, because that shifter is easier to handle. Both engines do not need to be reversed--just the thrust of one engine will swing the stern to toward the dock and stop the boat parallel to the dock a few inches off....assuming that you time it perfectly.

Regards,
 
When you disengage the liquid tie bar with the valve under the stern/starboard access panel only the port engine will turn when you turn the steering wheel. What I do is align the starboard engine straight ahead, disengage the tie bar, then turn the steering wheel to align the port engine parallel with the starboard. Once done, close the liquid tie bar valve.
 
Thanks -- I had a general idea of how to do it but from reading the doc I realize now that you use the port stop to correct toe-in and the starboard stop to correct toe-out.

Related question. Sometimes, when I move the wheel slowly, there is no resistance for maybe 1/4 to 1/3 of a revolution before it stiffens up and starts to move the boat. However, if I move it quickly, it stiffens up immediately. What is happening here?

Thanks,
Warren
 
Doryman":3vva5fbu said:
Thanks -- I had a general idea of how to do it but from reading the doc I realize now that you use the port stop to correct toe-in and the starboard stop to correct toe-out.

Related question. Sometimes, when I move the wheel slowly, there is no resistance for maybe 1/4 to 1/3 of a revolution before it stiffens up and starts to move the boat. However, if I move it quickly, it stiffens up immediately. What is happening here?

Thanks,
Warren
Click to expand...

When you turn to a different direction you are sending the fluid in the opposite direction, there are check valves that have to open and close essentially based on the direction you turn the wheel. From memory the 1/4 - 1/3 turn seems like a lot. Do you mean you turn 1/4 a turn without moving the engines?
 
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