More on Driveway Testing before the Water......

[mohead1]

Ok, a week ago I had a thread talking about testing water flow with muffs on the trailer at home before I went to the lake and made a butt out of myself. Working on a 5.7 Merc w Alpha 1, in a 210 Wellcraft. Tore the lower off tonight and replaced the complete water pump including the lower housing. Only thing I found was the water tube melted. The impellor was in good shape, not hardened or brittle, think it was changed not too long ago. So the poor flow of water and the high temp on the motor would be because of the melted tube? Obviously the impellor was good and should have been pumping water without issue. Then of course, while filling the lower back up with lube, I only bought a quart and that aint enough....sh-t fire...now gotta find some on a Sunday so I can test again. Anyone wanna step in here please do....I wondering now if the thermostat may be stuck or bad...


Took a few pics as it came apart....

 

[Don S]

Re: More on Driveway Testing before the Water......

Tore the lower off tonight and replaced the complete water pump including the lower housing. Only thing I found was the water tube melted.

Looking at the first two pictures, I can tell you that you did not have the copper tube coming out of the upper gear in that water tube guide, or it would not look like that. Therefor, no water got to the engine.

 

[jayrodoh]

Re: More on Driveway Testing before the Water......

I would replaced that impellor while in there anyway, cheap enough and important on a seawater cooled system. I do mine every other season. Yeah, a quart ain't gonna do it, but it won't take more than 1/2 of that second qt.

Thermostat could be stuck, but I'd fix that meled pipe first, hard to get water in the engine with that. I service my buddies 88 5.7 Alpha setup and it runs way cooler. muffs or lake water.

 

[mohead1]

Re: More on Driveway Testing before the Water......

Thanks Jayrodoh,
I replaced everything. All new pump upper and lower housing, o-rings, impellor, water tube, the works. I made sure the tube went over the copper pipe on assembly. I hope this was the cause. Why would it have done that anyway? Someone have it apart and missed the insert into the copper tube on reassembly? Anyhow, as soon as I get some more gear oil, I will try it on the muffs again..

 

[Don S]

Re: More on Driveway Testing before the Water......

In the picture below, the green line indicates where the copper tube from the upper would have been. How would that white plastic tube bend that far with a metal tube in it.

 

[zx9rstv]

Re: More on Driveway Testing before the Water......

I take it that when you removed the lower you only found this melted tube and no copper pipe correct? ( did you look up inside the upper and see if it was stuck in the upper bushing?) If this is the case. Then whoever installed the water impeller the last time forgot to insert the copper tube. This making it impossible for water to reach the engine and the root of why water was coming out of places it shouldn't have been as described in your previous post's water leakage problem. That plastic tube is only a guide for the copper pipe to reach it's destination while assembling the two halves.

 

[mohead1]

Re: More on Driveway Testing before the Water......

This boat is new to me, so whoever had it apart last time screwed it up. The tube was hanging down and I guided it into the plastic sleeve as it went together. I hope this is the fix cause I'm wantin to get on the water. What u think chewed up the slinger thing on top of the pump housing? Heat?

 

[Don S]

Re: More on Driveway Testing before the Water......

What u think chewed up the slinger thing on top of the pump housing? Heat?

Heat for sure.

 

[zx9rstv]

Re: More on Driveway Testing before the Water......

The tube was hanging down and I guided it into the plastic sleeve as it went together.

Ok so there was a copper pipe when you pulled it apart. It just wasnt inside the plastic tube correct? Did you make sure the copper pipe was the correct length and not too short? Perhaps someone who messed with the boat before messed with the length of the copper pipe as well. If that copper pipe is too short it doesn't matter if it was guided into the tube upon assembly. It will still not seal the two halves water passage together.

 

[mohead1]

Re: More on Driveway Testing before the Water......

zx9rstv,

I didnt measure it exactly, but it seemed to be long enough to engage the seal on the top of the outlet of the pump. Im thinking Im back to normal again. As soon as I find another quart of gear oil then I will test.....
Whats a normal way to see if the thermostat is opening on a boat? I know on a vehicle but Im guessing a boat is much different because its an "open" system, at least on this boat (raw water instead of a closed system).

 

[fat fanny]

Re: More on Driveway Testing before the Water......

Why look for lube go to the auto parts store and buy some 90w and use it in place of what you have put in until you get more of what you want. At least it will get you throught the test and maybe on the water for a day or 2.

 

[Don S]

Re: More on Driveway Testing before the Water......

Walmart carries the Hi Performance gear lube.

 

[zx9rstv]

Re: More on Driveway Testing before the Water......

Whats a normal way to see if the thermostat is opening on a boat? I know on a vehicle but Im guessing a boat is much different because its an "open" system, at least on this boat (raw water instead of a closed system)

The thermostat works the same. On my engines I have 145 deg thermostats on them. I always know when the thermostat opens because the temp gauge will drop down to about 120.
You will need to know what temp t-stat you have. If the temp keeps climbing above 165 on the test then shut her down because you still have a problem. when reassembling your water impeller, did you make sure the woodruff key was on the shaft properly to engage the impeller? If so and you know your impeller assembly is correct. then the problem will lie on the engine side.

 

[mohead1]

Re: More on Driveway Testing before the Water......

Well, those who chimed in on my original and this thread thanks so much. My work schedule has been hectic so I just got to test the impellor replacement job I did last night. You remember (pics tell the story) how my water tube was found melted and the slinger gone. I put in a complete water pump, including the lower housing. Happy to report that I tested last night, went easy on it to allow "break in" if you will, and had the muffs flowing full out. At idle it had the exact flow characteristics as pics yall sent showing flow, it mimiced that exactly. I was very happy! I let the motor warm up, increases to 1000-1200 rpms, gunned it a few times, let it run for approx. 20 min. and the temp never went above 130 deg. So, if the gauge is right, Im good, thanks to all for the help. Now one more thing, the water pump on the motor is making so rattling like the bearing is gettin ready to go. That is just a small block Chevy pump right? I dont need to have a "Mercury" one? Also, on both exhaust manifolds, the two center bolts (to the engine block) are weeping water and it looks like they have been in the past (this is a new boat for me). Just pull them and seal them? I wouldnt think they are on the water side of the manifold. Am I in trouble here and need new manifolds now? Jeez laweez.....somebody get the prozac.....

 

[WILSONS88]

Re: More on Driveway Testing before the Water......

You will need a marine water pump. The impeller in the pump is of different material than an automotive pump. I think the automotive has a steel impeller and will corrode.

 

[mohead1]

Re: More on Driveway Testing before the Water......

Of course!! Didnt think I could use a $40 pump instead of a $200 dollar pump.....now I only run in the lakes here around me in Tennessee.....so.....it shouldnt be any more of an issue than running water through a car engine? Of course no anti-freeze......

 

[jmorgan87]

Re: More on Driveway Testing before the Water......

hey mohead, nice job on the water pump replacement.. Not sure if you've had this out in the water yet, but one thing I almost forgot to check was my bilge pump. You might want to test that before taking her to the lake for the first time.

 

[mohead1]

Re: More on Driveway Testing before the Water......

Thanks Jmorg, as a matter of fact, I was laying down looking back at that yesterday, and there are some old leaves and crap laying back towards the back, I need to clean then check to make sure the discharge hose is clear.....just pour water back there and see if it will pump it out, supposedly it has a float switch, but there is a bilge pump switch on the console at the dash too......

Anybody got something on the two center bolts weeping on the exhaust manifolds? The ones that go into the cyl. heads? Rust stains there like both sides have been doing this for a while now. I dont remember if those center holes on the GM smallblock heads go into the water jacket or not.....I guess pull them and add some pipe sealant.....

 

[zx9rstv]

Re: More on Driveway Testing before the Water......

Of course!! Didnt think I could use a $40 pump instead of a $200 dollar pump..

check on ebay. I've seen the marine pumps there for around 60 bucks. Just make sure they are marine pumps and say so. Some people try to sell the automotive pumps as marine

 

[mohead1]

Re: More on Driveway Testing before the Water......

Cool, thanks zx9......