I just got a 2001 cummins ram with 124k on it. (I'm new to the diesel world) and I was wondering if anyone knows about how long the life expectancy is on the motor. It seems to have been taken care of in the past so I'm hoping to get at least 300k out of it?

 

300k should be no problem. If treaten well, I would say between 500k and 600k is reasonable, but if you mod it then that will decrease. The one weak point is the lift pump, if never changed you'll want to swap that out asap or risk burning up your vp 44, very pricey to replace

 

Jake, check out this guy's theyry about lift pumps ...

http://www.cumminsforum.com/forum/98...4s-friend.html

( first post )

Watch his video too.

 

Sounds like he knows his stuff, thats why the fass has a return line coming off the pump back to the filler neck. The stock return line has to much restriction to flow that much fuel effieceintly.

 

Did you notice his last comment in his post where he comments on people mounting FASS's up under the hood? I thought of you right away when Isaw that !!

 

I'm not worried, but only time will tell. Plus the pump has a 6year warrenty.

 

Now that is interesting!

 

IMHO he is just a bit off, cavitaiton is caused by the pump not moving enough fluid to keep it cool, hence when he pinched off the discharge, when it looses enough cooling flow the liguid in the pump starts to boil. my guess from the video is there is some sort of relief device in the pump to protect it from over pressure. I am assuming that the pump is a positive displacement type so if it can't move enough fluid it will just keep building pressure until it tears itself apart that is why they put relief devices on them or minimum flow lines.

 

His theories are pretty interresting though, and props to him for sharing his theories with us. Wether we agree or not, props to him for making us at least think about it.

As far as the bubbles go, I always thought the only way to get bubbles was to introduce air. I'm still confused about how you get bubbles without air, but his submarine theory really made me think.

 

The pressure relief is not on the lift pump, its on the vp44. That is why he was able to cause the pump to cavitate by restriciting the outlet line.
Right out of the encylopedia for ya mayfair. NOW SIT DOWN AND LEARN SOMETHING[sm=boink3.gif]

Suction cavitation
Suction cavitation occurs when the pump suction is under a low pressure/high vacuum condition where the liquid turns into a vapor at the eye of the pump impeller. This vapor is carried over to the discharge side of the pump where it no longer sees vacuum and is compressed back into a liquid by the discharge pressure. This imploding action occurs violently and attacks the face of the impeller. An impeller that has been operating under a suction cavitation condition has large chunks of material removed from its face causing premature failure of the pump. [edit]

Discharge cavitation
Discharge cavitation occurs when the pump discharge pressure is extremely high, normally occurring in a pump that is running at less than 10% of its best efficiency point. The high discharge pressure causes the majority of the fluid to circulate inside the pump instead of being allowed to flow out the discharge. As the liquid flows around the impeller it must pass through the small clearance between the impeller and the pump cutwater at extremely high velocity. This velocity causes a vacuum to develop at the cutwater (similar to what occurs in a venturi) which turns the liquid into a vapor. A pump that has been operating under these conditions shows premature wear of the impeller vane tips and the pump cutwater. In addition, due to the high pressure conditions, premature failure of the pump's mechanical seal and bearings can be expected. Under extreme conditions, this can break the impeller shaft. Discharge cavitation is believed to be the cause of the cracking of joints.Serious damages are caused by cavitation.