Engine water pump relocation-gctid344841

[Guest]

Hi,

A friend of mine at the marina asked me if it's possible to relocate a sea water pump? His engine is a Volvo 8.1 on a 2855, I think the year is around 2000 something. Problem is that in order to change the impeller, the shop has to pull the engine each time because the pump is too close to the main fuel tank! I think there must be a way change the setup to either electric or something else. Your thoughts please.

Gary.

[2850Bounty]

Gary, an electric sea water pump is out of the question..... the sea water pump supply volume must remain RPM driven.

IOW, it must be mechanically in sync with engine RPM, just as the GM circulating pump is.

Assuming that this is the Volvo Penta crankshaft sea water pump that we're talking about..... it's hard to beat the crankshaft pump, IMO.

But if so, and in his scenario, I certainly understand switching to a belt driven pump, and one located up and off to one side or the other.

I'm not sure if the 8.1 had this for an option, but one of the earlier BB may have.

Perhaps a Merc belt driven pump could be re-tro fit.

Sounds like whoever did the install, forgot to layout, layout and then layout!

What a knucklehead! And what a dissersice to the owner! rod

Bummer!

Edit:

There's a remote chance that a Jabsco, Johnson or Sherwood crankshaft pump could be retro-fit.

This would depend on the front engine crankshaft pulley arrangement..... and it may require re-working..... in fact, I know that it would!

But compare that to engine removal for an impeller replacement !!!!!!

Look at the Volvo Penta OEM crank pump compared to the Johnson, Jabsco or Sherwood style.

Rather than just a front cover removal....., the entire impeller housing must be removed from over the impeller and shaft, and then FWD and off.

You literally pull part of the housing away to access the impeller, and it requires enough forward space (at least the width of the impeller) in order to be removed and accessed.

It's quite different from how the Jabsco, Johnson or Sherwood crankshaft pumps mount and/or offer impeller access.



Wtih the Jabsco, Johnson or Sherwood, the entire pump could be removed via three fasteners and two hoses removed.

One of these may require only 1" or so forward space to remove the entire pump ...... and actually, that's no big deal compared to pulling the engine each time.

You'd need to have the components in hand, and lay this out and do the math.

It may or may work.... don't know, just a suggestion.

But consider this initial work and cost against pulling the engine for every impeller change.

Also consider that pulling the engine will very likely defer impeller remplacement.

Now add.... what do you do while out in the water and if you were to have an impeller failure???? Not good!

I'd be willing to bet that the cost of one engine R&R and impeller change could easily be offset by doing this one time only!

Food for thought!

.

[Guest]

Knuckleheads for sure but from a business point of view, they were securing long term work. I'll have go see his engine in person to see if it's possible to install something like a belt driven pump somewhere else. Maybe where the power steering pump bolts to, who knows. It would be nice to know if someone else has found a solution to this issue. I'll take pictures and post when I get a chance.

Gary.

[2850Bounty]

garball wrote:

• 1 wrote:
• Knuckleheads for sure but from a business point of view, they were securing long term work.
• I'll have go see his engine in person to see if it's possible to install something like a belt driven pump somewhere else. Maybe where the power steering pump bolts to, who knows. It would be nice to know if someone else has found a solution to this issue.
• I'll take pictures and post when I get a chance.

Gary

• 1 wrote:
• As a result of lack of engineering, I may agree!
  
  A friend of mine bought a brand new 1968-69 (not sure what year exactly) Shelby Mustang w/ the 427 engine.
  
  In order to change some of the spark plugs, the engine mounts needed to be removed, and the engine lifted slightly.
  
  Perhaps the 8.1 installer attended the same school as the Shelby designer did!
• This is a rather unique installation. Doubt that there's too much info out there on this.
  
  Perhaps take a measurement from a front engine surface to the fuel tank. Not the pulley, because this will change some.
  
  That will give him a base line to work from, if the Johnson style crankshaft pump is to be considered.
• That works!

The guys at Cooke Engine (on Tomahawk Island, here in Portland), would be a good place to ask this question.

They may not be very willing to offer help over the phone, but it may be worth a shot.

.

[Guest]

Ok, finally got pictures of this install ... doesn't look good. There is a PS pump on the engine which could have been a good relocation spot for the impeller so that's a no go. Anyway, tell me what you think.Gary,

[img]/media/kunena/attachments/vb/663279=25309-IMG_1421.JPG[/img]

[img]/media/kunena/attachments/vb/663279=25310-IMG_1422.JPG[/img]

[img]/media/kunena/attachments/vb/663279=25311-IMG_1423.JPG[/img]

[img]/media/kunena/attachments/vb/663279=25312-IMG_1424.JPG[/img]

[img]/media/kunena/attachments/vb/663279=25313-IMG_1425.JPG[/img]

[2850Bounty]

Gary, I never thought that I'd see the day when I'd recommend a belt driven sea water pump.... but perhaps that day has come!

What were those knuckleheads thinking of?



.

[Guest]

They were thinking of their bottom line. That is ... they told the client that it was no problem to pull the engine each year to replace the impeller as part of the yearly haul out. I guess they forgot to tell him what that would cost.

I'm still trying to figure out how he can do this but I can't see how.

Gary,

[Guest]

I can't believe what I just saw! For a minute, I was trying to convince myself you had some great Photoshop skills and were trying to pull a fast one, but April Fools Day is still over 2 weeks away.

Personally, I'd have the gas tank modified. It could make up for the cost of pulling the engine every time.

[2850Bounty]

The crankshaft pump makes perfect sense, but sucks in this scenario.

A belt driven pump doesn't really help all that much.

Anything other than an engine driven pump doesn't make sense because a sea water pump must remain in sync with engine RPM.

Astral Blue wrote:
Personally, I'd have the gas tank modified. It could make up for the cost of pulling the engine every time.

Exactly my next thought.

In the large scope of things, they could have pulled the fuel tank, had it modified to accommodate the pump, and went from there.

One big hassle, but one time only!

[JimMc]

My 5.7L Mercs have belt driven seawater pumps.

[Guest]

Astral Blue wrote:
I can't believe what I just saw! For a minute, I was trying to convince myself you had some great Photoshop skills and were trying to pull a fast one, but April Fools Day is still over 2 weeks away.

Personally, I'd have the gas tank modified. It could make up for the cost of pulling the engine every time.

Man, talk about thinking outside the box! Great one.

[2850Bounty]

Gary, just as Ed did, when I saw the engine for the first time, I thought feul tank mod!

I wonder if it would be feasible to remove the engine one last time. I know.... I know.... yuck! rod

Pull the fuel tank, and have someone who knows how to purge one and make the modifications to it.

However, I have no clue as to access in removing this fuel tank.

Is that possible with the engine removed..., or is there much more involved with this hull?

[yachtman]

This is right up there with my Dodge minivan I had where the intake manifold had to be removed to change the spark plugs. It would have been easy to make the manifold go the other direction to allow access. I don't think its job security as the newer ones arent, designed that way. I worked for Chevrolet for 15years long enough to know some engineers are dumb asses.

Any way there are mountings that can be used to change the water pump position. I have them on my boat and have been dealing with it recently.

Here is the problem.... probably all the accessories up front will need to be relocated and theIcooling system plumbing modofied. My sea water pump has the alternator on the same mounting bracket. Which is on the right side of the engine facing the front of it.

Not every thing can be on the same side. Most likely the power steering will have to be relocated to the other side. There are mountings for that.

As for the gas tank. A couple of things any one who welds on a fuel tank that has been filled is going to live a short life. Yeah yeah I know its been done but still not too smart.

I cut apart a fuel oil tank last summer and even after having it full of water and hadn't had any thing in it for many years it was still rumbling when I cut it open.

The other problem.with modifying the tank is that all marine tanks are supposed to be coast guard approved certified and pressure tested. Im not sure that it would be worth it. Also may have an insurance issue if not certified.

There are plenty of boats out there with side mount pumps it will just need some home work.

[2850Bounty]

Dangerous.... I agree, it sure can be...., but be smart about it.

The right person will know how to purge the fuel vapors from the tank. Some will fill the tank with water, tilt it as needed, and purge with an inert gas only at the area where the work is to take place.

[yachtman]

Here are some pics of how it might look.

[img]/media/kunena/attachments/vb/663404=25331-V111.jpg[/img]

[img]/media/kunena/attachments/vb/663404=25332-V108.jpg[/img]