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View Full Version : curious, what point is external steering important



JayZ
03-29-2012, 05:50 PM
thinking down the road here...

I happened upon a bracket for the King Cobra drive to work with external steering but not sure I'll ever need it...

Dr. David Fleming
03-29-2012, 07:46 PM
JayZ,

You might think that few change automotive steering why would there be an option on boats. Well the steering comes in a couple of levels of quality.

#1 - Basic cable steering which is mechanical from the wheel to the power steering drive cylinder in the engine compartment. This is your basic MerCruiser system. Generally you must keep pretty tight control of the wheel to keep control of the boat. This system uses GM Sagnaw Steering Gear pump. This Mercruiser system uses a dashboard steering gearbox made by Teledyne company.

#2 - External hydraulic steering is modification to the above system which uses a different hydraulic unit inside the engine compartment and a slave hydraulic cylinder outside of the hull. This Mercruiser system is significantly better at high speed running - say over 60 mph. You can drive at speed with considerably more control. This system uses Latham External Hyrdraulic cylinders, brackets, hoses etc., and the same Teledyne dashboard steering gearbox. Also several other similar aftermarket hydraulic systems are available which are like the Latham.


#3 - External full hydraulic steering is like #2 above except that it does not use the cable system from the wheel to the engine compartment valve unit. Hydraulic lines are run from the dashboard unit to the hydraulic system at the transom. This is another high speed system. The steering wheel will not index in the same position when the engine is off. It requires a different dashboard steering wheel gearbox that is completely hydraulic. Latham and others produce this system.

Google to Latham Marine steering in Florida they should have considerable information for you.

zelatore
03-29-2012, 09:58 PM
curious, what point is external steering important


thinking down the road here...

I happened upon a bracket for the King Cobra drive to work with external steering but not sure I'll ever need it...



The general feeling seems to be around 70 mph is the point where you need to be thinking external hydraulic.

I would say if the bracket isn't too expensive go ahead and snatch it up. They don't come up often; worst case you could probalby re-sell it to somebody here.

osur866
03-29-2012, 11:25 PM
If you plan on running 70 and above then you need it, not only for better control but for safety, you do not want your cable system to break at higher speeds!! If you choose to do a full system you will never ever wanna run without it and you'll ask yourself why didn't I do this sooner, it is in the top 3 if not the best improvement I made to my boat hands down, if you got the coin go for it!!! My .02 Steve

Ghost
03-30-2012, 05:29 AM
The only note I'd add to these is that going fast puts much higher loads on the drive. External hydraulic cylinders directly push/support the rear of the drive on angles back to the transom. As one might expect, this is much nicer to the gimbal bearing than using the internal steering arm and having to transferr all the steering force back to the drive through the pivot of the gimbal.

zelatore
03-30-2012, 12:10 PM
Mr. Tartan has a good point.

justleft
03-30-2012, 03:51 PM
Adding a nosecone also makes you want external steering. I am told that it moves the steering moment
forward on the drive, so any steering slop will exaggerated.

Carl C
03-30-2012, 05:18 PM
If you post about doing any performance enhancements then you had better do the steering first or the steering police will be all over you. For real!!!!