Inlet Suction Hoses for Raw Water Pump

[Viper]

Source of the post..... You can see how the hose goes back under the engine. It turns and connects to the back of the water pump which is on the left.....

This is the way MOST of these are plumbed. From one side of the engine, under, around the back to the other side and up to the pump. You have more than enough room to make the turn with just the hose.

[Eggbert]

I guess I should have posted that last picture and stated the width between stringers earlier. From your responses I feel reassured I can find some appropriate hose that will take the bend. Thank-you.

I still worry a bit about the force the hose might make trying to straighten itself. Here’s why. A few years ago I had to replace the impellor on my pump. I found out that my pump was an older style made up of many layers at the aft end. The new pumps had a single piece housing and seemed more reliable. A kit was available and it contained the impellor and all parts to make the single housing conversion.



However, the single piece housing is plastic with plastic hose connections vs. the old system which had metal connections. I’m sure the plastic is strong enough for the initial connection, but having steady sideways force under the vibration of the operating boat concerns me.

I will try to install just the hose and get a feel for how much force it exerts on the pump connections. If it’s too much, I can always make up a little strap to hold things in place. Probably out of PVC and the weight would be negligible.



I showed the strap idea earlier, but I‘ve changed it to show use of the additional space between stringers compared to the center-to-center distance between pump and seacock inlet (now light-bulb shaped, like a girlfriend I once had... an upside down light-bulb). Just an idea at this point.

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Now for something completely different and a chance for all of you to have a laugh at my expense.

This boat was my first inboard and I really didn’t know much about how to do a few simple things. Just imagine changing the oil without realizing there is a pump available that screws to the dipstick tube. So I crawled down in front of the engine, and being in some pain from things digging into me, I could just reach back and remove the drain plug.

Yes, drained it into the bilge. What a mess to clean up! Not wanting to deal with this again, I installed an oil pan ¼ turn locking valve with a hose connected to it. You can see the hose laying in the bilge in the picture I previously posted. I just push the hose through the garboard drain and…. wait, and wait and wait…. usually overnight, and the oil drains into a bucket. Yet another reason to drain hot oil.



I eventually purchased a pump, but I’ve left the hose on just in case… in case of what, I don’t know.

Just for interest, the valve does protrude slightly into the pan, so there will always be a tiny bit left over, but not really any worse than the dipstick tube as it doesn’t go all the way to the bottom of the pan either. Mind you, it goes to the corner of the pan, so the boat can be tilted slightly to help things along.

Getting the oil filter changed isn’t all that easy either and even for sparkplugs, I have to sit on the batteries facing the front of the engine and reach back.

All in all, when I first opened the hatch, it was deceiving and looked like lots of room to work on things… and it is, if you’re 5 years old.

[tomschauer]

I had a 2005 crownline that had drain hoses for both 350 mags factory installed like what you installed. but without the valve. it had hanger for them on the back of the blocks. When on the hard, I just dropped them off the hangers, pushed them though the drain plugs, removed the hose plugs and drained the oil into a bucket. Almost as nice as sliced bread. a lot faster and easier than pumping through the dip tube.

[Viper]

Source of the post I guess I should have posted that last picture and stated the width between stringers earlier. From your responses I feel reassured I can find some appropriate hose that will take the bend. Thank-you.

I still worry a bit about the force the hose might make trying to straighten itself. Here’s why. A few years ago I had to replace the impellor on my pump. I found out that my pump was an older style made up of many layers at the aft end. The new pumps had a single piece housing and seemed more reliable. A kit was available and it contained the impellor and all parts to make the single housing conversion.....

However, the single piece housing is plastic with plastic hose connections vs. the old system which had metal connections. I’m sure the plastic is strong enough for the initial connection, but having steady sideways force under the vibration of the operating boat concerns me.

I will try to install just the hose and get a feel for how much force it exerts on the pump connections. If it’s too much, I can always make up a little strap to hold things in place. Probably out of PVC and the weight would be negligible......

I showed the strap idea earlier, but I‘ve changed it to show use of the additional space between stringers compared to the center-to-center distance between pump and seacock inlet (now light-bulb shaped, like a girlfriend I once had... an upside down light-bulb). Just an idea at this point....

You're complicating things way more than necessary. If you're worried about the hose putting stress on the pump, clamp the hose to the inside of the stringer a foot or so before the pump or fasten to the best convenient spot such as the rear engine mount, etc., but most times the hose just hangs there, and I've never seen a cracked pump housing as a result of that.

[Eggbert]

A little update:

I managed to visit the local marine supply house today. They had a 6 or 7 foot piece of Shield 200 hose there and it was quite flexible, although it did kink right at about the 20" spacing (maybe a little tighter at 19" outside to outside) I had available. However this hose doesn't have the wire spiral. It's the Shield 250 series with the wire I need to try and there is another marine supply house I can visit that may have it.

The 200 series was easy to hold in a 180, and as the 250 series appears to be basically the same hose, I doubt the wire spiral will cause much more pressure to self-straighten, so my plan of having a strap isn't likely to be required.

[Eggbert]

Yes, I know this thread is becoming a little bit too long, but I havn’t finished quite yet and it could be of use to someone in the future searching for help. In the meantime I dug out the hoses that came with the boat and worked fine (as far as I could tell) for me as well as for the previous owner.



I can see now why the corrugated hose kinked so badly. The molded hose goes to starboard from the seacock which keeps makes the corrugated hose bend sharper. Even if I was to rotate the molded hose to port, the corrugated hose would become too short and it would kink near the joint.

By the way, the joint wasn’t a piece of brass tube as I remembered it. It might be bronze, but it has slots in the inside, sort of like a splined receiver. But they are too small for that. I suspect it was piece of an old cutlass bearing. This is something more likely available in the junk-box at a marina that does servicing than your typical boat owner. So whatever Carver installed, this was probably a repair by “professionals”.

Neither of these hoses have a wire reinforcement and they seemed to work OK. The engine would heat up a bit at higher rpms, but I suspect this was due to the efficiency of the heat exchanger and not the hose kinking. It never did overheat.

With all that, I still intend to identify wire-wound suction hose and use the 90 degree long-radius fitting. I just added this post to show what I was dealing with before I switched to the radiator hoses.

[Eggbert]

I finally picked up my hose today. It is Shieldsflex II (wire core suction hose) and bending to my 20” outside width, there is no sign of kinking. I also picked up my bronze 90degree shallow radius fitting. I think I am ready for the next season now.

Just for interest, I did find a more flexible hose, and I have a picture below. Unfortunately, no one seems to have it even though they are Vetus Dealers.

Here it is; the picture being a composite of some different advertisements of the same thing. Check the small bend radius. It looks good, but not available to me yet.



Thanks again for all the help getting me pointed in the right direction.