I just got off the phone with the local Bosch Tech, and the news he tells me is not good. I tried getting the 3200 spring from him and he says he won't sell it to me. He's had the pump housings fail to often when the fuel rate it allowed to run that high in the RPMs. He says the pump is simply not built to pass fuel at that high a rate, and 6 months from now i would need a new housing and plunger for sure. I have yet to go inside this pump so I am taking his word for it. I was wondering if any of ya'll have had this pump turned up with the 3200 spring install for a number of years and have run thousands of miles with no trouble. Right now I'm sticking with the stock spring, and the pump mods I've got. I need my truck to run thousands of miles per year, not 300 foot sled pulls one weekend per month. One question that does bother me is if the springs are so terrible, then why does bosch even make them??? Let me know what ya'll think/know.

talk later,
Stanley

 

alot of it dpends onhow many miles are already on your pump, my grandfather's 89 cummins has 327000 miles on it, never have taken a wrench to the motor, only thing replaced was the alternator, so these pumps can run forever stock, im not sure about being turned up

 

If the pump couldn't take it, why the hell would BOSCH the FREAKIN PUMP MANUFACTURER make the spring? Not mad at you, mad at the stupidity of that guy. I've never heard of a pump housing failing. It's not like it's running high pressures into the pump.

 

oh i agree with you 2001shrtbedcummins, im just saying, they may not be allowed to sell you that spring if your pump has "x" amount of miles on it for warranty reasons. id sy go for it and see what happens, im willing to bet you'll be okay.

 

what's the worst that can happen...you have to buy a 785 dollar pump?
Naw, it'll be alright.

 

there are hundreds of guys on first gen websites that have run thes springs for 10's of thousands of miles and never had a problem.......sounds like the guy is an idiot personally and is just like the pump shop down the street, if its high performance its BAD!!!!!!!............and this is why the diesel industry will always have a sore spot to it......people like that.....

 

I doubt he's an idiot, he probably has seen damage. I'm sure that 3200 RPM is going to wear things out a lot faster than 2600 RPM. I probably wouldn't go over rated spec on an engine doing actual work, like a hydraulic or water pump.

Bosch makes different springs for different versions of the VE pump. Our trucks have 12mm plungers stock and spin to 2600 RPM. Bosch makes another VE pump with 9mm plungers for Volkswagens, and those spin to 5000 RPM. A 12mm plunger is going to wear out a lot faster at 5000 RPM than a 9mm plunger. It'd probably a splode.

That said, 3200 RPM isn't going to hurt anything immediately. I put around 15,000 miles on with the 3200 in my last pump, and a few thousand miles of those were non-overdrive freeway runs through the desert where I was keeping the engine above 3000 RPM for hours at a time (at 1200 degrees EGT and 10-15 PSI boost). Half of the total miles were around 3000 RPM. And that was with the pressure turned up as far as it can go too, and on a pump that had 300,000 miles on it before I touched it.

Increasing pressure with the full power screw is probably more of a lifetime-limiting move than running at 3000 RPM.

Now, all that said, just because you have the 3200 RPM spring doesn't mean you need to use it between every gear every day. It sure as heck isn't going to hurt anything if you just wrap it out for a minute or so every day.


Call the Bosch guy back and tell him that you know guys running trucks with timing advanced a full tooth and a half, pump pressure turned to the max, no AFC and 50 PSI of lift pump pressure... That'll make a guy used to industrial applications streak his drawers.

 

Justin, just get the spring and enjoy it. I've already put over 10k on the spring in my 92 and my dually has had one since '98. Its not just a mod to get you a few hundred more rpm, it changes the fueling throughout the whole band.

 

It was thought (even by Piers Harry) that the VE would never hold up and be dependable at more than about 280rwhp (in 99-2000). Then it was discovered that the reason the pumps failed at higher power ratings was lack of supply pressure and volume. Take care of that with a low pressure piston pump, and all should be well. At the least, get a fuel pressure gauge and keep the pressure above 3psi at all times, preferrably 5-10 (if the pump will do that; stock diaphragm pumps only make about 6-8psi).

I have about 30K on my pump with the 3200rpm spring. No problems yet, except excessive fuel consumption when I use the RPMs. If I had it to do again, I wouldnt get it since I have 3.54s, but I wouldnt be without the spring if I had 4.10s in the rear.

Daniel