Am I overheating?

If you do choose to go with an upper corrugated hose, it has to sort of "S" around from the engine to the upper rad outlet. I was concerned the hose would either droop into the pullies, or lift and rub on the coach floor with pressure and heat changes over time. I ended up taking a large adel clamp, and mounted it to the top bolt on the alternator. I then ran the hose through the clamp with the hose surrounded by a cut and split piece of my old hose, which seems to do a good job isolating and securing it.
 
If you do choose to go with an upper corrugated hose, it has to sort of "S" around from the engine to the upper rad outlet. I was concerned the hose would either droop into the pullies, or lift and rub on the coach floor with pressure and heat changes over time. I ended up taking a large adel clamp, and mounted it to the top bolt on the alternator. I then ran the hose through the clamp with the hose surrounded by a cut and split piece of my old hose, which seems to do a good job isolating and securing it.
March 455 Ultra Mid-Mount.webp

This is the March Racing System that I had Cliff Golby alter by not using the engine driven dash air conditioning compressor and replacing with a second Balmar alternator.
March 455 Dual Alternator.webp

This was my design for the alteration.

So the design meant that there is a new water pump, power steering pump and 2 new Balmar alternators.

In my design, the 12vdc Balmar alternator did not fit exactly in the two mounting holes, so a custom 3 hole bracket was required for the lower right mounting bolt. I still would have to u=install a custom length belt but it would be much closer in length to the "stock" one.


IMG_1616.webpHowever, when Cliff installed it he said that he had to design and build a custom bracket for the new alternator because the cooling waster hose was in the way.

Also, he switched the positions of the two alternators, with the red alternator on the top instead of on the bottom.

I also have a box of parts from the March system that were not installed, including the original belts that were not used.

I also have a brand new, never used engine driven air conditioning compressor. It is a bright shiny aluminum Sanden 7176 compressor.

The bolt to bolt dimensions for the Sanden (5.787") was slightly larger than the Balmar 604-120-K6 alternator (5.470"). The difference in distance is that the Balmar would rotate slightly clockwise by tightening the tensioning turnbuckle by 0.32" or about 5/16".

This would slightly shorten the belt, while the other alternate would lengthen the belt.

Can you spot the differences?

I have often been unhappy with this arrangement. It also means that the longest flat belt has to be longer than the belt that was sized for the Marsh system. Therefore, it is a very odd duck.

I thought that if a 90° hose elbow at the water pump, perhaps the alternator could be moved back into the originally designed position.

The engine is running fine as Cliff installed it.

Should I do anything or should I just let the current installation be?
 
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I too had the issue of the upper radiator hose collapsing. Only happened at higher rpm. Letting it sit idle slowed down the water pump which reduced the suction and allowed the hose to open up again, which made it hard to troubleshoot. Even revving the engine did not do it... It had to be at sustained highway speeds. After a minute or 2 on the highway, it would just slowly start to suck closed.

Typically, only the lower hose will suck closed, and I was already running the reinforced corrugated hose (the one Richard RV mentions above) on my lower so I did not think that was my issue. I only found it by driving around with the hatch off. I too was shooting a non-contact thermometer at parts of the engine and noticed the upper hose was flat.

Switching out the upper hose to the same corrugated design fixed my issue. I think the corrugated hose is a better option than the running a spring inside a stock hose, as the spring is integrated into the corrugated hose and surrounded by rubber. I've seen those springs on the inside of a normal hose corrode, and the pieces get sucked into places they should not be.

I also was running a flow-kooler pump, which I think actually exacerbated the issue as it created more suction when the thermostat was closed.
Where did you source a reinforced hose? I looked on Applied, and they only have the non-reinforced ones (the same that I'm currently running)

I was pretty sure collapsing wasn't my issue because when they are hot I've seen them be "bloated" and under pressure. But the other day I noticed (maybe as colder water flushed in from the radiator), they started to collapse (top and bottom). I suspect the reduced temps caused the pressure to drop. I don't actually know if they were so far collapsed that they were blocking flow. But I'd like to rule that out.
 
Where did you source a reinforced hose? I looked on Applied, and they only have the non-reinforced ones (the same that I'm currently running)

I was pretty sure collapsing wasn't my issue because when they are hot I've seen them be "bloated" and under pressure. But the other day I noticed (maybe as colder water flushed in from the radiator), they started to collapse (top and bottom). I suspect the reduced temps caused the pressure to drop. I don't actually know if they were so far collapsed that they were blocking flow. But I'd like to rule that out.
It would be an easy test just to see if that is your issue... What I did was take the non-reinforced hose to the local auto parts store, and found ones with the same diameter and length.... At least for the upper. The lower came from Applied, but I no longer see it there, either.

I'll see if I can find any part numbers stamped on the hoses I have when I get home.
 
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Where did you source a reinforced hose? I looked on Applied, and they only have the non-reinforced ones (the same that I'm currently running)

I was pretty sure collapsing wasn't my issue because when they are hot I've seen them be "bloated" and under pressure. But the other day I noticed (maybe as colder water flushed in from the radiator), they started to collapse (top and bottom). I suspect the reduced temps caused the pressure to drop. I don't actually know if they were so far collapsed that they were blocking flow. But I'd like to rule that out.
Or you could go the OEM route and use an insert spring to keep the hose from collapsing.

 
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I did a pressure test on the cooling system. I couldn't get a perfect seal on the cap. I sprayed soapy water on everything and got bubbles only at the cap. It's hard to say for sure, but the bubbles seemed to "account for" the very slow pressure loss. Maybe most importantly, I started the engine with the pressure still in the system and it did not spike. In fact it continued to slowly lose pressure just like when the engine was off. I'm hopeful this, along with the compression test, rule out combustion gases entering the coolant system.

Currently I suspect a defect or obstruction in the radiator. I'm going to pull the hoses off the radiator and put springs in them. And while I have them off I'm going to use a garden hose to test that I don't have restricted flow through the radiator.

🤞
 
I did a pressure test on the cooling system. I couldn't get a perfect seal on the cap. I sprayed soapy water on everything and got bubbles only at the cap. It's hard to say for sure, but the bubbles seemed to "account for" the very slow pressure loss. Maybe most importantly, I started the engine with the pressure still in the system and it did not spike. In fact it continued to slowly lose pressure just like when the engine was off. I'm hopeful this, along with the compression test, rule out combustion gases entering the coolant system.

Currently I suspect a defect or obstruction in the radiator. I'm going to pull the hoses off the radiator and put springs in them. And while I have them off I'm going to use a garden hose to test that I don't have restricted flow through the radiator.

🤞
Yeah, the radiator cap is in a real easy to get location, for sure! 🤦🏻

I had the same problem with the parts store loaner kit so I MacGuyvered a workaround. Disconnected reservoir end of the overflow hose, used a Schrader/barb fitting in the end, and used a bike pump. It worked and located the ninja coolant leak.
 
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Update:
I pulled the radiator hoses and hooked up a garden hose to the upper radiator port and verified that I have excellent flow through the radiator. I then replaced the lower radiator hose with the Gates 26616 Flex Tube which has an anti-collapsing spring (and actually just fits better than the "custom" one from Applied). After refilling and burping the system again I'm pleased with the results. I drove around for quite some time and the temps were much more stable. No "run-away" heat events. Temps remained between 210º-220º. With the reinforced lower hose I did notice that the temps drop when the engine is spinning faster, even if its under moderate load— which is what I'd expect, as the pump is moving things around faster. That's not what was happening before, so I think the lower hose collapsing was actually a huge contributing factor after all.

At idle the engine settles to a cool 205º reliably. Love to see that.

Given that the motor is fresh and still in the break in period, I'm babying it— but I did gently "push it" a little to tempt it to over heat, and the heat actually dropped a bit with the extra flow and extra airflow. SO that seems like an excellent result.

220º still seems a bit high, for the very gentle driving I was doing, so I'm still reluctant to declare Mission Accomplished.

I think it's still likely that there's a bit more air in the system that I didn't get out in my first burping session that'll escape as I drive it a bit more.

I think my next step is to run a slightly higher PSI radiator cap (Applied sent me a 7 PSI cap, thought the manual calls for 9PSI) so that I'm not ridding so close to the boiling point during "Normal" driving.

The temps, while maybe slightly high, are not high enough to do damage, so the plan now is to keep a careful eye on it and put some more miles on it. I'm hoping that as I get 100-200 miles on it things will have seated a bit more and there will be less friction and maybe it'll run that 5-10º cooler. 🤞
 
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That's good to hear the hose improved things. That's still hot enough to make me a little uncomfortable, especially this time of year. I'd be worried that summertime mountain climbs would overheat the engine.

I'm running a 195 degree Flowkooler thermostat, and the coach stays VERY close to 195 pretty much all the time. That should be achievable.

If your 7 psi cap hasn't been allowing it to "boil over", then switching to 9 psi will have no effect on cooling. It will raise your boil-over temperature a bit, allowing the engine to reach higher peak temperatures before boiling can help keep it cool for a few moments.
 
That's good news, Kelly. After thinking about a little more, the fact that your engine is really fresh might have something to do with the overheating problem. It will probably get better with a few more miles on it.

I can talk to my mechanic buddy tomorrow and see if he has any suggestions. Do you still want me to see if he can work in a visit from the patient?
 
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That's good news, Kelly. After thinking about a little more, the fact that your engine is really fresh might have something to do with the overheating problem. It will probably get better with a few more miles on it.

I can talk to my mechanic buddy tomorrow and see if he has any suggestions. Do you still want me to see if he can work in a visit from the patient?
Yes please! I'd appreciate that greatly. I'd love to have another, wiser, pair of eyes on it to double check I dont have something wrong.
 
Okay, I talked to Jim, my mechanic friend. He said he could probably get you in after Thanksgiving sometime, but he brought up something that I hadn't even thought of that would explain the problems you are having.

He asked what kind of water pump you have on it and I said it's a high volume pump. He said that on some of those, the impeller can stick out the back too far and contact the cover, actually shearing the impeller off so it is not turning. The pulley will continue to rotate as usual, but the pump is not pumping any wayer. This could be caused by too thin of a gasket or just the wrong pump for the application.

I've never heard of this before, but it explains the whole scenario that you are experiencing. It's kind of a big job to replace the water pump, but I have a feeling that it will fix the problem.
 
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Okay, I talked to Jim, my mechanic friend. He said he could probably get you in after Thanksgiving sometime, but he brought up something that I hadn't even thought of that would explain the problems you are having.

He asked what kind of water pump you have on it and I said it's a high volume pump. He said that on some of those, the impeller can stick out the back too far and contact the cover, actually shearing the impeller off so it is not turning. The pulley will continue to rotate as usual, but the pump is not pumping any wayer. This could be caused by too thin of a gasket or just the wrong pump for the application.

I've never heard of this before, but it explains the whole scenario that you are experiencing. It's kind of a big job to replace the water pump, but I have a feeling that it will fix the problem.
Well I pulled the water pump off because I suspected a blockage in the water ports. The pump looked fine and spun as expected. I actually thought I might have the opposite problem — too much clearance form the plate causing cavitation so I made and effort to put less gasket sealant on this time to get it closer to the plate. It didn't have any effect.