Old Gives Way to New

[hanleyclifford]

After years of successful use of the electric cooling pump concept I have decided to go back to the more conventional since I will not always have Destiny and other owners may not be willing to tolerate repetitive cartridge changes. Did a dry run last night with the MM 501 pedestal (which together with the MM 502) constitutes IMO the best set up on the water. Actually the inspiration comes from the "Romantic Comedy". Next will be to take it back down for painting and a few final touches which will include a strainer on the seacock inlet and possibly the flow indicator from MMI. I'm also going to study ways to use the Dutton Device (belt tensioner) on this pump. Notice the 3/8" NPT from the pump brought to nipple for 3/4" hose as expeditiously as possible. The last picture is the Old Soldier.

[ndutton]

Easy Hanley, at least the upper part which is all I can see in the pictures.

Assuming the threaded piece with the blue paint is a jackscrew to manually tension the belt, just remove the upper bracket on the tensioner and put it through your hinge plate instead of your jackscrew. It's best if you put it through a square hole like in the original angle bracket to keep it from turning during adjustment but not critical.

Can't suggest anything on the bottom without seeing it.

[hanleyclifford]

You're right, Neil; it is a jack screw coming from a small bracket bolted to the oil pan cap screw directly beneath. I'll get some better pictures. The one pictured is just a (1/4") pattern. The finished size (5/16") will be more suitable for the tensioner.

[ndutton]

The tensioner jackscrew is 3/8-16 and I recommend staying with that size. All the associated parts are sized to fit it.

edit: thinking on it overnight, please remember the tensioner was designed for alternator loads, not pump loads. You may have to throw the adjustment instructions out the window (port?) to keep the belt from slipping, may even need to replace the compression spring with one of a higher K constant for this application.

The original design parameters were for the alternator pulley to hold 11~12 ft-lbs. torque before slippage (a specification borrowed from Lycoming aircraft engines) considering a 3/8" V belt and slightly less than 180° belt contact around the pulley. Pump requirements, belt differences and contact variations were not considered. Bottom line - this may not be a good application for the tensioner.

[hanleyclifford]

Changeover to all mechanical/all Moyer Marine coolant pumping now complete. On "expert" advice the use of the Dutton Device has been rejected for this application. But look what a great job an Atomic 4 valve spring does!

[ndutton]

Did you have a specific tension you were aiming for? Maybe just up to the point the belt doesn't slip and a hair more? The goal of our tensioner had little to do with the belt but rather preserving the acc drive and alternator bearings by applying only the minimum force necessary for operation. The belt benefits too but it was the bearings we were focused on.

Our early proof of concept prototype utilized a valve spring (small block Chevy I think). We learned a lot from it but also found it was far too strong to achieve the tension goal we'd set. Our application was less demanding than yours.

Where does the lower end of the threaded rod attach?

[Al Schober]

Uhhh Hanley,
Where's your alternator?
I'd guess it's on the engine on the other side of the boat. Aren't you running twin A4s?

[hanleyclifford]

Uhhh Hanley,
Where's your alternator?
I'd guess it's on the engine on the other side of the boat. Aren't you running twin A4s?

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