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Engine Conversions for Eagles

This is a public forum to discuss Eagle related technical issues. If you are having a problem with your Eagle, this is the place to find help.
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beltguy
Site Admin
Site Admin
Posts: 2663
Joined: Wed Oct 08, 2008 4:39 am
FMCA #: F246286
Bus Model: 1985 Eagle 10 with Series 60 and Eaton AutoShift 10 speed transmission (SOLD)
Location: Evergreen, CO
Contact:

Engine Conversions for Eagles

Post by beltguy »

Lots of folks think about replacing their two stroke engines with modern 4 stroke engines.

With the exception of one nameless member of this group :D :lol: most folks choose Series 60s or Cummins M11/ISM (please don't report me to the moderators because I "bashed" Sonnie -- wait, I am a moderator :lol: )

Folks have stuffed all kinds of engines in Eagles. Sonnie has the big Cat., Jack Campbell has a Series 50 and the list goes on. Hopefully folks will jump on this thread and discuss their conversions.

There are lots of things to consider when switching to a four stroke engine. The biggest issue is gearing. Two strokes can cruise all day a 2100 RPM,but four strokes work best at 1300-1500 RPM. Changing the gearing can be a big issue with 05/10/20 Eagles as there are only two COMMON gear ratios (3.73 and 3.36). Neither puts you in the "sweet spot" for a four stroke.

With a Series 60, you must raise the floor at least 10 inches. The M11/ISM is quite popular, since it can fit in the engine compartment without major modifications. ISMs in some applications are rated up to 500 HP and 1500 foot pounds. Those are hard to find, but you can find 400 HP ISM engines in trucks.

I detailed my engine conversion in my project pages (see signature below).

Another great engine conversion site is Brian Diehl's: http://home.earthlink.net/~diehls0792_1 ... ion10.html. Brian selected and ISM/Eaton AutoShift 10 speed transmission for his conversion. Brian's bus is an MCI ;) , but his documentation is excellent and fun to read. The details of this conversion would be very similar to a conversion in an Eagle.

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.
Sonnie Gray
Club Officer
Club Officer
Posts: 80
Joined: Mon Oct 13, 2008 5:29 pm
FMCA #: F215907
Bus Model: 72 0/5 Eagle 3406 Cat, 70 0/5, 85 Model 10

Re: Engine Conversions for Eagles

Post by Sonnie Gray »

Hey Jim

I noticed in your profile, that you liked anything mechanical.

So duh! my 3406 B Model Cat is mechanical ?

Thats ok! it just doesn't mark it's spot every time I stop.
nor does it sound like one of those whiz-bangs.

Catskinner!
Sonnie Gray
72 0/5 Eagle 3406 Cat
Pottsboro, Texas
User avatar
luvrbus
Club Member
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Posts: 2981
Joined: Mon Oct 13, 2008 12:50 pm
FMCA #: F262917
Bus Model: 05

Re: Engine Conversions for Eagles

Post by luvrbus »

Jim, after talking to the guy with the purple Eagle last year at Quartzsite I have been looking into having gears cut for the drop box to get a higher gear found a place to have it done but I don't if I am going to change engines or not .It is a lot of work for a few benifits you get I get descent fuel milage now and have plenty of power just not a high enough gear,and no way would I go through what Wayne and Sonnie did to get higher gears besides I like the Eagle boggie look good luck
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beltguy
Site Admin
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Posts: 2663
Joined: Wed Oct 08, 2008 4:39 am
FMCA #: F246286
Bus Model: 1985 Eagle 10 with Series 60 and Eaton AutoShift 10 speed transmission (SOLD)
Location: Evergreen, CO
Contact:

Re: Engine Conversions for Eagles

Post by beltguy »

Clifford, I had forgotten about the possibility of changing the drop box gearing to get an overdrive.

Bill Stoner did have the gears made for his Eagle drop box. I talked to him a bit at Branson and he told me that he made a one tooth change on the input and output gears. He did not change gear locations in the box. Not sure how all that works (gear center distances are very critical).

He has had good luck with his application. I am not sure how much overdrive he got out of his change, nor the cost to make the conversion.

I had looked into doing that to my drop box and offering it to others several years ago. I had a very qualified gear manufacturer lined up. I asked folks on the board if anyone had a drop box that I could play with and got no response.

Sonnie, what can I say? Some of us OLD mechanical guys can make the conversion to MODERN technology :lol:

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.
User avatar
luvrbus
Club Member
Club Member
Posts: 2981
Joined: Mon Oct 13, 2008 12:50 pm
FMCA #: F262917
Bus Model: 05

Re: Engine Conversions for Eagles

Post by luvrbus »

I see Mel on the board now maybe he can post photos of his full grown Cat in his Eagle A C15 is a monster for a bus Good luck
User avatar
Songman
Club Member
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Posts: 2107
Joined: Tue Oct 07, 2008 1:48 am
FMCA #: F404262
Bus Model: 1993 Silver Eagle Model 15-45
Location: Nashville, TN
Contact:

Re: Engine Conversions for Eagles

Post by Songman »

Here is a picture of Sonnie's Cat from the Branson rally. Not close enough to show detail but it sure looks like a hot rod!

Image
Dale Houston
1993 Eagle 15-45
Nashville, TN
User avatar
luvrbus
Club Member
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Posts: 2981
Joined: Mon Oct 13, 2008 12:50 pm
FMCA #: F262917
Bus Model: 05

Re: Engine Conversions for Eagles

Post by luvrbus »

Dale, Sonnie does have neat setup with the engine I think David at Southern Oregon Desiel had the 1st Cat engine I know of 7 that have Cat engines and 2 were factory installed for a tour line in Ill that ran charters for Cat (no DD for them) goood luck
van
Club Member
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Posts: 1437
Joined: Mon Oct 13, 2008 1:35 pm

Re: Engine Conversions for Eagles

Post by van »

Hey cliff you leave yet/ :roll:
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