I have owned the Greydog for 15 years and have done everything the most helpful people on this board have suggested it still was a chore to drive and keep cool so was not a very enjoyable experience.
I have been considering this for some time and finally said what the h##l and did what people said would not work.
Checking truck wrecking yards I found a grill from a Freightliner and a 3 foot by 4 foot radiator from a cab over truck. I took off the rear doors and using a existing mounting system, must have been for some sort of a platform, I had a friend expand on my idea and we mounted the radiator to the rear of the bus in place of the doors. This now has 6 electric fans wired on separate fuses so not all can go out at once. This is in line with the original radiators which I had re cored before I even was able to get it home. My misting system was also added in line using a 1/4 inch cooper tube with 40 thousands inch holes drilled every 2 inches. The whole thing will swing about 30 degrees so can have limited access to the engine. I wish I knew how to post a picture of the thing. Geoff has seen the system and he scratches his head. IT WORKS Just returned from a 1600 mile trip towing at 24 foot toy hauler which weighted about 10000 pounds to Colorado starting in the Verde Valley, AZ 17 mile 7% grade to flag then on I40 to Albuquerque, NM then I#25 over Raton Pass and return. I only had to use the misters 10 or 15 times each way to keep it below 180 degrees. So now when you come up behind me you will see a Freightliner grill. Sorry for the long post but I am exited. Thanks for all the suggestions over the years, I followed all of them.
Is your new radiator in series with your existing rads, or in parallel with them, or something else? Are the new electric fans blowing out or in? Do you have an extra coolant pump to help move coolant through the new rad, or does the engine's water pump move the coolant well enough?
Sorry for all these questions, but things like this always intrigue me, especially now that I've just finished completely replacing my entire cooling system to try and eliminate perennial cooling problems.
Thanks, John
I once saw an MC7 for sale in San Diego that had a radiator mounted on the back. We have done several things to keep our 8v71 cool, but I am sure that it would not be good enough for an 8v92 though. Would love to see a picture.
hi Ed, hope you can make it to that dam rally in Nov, Van and Gary will be there and will get picks to post here, and let's get Gary to have an article in the magazine, tom, lvmci...
8V-92TA is THEE hardest engine to keep cool. Good Luck, TomC
Quote from: TomC on October 13, 2016, 09:51:26 PM
8V-92TA is THEE hardest engine to keep cool. Good Luck, TomC
I know the reasoning behind the MCI 2 top mounted radiators but it is a poor design to cool a 8v92 with pushing the coolant above your head IMO
Quote from: luvrbus on October 14, 2016, 06:27:55 AM
I know the reasoning behind the MCI 2 top mounted radiators but it is a poor design to cool a 8v92 with pushing the coolant above your head IMO
Always been curious about that Cliff. So do tell....what is MCI's logic behind the split radiator setup?
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Quote from: thomasinnv on October 14, 2016, 07:08:50 AM
Always been curious about that Cliff. So do tell....what is MCI's logic behind the split radiator setup?
Thomas -I seem to remember reading something a long time ago (maybe in Larry Plachno's book) about MCI's design that was related to the Canadian road conditions back in the 50s and early 60s that their coaches had to operate in. (This was long before they started appearing for Greyhound in the US.)
Seems that in the prairie states (where MCIs are built), lots of roads were still gravel, so plenty of dust in the summertime and mucky conditions in winter. The high radiator placement reduced the amount of dust and muck sucked into the radiators. No real heating issues with this design when you're only running a 4L71 or 6L71 in the cooler Canadian climates, but when the horsepower races began by stuffing the 8V71 in the tail, and running them in the hot US Southwest, the limitations of the design began to rear their ugly heads.
FWIW & HTH. . .
;)
with stops/towns in the Canadian plains a day apart and long flat roads eventually even a DD 4L71 could reach 68 mph :) and then not have to shift out of high for the rest of he day :)
We will are going to the Damn rally. The new radiator is in series with the old ones, the water is pumped up to the old radiators then drains into the new one. The fans blow toward the engine. Geoff said the original water pump would pump more than enough water and it works great.
I will ask Gary or Van to take pictures of the set up and I will get a more detailed article ready for Gary to edit.
It sure is nice to be able to run with the big boys towing that big trailer and not have to worry so much about the cooling. One more thing to cover up the mounting of the radiator from the back and sides, I had to move the radiator out 9 inches, I had bright diamond plate aluminum cut and bent to cover the back and sides and of course added more lights.
I would also love to see a picture of that.
I have the 8V71, and one of the first things we did was replace the side louvers with air scoops. I've never had any issue with heat...ever, AND I use the scoops as a cheaters way to back into any possible location. Might sound silly, but it saved me the cost of a camera system 8)
I did much the same thing when I installed the Allison automatic in my MCI 7. The rear doors came off, and a temporary door with wire mesh was fitted. A Hayden oil cooler was mounted against the mesh, and 2 electric fans to the cooler. Two 1" stainless braided lines run to the transmission for supply/return through a filter.
I installed a temp gauge as well, and see temps of about 250F during a long hard pull, like Globe and ShowLow,AZ.
In much,MUCH cooler weather the temps run about 140F-160F.
I would definitely recommend this method.
Would just like to know why it is that Grayhound and other bus lines can run these buses a zillion miles with out over heating issues but when we convert these things it seems to be an almost constant problem.Is it because we have them loaded more ,does the cooling system get clogged from age or do we do something to restrict the air flow when we convert them? Just wondering!!!
Greyhound always had the engine turning above 1800 rpm and they also had cooling problems too, 200* didn't bother Greyhound drivers like it does a owner now either
My former Golden Gate Transit came with a 205f shutdown system that I have tripped a couple of times when I got hot. Absolutely no damage to the 6V92TA afterwards.
--Geoff
Back when I was driving in the 70's,never gave a thought to the temp gauge on those old 3751's and Scenicrusers .Of course we got paid to drive and that was pretty much what we did.Been a long time ago but to the best of my memory ,I don't recall a heat related blow up.
We mostly use larger injectors than they did more fuel, more heat. Also fairly new and well maintained cooling systems.
MCI has always kept the HP in check to prevent heating you still come across the MCI's that have a 8v92TA set at 365 hp and Greyhound never used a injector in the 8v71 larger than a C60
Also the fact that back then, we were taught to drive them "on the governor". Lugging them was a sin. We always run them up to the governor, then shifted up. Same thing down shifting: when we got down to that speed that was right for down shifting, out of gear, put your right foot to the floor, and slide it in the next lower gear. Didn't matter if it was uphill, flat, or downhill, those 2 strokes were revved up, like they are meant to be. It was a big adjustment for me when I started driving 4 strokes in buses and trucks, to shift at or below 1200 rpm, far away from governed speed.
JC
I also forgot to mention I had previously had the same friend build me a trans cooler. I got a oil cooler from a GM bus form Luke and put that in line with the standard trans cooler but he then put in a total independent radiator system using a radiator and pump from a race car with its own electric fan mounted to the left side lower door to the engine. That way the trans fluid went through a cooler before the engine radiator.