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How strong is a trim pump and cylinder?

M

Merc1973

New member
New to forum, not a boater.... yet. Too many toys the wife will approve of now, lol.

Im considering other applications for a typical trim setup like the Alpha 1 for raising the snow plow up and down on my garden tractor. I cant find any specs on these for weight or power or speed in motion and static. Thanks.
 
Let me tell you, the force needed to push that lower unit up under the thrust of up to 300 horsepower is enormous!

Jeff
 
If you assume that the effective area of each piston is 1 sq in., in the "up" direction and the pump puts out over 2000 psi, then the maximum up force is 2 x 1 sq in x 2000 lbs per sq in = 4000 lbs ( for a piston pair). Since flow rate of pump is not specified ( just the pressure at max, i.e. stall) how fast it would move is un-calculable. In the down direction, the force is much less due to lower down pressure and the fact the the effective area of the piston in the down direction is substantially less.
 
Ayuh,.... Merc has used several different trim pumps over the years, some called high pressure, some called low pressure,....
I believe they range from 1500 psi to 2000 psi in the up direction to several hundred psi in the down stroke,...

As Bob explains, it depends entirely on the pressure the pump puts out, 'n the size of the piston(s),...
 
If you want to raise and lower a plow there are gazillions of better suited options. I dunno if it comes into play but one of the safety features of the trim is a built-in kick up. If you're tooling along and whack a submerged log or something, the trim rams have a valve in there that pops open to relieve the pressure...allowing the drive to kick up.
 
Ayuh,.... What sorta amperage does it charge at,..??

Ya might need a bigger battery, or leave it hooked up to a battery charger when not in-use,....
 
o2batsea said:
If you want to raise and lower a plow there are gazillions of better suited options. I dunno if it comes into play but one of the safety features of the trim is a built-in kick up. If you're tooling along and whack a submerged log or something, the trim rams have a valve in there that pops open to relieve the pressure...allowing the drive to kick up.
Click to expand...

I have heard this many times but I have never seen this function. My uncle destroyed a lower unit in Canada in some rocks and a friend of mine I both lost skegs on Mercury motors with tilt/trim. Possible that this kick up can't function when the motor is near WOT
 
JeremyB said:
I have heard this many times but I have never seen this function. My uncle destroyed a lower unit in Canada in some rocks and a friend of mine I both lost skegs on Mercury motors with tilt/trim. Possible that this kick up can't function when the motor is near WOT
Click to expand...
I don't think anyone wants to see it function.
In this diagram you can see the relief valve assembly:
mercruiser_pages_84.gif
 
..." Possible that this kick up can't function when the motor is near WOT "

Or even at cruise speeds. Often thought that myself.

Jeff
 
I don’t think the kick up safety is for saving the lower so much as absorbing a shock that otherwise could cause tons more damage resulting in a sinking.
 
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