Relocate the Water Pump

[tritonyawl2]

For over 20 years the location of the water pump on my boat has been a torture. There are only 2 bolts and 2 hoses that must be removed to get this water pump out. Years ago I installed the long bolt Moyer offered for the bottom bolt. I even put in a much larger hatch (17 x 24) to have better access. Both improvements helped, but it is still a bear of a job.

So this year I bought the impeller puller with high hopes. So far the four screws holding the cover are not cooperating after 2 days of PB Blaster. In my case the gear shift is in the way as well as the intake seacock and some plumbing. But the screws are not moving.

I'd be willing to pay a lot if the pump could be relocated near the front of the engine. The flywheel shaft or the alternator belt are a couple possible sources of power. Or even an electric pump would be a godsend.

Replacing the impeller is by far the worst job on my boat. It can take a couple hours. And I don't want to think about the impeller ever letting go while motoring with no wind. You'd have to remove the pump no matter the conditions.

Sorry for the rant. My boat may have this worse than others. The Atomic 4 and Moyer's service are great and I'm grateful for both. And I'm hopeful the 4 screws will eventually turn. Anyone else tired of dealing with this problem?

[ronstory]

Regarding the stubborn screws, do you have space to use a good old impact screwdriver?

https://www.harborfreight.com/6-bit-impact-screwdriver-set-with-case-64812.html?cid=paid_google|||64812&utm_source=google&utm_medium=cpc&utm_campaign=&utm_content=&gclid=Cj0KCQjwppSEBhCGARIsANIs4p6_0msAj878jKRL8fGJXreYMtmAnPe1nC-kDsjzTWds9wy8e0nKwPcaAlfVEALw_wcB

Also, while changing the impeller does qualify as a yoga class session, it's a 30-40 min job for me on our boat. That said, I'm using a Moyer pump with sealed bearings (no grease cup ) and captive thumbwheels on the cover.

I just remove the cover using fingers only (and a towel), grab the impeller with a short a needlenose, wiggle and yank. Note the orientation of the slot during removal for easy installation. The shaft comes out and I replace the impeller from the comfort of the counter put a touch a synthetic grease on the shaft and then slide back in.

The only tricky thing is making sure the rubber O-ring in the cover stays in the groove. I help with retention using a bit of synthetic grease to keep things in place and on the threads of the thumbscrews.

The thumbscrew cover is simply a godsend.

I also wondered if you really need the retention clip with the impeller being captive in the chamber, as is the shaft via aux drive. That said, I still haven't be brave enough to skip it.

[tritonyawl2]

Thanks, Ron. Very good suggestions. Will get that impact driver tomorrow. I think it might fit. And when I get the pump or cover out, will replace with the thumb screw cover. I like finger screws.

Just discovered there is an electric replacement. Still requires raw sea water. Expensive but may be a good idea. Why not a closed system - radiator with fan like a car?

[ronstory]

It does not take much force on the impact drives. Just spin counter-clockwise on the screw to take up any slack in the rotation before you whack it.

Interesting. Who makes an electric version? I would be curious of the design since with a waterlift muffler, the flow likely needs to vary with engine RPM. With one a constant speed, you could risk flooding the motor due to not enough exhaust pressure (eg. idle) or alternatively too low of flow for high RPM cooling.

[ndutton]

1. Relocate the pump: More like abandon the inaccessible engine mounted pump and install a PTO pedestal mounted pump driven off the flywheel, same as the Moyer fresh water cooling system uses. There is nothing to re-engineer, all the parts are available. If I were considering this, I'd remove the original pump for good and fashion a blank plate in its place, gasketed of course.
2. Electric raw water pump: I'll repeat the point Ron made, depending on exhaust type you may require proportionate flow to the engine RPM and corresponding exhaust flow. If your exhaust is a straight pipe, stand pipe or water jacketed, no problem with full flow regardless of engine RPM. If it's a waterlift, proportionate flow becomes critical.
3. Automotive cooling system with a radiator: You won't have sufficient air flow to keep up with the engine heat. It's not like your radiator is cruising down the highway with 80 MPH worth of air running through it.

[tritonyawl2]

Thanks! the PTO pedestal mounted pump is worth investigation. Electric sounds possible, but would require more engineering.

[JOHN COOKSON]

I finally gave up on the cover screws on the H2O pump and went to bolts that I could get a 1/4" socket on. Life was much happier afterwards.

ex TRUE GRIT

[sastanley]

What Ron & Neil said. You can simply abandon that pump and let it spin away, and either mount something to run off the flywheel (Moyer has the bracket, https://moyermarine.com/product/seaw...nting-bracket/), or Indigo makes a mount to hold a Moyer pump in between the alternator and accessory drive pulley (part of one of their FWC system), but I assume you can buy just the bracket if you didn't want to fabricate something.

[tritonyawl2]

FWC is sounding better if you can just abandon the existing Oberdorfer pump and run the hoses to the new system which is in a easier to reach location.

The FWC they offer here does not provide a lot of detail. I'd like to see a very detailed article on how to plan and install it.

[ronstory]

Indigo has two FWC systems, one mechanical and one with an electric pump.

I'm using the electric version and I just upgraded to their latest electic pump during my rebuild a few months back.

[ndutton]

FWC requires two pumps (1@ raw water and 1@ antifreeze) any way you decide to go therefore the previous proportional raw water concerns apply.

[sastanley]

sorry..didn't mean to confuse the issue. I was thinking about taking the MMI pump that Indigo makes a mount for, and install it in the alternator loop to help with your access issue. If you wanted FWC you'd need a 2nd pump regardless. The belt driven for raw water, and an electric pump for antifreeze is a definite possibility.

[ronstory]

This is just my opinion, but one of the things I really like about our A4 is in its base form, is there are zero exposed spinning parts on the "front" of the motor.

We've all had to debug issues on running motors, and for me, a cat in a roomful of rocking chairs comes to mind. With the A4, being able to lean over and fiddle with things where the only thing I have to worry about is the alternator belt on the back of the engine... is IMO an understated plus.

I never have the worry of "pulling a Frodo" and ending up with less than 10.

[tritonyawl2]

The more I think of it, relocating the pump is the best solution. I would like to remove the Oberdorf and move it to the flywheel. Connect the flywheel shaft directly to the water pump shaft and lengthen the two hoses.

Why add a second pump?

Think you'd have to bolt the pump to the flywheel cover, but the main challenge is connecting the two shafts. What do think? Some minor carpentry would be required. Checking the impeller would take 5 minutes and would be laughably easy.

[ndutton]

Why add a second pump?

The two pump discussion had to do with FWC only.

Think you'd have to bolt the pump to the flywheel cover, but the main challenge is connecting the two shafts.

If your flywheel cover is the heavy casting, that sounds like a viable plan to me. Also, transferring the pump's torque load to all of the smaller flywheel cover bolts would be good. If the flywheel cover is the newer sheet metal design, a heavier bracket will need to be fabricated and would do well to be fastened (again) by ALL the flywheel cover bolts.

MMI offers a crankshaft PTO adapter that may be a good place to start.

https://moyermarine.com/product/pto-shaft-cfwc_10_184/