Red Diamond HP & Torque Curves


IHC in the early to mid-fifties.

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Post Thu Dec 26, 2013 2:51 pm

Red Diamond HP & Torque Curves

Has anyone ever come across a graph of the horsepower and torque curves versus RPM's for any of the Red Diamond engines (372, 406, 450, 501)? I've been all over the web and can't find anything. Might be something in an old magazine ad somewhere. Would at least like to see one for my 372.

Redk5guy
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Golden Jubilee
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Post Thu Dec 26, 2013 6:09 pm

Re: Red Diamond HP & Torque Curves

No graph but you can find the specs. for all 4 Red Diamond engines here;
https://app.box.com/shared/otkihx6yoa/2/37788558

Part A,pg 3.
12 yrs.exp. in IH dealer parts dept.
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Yard Art
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Post Thu Dec 26, 2013 10:25 pm

Re: Red Diamond HP & Torque Curves

RD372
brake HP (max) 165 @ 3200rmp
brake HP (net) 146 @ 2850rpm
max torque (ft/lbs) 308 @1600rpm
net torque (ft/lbs) 298 @1400rpm
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Golden Jubilee
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Post Fri Dec 27, 2013 2:53 am

Re: Red Diamond HP & Torque Curves

All that info and more is in the service manual the link leads too. :t9409:
12 yrs.exp. in IH dealer parts dept.
Never argue with a fool...
If you don't have anything nice to say...say nothing.
If you don't learn something new everyday...you weren't paying attention.
THINK! Be sure brain is connected before mouth is in gear.
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Golden Jubilee
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Post Fri Dec 27, 2013 5:56 am

Re: Red Diamond HP & Torque Curves

I have a Service Engineering Bulletin about the LV-series engines, and if I remember correctly, there are some horsepower and torque graphs in them comparing the LV engines with the comparable RD engines.

Not sure where mine is stashed...but if I find it, I'll scan and post. Or if someone else has a copy, perhaps they can do so. It may take me awhile to find mine.
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Post Fri Dec 27, 2013 10:06 am

Re: Red Diamond HP & Torque Curves

Thanks for the info guys. If you come across those graphs that would be good information to share.

Redk5guy

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Post Fri Dec 27, 2013 11:34 am

Re: Red Diamond HP & Torque Curves

OK, Asked this question over in the Larger truck forum.
What do you fellows consider a Larger Truck?
Do you consider an R185 a large truck?
Where would the best place be to post for info?

Should it be a sub category under here or should a person with a truck like that be directed to post in the Large truck forum?
Where do you think the best area to get answers would be?

We always endeavor to make the forums better to serve their purpose, However, I know that not all people with knowledge read all areas, or every post as I do. Answers to these Questions will help us, Thank you.

Lloyd
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Golden Jubilee
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Post Fri Dec 27, 2013 1:13 pm

Re: Red Diamond HP & Torque Curves

From the perspective of IH manuals,(especially parts) the 185 & up is a "heavy" truck.
12 yrs.exp. in IH dealer parts dept.
Never argue with a fool...
If you don't have anything nice to say...say nothing.
If you don't learn something new everyday...you weren't paying attention.
THINK! Be sure brain is connected before mouth is in gear.

Pile of Parts
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Post Fri Dec 27, 2013 5:34 pm

Re: Red Diamond HP & Torque Curves

Yes, I've been basically posting the same questions for my R-185 here and on the Large Truck forum thinking that the L, R & S guys kinda stayed over on this forum and the large truck guys stayed on their forum. I won't do that anymore; I'll stay over here on the L, R & S side because there's more activity over here and what I think are more interesting posts.

For what it's worth, I've always considered my R-185 a heavy duty truck since it has the Red Diamond series of engines which are exclusive to the heavy duties and also shares the same front end sheetmetal as the R190's and on up. On page 228 in Fred Crismon's book (first printing), he states "The L-190 Roadliner was the top end of the L-180 series, but it used the sheetmetal of the larger 190 models. ........The 372 cubic inch engine developed 143 brake horsepower which was a substantial increase over the 100 horsepower of the L-180 standard engines. The transmissions and axles were also upgraded...................The recommended tire size was 10.00 X 20 for tractor service, as were air brakes, an auxiliary transmission and saddle tanks." This seems to indicate that Mr. Crismon viwed the R-185 as a heavy duty truck in line with the 190's and I think most of us would agree.
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Golden Jubilee
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Post Fri Dec 27, 2013 9:59 pm

Re: Red Diamond HP & Torque Curves

In reality there is extremely little in common between the L/R 185 up with any of the others. Some cab parts is about it.

I'd look or post in the "heavy" section for trucks of this size myself.

I still recall the very first part I had to look up and for who in my 1st hour at my new job,a wiper arm for a RD-190.I was alone in the parts room and was clueless,so I wrote all the info down and told him I'd call back asap. Luckily the service manager knew the parts books and helped me out. I think he was surprised I called back in about 20 minutes which made me some big brownie points with a man who I was told later was a real grouch. I never had a problem with him ever.
12 yrs.exp. in IH dealer parts dept.
Never argue with a fool...
If you don't have anything nice to say...say nothing.
If you don't learn something new everyday...you weren't paying attention.
THINK! Be sure brain is connected before mouth is in gear.

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