4BT getting warm.

[Shannon Ritzert]

I was wondering if I could pick some brains on an issue that I am struggling to find.

I recently finished refurbishing my Bertram 28 FBC. I have twin Cummins 4BT’s 150H.P. My starboard engine under a load is consistently operating at about 195-200 degrees. I had posted in here before about my other (Port) engine having overheating issues, but I have since worked those out per Tony’s instruction. The one thing I have not done is install the 6BT expansion tanks, and that’s simply because I don’t know how I am going to fit them in the engine compartment.

Here is what has been done, and this is both engines.

New raw pumps
New hoses
Flushed and acid dipped, cleaned expansions tanks, heat exchangers, and pipe that runs from raw pump to transmission cooler. I have new transmission coolers that have not been installed yet, but that will be done when I pull the boat back out for service next spring.
New 160 high flow t-stats.
New expansion tank “radiator” caps
New overflow tanks.
New gauges
New temp senders
Redundant temperature alarm
There’s not much on the cooling systems that have not been replaced, or pulled down, cleaned and inspected.

The back 3 exhaust ports at 2200 RPM thermal out at 350-375 degrees, where the front port, and all 4 ports on the other engine thermal out at 245-265 degrees. I was wondering if this issue was due to bad injectors on those 3 cylinders. I had a set of injectors, so I went ahead and replaced them. I figured it wouldn’t hurt anyway, and I will send the other off to have them remanned. this did not help my issue either. I am going to check the antifreeze for exhaust gas tomorrow, but I may be peeing up a rope with that idea.

I don’t know if this helps with ideas, but this boat was pulled out of the water in fall of 2019 for refurbish, and was not ran at all until April of this year, and that was on a hose with no load. It was not put back in the water until about 4 weeks ago.

Any ideas on which direction to go? What am I missing? This just has me completely baffled

Topic

[Shannon Ritzert]

I was thinking along your lines on the boat having prop issues. I dinged the port prop when I was testing for the overheat issue. I was telling my business partner that my thoughts on the egt on that engine is the prop ding, and that engine is overworking. When I say ding, I mean one blade tip was slightly curled. My background is tournament inboard ski/wake/surf boats. In our field, a prop will look perfect, but the slightest un-seeable bend will cause a buzz.

I’ll run her up to WOT when I’m back down in a few weeks, and see what we get.

[Francis Valerio]

We have the same boat BUT mine is the 1st year of the B28 (1971) and the hull thickness could make my boat heavier than yours. It is possible “from what I heard” they were afraid of fiberglass in the early days and layed less on as the years went by.

My gut tells me you are overpropped but we will not know unless you run the engines up and check the WOT / “showering down”. Only for 20 seconds to see what she has got.

These engines are tempermental about being overpropped….ASK ME HOW I KNOW?

You high EGTs are a sign of possible overloading / overpropping

I can maintain plane at 2200 but nd a bit more to get on plane

You WOT RPM will tell us what we need to know

[Shannon Ritzert]

Showering down I guess is country boy slang for throttling up pretty hard. lol.

I got her to the coast over the weekend. The hardest I ran her was about 2250-2300 rpm fully fueled, all fishing gear, 5 average size people. That RPM range gets me 20-21 mph. She seams to plane about 2200 rpm. I am uncomfortable running her harder than that at the moment.

The port engine was running a little hot on egt in my opinion about 1000 degrees. The starboard engine was about 900 degrees. I also developed an oil leak on the port engine that I am having a issue finding. Ill be back down on the coast on the 14th, and I will see what I can figure out there.

[Francis Valerio]

@ the smoke coming off WOT to Idle

I always come down incrementally when I am at high idle speed or WOT. That is just how I do it. When you say “shower down” I am not familiar with that term so I am not sure what you mean (sorry my ignorance).

When I say incrementally, I mean that I come down 200-330 RPM for a moment and then another 200-300RPM momentarily until I am where I want to be and I usually do the same when I bring it up till I get to about 2000rpm and then I will bring it up quick to get over the hump…

What numbers are you pulling with your boat?

My cruise speed at 2500RPM is about 18.5MPH or 16 knots.

I am underpropped slightly but would rather not work the engines so hard and I hit 2950RPM easily

[Shannon Ritzert]

second set

[Shannon Ritzert]

Trying pictures

[Shannon Ritzert]

Try this again:

I went out Friday, and drained all coolant, inspected every port, hose, etc. I put in another new set of thermostats, inspected both heat exchangers, expansion tanks. I wanted to leave no stone unturned. I found no blockage, coolant was super clean too. I did not pull the turbo and inspect that yet. I don’t have the gaskets to do the job, but I will order gaskets today and check it out for peace of mind.

I took photos of the gauges at idle in neutral, and at idle in gear, and underway at various RPM. I did notice my pyrometers aren’t exactly in sinc with each other. I don’t know if that’s something to be concerned with, as they do sinc up at cruising speed.

As you can see from the pictures, the temperatures pretty much mirror each other now. I cant say that I am 100% confident though, as I don’t know what changed other that the T-stats. I am going out today to put a couple hours on it, and see what happens.

Keep in mind, right now my boat is pretty empty on weight. 1/4 tank of fuel, and my whole 155 lb self. I only ran it up once for about 10-15 seconds WOT with myself and 2 other guys in it. I do not recall the RPM, and speed. It was not a concern of mine since I knew it wasn’t loaded.

I like how you did your tanks. I may have the room for that. My engines do look like they sit up higher than yours though. I was thinkin I would have to hook the remote tank to the thermostat housing, and back to the heat exchanger, and I couldn’t see making that happen. I see you tied your thermostat housing to your heat exchanger, and just ran the 1/4 inch hoses to your remote, that’s totally doable.

Something I have not noticed before, but I think I am being hypercritical of everything now. When you shower down on either engine, they both puff black smoke out the exhaust. This is in neutral, from idle, to WOT. The starboard engine, the one that was giving me overheat issues, has a very small amount of white smoke though.

The port engine WOT in neutral is 3146 rpm. The starboard same condition is 3148 RPM

Sorry I didn’t reply on the CAV pump timing the other day. I have not removed the pumps, but as you mentioned, that’s not to say it is not out of time.

[Francis Valerio]

Shannon
you mentioned on your other thread that your pump is leaking. I am sorry but which pump is leaking?

The fuel pump

The water pump

The raw water pump

[Shannon Ritzert]

I know, I tried twice to post, and I figured since I added pictures, they had to go through moderation. I will try again Sunday, I’m on a road trip now

[Francis Valerio]

Shannon for some reason your reply is not showing up in this thread. can you re post it?

[Shannon Ritzert]

I went out yesterday, and drained all coolant, inspected every port, hose, etc. I put in another new set of thermostats, inspected both heat exchangers, expansion tanks. I wanted to leave no stone unturned. I found no blockage, coolant was super clean too. I did not pull the turbo and inspect that yet. I don’t have the gaskets to do the job, but I will order gaskets today and check it out for peace of mind.

I took photos of the gauges at idle in neutral, and at idle in gear, and underway at various RPM. I did notice my pyrometers aren’t exactly in sinc with each other. I don’t know if that’s something to be concerned with, as they do sinc up at cruising speed.

As you can see from the pictures, the temperatures pretty much mirror each other now. I cant say that I am 100% confident though, as I don’t know what changed other that the T-stats. I am going out today to put a couple hours on it, and see what happens.

Keep in mind, right now my boat is pretty empty on weight. 1/4 tank of fuel, and my whole 155 lb self. I only ran it up once for about 10-15 seconds WOT with myself and 2 other guys in it. I do not recall the RPM, and speed. It was not a concern of mine since I knew it wasn’t loaded.

I like how you did your tanks. I may have the room for that. My engines do look like they sit up higher than yours though. I was thinkin I would have to hook the remote tank to the thermostat housing, and back to the heat exchanger, and I couldn’t see making that happen. I see you tied your thermostat housing to your heat exchanger, and just ran the 1/4 inch hoses to your remote, that’s totally doable.

Something I have not noticed before, but I think I am being hypercritical of everything now. When you shower down on either engine, they both puff black smoke out the exhaust. This is in neutral, from idle, to WOT. The starboard engine, the one that was giving me overheat issues, has a very small amount of white smoke though.

The port engine WOT in neutral is 3146 rpm. The starboard same condition is 3148 RPM

Sorry I didn’t reply on the CAV pump timing the other day. I have not removed the pumps, but as you mentioned, that’s not to say it is not out of time.

[Francis Valerio]

Here are a few pics of the remote tank. It needs to be up high. My hatch covers are raised about 5 inches.
I included pics of the manifold cap and the turbo/manifold gaskets that you could check for clogging or scaling

[Francis Valerio]

One other thing, if needed you can drain the coolant and inspect every fitting and elbow that the coolant passes through. The original fittings and barbs are steel and cast. These fittings can be scaled-up and restrict the flow of coolant.

There are pictures you can reference on this website in the coolant upgrades section for the 6BT. Same applies to the 4BT

I would also pull the turbo to exhaust manifold fitting and look at the gasket and holes for blockages and scaling and the same goes for the fitting on the other end of the exhaust manifold and cap. That one is important also because coolant flows thru a small elbow from there. Both of these should be checked if you have not already

FV

[Francis Valerio]

I will get some pictures later today. I know another person who also has a 28 Bertram / 4BT 150 setup as well. I noticed that his engines are about 5 inches more forward than mine but I think he is running different transmission. I have ZF45A transmissions and they are very short.
The point is that I may have room for the remote tanks that others may not.

What RPMs do you get in “neutral” at the dock when you go WOT?

What RPMs can you attain when you are driving the boat?

Those 2 questions do not apply to your running warm issue.

Are you 100% sure your gauges are reading correctly (possibly a wrong sending unit for the gauge???) Can you verify with an infrared thermometer pointed at the sender to verify temperature .

Much of this is redundant talk but it dont ever hurt to ask and ask again…

Again, I will ask you about the timing of the CAV fuel pump?
Does one engine smoke more or less than the other one?
Do the engines feel equal in power at all RPM ranges?

Timing is not easy to actually check on a diesel like this. It is however, easy to see if it is lined up on the timing mark. (is a line on the timing cover)
The timing mark on the timing cover is original to the original equipped CAV pump. A replacement pump (any time in the motors life) could be slightly off with a replacement pump.

I am pretty sure about that (about the timing mark) BUT if I am misstating I would appreciate if I need to be corrected since I am not 100% sure.

Timing can affect the temperature.

[Shannon Ritzert]

Hey Francis, I appreciate the reply.

I have actually looked at quite a few of your posts since we have the same boat. I have yet to have mine in the Gulf. I have it at the lake down the road from my shop trying to work out all the bugs. Hopefully I will have it at its new home the first of August, pending working out this issue.

The problem is happening at cruising speeds. At idle it runs a few 2-5 degrees warmer than the other engine. The higher the RPM, the bigger the gap between the two engines. I could probably run at 1800 RPM all day long and never “overheat”

I am 100% sure there are no restrictions on the raw water side of the cooling system. I have removed and inspected every hose. I thought the same thing initially. I have removed every joint and observed sea water coming from each hose, and obviously the exhaust port shows plenty of water being exhausted. I know there’s a unit of measure for these raw pumps. It has been a long time since I have read the Sherwood manual, but I am confident there’s plenty of water. Visually looking, it actually looks like more water is coming out of the overheat engine exhaust than the run cooling fine. One thing a friend of mine seems to think, is the exhaust water is actually cooler on the overheat side. This led me to think maybe I missed something in the heat exchanger, so I pulled it back down and inspected it, but no problems.

All sea cocks, and strainers have been cleaned or replaced accordingly as part of the refurbish. 100% restriction free.

On a side note, I had an engine once that would only overheat above 3500 RPM (gas engine). The problem ended up being to many elbows in the cooling system.

Anyway, I just got new T-Stats in from SBMAR, and I am about to replace them again, I’m hoping for a bad T-Stat out of the box. I have been in the marine service business since 1992, and have only replaced a handful of actual bad T-Stats, and a majority of those were under warranty bad production run, so needless to say I am skeptical.

I am considering running overhead on the engine to see if that helps. I just don’t know if that would help. I do not have much experience in diesel engines.

When you have time, I’d like to see how you put your remote expansion tanks in. I would like to do this upgrade soon myself.

I appreciate the help

[Francis Valerio]

I have the same boat and same engines.

Is this problem happening when you are cruising? Just to be clear this is happening when you use the boat not just idling at the dock correct?

I installed remote expansion tanks which was a help in the room department.

How is the timing mark on thew CAV Injector pump? Timing not correct “can” cause the motor to run hot. Was the CAV pump rebuilt recently (hours -wise)

Are you 100% sure that you have no restriction on the raw water intake…many times when there is a cooling issue and everything else checks out OK this is where the problem just might reside…
There could be some blockage in the strainer or in the valve itself. I would confirm this first to be honest with you.

I had an old gate valve that was not fully open and I did not realize it and it solved my running hot issue and then I replaced them with sea-cocks.

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