| Author |
Message |
rhumburg (206.148.77.239)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, January 16, 2003 - 2:59 pm: | |
hi would like to know the safe temps.on 6 v 92 thanks randy |
Gary Stadler (Boogiethecat) (68.7.217.217)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, January 16, 2003 - 3:47 pm: | |
My turbo guru says a general rule for any diesel truck engine is to Run with pyrometer pickup 6" past the turbo discharge at 1100 max. or if it's
Before the turbo, 1300 degrees max |
Joe Laird (Joelaird) (198.81.26.174)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, January 16, 2003 - 5:01 pm: | |
Randy,
Here are some "rules" I try to operate mine by.
Normally runs about 300 at cruise.
Will climb as power is made
Takes a pretty good pull to get over 750
If it goes over 900, I ease up on the fuel.
If it is consistently high, there is probably an air leak between the turbo and the blower.
I use it in conjunction with a turbo boost gauge.
Hope this helps, Joe |
Larry Baird (Airhog) (66.171.51.130)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, January 16, 2003 - 11:14 pm: | |
I have a question, I went to Valley Detroit today and ask about pyrometers and the answer was, not here! Anyone know where to get one in the So Ca area and at what temp for an 8v71 non turbo? Do I put it in the right side looking forward just after the cast iron? Thank for the help. |
Gary Stadler (Boogiethecat) (68.7.217.217)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, January 17, 2003 - 2:14 am: | |
Larry, do a search for "EGT" on ebay and you'll find a ton of them for sale, usually good deals. Get one that goes to 1100 or 1200 and has a nice readable scale. And get the one with the whole kit, wires, sensor, etc. Don't try to piece one together because it will probably not end up properly calibrated.
Cheers
Gary |
Quest (198.29.191.148)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, January 17, 2003 - 7:58 am: | |
Hey Gary
I thought that the temp we wanted to watch was water temp, but the egt's seem to be for exhaust temp.
Can you help me better understand what we are looking at, range and where exactly it has to be installed. I have an 8V71N - Quest |
Geoff (Geoff) (64.1.0.85)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, January 17, 2003 - 8:59 am: | |
One installion problem that hasn't been mentioned is that a pyrometer has to have a lead all the way from the engine to the dash-- that could be a 45-50' lead. When I bought my Isspro pyrometer I special ordered a 45' lead (just barely enough, I might add) and paid a good penney for it. Once I got it, I saw all they did was splice a 600 volt SO cable to a regular 14' pyro lead cable!-- I could of done that myself. Also, the pyro "weld bushing" should be installed within 6" of the turbo exhaust connection (muffler side).
--Geoff
'82 RTS CA |
Gary Stadler (Boogiethecat) (68.7.217.217)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, January 17, 2003 - 12:01 pm: | |
Quest,
Watching the water temp is a "general" way of determining the engine's operating temperature, but that will only tell you the temperature of the engine in general, averaged over a long period of time. For instance you could hit a steep but short grade, floor your accellerator pedal, and quickly make the top of the grade with little increase in water temp, but the moment you floor it the instantanious temperatures inside the combustion chamber could go very high... if you have a souped up engine with a turbo, it's possible to actually melt holes in your aluminum pistons before you even see a change in water temp. If you monitor the exhaust gas temperatures, you'd see that trend immediately, and know to back off a bit before any damage was done.
For the most part an EGT is probably not needed in a bus, but if you want to really have a handle on what's going on in your engine, it's the way to go. As was said before, all aircraft with piston engines goes by EGT. There's something in that!! And if you're doing something like propane injection where it would be extrememly easy to go well over your engines' maximum horsepower ratings, EGT monitoring is a MUST.
Typically the sensor would be installed 6" past a turbo discharge, or if you don't have a turbo, somewhere near the end of your cast exhaust manifold where all the chambers come together. ALthough some of the guys on this board set much lower maximums for themselves (not a bad idea at all), the turbo shop I use recommends absolute maximum temperatures of
1100 degrees if the sensor is mounted 6" after the turbo discharge. Or if mounted before a turbo (or non-turbo), 1300 degrees max.
For Geoff.... Regarding the wire for long runs, technically it should be "thermocouple wire" for the whole run, and the wire type would have to match the type of thermocouple you have. A thermocouple is nothing more than two dissimilar wires welded together at the "sensing" end. Heat across that junction creates voltage (actually only millivolts) which is well defined by the temperature vs metal type of the wires.
In fact, (and where a problem occurs) voltage is generated wherever two dissimilar metals are joined, for example at the other end of the wires where they hook to the gauge or where the wire is spliced. It's an interesting mind game here- to have the voltage generated at the tip of the thermocouple be the only thing that makes the gauge move, and not have other junctions in the system affect the accuracy. So if you use thermocouple wire "all the way" you will have potentially less accuracy problem than if you extend the wire with copper wire, because everywhere you make a splice creates two new thermocouples right at the splice... then there's two MORE junctions where the wires crimp to the gauge... follow me? Fortunately those two new junctions usually cancel each other out fairly well if they are made with exactly the same kind of crimp material. And another thing in our favor is that we are concerned with tens of degrees, and perhaps only hundreds of degrees, but we don't need one degree accuracy by any means, so a lot of what would generate horrible errors in an industrial environment won't bother us in a bus. But best by far would be to fine out what kind of thermocouple you have (usually called "type" ie type K, type J, etc) and get wire that is the same kind to do your extension. That wire is availiable thru McMaster-Carr or Omega, and it's a possibility that I even have a ton of it depending on what type the thermocouple is. (I have rolls and rolls of something, I havn't looked lately- maybe I oughta!!)
Phew! Hope that answers some questions in a way that makes sense... I know all this stuff cold (no pun!) but I've always had a harder time putting it into understandable words....
Cheers
Gary |
Geoff (Geoff) (64.1.2.226)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, January 17, 2003 - 1:03 pm: | |
Gary-- The 45' pyrometer lead was special ordered from Isspro, and like I said all they did was slice 600 volt SO cable to a regular 14' pyrometer lead (they use "K" type thermocouples). Pyrometer leads are only made in 6', 10', and 14' lengths by Isspro so if you want one any longer you have to make it yourself or order one. Next time I'll make my own! If you have quality lead cable for slicing I'm sure a lot of people around here would be interested...
--Geoff
'82 RTS CA |
Geoff (Geoff) (64.1.2.226)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, January 17, 2003 - 1:21 pm: | |
I forgot to mention temps-- I hear a lot of people with engines other than Detroit 2-cycles having pyro temps up in the 1100-1300 range (like Gary mentions), but actual practice for me with my 6V92TA, 350 HP w/ 9G90 injectors has my temps even lower than Joe's-- I run 300 on the flat highway, but have never had it over 650 pulling a hill. Of course, that was with a basically empty bus. The trip I made with my 20' trailer my pyrometer thermocouple took a crap (3rd time) so I couldn't see how hot it was getting-- and it would have been a lot hotter than usual with the load. Would anyone have any idea why the type K thermocouple would keep crapping out on me so often?-- it seems they work good when I first put one in, then after a few trips it works on and off, then it quits working altogether. I am on my third thermocouple in less than 10,000 miles.
--Geoff
'82 RTS CA |
FAST FRED (209.26.115.217)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, January 17, 2003 - 3:37 pm: | |
If your engine has not been hot rodded and has stock output , just watching the water gage has probably worked for the last few million miles.
If its been "adjusted " to operate as defuller, extra caution is required.
FAST FRED |
Richard Bowyer (Drivingmisslazy) (66.190.119.82)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, January 17, 2003 - 9:55 pm: | |
Geoff, I have been told by the Alaska Diesel gurus that the EGT should be over about 500 degrees for proper operation of the engine. Sounds like yours is actually running too cold which is not good for the engine also.
Richard |
Geoff (Geoff) (64.1.1.24)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, January 17, 2003 - 10:26 pm: | |
My temperature gauge is normal so I know my engine is not running too cool, Joe's 8V92TA pyrometer also runs at 300, and that seems to be a figure I have heard some truckers say is their cruising heat. But perhaps our 45' leads from the exhaust to the dash is responsible for low reading? I asked Isspro if the long lead would cause an inaccurate reading and they said no. I also checked resistance on the cable at the front by grounding it out at the engine and there was none as I remember. So, does anyone else have a pyrometer in their bus who can share their readings?
--Geoff
'82 RTS CA
--Geoff |
Joe Laird (Joelaird) (198.81.26.174)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, January 17, 2003 - 11:24 pm: | |
Geoff, Mine may run in the 250-300 range at cruise also. I don't pay any attention to it until I'm doing something I know will affect it. When you mash my injectors they raise the EGT!
I don't think EGT and water temp have anything to do with each other. I can jake down a loooong hill and the pyrometer will still stay around 300. Engine will be at thermostat temp. I can climb a long steep hill and get water temps to rise a bit but EGT is still a function of how much fuel I'm delivering. I think it works like this:
Lots of fuel (big injectors a/o heavy foot) plus plenty of air (Efficient turbo) = big bang = higher EGT
I bought 70' of standard thermostat wire (that's right, for a house) for $.07CD per foot. About $2.75US at Home Depot in Edmonton when I put my engine in 2 1/2 years ago and it's still working great. The only time it stopped working it was because the ends where I joined the thermostat wire to the leads corroded. I cleaned them and it works great again. I bolted them together because the sender wires had those connections. If they corrode again, I'll take the ends off and try soldering them.
We have pyrometers on our S60s in the tour buses, H345s and Renaissances, they seem to run about that 300 temp also when not working.
I don't think I could get mine over 750 with only the bus, but with the trailer I can.
She's boosting 19lbs at 900 usually.
Joe Laird
Eagle 8V92TA |
|