Intake manifold temperature

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Intake manifold temperature

July 30, 2010, 11:52:47 pm

I started monitoring this on the advice of the Silverleaf VMSpc24 manual. It states that this parameter is a good early warning indicator of engine overheating. I have the ISL400 engine and this parameter typically runs about 110 degrees in moderate temps. Today we drove about 350 miles across NE Oregon and southern Idaho and the air temp was in the high 90s. The manifold temp got up to 128 at times, but usually ran about 115-120. Does anyone have any experience with this parameter and if so, what is to be made of these values.

Thanks in advance

Re: Intake manifold temperature

Reply #1 – July 31, 2010, 12:24:56 am

George,

Somewhere in my VMSpc manual I read where it is good to wait until the engine intake manifold temperature is no more than 40 degrees above ambient before shutting the engine down. With that in mind I would think that temperatures below 130 would be just fine with ambient in the high 90s.

Of course you now know everything that I know about intake manafold temperature maybe you should keep researching.

Paul
36' 2000 U320

Re: Intake manifold temperature

Reply #2 – July 31, 2010, 08:47:38 am

I can not say on my ISC since I did not have Silverleaf but on my M11 I rarely if ever get that high. The highest I have seen is about 110-115.

Re: Intake manifold temperature

Reply #3 – July 31, 2010, 09:13:32 am

George,

Don't worry about intake temperature. It's exhaust temp that you should worry about. Does your system give you that? You should wait until exhaust temp before the turbo reaches 350 degrees before shutting down (300 after turbo) and not exceed 1200 running.

Re: Intake manifold temperature

Reply #4 – July 31, 2010, 09:36:32 am

Hello All;
I have a VMSpc and would like to add a pyrometer to it. Silver leaf said that was not available. I am now looking for a standard pyrometer with a 50 foot lead wire(at a good price). Then comes the problem of where to install the thermocouple ,,
"before" or "after" the turbo,,,
"before" gives the best reading at the risk of damage to the turbo,,,,
"after" gives a relative lower reading due to the cooling effect of the turbo
I have looked at Banks and Isspro,,,Isspro being the best choice altho more expensive
any comments will be welcome,,thanks Gary

Re: Intake manifold temperature

Reply #5 – July 31, 2010, 11:09:31 am

Quote from: amos.harrison – July 31, 2010, 09:13:32 am

George,

Don't worry about intake temperature. It's exhaust temp that you should worry about. Does your system give you that? You should wait until exhaust temp before the turbo reaches 350 degrees before shutting down (300 after turbo) and not exceed 1200 running.

Yes, exhaust temperature IS important to engine life, particularly if you have modified the engine (i.e. are over fueling/over boosting).

BUT, intake temperature is also important. Monitoring intake temperature gives you a good indication of when it is time to clean your CAC (Charge Air Cooler-- aka inter-cooler and after-cooler). 20 degrees above ambient is fairly normal. Above that (except on steep grades where you are really working the engine) and you should clean the CAC to allow more air flow. Sure, other (read more expensive) things can cause issues here, but the most common, easiest to correct and least expensive is to clean the CAC and radiator.

Brett Wolfe

Re: Intake manifold temperature

Reply #6 – July 31, 2010, 11:33:12 am

Hi George and Others, I had the attached article about turbo chargers filed away, so I thought I would share it with you..
http://www.bankspower.com/techarticles/show/25-why-egt-is-important
After reviewing the original post this may be off topic and could be moved if the moderator would like to do that.. GRV

Re: Intake manifold temperature

Reply #7 – July 31, 2010, 02:22:39 pm

I added an EGT from Banks, ( http://www.bankspower.com/products/show/150/51 )which can be ordered with a 50' thermocouple lead. I installed it after the turbo on the advice of several trucker friends and Cummins. I welded the threaded bung directly into the exhaust pipe in place with no trouble (access from under the bed.) You could also remove the pipe before welding, but there is plenty of clearance on top of our engine / our year.

With the thermocouple probe after the turbo, Cummins said that the temp to not exceed is 1100F (1400F before the turbo), so I try to keep it below 1000F. I watch the temp when I pull in somewhere and let the engine run until it's below 350F before I shut it off. As several have noted, just the drive down the exit ramp and entry to a truck stop is enough to cool down the turbo.

Re: Intake manifold temperature

Reply #8 – August 02, 2010, 06:50:58 pm

Thanks for all the information! We were in a park in Ely, NV where the WiFi was out because of a lightening strike... thankfully before we got there. I kept a close eye on the Inlet Manifold Temps today on the way down to Boulder City, NV from Ely (nice drive by the way). It was hot (90-103) and the IMT ranged from 16 above ambient (low to no load) to 27 degrees above ambient pulling hills. This parameter seems to be a good addition to the Silverleaf screen, especially when shutting down.

Those exhaust temps cited explain why some of those plastic washers holding the thermal blanket (on the surface above the engine) have melted. I think nylon melts about 450 degrees.

Re: Intake manifold temperature

Reply #9 – August 02, 2010, 10:11:12 pm

It's easy to install a pyrometer probe in the exhaust manifold. Just put some grease on your drill bits and thread tap, then check for any loose chips with a magnet. Any little particles you miss will go right out the exhaust without causing any problems.

Re: Intake manifold temperature

Reply #10 – August 02, 2010, 10:56:10 pm

Brett;
Thanks for the info. Banks has a instruction page online,also. I wonder if it would be wiser to install after the turbo in case the thermocouple fails or rots off. It probably would never happen BUT....and "after the turbo" would be a much easier install.

Re: Intake manifold temperature

Reply #11 – August 03, 2010, 12:19:48 am

Quote from: Dave M – July 31, 2010, 12:50:21 pm

The exhaust temp on my ISM, using the VMSpc is a calculated number, not actual measurement of temp. The VMSpc provides a lot of numbers all from calculations, like HP, Torque, Manifold Temp, Exhaust Temp etc. Not actual meqsurements, just high class guessing derived from the engine you entered into the initial setup, throttle position, rpm and mph.
Silverleaf does a great job with their numbers. I have been very happy with the fuel burn numbers they have worked out, very close to fact.
Temp for Trans and engine, oil pressure are actual real time values.
Dave

Dave,

Where in the VMSpc gauge menu did you find exhaust temp?

Re: Intake manifold temperature

Reply #12 – August 03, 2010, 06:14:53 am

Gary,

These thermocouples are very robust. I've never heard of one "breaking off". I've personally had them last 12 years and 250,000 miles.

Re: Intake manifold temperature

Reply #13 – August 03, 2010, 12:27:57 pm

Hi all.
I am curious like George is, "Where in the VMSpc gauge menu did you find exhaust temp?"
Thanks

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Intake manifold temperature

July 30, 2010, 11:52:47 pm

Re: Intake manifold temperature

Reply #1 – July 31, 2010, 12:24:56 am

Re: Intake manifold temperature

Reply #2 – July 31, 2010, 08:47:38 am

Re: Intake manifold temperature

Reply #3 – July 31, 2010, 09:13:32 am

Re: Intake manifold temperature

Reply #4 – July 31, 2010, 09:36:32 am

Re: Intake manifold temperature

Reply #5 – July 31, 2010, 11:09:31 am

Re: Intake manifold temperature

Reply #6 – July 31, 2010, 11:33:12 am

Re: Intake manifold temperature

Reply #7 – July 31, 2010, 02:22:39 pm

Re: Intake manifold temperature

Reply #8 – August 02, 2010, 06:50:58 pm

Re: Intake manifold temperature

Reply #9 – August 02, 2010, 10:11:12 pm

Re: Intake manifold temperature

Reply #10 – August 02, 2010, 10:56:10 pm

Re: Intake manifold temperature

Reply #11 – August 03, 2010, 12:19:48 am

Re: Intake manifold temperature

Reply #12 – August 03, 2010, 06:14:53 am

Re: Intake manifold temperature

Reply #13 – August 03, 2010, 12:27:57 pm

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