Thermostats

[chamoale2k]

Ive got a 6bt5.9m3 cummins I know its not the best thing to do but has anyone ran one without the thermostat? Any issues?

Topic

[Tony Athens]

IR Gun Temperature Check

Surface temps on coolant cooled castings on the engine will always be less than the “coolant temps” inside… Plus, much of what you measure depends on the color of the surface, and the angle and distance you are away with the “red dot”..

Tony

[chamoale2k]

Exhaust temp

Tony the ” exhaust temps” i am referering to would be the exhaust manifold temperatures. I used an infared heat gun to measure the manifold temperatures while running the boat on a seatrial. Was wondering what the exhaust manifold temperatures should be on a 6bta .

[Tony Athens]

I have no clue what you me by “exhaust temp”.. Exactly what are you measuring, how you are doing it, and where is it taken?

Tony

[chamoale2k]

Next step

Tony, I was able to do to engine flushes with the restore plus. Ran clean water through the engine draine it then refilled with prestone 50/50 antifreeze. Took the boat out this morning slowly working up the Rpms the water pump was replaced the new 160 degree thermostats installed. The engine temperature never went above 145 the exhaust temps at trolling the exhaust temps never went over 160. My question ow is what should the exhaust temp be at 2800 rpm? My readings were around 186.

[donald roth]

Even after flushing and cleaning, you may still have bits of rubbish lurking in the coolant passages. I’d try to add an inline strainer to collect any remaining junk, possibly a Y strainer with hose barbs attached.
Good job on locating the problem, used motors are like a box of chocolates!

[chamoale2k]

Thanks for the info flushed the engine cooling passages already next step is to run the restore throught it.

[chamoale2k]

Tony, I whole heartedly agree never let one get in that condition. I kinda inherated this one did the swap out then started finding all of the issues. Thanks for the inputs I’ll let you know how it turns out. So far it seems the engine did not suffer an overheat it was just the restricted flow through the exhaust manifold.I ran it in gear dockside up to 1k rpm and used a heat gun to monitor the temperatures engine stayed around 125 to 150 but the exhaust went up to low 200s. Thats what had me digging into the exhaust piping
I did back flush everything with about 60 psi water hose till I got clear water out the waterpump cavity.

1 user thanked author for this post.

Bob Patterson

[David Amble]

Restore Plus

I have used both Restore and Restore Plus; one is alkaline, the other acid. Attached is a brochure that may help but I would suggest you need Restore Plus.
As Tony mentioned, you need to wash out all of the passages, etc to get rid of that excessive build up of crud to ensure good circulation of the flushing liquid for it to work effectively.

[Tony Athens]

No direct experience, but I’d guess it works as is says if you follow the instructions.. The long term here it to never neglect an engine in low hour marine service to ever need a product like this…All of these types of products were developed around much larger wet linered diesel engines in truck and off-road construction equipment that run 1000’s of hours per year.. …

Tony

[chamoale2k]

Tony have you ever used the fleetguard Restore Plus?

[Tony Athens]

Never in the 30+ yrs have I seen any B series engine engine clog there.. You need to “wash out” the block, HX, X-tank etc etc, some how..

This is beyond a “descaler”

Tony

[chamoale2k]

Thanks Tony ordered a new thermostat from you yesterday planning on installint it and a new pump after I run some descaler thru the engine.

[Tony Athens]

POST GOOD PICS of your engine and the clogged fitting location.

Do your have a early 6BT/6BTA ?

Regardless of all else, YOU DO NOT want to remove the thermostat from any B series engine–That is IPPSO-FACTO………

If you want superior flow, use our High Flow 160……….. Took years to develop & test..

Tony

[chamoale2k]

Follow up start with a summary of events. Last week attempted a seatrial ,as soon as I started giving some throtle (1000) rpm the exhaust manifold started to smoke shutdown the engine then coolant started to spew from expansion tank cap. Yesterday we simulated at the dock in gear 1k rpm exhaust manifol temps got into the 200* f plus range. Today removed the circulating pump it didnt look bad then I pulled the 1 in line from the exhaust manifold to the circulating pump elbow. Dang thing was plugged. Hooked up water hose back flushed through the manifold through the block ang out the circulating pump cavity. Wont be able to get new circulating pump till tomorrow fingers crossed!

[chamoale2k]

Interesting read. Im heading to my boat going to remove coolant pump and inspect it and the internals might even run a water hose through some of the hoses to back flush the engine and see what happens.

[Clark Leighs]

I wrote a tome for situations like this. There is a lot more to the cooling system than you have covered.

Of course it may not cover everything but have a look.

1 user thanked author for this post.

Rob Schepis

[chamoale2k]

6bt overheats

My 6bt overheats when I put it in gear after maybe 15 minutes running at 1000 rpm. I can run it all day in neutral at any rpm and the temps fine. My buddies that also have 6 bts keep sayin take the t stats out it will be fine so I did but the problems still there. Raw water pump impeller was just changed and it seems I have plenty of flow through that part of the system. I ccleaned the after cooler, trans oil cooler and inspected the heat exchanger. Next step is what I wanted to do while I had the coolant drained and thats to remove inspect and replace the coolant water pump. Any other thoughts would be greatly appreciated. Oh and Tony do you have 165* t stats?

[Clark Leighs]

Some engines can actually be overheated by not using a thermostat. As the stat opens or closes it forces water to go go where needed, back to the engine or to the heat exchanger, to maintain the minimum temp.

Otherwise the water will go wherever it is easiest to go, not where necessary.

Now to be clear I don’t know about your engine in particular but if you try that be very carefull you do not suffer an overheat.

[David Wesner]

why?

What are trying to accomplish? The engine will never get warm and I suspect will have lower efficiency and increased wear. I don’t believe the cummins B is designed like my volvo thermostat housing. In the volvo, removing the thermostat would not allow coolant to be directed to the heat exchanger. It opened one passage and closed another. But, like I said the cummins is not this way.

D

[Author]

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