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Sonnie Gray's Engine Conversion

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beltguy
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Bus Model: 1985 Eagle 10 with Series 60 and Eaton AutoShift 10 speed transmission (SOLD)
Location: Evergreen, CO
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Sonnie Gray's Engine Conversion

Post by beltguy »

Many folks have asked about details of the very unique engine conversion that Sonnie did on his '72 model 5 Eagle.
Sonnie Gray Eagle long view.jpg
Several years ago Sonnie sent me several photos detailing the amazing installation of the CAT 3406 engine. The conversion included huge "frame" modifications (moved drive axle to bogie position) so that the engine could be centered in the engine cradle system and the dropbox eliminated.

Right now I am slammed with "stuff", so it will take a few days to build this thread. If anyone has photos of the engine conversion, please post them here.

Jim
Jim Shepherd
Evergreen, CO
'85 Eagle 10 with Series 60 & Eaton AutoShift 10 speed transmission SOLD
2005 Dodge 2500 with 5.9 Cummins and 6 speed manual 2022 Sunset 28 foot trailer
Bus Project pages: http://beltguy.com/Bus_Project/busproject.htm
Blog: https://beltguy.com/Travelogue/
Email: eaglesinternational.email at gmail.com   NOTE this email box is only for general correspondence related to the forum and not technical advice.  Technical questions will not receive a response.
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beltguy
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Re: Sonnie Gray's Engine Conversion

Post by beltguy »

To set the stage for this thread, we need to sort out the axle configuration of 3 axle Eagles. The model 01 had the drive axle ahead of the tag axle. All of the other Eagle models (05, 10, 15, 20, etc) had the drive axle behind the bogey axle and used a dropbox configuration. In this configuration, the engine is offset to the driver side, the drive shaft goes over the drive axle and connects to the dropbox (see photo below).
Eagle Drive Layout.png
Eagle Drive Layout.png (13.28 KiB) Viewed 4337 times
In the photo, the dropbox is item 4.

The model 01 was a direct "T" drive with the engine centered.

Sonnie "replicated" the 01 configuration by completely modifying the suspension structure so that the drive axle is in front of the tag axle. The tag axle has air bags and a dropped axle tube so that the drive shaft can go directly from the transmission to the differential (see photo below).
DSC00033.JPG
DSC00033.JPG (62.54 KiB) Viewed 4337 times
More to follow.

Jim
Jim Shepherd
Evergreen, CO
'85 Eagle 10 with Series 60 & Eaton AutoShift 10 speed transmission SOLD
2005 Dodge 2500 with 5.9 Cummins and 6 speed manual 2022 Sunset 28 foot trailer
Bus Project pages: http://beltguy.com/Bus_Project/busproject.htm
Blog: https://beltguy.com/Travelogue/
Email: eaglesinternational.email at gmail.com   NOTE this email box is only for general correspondence related to the forum and not technical advice.  Technical questions will not receive a response.
N8788w
Posts: 4
Joined: Tue Oct 27, 2015 5:34 pm
Bus Model: 1969 model 05 318 detroit allison ht740 currently being converted from entertainer to family coach

Re: Sonnie Gray's Engine Conversion

Post by N8788w »

Great information Jim looking forward to more I've seen those type of axles on bulk
Semi trailers the u shape is for an unloading tube that comes out of the back of the trailer
I am interested to know what modifications were made to the frame to allow the bus to carry the weight in this new location. also what did he do with the fuel tanks I assume he mounted a large tank in the rear most luggage bay thanks
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beltguy
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Re: Sonnie Gray's Engine Conversion

Post by beltguy »

Sorry, I do not know how Sonnie handled the fuel tank. Obviously the 05 tanks would not work with the axle relocation.

Also, the question about the loading of the drive axle Torsilastics is pertinent. The new tag axle with the air bags has considerably more load capacity that the stock bogey/Torsilastic axle. That said, if the air bags are not inflated properly, the drive axle Torsilastic will be overloaded. I think I recall that Sonnie had air gauges on the dash to let him know that the tag axle was doing its job.

All large 4 stroke engines (Series 60, CAT 3406, Cummins N14) require that the floor be raised and the rear cross member be reconfigured. The photo below shows the raised area (most of us use that as a bed platform) in Sonnie's bus.
DSC00065.JPG
DSC00065.JPG (61.31 KiB) Viewed 4292 times
The photo below shows the engine bay structure. It looks to me like Sonnie modified the engine rails using large square tubing. I believe that he later attache his trailer hitch into the square tubing. Knowing Sonnie, I am sure that he carefully checked the structural tubing that supports the engine rails, or replaced the tubing. In that area, Eagles tend to have tubing rust that starts on the inside of the tubing. In my case, I double tubed all of the major tubing. The center of the engine weight is further out in the structure and care must be taken to make sure that there are no hidden defects.
DSC00032.JPG
DSC00032.JPG (60.15 KiB) Viewed 4292 times
The last picture for this post shows the engine in the bus. Note that the engine is now centered yet the engine rails are not centered (per factory design).
DSC00073.JPG
DSC00073.JPG (60.09 KiB) Viewed 4292 times
Jim Shepherd
Evergreen, CO
'85 Eagle 10 with Series 60 & Eaton AutoShift 10 speed transmission SOLD
2005 Dodge 2500 with 5.9 Cummins and 6 speed manual 2022 Sunset 28 foot trailer
Bus Project pages: http://beltguy.com/Bus_Project/busproject.htm
Blog: https://beltguy.com/Travelogue/
Email: eaglesinternational.email at gmail.com   NOTE this email box is only for general correspondence related to the forum and not technical advice.  Technical questions will not receive a response.
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rusty
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Re: Sonnie Gray's Engine Conversion

Post by rusty »

I used the same tag axle that Sonnie used. If you go to my project thread on page 2 you can see some pictures of axle and the frame. also you can see what I did for a fuel tank. The fuel tank is only 100 gallons so I will have a smaller tank in the rear bay. I am trying to get the fuel mileage up around 10 miles so a larger tank is not needed. If I don't get the mileage I hope for then I will have to stop more often.

Go to Wayne Schell 15/45 thread

Wayne
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