DB2 Max Governed RPM

[Hydro-idi]

Hey guys,

A while back, I noticed that my baby moose IP puts out a few more rpm's than the previous DB2 that was on my rig. I was surprised to find that the moose spins upward of 3850 rpm with foot to the floor. And man is she screaming . Seems that my old pump could only muster about 3400 rpm if memory serves me right. So my question is: What is the stock governed rpm for these pumps?

 

[Clb]

Mel is using the turbo guts' and the old worn unit wont spin up as well, that said, when I get back I can look it up in my fsm is no one chimes in,,, although 3850-4000 sounds familiar ???? 3600 and mine is layin down. HARD

 

[snicklas]

If I remember, the Ford Pickup spec'ed pumps should top out about 3800RPM. So your Moose is right on target. I think they begin to de-fuel around 3400 and drop off completely by 3800.

For the IH Medium Duty and U-Haul spec'ed pumps, they were governed at 2800RPM. This helped with the longevity of the engine in the heavier, taller geared trucks......

One thing that holds true with all the IH (Navistar) produced engines put in Ford trucks, the Ford governor will be higher than the IH governor.... Even with the newer engines. The 6.0 redlines north of 4000 RPM (4200 If I remember right, been a few days since I drove the truck). The VT365 in IH trucks is limited to 3200 I think......

 

[Hydro-idi]

Thanks for the info. I hardly wind the engine that high......but with the turbo n all......its been kind of hard to resist lol. It was a good thing I tested her out after the transmission was rebuilt because it was not shifting properly under WOT. Finally got her dialed in and everything seems A OK!

 

[Hydro-idi]

I do recall driving a 7.3 idi uhaul many years back and remember engine taching out at about 2600 rpm. Maximum speed was about 60 mph .

 

[cpdenton]

All the pumps I had on my truck were governed at 3300.

I asked Mel about mine and he told me they set their governors at 3800. He said some folks liked a little more reach than the stock pumps.

 

[Hydro-idi]

All the pumps I had on my truck were governed at 3300.

I asked Mel about mine and he told me they set their governors at 3800. He said some folks liked a little more reach than the stock pumps.

That explains it. Thx

 

[sjwelds]

Yeah mine seems to only hit about 3200 as well.

 

[IDIoit]

mines only hitting 3500ish.
i suppose having 3.55's and 33's effects it
altho ive never made it sing for more than a few seconds.

 

[Hydro-idi]

I have found that old/aftermarket throttle cables will sometimes stretch and not allow full travel of IP lever. This happened to my "Autozone Especial" throttle cable and I put a 1/4 split shot weight on the cable to pick up the slack. This solution has worked for a couple years but have recently found that I really have to mash the throttle to get full travel once again. Went ahead and ordered an OEM cable from Ford's website a couple hours ago. From what I understand, the OEM cables do not stretch as easy as the aftermarket ones. I also eliminated the stiff IP return spring and replaced with a lighter gauge spring which will probably help the cable from stretching as much. Not to mention its much easier to press down on the go pedal .

 

[chris142]

My pump was rebuilt by a stanadyne shop in Fairbanks Alaska sometime before I bought the truck. It will spin up freely to 3800 then its all over by 4000

 

[icanfixall]

I have found that old/aftermarket throttle cables will sometimes stretch and not allow full travel of IP lever. This happened to my "Autozone Especial" throttle cable and I put a 1/4 split shot weight on the cable to pick up the slack. This solution has worked for a couple years but have recently found that I really have to mash the throttle to get full travel once again. Went ahead and ordered an OEM cable from Ford's website a couple hours ago. From what I understand, the OEM cables do not stretch as easy as the aftermarket ones. I also eliminated the stiff IP return spring and replaced with a lighter gauge spring which will probably help the cable from stretching as much. Not to mention its much easier to press down on the go pedal .

Be careful about throttle return springs on these engines. the oem spring actually was a double spring if you look carefully at it. Reason for that is a federal mandate saying we need a back up to the spring just in case one breaks. Slight bending of the cable mount at the intake manifold will remove some cable slack too.

 

[ironworker40]

I had a 1997 IH 4700 with a T444E which is same as a 7.3 powerstroke. It was governed at 2800 iirc. Since it was mine and I bought it new I wanted it turned up. The mechanic at the dealer told me the reson for the lower rpms on the biger trucks is the because the transmisions cant handle the higher rpms. he took out the speed limiter but wouldnt bump the rpms. U haul of corse is another storie. They want to slow you down

 

[OLDBULL8]

To me, it's just crazy to pump a diesel over 3200 RPM, that's 53+ RPM per second. Better be pretty well balanced,or your gonna put a window in it.

 

[FarmerFrank]

I played with my old 6.9 pump and got it to spin around 4100-4200. Yup, I spun 3 main bearings with 230k on it. Sure sounded mean while doing it.