Engine/Transmission (1994 - 1998) Take your plate out!!!!!!!

[Joseph Donnelly]

I'm trying to keep my dog outta this fight

However, I need to comment here:



++When the truck is cut off, the governor springs push the rack forward to increase fueling. ++



They would, and that would increase engine speed, except that there is another lever that pulls back the rack all the way when the electrical fuel shutdown solenoid loses power.



Wanna buy an almost new 370 hp pump--disassembled, cleaned checked, reassembled, balanced by the Bosch guy? Or how about a new 913 pump for twice the money? Which one is the better value and which one will make you more power? Which one will give you more happy hours caressing it and making appropriate noises while moving the levers

 

[Don M]

CS,



We are just going to have to disagree on some things.

I do agree a stock truck may not be able to get the plunger rotated far enough to get over to the advance protrusion.



Im tired now.



CA,



Maybe tomorrow. Im tired.



Don~

 

[Sled Puller]

Originally posted by Don M

CS,



We are just going to have to disagree on some things.

I



Don~

No way man!!!

You just can't quit that easy, you have not broke 20 pages yet!



To me, you can't just agree to disagree, there is a right and a wrong here, and I have not made up my mind yet, I expect to see you back in the AM.

Gene

 

[Cummins Corvette]

I'm REALLY wanting to see that pic Don. Just the same as the other but hold the plunger square to the camera so I can get a good look at the helix. thanks

 

[TxDieselKid]

Originally posted by Sled Puller





No way man!!!

You just can't quit that easy, you have not broke 20 pages yet!



To me, you can't just agree to disagree, there is a right and a wrong here, and I have not made up my mind yet, I expect to see you back in the AM.

Gene

Don? You quit? Your not Don, your a DD man keeping us from learning!lol



Hope you get some rest, and start up again tommorw!



Andrew

 

[Don M]

Chris Strickland,



To sum up.



The plunger does not retard the timing ever. Maybe you could say it does retard the timing from an advanced position. It is word play though and not really the proper terminology.



I believe you are correct that the timing is never advanced in a STOCK pump because the rack cant move far enough forward to ever rotate the plunger to that point. If we begin to talk about modified pumps the advance could be used in the upper rpm bands. Perhaps this has been my point all along



I do know that when the pump is cold the rocker will move under the cam plate and go into the cold start region. This is full forward and rotates the plunger all the way back to the protrusion again. Im beginning to think the plunger is only using the protrusion to start the truck and does not idle in that position. It seems rediculous to idle at a higher timing setting than you set it static.



I certainly apologize for yesterday. Your the last fella I wanted to get it going with. I was not understanding what you meant when you said the timing "retarded" I gotcha now!



Looks like we agree on the plunger never being able to advance the timing in a stock pump, but disagree that the pump plunger is advanced when the engine is at idle.





CA, I will take all the dern pictures you want.



Don~

 

[Strick-9]

Joe,



You're right. The solenoid does push the rack backward to kill the motor. Otherwise it would continue idling. But if you'll read my instructions on how to visually inspected the relationship between the spill port and the top of the plunger protrusions, you'll see that I included a step to "pull up the shut off solenoid. "



BUT, once the shutoff solenoid is pulled up, with the engine off, the plungers are rotated to a heavier fueling position than where the truck idles. It's very important to grasp this concept as this will tell you what portion of the protrusion the fill port uses during idling.



We could take anyone's pump apart and in about 30 minutes, and show that the pump idles using one of the protrusions on top of the plunger. But that's very hard to describe to people on the internet.



If the truck idles using one of the protrusions, than there is NO WAY timing can advance from that position.



It can ONLY retard.



-Chris

 

[JIM S.]

little dog sneaking into the big dogs playground.

So... . am I right in thinking that the little pump (160 HP) does not have any of these protrusions?... . that the top of the plunger on mine is just flat. if so that would mean the little pumps run at static timing all the time???

Jim

 

[Don M]

Jim, yes this is correct. The plunger has no built in advance. Flat. The only thing you will see looking down the barrel is the lateral groove that leads to the helix below.



Don~

 

[jimk]

pump timing

Don will the 215 hp pump net better mileage along with better throttle response, every thing else equal?. Because of the better pump along with other things, I had thought a 98 with a five speed would suit my needs. Thanks Jimk

 

[Don M]

The 215 pump has performance advantages over the little 160,175, and 180 pumps.

I had mileage readings of 20plus MPG with my 215 pump with a number 11 plate and still made 348HP.

The most I have seen with the smaller pumps is about 450HP.

Im sure others are getting more, but I dont know them.

All in all the 215 pump is my favorite right now. Maybe the Piers pump with larger plunger and barrel elements will be better. Who knows.



Don~

 

[Sled Puller]

I have seen 180 pumps over 500hp.

 

[Strick-9]

To sum it up using Don's words:

I do agree a stock truck may not be able to get the plunger rotated far enough to get over to the advance protrusion.



I believe you are correct that the timing is never advanced in a STOCK pump because the rack cant move far enough forward to ever rotate the plunger to that point.



Looks like we agree on the plunger never being able to advance the timing in a stock pump.

You keep trying to convince everyone that there is timing advance built into these pumps as rack travel increases. Yet, after a little lesson, you now agree that it doesn't happen on stock trucks.



These plungers weren't built so we could rotate the barrels, remove camplates and stop plugs just to get a few degrees of advance under maximum rack travel. That's NOT the reason for the protrusions. They were built for STOCK trucks.



Why do you think the Bosch engineers put those protrusions there for stock applications?



I'd love to hear your answer for that.



Remember that everything works together as a system. With a stock pump, the governor starts defueling the rack as rpm increases. So regardless, of throttle position the rack will be defueling and moving up to the higher timing. More RPM = less rack travel = more timing advance.



I think that's what you keep looking for. Timing should advance as RPM increases. But governor spring kits throw that out the window because they keep the rack further forward at the 'lower' timing.



More rack travel = less timing.



As with automatic trannies or pumps or turbos or anything, you really have to understand the entire system before you can TRULY understand any one part. Looking at a P&B in hand doesn't help if you don't know how the control system (governor) operates it.



Can we agree that is how the stock system was designed to work? As the rack is pulled back by the governor as rpm increases, the timing advances.



-Chris

 

[JIM S.]

OK I have a question... . Ive had impression the P7100 pump was originaly made for the 8. 3, in that case the pump would be pumping alot more fuel... and use the protrusions in a "stock truck"... I dont know... just an Idea, probably a bad one

Jim

 

[Strick-9]

Jim S.



The amount of fuel delivered from a P7100 at the bottom of the helix is WAY more fuel than even an 8. 3 can burn properly.



Don M,



Don't be afraid of the truth man. Come on back. Those cows flying around yet? LOL!



It takes a big man to admit he was wrong.



-Chris

 

[HoleshotHolset]

GOOD THREAD!!



Matt - still plateless..... time to grind the stock plate... . I went for a ride today and noticed at high rpms the smoke isn't quite black. Gee... . having all that fuel unburnt isn't so good afterall... ...

 

[Dfeland]

What the END????? What the **** is the matter with you guys this was just getting good!:{

 

[Cummins Corvette]

Don- how about that picture... ... ... ... ... ..... pleeeeeeeeeeeeeeeze!!Oo.

 

[Todd T]

Excellent thread guys. the branch nearly broke a few times but you climbed back in to save it.

 

[Cummins Corvette]

Don?