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TAMD40 tempearature question

S

stringer_bell

Regular Contributor
"For the last 4 months I have

"For the last 4 months I have been running a 26ft charter boat (scuba) with TAMD40A. Engine has thru-hull exhaust, and raw water pickup from the grate in the hull. Run great with no smoke, fresh oil and filters. With Morten's advice i was able to get the correct prop for it (16x15) and have been very busy lately, with more and more passengers. I have noticed lately that when I fully load up the boat (with about 2000 lbs of people/tanks/gear), i lose some top speed (as expected) and i also run approx 25F hotter (expected as well??).

Empty boat (just me and full tank) 175F @ cruise RPM
Full boat (me, full tank, + 2000lbs) 205F @ cruise RPM

I run continuously @ cruise for approx 45min to an hour to my furthest dive spot. Temperature reading is always solid and steady, and gauge doesnt fluctuate. It never got above 205F (~95C).

Is this normal for the boat to run approx 25F/30F hotter when loaded down?

Thanks!"
 
"If temp is stable and does no

"If temp is stable and does not continue to climb I would not worry.
If Your cruising RPM is the same with boat empty or loaded, the engine will run with a higher throttle (fuel delivery) setting when boat is loaded."
 
"Thanks Morten. Yes temperatur

"Thanks Morten. Yes temperature is very stable and does not climb past 205F no matter how long I run it loaded.

I was thinking about using some additive in the coolant (like Reline WaterWetter) to help lower temperature some? I have cleaned the raw water intake grate, and will keep an eye on coolant too, going to flush it with new fluid in about 30 hours @ next oil change."
 
"Two things are important and

"Two things are important and often left a bit behind.
Oil takes about 30% of the total cooling, so keep oil-cooler clean and use a high grade oil. Next is air, both temp and 'volume'. Be sure the engine gets plenty of air, and if possible not from transom mount intake as that will even include quite some water mist that clogs up the air filter."
 
"I switched back to the OEM Vo

"I switched back to the OEM Volvo 16x15 prop (was fouled up, and went to the shop for reconditioning), and now temp is 195F @ cruise when loaded.

I am at about 90 hours of run time, so oil change is coming up in few hours. I found a small leak under the turbo compressor plastic intake pipe (looks like oil return line gasket or something?), and another small leak at the raw water pump (and I put a brand new seal in there??), gotta fix those.

As for the air supply, my engine doesnt really have any direct air ducts bringing fresh air to the intake filter. I am debating cutting a hole in the engine cover in the intake corner and installing a stainless vent, to allow as-fresh-as-posslible-air to the motor.

Have another question. My ocean access is thru Boynton Inlet (please watch the video: http://www.youtube.com/watch?v=XUOsgXg7Gwg). Its like whitewater rapids in there during incoming/outgoing tides....18ft fixed bridge, and some 130ft wide...tight fit. Sometimes when making a sharp turn (when entering inlet, and while in the inlet's turbulent water), or when in quartering following seas, or when crossing another boats wake (while both boats are going in the same direction), I feel the prop spin more freely and bump up revs approx 100-300rpm. Kind of like catching some propwash aerated water. Makes the boat dig in back, and throws me off the plane. I dont remember the boat doing that before, so I was kinda concerned that it might have something to do with the outdrive (280SP).

Thanks in advance as always."
 
"That temp goes down at less e

"That temp goes down at less engine load is normal. Having had a peak at the video, I understand that your prop may do a spin out from time to time. You may probably have to cup it to reduce that effect."
 
"Today 3 passengers temp 180F

"Today 3 passengers temp 180F
Yesterday 5 passengers temp 195F

Temp stayed steady. I am dumb for leaving that generic spare prop on there for so long....now i finally realize how crucial is the OEM oversize blade design.

I am getting prop spin out sometimes when just driving up the calm intracoastal, with no boat traffic around. Very weird, I do not remember ever getting it before unless it was in turbulent water or i drop back from a wave and choke out the prop.

This happened with two separate propellers, which makes me think its not the prop hub that is spun. There is no rule to it, it powers nice and strong thru the inlet, and then spins out when cruising up the intracoastal. Any idea what might be causing it? It almost never happens below 3000rpm, and is happened handful of times for no apparent reason @ 3200pm or so.

Outdrive fully serviced 100 hours ago, with new fluid, all correct washers and specs, and pressure tested.

Thanks in advance!"
 
"As for the prop 'spin out

"As for the prop 'spin out'.
What is happening, is most likely that the prop is beginning to loose its blade profile. Almost normal for alu-props of that dia on a diesel with that torque. The blades simply 'bends' and looses shape over time. When you get your Volvo 'Mikey Mouse' prop back, send the spare to the shop and have it checked out. At the same time ask them to make a 'soft' cup.
As for the temp, it seems to be under control. As a double security and check, you may install another temp instrument with the sensor at the raw water output from heat exchanger. If that starts peaking up, you know you are heading into a raw water problem. You may just use a contact sensor as used on outboard on the water tube."
 
"Morton,

Do you have any 40

"Morton,

Do you have any 40b parts? I am looking to cxhange out tmd40b to a tamd40b. I need the oil cooler and the piping. I can give you the part numbers if you need them"
 
"I actually just found complet

"I actually just found complete running TAMD41P-A at a great price, and am preparing the boat for the swap
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"Can't wait!!!

Currentl

"Can't wait!!!

Currently I have 280 SP drive. Electro/mechanic tilt. 41P-A has the aftercooler pipe in the same location it seems...what are my options (what needs modified) to install 41P-A and keep the 280 drive with the tilt?? I also have 290 DP-S drive but need to get boat back in the water quickly (for work) and would rather keep it simple and use 280 SP drive thats already on the boat....280SP shaft is big and sturdy, what I need for commercial use.

Thanks for your advice!
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"Should be a rather straight &

"Should be a rather straight 'bolt-on' conversion.
Personally I prefer to remove the drive and lift out engine with bell housing, to avoid bending shafts.
One 'problem' that might arise is cooling as You will be on the limit if using drive for supply.
Might thing of a 'big' through hull pick up.
The 41 'eats' airfilters, I used to throw them away and use a 'mosquito' net instead."
 
"I have to remove the drive to

"I have to remove the drive to replace the bellows (have some water intrusion, and starter is getting water sprayed onto its shaft inside bellhousing), so engine will be lifted with the drive off. Boat is already setup for thru-hull pickup for water, and transom exhaust (nothing goes through the drive).

The aftercooler pipe that connects it to compressor turbo side seems to sit exactly in the same position as where my current tilt microswitch box is situated....hopefully it clears so I can keep the current outdrive

I saw how small the filter is....going to replace it with mosquito net as well"
 
"If the 'black box' fo

"If the 'black box' for the tilt makes a problem, I have in some occasions 'moved' the content to a bracket on the transom to make better space.
Don't let minor problems spoil your day!"
 
"Since 41P is not ready for in

"Since 41P is not ready for installation yet, i removed the TAMD40A out of the boat, serviced the drive and replaced the bellows (torn), and all the bearings/seals, including the rear main seal. I also cleaned the bronze intake grate (thru hull) for raw water, it was partially plugged up with coral growth. I was very excited and expected the motor to run MUCH cooler than before. Put everything back together, and went for a test run. Started it, noticed that raw water impeller housing cover was warmer than normal, shut it off and replaced the impeller (one blade was broken, and I removed old impeller and also found and removed broken blade). Now cover is cool to the touch. During the run, it was just me on the boat, and temp climbed to 200F in under 2 minutes of cruising at 3000rpm!
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It used to take 20-30min of cruising for temp to slowly climb towards 200F. Temperature was also VERY slow to go back down, where it normally used to fall back to 150F as soon as I would come down to idle speed. Right now even at idle temp stays in 170-180F range.
Radiator cap had alot of pressure under it, and it coughed up some coolant when I carefully opened it. I also have a wooden wedge behind the end cap on the HE.

I dont have the IR heat gun to check temps in various places on the motor, can anyone suggest where to start looking? Thanks in advance!!!
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My guess is air lock... try to

My guess is air lock... try to purge system of air and refill and try again with another run.
 
"200F (93C) OK, 210 a

"200F (93C) OK, 210 a bit too high at full load.
175F (80C) at idle perfect as well!!
Note that this engine has 2 thermostats with DIFFERENT opening temps. One to control at idle, the other for high speed. They work in parallel however in the same system. Running in extreme hot water, you may change both to the lower type, but it might increase smoke.
How was performance?"
 
"Morten, there was no performa

"Morten, there was no performance, it would overheat in 2 minutes and I was unable to run the boat further than that. I could literally watch the temp gauge move up quickly to over 200f and throw temp alarm. Coolant was boiling. I think its either air lock or major blockage in raw water system....I will try to test and eliminate possible causes one by one starting with intake graten to the exhaust elbow. It was running warm beforte but nothing rediculously hot like this.

Thanks for suggestions. Is port or starboard thermostat the one with higher temp opening? Would removing thermostat or both help any?"
 
"Firstly an IR gun is close to

"Firstly an IR gun is close to a must in this case, as it gives you the possibility to monitor the raw water temp out of the exchanger. If that keeps climbing, you have a raw water problem.
It does not matter if it is stb or port thermostat which is the lower/higher one as they are in parallel. You have to remove and read the specs on them. They are probably stamped in C degrees, but do not remove them.
Double check the venting line from turbo to tank. The banjo bolts have a tendency of clogging up in the small holes and not vent out properly.
Do you still have the exhaust brake/solenoid with the flapper in the exhaust outlet?"
 
"I don't think I have exha

"I don't think I have exhaust brake flap, its just the elbow after the turbo and then some simple piping to the transom rubber flap. I will buy ir gun asap. Will not remove thermostats. Has to be air lock or something clogged bad....maybe exhaust elbow? I will vent at turbo coolant banjo first see what that does....tnx"
 
"Went in and double checked th

"Went in and double checked the 41P cooling.
It seems they have changed the thermostats to 2 equal, 81C which gives about 178F. At least your idle temp is perfect.
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"The turbo ventilation hose I

"The turbo ventilation hose I talked about earlier is the #20/21. It might be some different versions out.
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"Not sure how engine removal c

"Not sure how engine removal could create air lock in coolant side, that system remained closed....is there air lock possibility in raw water and how do I vent that?"
 
The whole cooling 'problem

The whole cooling 'problem' both on this engine and the previous one might be related to your through hull water intake.
Where is it located?
Do you have a pick?
If possible run a clear plastic hose between intake and filter/pump and see if any air bubbles appears.
 
"Morten these problems are on

"Morten these problems are on my old tamd40a not on 41p. 41 is not ready for swap yet, gotta service the 290dp first.
My idle temp used to be 150f"
 
"The 40A had the different the

"The 40A had the different thermostats, 70C and 76C.
My guess is that one of the thermostats are hanging, not opening.
Is below pick relevant?
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"Yes, that looks exactly as my

"Yes, that looks exactly as my system on 40A.

Thru-hull pickup is 3" x 8" brass grate, i cleaned it really nice. New impeller. No leaks of coolant or raw water.

I will start checking things out in the morning, and will report back. Thanks for your help and ideas"
 
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