| Author |
Message |
Peter E (Sdibaja) (67.115.10.155)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 25, 2003 - 11:32 am: | |
I was running up in the high country yesterday (4800 feet), it was real hot (120+). for the first time my 8v71 in a 4905 ran up to 195 before I noticed it... I backed off and it went back down to it's normal 180 range. |
eagle 5 (67.30.23.48)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 25, 2003 - 1:01 pm: | |
WHERE was it 120 yesterday?
195 not too hot |
Peter E (Sdibaja) (66.123.254.151)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 25, 2003 - 1:13 pm: | |
Mojave desert, it gets warm there sometimes
OK, I may have exagerated a little bit...
Peter
BTW, you all should check out state highway 138 between I-15 and Palmdale... quite a grind on the East end of the strech but it is real beautifull country. |
Frank Allen (205.188.208.39)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 25, 2003 - 1:54 pm: | |
i would say its normal, i shut down at 200+ they say 210 is the place where self destruction begins, thermostates open fully at 185, shouldnt hurt anything
Frank Allen
4106 |
Don KS/TX (66.82.9.13)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 25, 2003 - 5:15 pm: | |
Might check your books for recommended thermostat Frank, MINE recommended the 195 thermostat on 8V71. One thing for sure, they sure run better at higher temps. Often people try to run them as cool and they can, apparently thinking that is better. It is not. |
Frank Allen (205.188.208.39)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 25, 2003 - 6:18 pm: | |
i dont know what is recomended i only know where mine open,it does just fine , just trying to answer a question, nobody asked me about the thermostates, or what they recomend
Frank Allen
4106 |
Frank Allen (205.188.208.39)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 25, 2003 - 6:26 pm: | |
don, looking at my book right now, it says strts to open at 170, fully open at 185, does not say anything about 195 which i think is too hot, the engine self destructs at 215
Frank Allen
4106 |
Peter E (Sdibaja) (66.123.254.151)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 25, 2003 - 6:33 pm: | |
OK, I read my book too. Could not find thermostat operating range but "cold" is defined as under 170 and the "overheat" warning light is supposed to go on between 210 and 214...
read between the lines I guess.
A side note: the hotter I run, the better it performes and the better the fuel mileage.
In my Harley days we said "they alyas run the strongest before they blow" Peter E |
Peter E (Sdibaja) (66.123.254.151)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 25, 2003 - 6:40 pm: | |
I was last quoting the GM 4905 manual
the DD V71 book says 2 differnt thermosatats are used
170 = 170 to 187
180 = 180 to 197 operating ranges
"210 must not be exceded..." see charts in Section 5, pages 7 and 8
end of story!
Thanks guys!!!
Peter E |
Don KS/TX (66.82.9.42)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 25, 2003 - 8:08 pm: | |
Thanks Peter, that is part of what I was trying to quote and did it so poorly. Point is, they WANT them to run around 190 as I recalled. Jim, it is time for the school trained DD mech to get in here and guide! |
FAST FRED (67.75.106.223)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, September 26, 2003 - 5:09 am: | |
When DD built them they were to run with the 170 stat, only a tiny reduction in exhaust visibility caused the change up 10 deg.
AS they will DIE if overheated beyond 210 , makes more sense to me to have a lower temp and more "room" before distruction.
Why run on the ragged edge for the sake of Opacity?
FAST FRED |
Don KS/TX (66.82.9.30)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, September 26, 2003 - 10:12 am: | |
Because it is a diesel Fred, diesels like to be warm (and so do I). I never bought into the idea that running at low temp gives a lot of gap to the "ragged edge". If you have an adequate cooling system, it makes not a bit of difference what you are operating at, except for what the DD is happiest at. I ran mine with no thermostats for over a thousand miles, when I went to the recommended ones, the bus gained a couple mpg, and ran like it had a major tuneup. You could be correct as to why they upped the temps over the years, I always just supposed it was because the oil, coolants and systems improved lots over the 60 some years that engine has been around, and they performed so much better at the higher temps. Where the heck is Jim when you really need him? |
two dogs (67.30.23.44)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, September 26, 2003 - 10:19 am: | |
Diesels like to be warm...worst thing you can do to a diesel,is shut it off...still say 195 or 200 is o.k.....all they ask is to let them warm-up before you start beating them over the head |
Gary Carter (68.24.241.183)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, September 26, 2003 - 1:10 pm: | |
You can run a DD 2 stroke up to about any temp you want. The destruction starts happening when the coolant turns from a liquid into a vapor. Once you have created vapor you develop internal hot spots and the hot spots tend to crack.
So much depends on your cooling system. The higher the pressure the higher the boiling point of the coolant.
Just as antifreeze lowers the freezing point of the coolant, it also raises the boiling point. Not sure what it is, but believe at sea level pressure this is about 240 degrees. Also keep in mind the higher the altitude the lower the boiling point, so your margin of engine safety is less at altitude.
In the cold country we ran a 50/50 anti-freeze to water ratio. After departing the cold country to live where ever the temperature was more sane, I change to a 1/3 anti-freeze mixture. This is enough to provide the cooling system protection needed. Now to the catch 22. Water carries away more BTUs than glycol, therefore making for a better cooling system. On the down side, I lowered the boiling point of the mixture, therefore creating vapor sooner.
And finally, is your temperature gauge accurate. |
Peter E (Sdibaja) (66.123.254.151)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, September 26, 2003 - 2:01 pm: | |
"any temp you want. The destruction starts happening when the coolant turns from a liquid into a vapor. Once you have created vapor you develop internal hot spots and the hot spots tend to crack"..."is your temperature gauge accurate"
no that makes real sense, thanks Gary |
al anon (67.30.23.93)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, September 26, 2003 - 2:39 pm: | |
don't pay any attention to anybody named Gary...they just like to hear themselves talk |
Gary McFarland (Gearheadgary) (209.128.99.4)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, September 26, 2003 - 3:31 pm: | |
Hi Al Anon,
You know we're not nearly as bad as that two dogs guy, he's really a headcase.
Gary |
Johnny (65.224.20.42)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, September 26, 2003 - 6:59 pm: | |
For asny engine, I suggest a bottle of Red Line Water Wetter...I think it raises the boiling point, & I know it helps an engine run cooler.
For the truly paranoid, there's Evans NPG waterless coolant...but at $20 per gallon, that could get really expensive for a Detroit. |
FAST FRED (67.75.106.228)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, September 27, 2003 - 5:30 am: | |
The problem can come at a lower temp than what the gage shows.
IF the cooling system has not been properely maintained (leave the antifreez in too long & don't flush properly , or fill with high mineral tap water OR,,,) there can be POCKETS of steam created in certan hot spots.
This is why most GM loose the cylinder heads , First , on overheating.
The passages were poorly maintained & the localized heat cracks the heads.
On my coach the previous operator was a small charter outfit , that usually carried welfare folks to the casino to thro their money away.
One day he got a charter to Penn.
He had "Heard" there was somthing special about antifreez in DD , but never asked anyone.
So he filled the entite system with Prestone & NO WATER!
Doing the flat runs from NYC to ACY (Atlantic City) he had nary a problem ,
first hill in Penn the heads went.
I Got the coach for the price of the rebuild.
FAST FRED |
BrianMCI96A3 (65.40.144.254)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, September 27, 2003 - 5:46 am: | |
Fred, now that is my kind of deal! |
Jayjay (198.81.26.104)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, September 27, 2003 - 10:38 pm: | |
As you increase the pressure in a closed system, the boiling point of water goes up 3 degrees for every pound of pressure increase. A 50/50 solution will allow an even higher temerature rise. A 15 lb. system at 50/50 will boil over at about 264 to 268 deg. Fah. Add altitude and those numbers go up dramatically. At 10K ft. pure water boils at 232F.!!!! ...JJ |
Peter E (Sdibaja) (64.165.8.131)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, September 28, 2003 - 11:07 am: | |
Yes JJ, but I always understood that at higher altitudes the pressure goes _down_ and so does the boiling point... that is one reason you see cars on the side of the road on those high mountain passes...
http://www.pump.net/liquiddata/boilingpointwater.htm
Peter E |
Gary Carter (68.24.218.112)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, September 28, 2003 - 1:05 pm: | |
I think JayJay was referring to a closed 15lb system. |
John Rigby (24.174.239.244)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, September 28, 2003 - 9:58 pm: | |
I was talkiing to Tom Hall with Coach Conversion Central the other day and he hit on what i thought was brilliant. We were discussing the accuracy of the drivers gauages for water temp and oil pressure, when he recomended picking up an extra wire in one of the looms that travel from front to back and doubleing up on the wires feeding each gauge, thefore eliminating extra possible resistance that could be in the one wire feed. ( I had mentioned a 10% diffrence between the drivers gauge for water temp and a manual I had mounted back on the engine and was reading in the rear bedroom)Althouth I have yet to find the wires and connect, TOMS IDEA IS BRILLIANT.
John |
Gary McFarland (Gearheadgary) (209.128.99.4)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, September 28, 2003 - 10:42 pm: | |
Tell you what.
To test the theory, get a spool of wire and run it on the outside of the bus up to the dash.....I bet it reads the same.
Electric gauges are inherently less accurate than mechanical gauges. the one in back is likely not electric.
I believe you can swap senders around until they agree.
Gary |
FAST FRED (67.75.113.122)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, September 29, 2003 - 5:42 am: | |
Murphy Corp will build you a mechanical gage with any sized cap tube run.
Installation extra , but there not very costly.
FAST FRED |
BrianMCI96A3 (65.40.144.214)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, October 02, 2003 - 12:55 pm: | |
Fred, approximately, what kind of 'not very costly' are we talking about?
I might like one of those...and for my diesel gen. too, if your 'not very costly' is similar to my 'not very costly'
Brian |
FAST FRED (67.75.106.190)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, October 03, 2003 - 6:25 am: | |
A QUALITY cap tube water temp gage from a US mfg is about $60.
These Murphus are a bit more , but only get pricy if you need very fancy (oil filled for shock resistance) ,
Believe they have a web site ,
FAST FRED |