Reply
 
Thread Tools Display Modes
 
Old 09-17-2019, 07:26 PM   #1
New Member
 
Join Date: Aug 2019
Location: Houston, TX
Posts: 9
Year: 2001
Engine: Cummins 8.3L ISC w/CAPS
8.3 ISC inframe rebuild...

Anyone here have any experience with rebuilding/turning up an 8.3 ISC w/CAPS?

My current engine rating is 260HP/660 TQ (CPL 2690) and I'm looking to "turn up" the factory rating to 350HP/1050 TQ (CPL 2695) by changing the injectors and pistons as prescribed by a Cummins Application Engr.

The best/most cost-efficient way I've found to accomplish this is by ordering an inframe rebuild kit (RP934155) which includes the needed pistons and ordering the injectors from a reputable shop.

This will be a DIY project and any guidance/wisdom would be greatly appreciated.
Audeamus18 is offline   Reply With Quote
Old 09-17-2019, 08:02 PM   #2
Bus Nut
 
TJones's Avatar
 
Join Date: Jul 2017
Location: Rapid City, SD
Posts: 414
Year: 2001
Coachwork: Blue Bird
Chassis: CS RE
Engine: ISC 8.3 L 260 hp
Rated Cap: 36
Quote:
Originally Posted by Audeamus18 View Post
Anyone here have any experience with rebuilding/turning up an 8.3 ISC w/CAPS?

My current engine rating is 260HP/660 TQ (CPL 2690) and I'm looking to "turn up" the factory rating to 350HP/1050 TQ (CPL 2695) by changing the injectors and pistons as prescribed by a Cummins Application Engr.

The best/most cost-efficient way I've found to accomplish this is by ordering an inframe rebuild kit (RP934155) which includes the needed pistons and ordering the injectors from a reputable shop.

This will be a DIY project and any guidance/wisdom would be greatly appreciated.

There are some good you tube videos of engine inframes. I haven't found one for the isc. Will you transmission be able to handle the increase in torque?

Ted
TJones is offline   Reply With Quote
Old 09-18-2019, 08:50 PM   #3
New Member
 
Join Date: Aug 2019
Location: Houston, TX
Posts: 9
Year: 2001
Engine: Cummins 8.3L ISC w/CAPS
Not sure what the difference(s) are between my MD3060, 2500RDS, General purpose trans and an MD3060MH (motorhome) trans, but they often run with 330-350HP and 900-1050TQ stock.

I plan to ask my Allison rep for clarification.


Has anyone else attempted either an ECM flash or a change in components for more torque? I'm curious what others have experienced with this setup.
Audeamus18 is offline   Reply With Quote
Old 09-18-2019, 09:45 PM   #4
Bus Nut
 
TJones's Avatar
 
Join Date: Jul 2017
Location: Rapid City, SD
Posts: 414
Year: 2001
Coachwork: Blue Bird
Chassis: CS RE
Engine: ISC 8.3 L 260 hp
Rated Cap: 36
Quote:
Originally Posted by Audeamus18 View Post
Not sure what the difference(s) are between my MD3060, 2500RDS, General purpose trans and an MD3060MH (motorhome) trans, but they often run with 330-350HP and 900-1050TQ stock.

I plan to ask my Allison rep for clarification.


Has anyone else attempted either an ECM flash or a change in components for more torque? I'm curious what others have experienced with this setup.
I think the md3060 are rated to around 700 ft lbs of torque. I wonder of the MH version is the same transmission just not expected to last as many miles. To get the higher horse power and torque will you also have to go to a bigger turbo or is that taken care of by reprogramming?

Ted
TJones is offline   Reply With Quote
Old 09-20-2019, 03:13 PM   #5
Bus Crazy
 
Join Date: Feb 2012
Location: Salt Lake City Utah
Posts: 1,580
Year: 2000
Chassis: Blue Bird
Engine: ISC 8.3
I've replaced the injection control valve which is in the middle of the stack of the CAPS pump. Also replaced a head gasket and head bolts. That 8.3 head is HEAVY and the bolts are torqued pretty hard - I used a cheater bar. Did all of these at home, but I don't have any video or pictures.


You'll need the Cummins 'engine barring' tool. It's a little gear that goes in through a hole in the bell housing. It engages with the starter ring so you can turn the engine over manually. That's the only special tool I recall needing so far, but there could be others needed for pressing in/out the cylinder liners or something.



You can find a wealth of information for free through Cummins Quikserve. Create an 'owners' account for yourself, add your ESN, and poke around for the service info. It gives instructions, drawings, torque specs, etc.


I'd love to turn mine up some day too.. keep us posted.
family wagon is offline   Reply With Quote
Old 09-21-2019, 09:23 AM   #6
New Member
 
Join Date: Aug 2019
Location: Houston, TX
Posts: 9
Year: 2001
Engine: Cummins 8.3L ISC w/CAPS
Ted,

My current turbo HX40W (3591020) is also on the CPL2695, so I'm assuming so, but I'll have to double-check with Cummins.

The only true 8.3 ISC overhaul vid I've found was on a 6CT Marine, but it did cover most of the components. I'll admit I'm nervous about this, but still determined.
Audeamus18 is offline   Reply With Quote
Old 09-21-2019, 09:32 AM   #7
New Member
 
Join Date: Aug 2019
Location: Houston, TX
Posts: 9
Year: 2001
Engine: Cummins 8.3L ISC w/CAPS
Thanks for the note on the barring tool! I've seen it being used but didn't know the nomenclature.

Was the inj. control valve for a bump, or repair? My first order of business is adding a FASS fuel pump and replacing the fuel lines. Keeping that CAPS happy is a priority.

Anyone had or heard of any success with swapping larger intake/exhaust and/or straight pipe? I see that often in the light-duty world and assume it couldn't hurt.

Michael
Audeamus18 is offline   Reply With Quote
Old 09-21-2019, 10:02 AM   #8
Bus Geek
 
Join Date: May 2009
Location: Columbus Ohio
Posts: 12,004
Year: 1991
Coachwork: Carpenter
Chassis: International 3800
Engine: DTA360 / MT643
Rated Cap: 7 Row Handicap
https://www.allisontransmission.com/...k.pdf?sfvrsn=2


it looks like the school bus version are good for 300 HP.. and the 3200 Motorhome is rated for 450..


some of the notes are confusing. and remember these ratings are for new units with 5th gen controls.. 5th gen controls often work wit hthe newer engines for SEM.. SEM defuels the engine on shifts to prevent glazing the clutches on steep shifts.. during up or downshifts is the most likely time for a transmission to break...



I dont think SEM was available on the ISC in the years we are talking.. so take the ratings at face value...



-Christopher
cadillackid is offline   Reply With Quote
Old 09-26-2019, 12:35 AM   #9
New Member
 
Join Date: Aug 2019
Location: Houston, TX
Posts: 9
Year: 2001
Engine: Cummins 8.3L ISC w/CAPS
Talking Allison update...

Got some great news from my local Allison Distribution branch, Stewart & Stevenson in Houston, TX.

Apparently, the only difference between my MD3060 and the MD3060MH version is a TCM flash or "recalibration"...and a retarder (I'm looking into the PacBrake PRXB = $1,273 for parts). This flash would take care of 6th gear OD unlock and increase HP/TQ capacity, all for 1hr labor = $158!

I'll just need to remove the TCM from the trans and bring it into the shop. Then we start the fun part
Audeamus18 is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


» Featured Campgrounds

Reviews provided by

Powered by vBadvanced CMPS v3.2.3

All times are GMT -5. The time now is 02:15 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
×