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Author Topic: MCI5 Series, repower?  (Read 6538 times)

Offline wg4t50

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MCI5 Series, repower?
« on: December 16, 2012, 06:42:19 PM »
Being sort of a hot rod at heart, and having had the MCI7, I often wondered it the MCI5 Series would handle a bigger HP setup OK, reason I ask, Iseem to recall they used the drop box type rear gearing and wondering how tuff it really is.  The MCI7 had the 23,000 lb rear, and plenty tough unless your a total fool.
ANyway, just wondeirng if anyone ever used a 8V-92 above 500 hp setting.  Feel the weak link would be the drop box like used on the Eagle / Iggle.
I can see a day coming to play the MCI5.
Have a very fine Foretravel, however it is just another Foretravel, unlike a one of a kind bus conversion that shows ones better ideas. ;D
Many Thanks
Dave M
MCI7 20+ Yrs
Foretravel w/ISM500
WG4T CW for ever.
Central Virginia

Offline TomC

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Re: MCI5 Series, repower?
« Reply #1 on: December 16, 2012, 08:44:45 PM »
This has come up several time about repowering a 5. Because of the short distance, about the only setup would be a 6V-92TA and Allison HT740. That will give you 350hp and 1,000lb/ft torque. Plenty for that bus. Good Luck, TomC
Tom & Donna Christman. '77 AMGeneral 10240B; 8V-71TATAIC V730.

Offline bevans6

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Re: MCI5 Series, repower?
« Reply #2 on: December 17, 2012, 04:06:07 AM »
As noted the length is the issue, not the drop box.  It's the same one used on Eagles where 8V-92 is more common.  Can you put an 8V-92 in a MC-5?  Yes, Steve5B has an 8V-92N in his MC5B.  Can you put one in with a 740 trans? No, but a 640 series fits, as does the Spicer 4 speed.  Is more power an issue?  No, I put a 400 hp (nominal) military 8V-71T in my 5C and it just plain loves it.  No overheating, and it goes up hills better than my pickup truck.  The issue other than length is height.  There is essentially no clearance on top of an 8V-71N in the MC5 engine bay, so you either put the turbo on the side or raise the roof.  I fabricated a custom manifold and blower top to put my turbo on the side, while one member here has a beautiful MC5 with a 6V-92 with the turbo on top, with a raised roof and a raised radiator/fan blower compartment, including raising the radiator intakes on the side.

Here is a picture of my setup.

Edit: if you were to find yourself a powerpack out of an M109 self propelled howizter, it is the same engine as mine but has the turbo already on the side.  Passenger side, whereas I put my turbo on the drivers side.  Pic is halfway down the page:  http://www.inetres.com/gp/military/cv/arty/M109.html  We had M109's as the current artillery piece when I was in the Artillery, so many years ago.  Being in the Reserve I never worked on them, but they were all around in the parking lots.  Never looked at the engine back then, I wasn't interested in Detroit's yet...

« Last Edit: December 17, 2012, 04:20:43 AM by bevans6 »
1980 MCI MC-5C, 8V-71T from a M-110 self propelled howitzer
Spicer 8844 4 speed Zen meditation device
Tatamagouche, Nova Scotia

Offline Ed Brenner

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Re: MCI5 Series, repower?
« Reply #3 on: December 17, 2012, 06:06:45 AM »
I've got a Mt654CR (5 speed auto) out of my Eagle if any one with a MCI 5 is wanting to get rid of their
manual trans and leave the 8v71 in. Works great but the 8v71 just ain't enough for me, when I've seen what a 60 series does to these Birds!! I don't want to slow down uphill, might not make it to the top!!! :o :o
Ed
Ed Brenner
77 Eagle 05  Murrells inlet, SC
 " While We're At It " A Busnut's most costly Phrase !!

Offline Ed Hackenbruch

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Re: MCI5 Series, repower?
« Reply #4 on: December 17, 2012, 06:19:30 AM »
The spec sheet that i have on my 644 shows that the rating for net input hp is 300 max, and net torque input is 780 lb. ft. max. Same specs for the 654 trans. I would imagine that there is a fudge factor in that rating of maybe 5-10%?  Anything over those amounts would probably mean a shorter life for the tranny but who knows what that would amount to.
1968 MCI 5A with 8V71 and Allison MT644 transmission.  Western USA

Offline wg4t50

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Re: MCI5 Series, repower?
« Reply #5 on: December 17, 2012, 06:36:55 AM »
Bevens6, & Others
That is the info I was hoping for, being very familiar with the MCI7, not the 5 and never really had a good look when I had the oppurtunity. Do like the plumbing on the turbo side mount, nice looking.  Now the transmission issue, length of tranny is issue. wonder how luch length between the trans yoke and the rear input yoke.  When I did the 12V in the 7, I wound up with a driveshaft 9.375" center to center of U Joint that included the slip joint mid position, could have been closer as has about an inch spacer welded it.  So maybe could manage 8.5" c-t-c. That was using the RTO10, it is slightly longer than the 940 I seem to recall from years ago.
The only other issue would be the cooling, recall the 7 setup was too small even for the 8V-71 @ the 318 rating.
Just trying to find a worthwhile project for a dim wit.
Dave M
MCI7 20+ Yrs
Foretravel w/ISM500
WG4T CW for ever.
Central Virginia

Offline Sam 4106

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Re: MCI5 Series, repower?
« Reply #6 on: December 17, 2012, 06:58:35 AM »
Brian,

Your exhaust piping and intake demonstrate that a TIG welder in the hands of a skilled craftsman can create a work of art. Thanks for sharing your pictures. Sam
1976 MCI-8TA with 8V92 DDEC II and Allison HT740

Offline wg4t50

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Re: MCI5 Series, repower?
« Reply #7 on: December 17, 2012, 09:08:49 AM »
Another question, Weight of the 5, in general, recall the 7 ranged between 30.000 to 34,000 depending on engine and water, fuel load, so trying to figure the approximate weight
Thanks
Dave M
MCI7 20+ Yrs
Foretravel w/ISM500
WG4T CW for ever.
Central Virginia

Offline bevans6

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Re: MCI5 Series, repower?
« Reply #8 on: December 17, 2012, 12:16:05 PM »
My MC-5C is right around 26K lbs, with a moderate load on.  Sam, thanks for the compliment, here is another picture of the air intake.  To give you all an idea of the height issue, it was 1/4" too tall to go in, I had to take it off and slice a bit off the top, and re-weld it.  It started out as the manifold on the engine in the bottom picture, which is what the stock military engine looks like, turbo hung off the back of the engine.
« Last Edit: December 17, 2012, 12:20:52 PM by bevans6 »
1980 MCI MC-5C, 8V-71T from a M-110 self propelled howitzer
Spicer 8844 4 speed Zen meditation device
Tatamagouche, Nova Scotia

Offline wg4t50

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Re: MCI5 Series, repower?
« Reply #9 on: December 17, 2012, 01:10:06 PM »
Just caught the 92N, that is an interesting engine too, with the highspeed blower drive setup, only other high speed blower drive was on a 12V-71N was set for 1200 rpm on a military generator, loved the overdirve setup on that one, it might still be on a shelf smewhere.
I thank you for the pix and sure makes me start getting into that project, there is no fun in a  store bought RV, and no pride, but a MCI7 with a `12V-71, solves all sorts of problems, sorta like tying a bone around your neck so the dog will play with you.  Buddies come out of the woodwork younever knew.
Cheers
Dave M
MCI7 20+ Yrs
Foretravel w/ISM500
WG4T CW for ever.
Central Virginia

Offline Ed Hackenbruch

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Re: MCI5 Series, repower?
« Reply #10 on: December 17, 2012, 02:48:16 PM »
We are at just over 29,000, we have been fulltiming for 9 years so we carry a lot of things. ;D
1968 MCI 5A with 8V71 and Allison MT644 transmission.  Western USA

Offline Fredward

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Re: MCI5 Series, repower?
« Reply #11 on: December 18, 2012, 11:36:29 AM »
Dave,
Another thought on the repower of the MC-5 topic. Not only is the distance between the engine and the drop box short, the engine/transmission is mounted at an angle pointing toward the driver's side of the bust to get to the drop box input which is located off to the left of the differential. I've heard that whatever transmission you try to install, could interfere with the body because of it being angled off to the left.

Ed Brenner, do you know if the 654 is the same size as the 644? I thought it was longer because of the extra gear. I"ve had my 871/4speed out of the bus and there's not much room there.

Fred
Fred Thomson

Offline Ed Hackenbruch

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Re: MCI5 Series, repower?
« Reply #12 on: December 18, 2012, 12:20:22 PM »
I will answer for  the other Ed, ;D    the 654 is the same width, same height, 60 lbs. heavier, and 5 and 3/4 inches longer than the 644
1968 MCI 5A with 8V71 and Allison MT644 transmission.  Western USA

Offline wg4t50

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Re: MCI5 Series, repower?
« Reply #13 on: December 18, 2012, 12:48:37 PM »
Fred, good point.  Ii have spoiled myself with the 7 as I removed the holding tank & etc from curb side, then removed the muffler from street side, all in the name of very easy access to engine & trans.  Of course the 7 has more room to play around in.
Merry Christmas
Dave M
MCI7 20+ Yrs
Foretravel w/ISM500
WG4T CW for ever.
Central Virginia

Offline Fredward

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Re: MCI5 Series, repower?
« Reply #14 on: December 18, 2012, 07:20:42 PM »
Thanks Ed. That would leave me with about a 6" driveshaft behind the 871!
Fred
Fred Thomson