Mammoth tunes

[Running rough]

Honestly how much hp and torque is a safe limit for heavy haul on the isx15, I have driven pretty much all versions of the red moter and at stock and 'tuned' ratings, currently have a 871 turbo on the cm2250 and I thought I had power with the stock turbo, honestly I was happy enough with 2050 torque, this thing here is just crazy now, probly get it put back to a more reasonable setting,

[Rig Wrench]

(11-17-2016 )Running rough Wrote:  Honestly how much hp and torque is a safe limit for heavy haul on the isx15, I have driven pretty much all versions of the red moter and at stock and 'tuned' ratings, currently have a 871 turbo on the cm2250 and I thought I had power with the stock turbo, honestly I was happy enough with 2050 torque, this thing here is just crazy now, probly get it put back to a more reasonable setting,

After I Dyno I'll let you know

[Rawze]

The problem is the liner height from the factory. It is not high enough for more than about 600 HP or so, and with the higher compression ratios of the CM2250 and even higher CM2350 engines, it is higher and higher risk for liner issues at high power levels.

Guys want monster power and torque out of their engines but they cry like little girls when they start getting head gasket and liner issues.

Personally, if it has not been hand built for extra power, and the liner height not corrected for it... much more than about 575 hp is not a good idea for long term (expected million miles) use out of an ISX.

If your willing to take the risks though, and are able to afford a new head and counter-bored block, and in-frame it because you just have money to burn and bag about to stroke your ego,.. because that is all you are doing,.. only stroking your ego by turning one up that high instead of re-gearing the truck for the application properly (much safer and cheaper in the end) ...

I have seen and set for people (because they asked me for it knowing the risks already), ISX engine in the 700 - 800 HP range that had no issues, and lasted a very long time. This is the exception though, not the rule. About 30% or more of the ones I turned up past about 575 or so,.. They always end up with a liner issue down the road... Then cry when it costs them $15,000 - 20,000 to get it fixed. - I know this, because they always bring the truck back around to have it turned back down to something more reasonable after it made them realize that more, more, more, only costs you more money and has nothing whatsoever to do with making a long term profit with the equipment.

These newer CM2250's and even worse, the CM2350 with its even higher compression ratio,.. the risk is much higher... Hell, they even have head gasket and liner issues from the factory,.. because they didn't bother to raise the liner height to compensate for the higher compression ratio from the factory.

No one takes that into account at all,... then you get a few guys trying higher power levels with them, going above 600+ and 625+ .. and they get away with it for a while, then they want more, because they see no problems so far ... .. And then peer pressure makes everyone else around them want it too,.. but it really is NOT a good thing at all for those engines unless they have been modified for it.

Even if you modify one for higher power, and have it counter-bored, head hand torqued, etc. and then turn one up to the 700+ or even the 800+ range,.. It will have a short lifespan compared to lower power levels, and it can get dramatically shorter. The head is usually what will not last long, not the bottom end. they simply only can take so much mechanical stress.


Just my own observations on them, I have custom tuned a few for dyno competition that were more than 900 HP on competition dynos, a couple at 1100 HP, run just fine and don't even make smoke out of them at those levels. .. Unilevers has helped build a CM871 for 1500-HP that holds up just fine,.. but everything was re-done, and it is for competition only... longevity is NOT their priority, and the people who have done this have money to burn if something falls apart.


if you ask me,..more power is NOT where it is at if you need to move something more efficiently. Getting equipment meant for what you are doing is more important and cheaper in the end. Lower gear ratios, heavier drive line and frame components, etc. is the correct way to solve those kinds of problems. NOT more HP out of the engine. It is the most expensive component in the drive-line and should never be pushed close to, and especially past its designed intention just to make someone feel better. -- GET A NEW HOBBY AND GO BUY A RACE CAR INSTEAD!,.

[Nilao]

I like mine at 485 hp. Just hand built mine and raised the liner height to .014. The thought of turning it up crossed my mind....for about a second. I decided a few extra seconds of time spent climbing a hill is worth a few hundred thousand miles of engine life.