CM 870 looking for more power

[CornHauler]

I have a CM870 CPL8519 with AB10339.17 that I am rebuilding to the higher hp CPL8518 which is basically adding the spring loaded idler and cam gears in the front from what I can see. But the question is how much power can I get out of this thing safely and what tune do I need to do it? It is out of a 2007 379 Pete with RTLO18913 and 3.90 gears pulling 154,000 gross most of the time. I don't really want to delete it I just want it to run right. I had the block machined and liner heights are at .013.

[Rawze]

First of all, putting in the spring loaded gears is simply a waste of moneys and frankly, bad choice vs the straight gears. They have absolutely no advantage whatsoever, are more problematic over time, and can cause catastrophic gear train damage if not installed exactly right. It will also NOT change anything power-related whatsoever.
Here is one example of this .. about half way down the post...
ref: http://rawze.com/forums/showthread.php?t...2#pid25522

The actual tier2 (mid-tier) to tier1(high power tier) hardware changes are bigger injectors, different injector and valve cams to go with those injectors, different pistons, and sometimes a different head with the bigger exhaust valve openings too.

Also, with a heavy haul operation and higher average HP loads, you need the larger 500-series model VG turbo to go with that too. The turbo with the titanium (high heat) exhaust turbine is required for heavy-haul.. and not the one that is made for more fuel efficiency.

3.90's aren't terrible, but they are in the upper end vs what you are pulling. Some 4.33's or better yet .. some 4.86's would be my choice.

Also, the 0.013" liner height is a bit low. Should have been 0.015" - 0.016" + re-torque head after letting it sit over night, + al the other things to do to make a million mile+ engine etc.
ref: http://rawze.com/forums/showthread.php?t...6#pid70606


lastly.. it is the high torque + driving it below 1500 in a hard pull that wears out these engines. 600 HP is fine .. but 1850trq is as high as someone should go.. plus learning to keep it above 1500 when pulling hard, backing off of it and using lower gear ranges so that your foot is not all the way in the floor all the time + to get the rpm up where it should be (1500 - 1900 range when pulling).

[CornHauler]

(01-07-2023 )Rawze Wrote:  First of all, putting in the spring loaded gears is simply a waste of moneys and frankly, bad choice vs the straight gears. They have absolutely no advantage whatsoever, are more problematic over time, and can cause catastrophic gear train damage if not installed exactly right. It will also NOT change anything power-related whatsoever.
Here is one example of this .. about half way down the post...
ref: http://rawze.com/forums/showthread.php?t...2#pid25522

The actual tier2 (mid-tier) to tier1(high power tier) hardware changes are bigger injectors, different injector and valve cams to go with those injectors, different pistons, and sometimes a different head with the bigger exhaust valve openings too.

Also, with a heavy haul operation and higher average HP loads, you need the larger 500-series model VG turbo to go with that too. The turbo with the titanium (high heat) exhaust turbine is required for heavy-haul.. and not the one that is made for more fuel efficiency.

3.90's aren't terrible, but they are in the upper end vs what you are pulling. Some 4.33's or better yet .. some 4.86's would be my choice.

Also, the 0.013" liner height is a bit low. Should have been 0.015" - 0.016" + re-torque head after letting it sit over night, + al the other things to do to make a million mile+ engine etc.
ref: http://rawze.com/forums/showthread.php?t...6#pid70606


lastly.. it is the high torque + driving it below 1500 in a hard pull that wears out these engines. 600 HP is fine .. but 1850trq is as high as someone should go.. plus learning to keep it above 1500 when pulling hard, backing off of it and using lower gear ranges so that your foot is not all the way in the floor all the time + to get the rpm up where it should be (1500 - 1900 range when pulling).

Thank You for the info. Comparing my 475 hp CPL8519 to the 530 CPL8518 it appears that my engine has the same injectors 4088665 and the same injector cam 4101432 and the same turbo. I don't have to use the spring gears if they are a problem I just went that route on the advise of a local mechanic that is pretty familiar with ISX's. Can you hook me up with somebody that could program this thing so it runs right when I get it going?

[Rawze]

Just for future info...

CPL8518 ...
camshaft: 4101432,4059331
piston: 4923743
injector: 4088665
head: 4925775

CPL8519 ...
camshaft: 4101432, 4059331
piston: 4923743
injector: 4088665
head: 4925775

As far as programming it .. forum member 'running rough' does most of the CM870's around here. His 870 programming is safe and has been reviewed many times.