Routing the raw water feed for the starboard engine

pschauss · Post by **pschauss** » May 8th, '22, 13:20

What is the best way to route the hose from the strainer to the raw water pump on the starboard engine?

The existing house takes a rather torturous path over the stringer, under the transmission, and then forward along the outboard side of the engine. Is there a better way to do this?,?

scenarioL113 · Post by **scenarioL113** » May 8th, '22, 15:31

If it makes you feel any better my port side engines runs a similar path. The Cummins have the raw intake on the "port" side of the engines. I use heavy duty reinforced hose and it handles the path and bends pretty well with no stressing bends

Carl · Post by **Carl** » May 9th, '22, 07:57

My raw water intakes are aft of the motors, the hose runs through bulkhead to the engine compartment.

If up and over take precautions for chafing, such as wire tie a larger hose over intake hose in that area. I wouldn't cut through stinger...but my gas motors had heavy wood sisters for motor beds that I might have considered drilling through or cutting down some if I was really concerned.
I am also a strong proponent of "If it ain't broke, don't fix it." That said, I am not sure what you are up against.

Rawleigh · Post by **Rawleigh** » May 9th, '22, 11:26

I cannot remember which engines you have.

pschauss · Post by **pschauss** » May 9th, '22, 14:51

I have 454s.

My starboard engine does not overheat but it has always run about ten degrees warmer than the port engine. Also, I get steam coming out of the exhaust.

The past two summers I have had a stalling/power loss problem with that engine which seems to be heat related. The raw water feed hose is made up in two sections, apparently joined by a short pipe of some sort. I’m wondering if that may be restricting the flow of cooling water.

Carl,

I saw where you had a similar problem with your old 440s a few years back.

Rawleigh · Post by **Rawleigh** » May 9th, '22, 14:56

It could also be sucking air at that joint, there by starving it of cooling water. Is it double clamped with the clamps offset by 180 degrees?

Stephan · Post by **Stephan** » May 10th, '22, 09:48

The joint in the raw water hose may also present an opportunity for growth to start and create a blockage.
Maybe check the thru hull shut off and see what sort of flow you have at the raw water pump inlet?
Good luck,
Stephan

Amberjack · Post by **Amberjack** » May 10th, '22, 13:57

Peter-Do the simple things first. If there is steam from that exhaust only we know its not a gauge issue. A good next step would be to replace the entire intake hose.

I had a similar issue with my old big block Crusader and wrestled with it for a couple years. It turned out to be worn fan belts slipping. No noise or squeal from them, just random occasions of overheating. I tried tightening them early in the process but it didn't cure the overheating. You can test this quickly and cheaply by buying a spray can of fan belt dressing. It won't work over time but will give a worn belt enough grip to indicate if that's the problem.

Stephan · Post by **Stephan** » May 10th, '22, 14:37

Dough makes a good point.
I have found a significant amount of stretch in the Crusader raw water and alternator belts. It is a regular part of commissioning for us to check belt tension each season.
I have also used one of those cheap temperature guns https://www.harborfreight.com/121-infra ... 63985.html to check the temp at different points of the risers and exhaust elbows. This may be useful for tracking down the steam.

pschauss · Post by **pschauss** » May 11th, '22, 08:11

Thanks for all of the suggestions. I was planning to check the temperature of my risers and elbows first, but, since with weather and other commitments have kept me at the dock for the past couple of weeks, I'm probably going to do the hose first.

When I replaced the impellers on my raw water pumps last year, I had planned to replace the hoses on both sides but ended up only replacing the one for the port engine. I still have a 12' length of hose which I am hoping will be long enough.

Carl · Post by **Carl** » May 11th, '22, 08:27

I had multiple issues that needed correcting.

The big one was the inline connector on the raw water line the prior owner installed. Checking the line one day...a line that went under the motor. I pulled hose closer for me to inspect and the connector just parted in two with water free flowing in. Oh what a feeling.

I found during one trip my intake valve was NOT 100% open when handles were IN Line...close but not 100%. I came down a few degrees, not alot.

The last item was a 90 degree fitting coming out of the exhaust riser to the dumps. I had never touched as it looked original but it didn't work well with the new hose so I changed it out to a straight. It was not only a 90 degree fitting but it was not a full flow design. 10 degree temp drop, problem solved.

FYI- on my boat with 440's, steam just was. Especially on those clammy humid mornings. I put it down towards the long run with big mufflers allowing water to settle after mixing.
I always check temps of manifolds, risers, dumps, hose and exhaust water out the transom when running...all nice and cool but still had steam. It just what it did and I learned to get used to it. More steam, yeah...time to change the impellor of clean intake filter. Take time to learn what normal and whats a problem. With twin motors you have the luxury of comparison.

Rawleigh · Post by **Rawleigh** » May 11th, '22, 13:28

My 440's produce a bit of steam when cruising. Always have.

Carl · Post by **Carl** » May 11th, '22, 14:14

Rawleigh wrote: ↑May 11th, '22, 13:28 My 440's produce a bit of steam when cruising. Always have.

hmm...maybe I need to start condensing my stories as Rawleigh got my vague paragraph into a sentence.
Maybe I should skip the story...

Stephan · Post by **Stephan** » May 11th, '22, 17:04

Carl wrote: ↑May 11th, '22, 14:14 Maybe I should skip the story...

I'm here for the story...

Rawleigh · Post by **Rawleigh** » May 12th, '22, 16:23

Carl wrote: ↑May 11th, '22, 14:14 hmm...maybe I need to start condensing my stories as Rawleigh got my vague paragraph into a sentence.
Maybe I should skip the story...

Wow, i have never been accused of being succinct before! Usually i run towards wordy!! LOL

pschauss · Post by **pschauss** » May 12th, '22, 20:55

Back to my original post: Here is what I found when I pulled the old raw water feed hose out of the bilge. Note the kink in the middle.

I installed a new hose, all one piece, running it over the stringer and under the transmission. I gave it enough slack so that it would sit well clear of the moving prop shaft coupler. I ran the engine long enough to verify that I was getting water flowing through the risers an out of the exhaust.

I still need to run the boat in the bay for a bit to see if I get any improvement in the cooling system.

http://www.ipernity.com/doc/307687/51316924

Tony Meola · Post by **Tony Meola** » May 12th, '22, 21:36

Peter

That is not original. Someone took a short cut and pieced the hose. I wish I remember how mine ran for that engine. If I remember correctly one side went through the engine bed stringer.

Carl · Post by **Carl** » May 13th, '22, 07:29

That 90 fitting is NOT the best way to achieve good flow. Getting rid of it was a good idea.

It looks like the hose ran short and they tried to make the turns too tight kinking the hose...to avoid put a 90. Fix one problem, create another. Long hose runs are not great, but better then kinks and 90's. At the very least it's less work for your pump.

pschauss · Post by **pschauss** » May 13th, '22, 19:40

Here is how I routed the new hose from the strainer over the stringer.

From where the photo leaves off, I have the hose running down to the hull and aft. Then it makes a wide U-turn up toward the raw water pump. The total length of the hose from the strainer to the raw water pump is about 8.5'.

http://www.ipernity.com/doc/307687/51319286

Rawleigh · Post by **Rawleigh** » May 16th, '22, 07:00

Much better! Good job.

pschauss · Post by **pschauss** » May 18th, '22, 16:35

Took her out on the bay for about 45 minutes today. Starboard engine temperature showed 150, port about 140. For the starboard engine that’s 5-10 degrees cooler that before. The water in the bay is still cool so I’ll know more later in the summer. I’m still seeing some steam coming from the starboard exhaust, but the risers on both engines were cool to the touch.

I didn’t have any of the stalling problems that I have had in previous years.

Carl · Post by **Carl** » May 19th, '22, 07:05

Are these saltwater / raw water-cooled motors?

For fresh water-cooled motors ( with heat exchanger, antifreeze) I "believe" (meaning get it verified by someone other than me) the temps should be a good deal warmer...like 180-ish. If I'm right it's time to look at your thermostats.

A prior Stewart may have had cooling issues. Instead of fixing the problems like you have been working on, they may have taken the quick and easy route of pulling, drilling, or changing to cooler thermostats to "workaround" a cooling issue.

If raw water, I again "believe" ( AKA- have infor verified...motor handbook, manual, or a good mechanic) they go with cooler temps to alleviate salt deposits...but even then I think its 170-ish. 140-150 sounds very cool.

SOME Steam "can" be normal...you have 8 cylinders with thousands of controlled explosions going off every minute when running, that create lots of heat, which heats the water used to cool the motors AND the HOT exhaust. That water gets hot and our run from the motors to the transom is a long one in a 31...that gives more time for the hot water and hot gasses to separate some. That is MY thought process on why our 31's can steam more than say a boat with motors closer to the exhaust ports which exhaust and water mix and get pushed right out.

FYI - I am not saying dismiss the steam...just saying it "may" not be an issue. Me, I would feel the exhaust hose in and around the dumps and gong back some...you should be able to comfortably KEEP your hands on them. Top, sides, bottom. If not then you "may" have an issue.

Carl · Post by **Carl** » May 19th, '22, 08:09

....Readers Digest version (remember those???)

You should be working to attain the correct motor operating temperature from idle to WOT...or very close to it with motors in a stock condition. That temp will be in the motor manual for YOUR engine the way it was set up by the company who marinized it.

Exhaust flow should be adequately cooled by water discharge...meaning risers and dumps touchable, exhaust hoses can be warm, but not hot.

Steam Can be an indicator...but you need a baseline of what a normal amount of steam is and not what you think should be normal...if that makes any sense.

pschauss · Post by **pschauss** » May 19th, '22, 21:03

Carl,

Thanks for all of your suggestions.

My engines are fresh water cooled. Risers are cool to the touch after running for 45 minutes. Next time out I will check temperatures further down stream.

Carl · Post by **Carl** » May 20th, '22, 05:58

Peter- I am more concerned about running the motors at such a cool temperature. In MY Non- Professional Opinion, running at 140-150 degrees is not good for the motors. I also believe they run less efficiently when not up to the correct operating temperature.

pschauss · Post by **pschauss** » May 20th, '22, 09:19

Carl,

Thanks. That probably explains why my port engine runs cooler. I will check out my thermostats next week when we get back to New York from visiting our grandchildren in Memphis.

Carl · Post by **Carl** » May 20th, '22, 10:59

First I'd look into what the correct temp is for your motors.

Rawleigh · Post by **Rawleigh** » May 20th, '22, 14:16

If it is freshwater cooled you can use automotive thermostats. I agree with carl that that appears too cool. I remember graphs from Smokey Yunick's Power Secrets that showed an exponential increase in wear as the temperature went down. I would take too cool over too hot, but I like it juusssttt right!

Yannis · Post by **Yannis** » May 20th, '22, 16:04

Rawleigh you have a multifaceted verbal quality that surely doesn't apply only to motors, LOL !!

Rawleigh · Post by **Rawleigh** » May 23rd, '22, 09:41

LOL! Thanks Yannis!

pschauss · Post by **pschauss** » Jun 7th, '22, 13:54

Thanks again for all of the advice.

I replaced the thermostats in both engines with 160-degree thermostats. Both, it turns out, were using 140-degree thermostats. After a 20 minute test in the bay, both engines were running at between 160 and 170.

The thermostat housings on my engines have a brass sleave in them. On my port engine, the thermostat was below the sleave, just above the water jacket in the intake manifold. On my starboard engine, the thermostat was above the sleave, just below the housing cover. Which is correct? I put them back together that way, starboard - above the sleave and port - below the sleave. Engine temperatures on my test run were ok so I am going to leave them as they are unless I see an issue. It was considerably easier to replace the thermostat on the starboard engine.

Carl · Post by **Carl** » Jun 8th, '22, 06:49

Is that what the motors call for thermostat wise? I would have guessed running temps to be in the 180-190 range for fresh water-cooled motors, BUT I base that on my very limited knowledge. In any case, that temp sounds much better than before.

Up down on the thermostat...I think I know which means I do not. Me, I'd look up in the manual. I love those things with pictures to back up the words.

pschauss · Post by **pschauss** » Jun 8th, '22, 08:57

Carl,

The picture in my shop manual seems to show the thermostat on top but it doesn't show the sleeve. My manual covers multiple engines including the Ford and GM V-8s and the picture they show for the V-8 models looks a bit different from mine, however. Just to add to the confusion, I found this diagram online ( https://www.perfprotech.com/mercury-mar ... =8M0089715 ) which appears to show the thermostat UNDER the sleeve. For now, I plan to leave my thermostats where they are, one up and one down, unless I see some issues.

From all my google searches everyone seems to be recommending either 140 or 160 for the thermostat, nothing higher.

Tony Meola · Post by **Tony Meola** » Jun 8th, '22, 20:28

Carl

180 for our cummings work but that is high for a gasser and I think Peters are an older model which would like to run cooler.

Carl · Post by **Carl** » Jun 9th, '22, 06:34

Tony-
As I said, I really don't know and going off what I remember from boats I was on, ran, had. My 440's I believe ran about 185-190 as did my dads. My friends 454's were at least 190...if I recall maybe even higher.

When I was on the old dock, most all of them had 454's. Everyone would toss out different "normals" from burn, cruise, to WOT. I never had 454's so just kinda listened and took it all in. Some I know had little idea what they were talking about, but that didn't stop them talking and providing advice. Others were thinking off the cuff, others guessing and some really knew their sh$t. All good and fun...

Whatever the case I knew where he was seemed really really wrong and in the ballpark now.

pschauss · Post by **pschauss** » Jun 15th, '22, 19:32

Apparently it does not matter whether the thermostat is above or below the sleeve. With the 160 degree thermostats installed, both engines run at 160-170 now.

Carl · Post by **Carl** » Jun 16th, '22, 09:42

Peter, I believe it does make a difference as one end (side) senses and regulates the temperature. I would expect the sensing end faces the direction the hot coolant is coming from, heating the sensing element in the thermostat and telling it to open.

Going the other way that hot coolant has to heat the thermostat and then it has to heat the cooler coolant on the other side of the thermostat to a point where the thermostat starts to open. Then Once it starts to open the hot coolant flows past the sensing end and I'd expect the thermostat would open and work properly from that point on.

If this is how it works...on a real cold day that motor has to get pretty hot to transfer the coolant heat to the other side of the closed thermostat. Or if cool motor is pushed hard before having the time to properly warm up enough to open.

I am guessing here, I am not a mechanic, nor an engineer, I'd hardly say I could make a shade tree mechanic. I just work on my stuff and ask or look up when in doubt....In any case, I think this is worthy of digging a bit deeper.

my .02

Rawleigh · Post by **Rawleigh** » Jun 16th, '22, 11:22

Carl: My take from what he said is that they are both pointed in the right direction, just one above the sleeve and one below. But then you and I are both guessing until Peter clarifies. Rawleigh

Carl · Post by **Carl** » Jun 16th, '22, 12:12

Rawleigh wrote: ↑Jun 16th, '22, 11:22 Carl: My take from what he said is that they are both pointed in the right direction, just one above the sleeve and one below. But then you and I are both guessing until Peter clarifies. Rawleigh

LOL...I feel like an idiot now. I never saw it that way.

Yes, that makes more sense now. If it fits n seal I'd think top or bottom makes little difference....with the same caveats of my mechanical knowledge.

pschauss · Post by **pschauss** » Jun 16th, '22, 15:52

Carl, Rawleigh,

Both thermostats are facing right side up. There isn't enough room between the top of the housing and the cap to put one in facing the wrong way.