how hot is too hot?

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cruiser user

cruiser user

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May 11, 2005
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Location
Lagrangeville New york
I just got my bj 42 back together yesterday after installing power steering and having the tranny and transfer case rebuilt. I also installed a set of isspro guages on the stock 3b. Around the back roads its fine , temperatures 6-900 , 1100 uphills at an easy pace. Then I took it out on the parkway and it was reading 1300 to 1450 at 60 -65 mph. Is that too hot ? If so, what can I do to cool things down ? Its a stock 3b, runs well , no smoke just the usual minor oli drips from the head. Has about 330,000 km on it. . I was hoping to take it to work occasionally, and that means 55 miles each way on the parkway. Can I run at those temps for that time or should I just save it for nice days and back roads?? Any suggestions and advice would be appreciated Tim
 
Hi Tim,

Check for a restrictive intake (air filter) and / or exhaust. The main reason one gets high EGTs (exhaust gas temps) is there is not enough air moving through.

Let us know what you find.
 
Now I know why I busted a head in southern Oregon about 5-6 years ago before I had the turbo. I can reach 1250 with the turbo pumping in air to cool things down.
It also helps us who are turbo'd to know what a naturally aspirated 3B runs at.
 
cruiser user said:
I just got my bj 42 back together yesterday after installing power steering and having the tranny and transfer case rebuilt. I also installed a set of isspro guages on the stock 3b. Around the back roads its fine , temperatures 6-900 , 1100 uphills at an easy pace. Then I took it out on the parkway and it was reading 1300 to 1450 at 60 -65 mph. Is that too hot ? If so, what can I do to cool things down ? Its a stock 3b, runs well , no smoke just the usual minor oli drips from the head. Has about 330,000 km on it. . I was hoping to take it to work occasionally, and that means 55 miles each way on the parkway. Can I run at those temps for that time or should I just save it for nice days and back roads?? Any suggestions and advice would be appreciated Tim
Click to expand...


(Cut the muffler off)....run Water Wetter in your coolant (which better be fresh), lots of air moving through the rad at 65mph.
 
Island Moose said:
(Cut the muffler off)....run Water Wetter in your coolant (which better be fresh), lots of air moving through the rad at 65mph.
Click to expand...

How much louder does the it get if you removed the muffler?
 
The temp(max) is debate able. I think lots of 3b's that are NA have been running those temps for years.

But if your exhaust looks ok and your air fliter is not restricative, I would turn the fuel down a bit. Try to get it around 1100 on the highway. As high power, or lower temps best.

These things have a hard time doing 110 kmhr normally. (suckie power)

At the back of the fuel injection pump is a large threaded part that has a thin nut on it. The end has a flat screwdriver spot. For using a large flat screw driver. You crack the nut loose, hold the nut while turning the screw in the loosening direction.This lowers fuel delivery. When you tighten the nut you have to hold the centre part so it doesn't re tighten. At the end get some wire and tie the nut so it cannot loosen. Very important.

Also you can tell if someone fawked with this adjustment before, it has a lead seal on the orginal wire used to safety it.

You should not run with those sustainable temps. But many have probably for 20 yrs. Why run it hot tho if you know about it?

G luck
 
as Bruce Lowen pointed out one day, sticking a EGT gauge into a NA 3B is about the worse thing you can do, it really shows you the abuse these engines can put up with. for 300K-400K-500K-600K and even as high as 700K these engine keep plugging along at "unacceptable" temps. a larger exhaust will definately help although i would still run a muffler (and a resonator) since i like to keep what hearing i have left and "loud" gets frustrating after a while...
my suggestion is a turbo to increase the air being introduced to the engine and this will reduce the EGTs as well...
 
Island Moose said:
(Cut the muffler off)....
Click to expand...

I would NOT recommend that on a naturally aspirated 3B. OK on a turbo but NOT naturally aspirated.
 
cruiser_guy said:
I would NOT recommend that on a naturally aspirated 3B. OK on a turbo but NOT naturally aspirated.
Click to expand...

Is this due to the lack of back pressure which will make it lose torque?
 
Lantec said:
Is this due to the lack of back pressure which will make it lose torque?
Click to expand...

No, the turbo acts as a muffler making a muffler somewhat redundant. The turbo disrupts the soundwaves and thereby queitens it. Without a turbo you have NO sound deadening device at all and a diesel which is unmuffled is LOUD.

When I installed my turbo I drove the truck to the muffler shop with only the downpipe installed and it was loud.

btw. Lack of backpressure is a GOOD thing! It means MORE power!
 
cruiser_guy said:
No, the turbo acts as a muffler making a muffler somewhat redundant. The turbo disrupts the soundwaves and thereby queitens it. Without a turbo you have NO sound deadening device at all and a diesel which is unmuffled is LOUD.

When I installed my turbo I drove the truck to the muffler shop with only the downpipe installed and it was loud.

btw. Lack of backpressure is a GOOD thing! It means MORE power!
Click to expand...

Ohh... I just heard somewhere that cars need some backpressure in order to have torque but it wasn't required on turbo cars because the turbo itself gives more than enough backpressure.

Maybe it's only limited to gasoline cars or something
 
Lantec said:
Ohh... I just heard somewhere that cars need some backpressure in order to have torque but it wasn't required on turbo cars because the turbo itself gives more than enough backpressure.

Maybe it's only limited to gasoline cars or something
Click to expand...

Not in what I've read. Read Corky Bell's book "Maximum Boost" for a good lesson on turbochargers.
 
Lantec said:
How much louder does the it get if you removed the muffler?
Click to expand...



What's that you say???

Seriously...LOUD.....but I should have continued to say that you can replace your muffler with a straight through performance muffler like the glasspack cherry bombs...they leave you with a nice rumble, but surely flow twice the air of that goliath factory muffler.

My system includes a glasspack, but it's also 4 feet shorter than it was, exiting in front of the right rear wheel.

I don't have an EGT sensor, therefore my truck doesn't run hot, it's perfect all the time.
 
Lantec said:
Ohh... I just heard somewhere that cars need some backpressure in order to have torque but it wasn't required on turbo cars because the turbo itself gives more than enough backpressure.

Maybe it's only limited to gasoline cars or something
Click to expand...


Backpressure bad. You don't want long headers because you lose exhaust gas scavenging from one cylinder to the next, but a free exhaust is a diesel's wet dream.
 
Those are the temps I normally see here at altitude with less air. 5,000 - 13,000ft

I usually don't take mine above 1200. Long slight uphill grades are the worst.
 
Good advice

Warpdriv had the right idea! I looked at my air cleaner, it was one of those pink things that are supposed to be recleanable, weighed about ten pounds. i had a nice new stock one from four wheel auto in Alberta so I stuck that in and went out on the parkway again, Big Differrence! Temperatures down about 150 to 200 deGrees!! I still can get up to 1300 if I keep my foot in it but at 65 mph on the level it stays about 1100 . Less down hill more up. you can just look at the pyro and watch it go up and down with the road grade. Still, I'm going to try backing off on that fuel adjustment on the pump, if I can find it.I'll let you all know in a few dayswhat happens there. Again, thank you all for the info and help! I had reservations about getting this crkuiser because I know zero about deisels but I feel much more confident with all the help I,ve been getting here! Thanks again! Tim
 
final report

Well, I backed off the fuel screw on the side of the injector pump about two turns, and have been happy with the results. I can still get it up to 1300- 1400 if I flog it up a hill but it will stay at 1100 if I go easy on it. On the parkway it will do 65 on the level and stay around 900. Based on that 60 mph is fine , I can live in the right lane and be happy! I'm also checking the milage, was getting about 24mpg, we'll see if that improves. The weather in New york is fine, the top's off and I'm having fun! Thanks again Everyone!
 
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