More Tomcat observations/chat

[Doryman]

Do you mean you turn 1/4 a turn without moving the engines?

Yes -- if I move the wheel gradually/slowly. It also is more pronounced at speed than at slow or docking speeds.

Warren

 

[matt_unique]

Do you mean you turn 1/4 a turn without moving the engines?

Yes -- if I move the wheel gradually/slowly. It also is more pronounced at speed than at slow or docking speeds.

Warren

Hmm....when I have had that problem I was low on fluid. I was low on fluid because I had a bad helm that would squirt the fluid out when I reversed. Take a look at the fluid level at the helm.

 

[Doryman]

Hmm....when I have had that problem I was low on fluid. I was low on fluid because I had a bad helm that would squirt the fluid out when I reversed. Take a look at the fluid level at the helm.

Can you add fluid without the special bleeding tool?

Warren

 

[matt_unique]

Hmm....when I have had that problem I was low on fluid. I was low on fluid because I had a bad helm that would squirt the fluid out when I reversed. Take a look at the fluid level at the helm.

Can you add fluid without the special bleeding tool?

Warren

You sure can, just remove the vent cap above the helm reservoir. You don't want it filled to the brim but it should be to about the bottom of the vent cap when replaced.

 

[Captains Cat]

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.

Huh! :idea: I just poked around the other day and saw that thing. Didn't know what it was for, and now I can correct my misalignment! Thanks Matt!

They got misaligned on a trip back from Smith Island when the oil change warning light went off and I didn't know what it was. So I shut that engine down and tilted it up out of the water. In steering around the dock and stuff, I guess the tilted engine got out of kilter!

Thanks again Matt!

Charlie

 

[matt_unique]

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.

Huh! :idea: I just poked around the other day and saw that thing. Didn't know what it was for, and now I can correct my misalignment! Thanks Matt!

They got misaligned on a trip back from Smith Island when the oil change warning light went off and I didn't know what it was. So I shut that engine down and tilted it up out of the water. In steering around the dock and stuff, I guess the tilted engine got out of kilter!

Thanks again Matt!

Charlie

Hey - glad I could help!

I'm well versed in the nuances of the Tomcat steering system at this point. In terms of the bleeding, I watched the system get bled twice the old fashioned way (upside down bottle connected to the helm reservoir whilst turning the wheel back and forth for 20 minutes, etc.) and finally with the Seastar high pressure bleed system. That system is sweet! You connect the hoses, flip the switch, and it takes care of business. I had a hard time finding a shop that had one but I finally found one and they did a great job replacing and fixing my steering system once and for all. I have not had a drop of fluid leak since having the helm pump replaced. I'm also able to run the engines in reverse without fear of loosing steerage.

Your system must be pretty good if you've been able to go this long without any tie bar adjustment!

 

[Bad Boy]

Charlie,

Keep in mind that it is not unusual to have to realign the twin engines from time to time.

I added power steering pump and TR1 autopilot at different times. Hydraulic hoses had to come off and on and changed out to different lenghts. It required that I bleed the system after each modification and I could never get rid of all the air. The upside down bottle also made a bit of a mess.

Finally, a power bleeder was used to fill and bleed the system and I couldn't believe the bits of air bubbles that would make their way out after I thought it was bled. The engines are more responsive and I haven't had to alignment them with the Liquid Tie Bar since then.

The wide engine separation necessary for a Tomcat makes for stiffer steering. Now that I have the power steering, I must say it is pleasure to cruise with the boat and makes easy one-handed steering in tight quarters with the other hand on the throttles. My wife enjoys being at the helm now.

 

[Doryman]

I added power steering pump and TR1 autopilot at different times

How well did the TR1 work for you on the TC?

Warren

 

[Bad Boy]

Warren,

I love my TR-1 autopilot. On my previous boats, I have had the Ratheon and Simrad units. I found out about the TR-1 Gladiator when Mercury said it was the only one they recommended for their Mercury Verado engines.

It does not need a heading sensor. It works in reverse, which is good for maintaining a position over a structure for bottom fishing (assumming you have wind and current enough to balance your boat idle speed. When I catch my next marlin, I am going to see how it tracks in reverse. It does a lot of neat things.

Found out they were recently acquired by Garmin, but haven't seen much advertising about it.

 

[Doryman]

Very interesting that you use a TR-1 on your Tom Cat. I had one on the 9.9 Honda kicker of my previous boat, a 22' Hewescraft. It worked well.

Warren

 

[drjohn71a]

Yes, Matt, thanks so much for the simple explanation you gave. My Teleflex instruction manual does not explain this and I do have the original.

Also, my experience has been exactly as Charlie of Captain's Cat says: When I tip one engine up and not running, the alignment goes astray.

I know Dr. Bob has recounted having only one engine leg in the water during long cruises, but it has not worked well for me. I do have the electric/hydraulic, wire driven engine controls, but the Seastar helms , both front and back look like normal hydraulic controllers.

Anyway, thanks to you, Matt, I am now on the "straight and narrow"!

John

 

[Bad Boy]

Warren,

Are we referring to the same TR-1? I am talking about the Gladiator TR-1 autopilot for the hydraulic steering. That seems a bit much for a 10hp kicker.

George

 

[Captains Cat]

Also, my experience has been exactly as Charlie of Captain's Cat says: When I tip one engine up and not running, the alignment goes astray.

Anyway, thanks to you, Matt, I am now on the "straight and narrow"!

John

Actually, my problem came only when I went "hard over" with one engine up. Not exactly sure why but, with Matt's explanation of the Liquid Link or whatever it's called, I was on board last night, disengaged it, and aligned the engines in about 30 seconds. No bleeding, etc, etc. as described elsewhere in the documentation I got!

Thanks again Matt!.

Charlie

 

[Doryman]

Are we referring to the same TR-1? I am talking about the Gladiator TR-1 autopilot for the hydraulic steering. That seems a bit much for a 10hp kicker.

The TR-1 Gold is for kickers. The TR-1 Gladiator is for main motors.

Warren

 

[thataway]

Just to qualify--the mileage tests were done with the opposite engine at the surace of the water in the trim up position, but not all of the way up. I have run the boat at slow speeds when running with some trawler friends. In that case both engines were down--and I often would run ahead at low planing speeds, and wait for my trawler friends, rather than try and run at 7 to 8 knots (a very inneffiecient speed--and one not easily obtainable with a single engine on the Tom Cat 255.

 

[drjohn71a]

I know we have differing outboard engines, loads and equipment, but I did so some checking out on running the Honda 150s one at a time, or together today. I tipped the non-operating engine up just to clear the water with the prop and I had a very heavy load: Full Fuel, 2 ice chests, 4 days' food and ice, clothes, bbq's, microwave, TV, computer, painting, drawing and photography equipment, Kayak equipment, etc..

In all my tests, the fuel flow was higher for the same speed using only a single engine than using twin engines. Winds varied from 0 to 9 mph, but it appears that the single engine's need to correct the tendancy of the hull to turn while using only one engine required from .2 to .4 gallon per hour more fuel. The .4 gallon per hour difference came from running 45 degrees into, a 9 mph wind, which took more power to keep the bow from falling off. The .2 gallon per hour difference was the least noted at any direction.

I am not the exacting technician that Dr. Bob is, but here are some sample readings I jotted down: statute miles

Of course, going 6 mph got almost 4 miles per gallon both engines.

8.6mph, 2050 rpm, 3.0 gal per hour, into almost 0 mph wind.

7.9 mph, 1850 rpm, 2.2 gal per hour, into 9 mph wind.

8.2 mph 1850 rpm, 2.2 gal per hour, into 4 mph wind.


Anyway, I could get from 2.86 to 3.54 miles per gallon running around the 8 mph speed with the permatrims tipped up quite a bit - I just kept trimming them up until the rpm and speed maxed out. Also note, these measurments on not on the ocean but a very large lake, so likely less interference from waves, swells, tides, and currents. We do have some pretty good currents here, though.

Just some observations,

John

 

[matt_unique]

Among my projects for next season will be fuel flow meters so I can see just what I'm burning. Using the numbers from other members here I have been able to plan fuel consumption pretty well.

Loaded for diving (meaning loaded heavy), I have twice run 75nm round trip and burned 40g of fuel. I was primarily at 3400 rpm running at 22 knots but I also ran at about 1800 rpm for 40 minutes (reduced speed water way). This gave me an average mpg of 1.875 nmpg, or roughly 2.156 statute mpg. Loaded light I'm sure that would bump up.

In terms of running on one engine, Dr. John, what engine did you use and what is the rotation of the prop? When I ran mine on one engine, I used the starboard engine (counter-rotating) and I did not notice any pull or odd handling. Did you "feel" it or did you determine it from your gph calculations? I also ran mine wide open and up on plane with just one engine and I did not feel a pull.

 

[thataway]

John,
Your numbers are far different than mine were on the other thread. Different gearing and props will give different RPM for the same speed. I have felt that at less than one gallon an hour, that the flow meters were less accurate.

John's boat was fully loaded--mine has a fair amount of gear, but only a few gallons of water, 1/4 fuel, no ice or food. My fuel flow is measured by Navman flow meters (in fuel line transducers, and over several thousand miles are within a few percent of what I use fillup to fillup) Why is there so much difference?

John--were your numbers for one engine or two? The ones I posted are with two engines, and converted to miles an hour from knots. Incidently, Matt's fuel use is very close to mine at 22 statute miles an hour.

I'll put both here for comparison: Speed in miles an hour for direct comparison.

Bob 1500 RPM/6.6 MPH/ 2.2 gal/hr/3 miles a gallon: ........ John, (no RPM given 6 mph/ 4 miles a gallon.

Bob 2000 RPM, 8.05 MPH/ 5.3 gallons an hour/1.5 miles a gallon: ......... John,1850 RPM,/ 8 MPH,/ 2.2 gallons an hour, /3.6 miles a gallon

Bob 2200 RPM / 8.5 MPH/ 6.6 gal/hr/ 1.1 miles a gallon: ........ John, 2050 RPM/8.6 MPH/ 3.0 gal per hour/2.8 miles a gallon

 

[Captains Cat]

And, I think if go downhill and open the windows, you'll do even better! :lol:

If I can figure out how, eventually I'll put meters on my CAT.

Charlie

 

[Doryman]

My mileage has been disappointing this year. I don't know if it is because of the increased wind resistance of the dink on top.

Typically I will get 1.8 mpg from about 2000 to 3000 rpm. If I boost it up to 3400 or 3500 rpm I got 2.2 mpg last time I was out.

When I first got the boat I was able to drastically affect the mileage and speed by adjusting the trim. Now, I get the same mileage regardless of the trim, but I am able to control how the boat handles the chop.

Any ideas about what might be going on? I tend to fill my tanks when at the fuel dock.

Warren