So who has bumped the power on a 6CTA cummins

[Dead Reckoning]

I backed out the main screw 4 turns. Its the one on top under the cover with the 10mm hex. It smokes slightly at idle when cold and none at all after she's warmed up. Makes a huge difference, but I want to make the other adjustments mentioned in this thread. I will wait till I get my boost gauge, and pyro installed though.

 

[cumminsbandit]

This is my truck with just the top screw turned out 2 3/4 turns and 6" exhaust.

https://www.youtube.com/watch?v=otGAPRUsxR0

 

[dochowz]

That black smoke is BEAUTIFUL!!! I'm in Southern California and registered "Historical Vehicle" so I'm hoping that I don't get bothered by anyone. I've installed my boost and pyro gauges already...hoping Saturday to do the mods. I like the exhaust too. I welded in a straight section in mine to bypass the muffler, but the "monster exhaust" looks pretty badass!

 

[Ford Mechanic]

opcorn:

 

[MtnSnow]

Did mine this weekend.... Ended up with 3.5 turns on the top fuel screw and 3 clicks on the governor springs. Now idles at 850 which I don't care for so I'm probably either going to get a real GSK (3k rated) or do a washer shim mod I found some info on for the MW and P7100 pumps. But I do like the increased performance and it seemed much more smooth/happy rolling down the road at 45-50 than it did before.

 

[nevrenufhp]

Did mine this weekend.... Ended up with 3.5 turns on the top fuel screw and 3 clicks on the governor springs. Now idles at 850 which I don't care for so I'm probably either going to get a real GSK (3k rated) or do a washer shim mod I found some info on for the MW and P7100 pumps. But I do like the increased performance and it seemed much more smooth/happy rolling down the road at 45-50 than it did before.

Dropping the idle is only one more adjustment.

 

[MtnSnow]

I tried to get it to drop but just didn't seem to ...I could get it to go up but not down unless I retuned the clicks back to stock...

 

[2old2humps]

I went 4 clicks on the gov springs. it idled @ 950. had to adj the accelerator rod because it was holding the rpm's up. then i could idle it back down to 750 in neutral. just don't adjust the rod to long or it won't go wot when you floor it.

 

[MtnSnow]

I'll look at the accel rod closer this coming weekend but it seemed like it had plenty of flex...as I'm putting in a Pacbrake GSK that I got ordered.

 

[racing4funn]

I just read all 21 pages.. My eyes hurt. What about this instead of me tampering with the pump.
Just buy a set of the 350 hp marine injectors and install. But will these injectors (NO PUMP MODS) alone cause too high an EGTs and warrant a turbo upgrade? I dont want to get into that. Plus I need to be able to tow up to 30K without melted pistons. I know I need an EGT gauge

 

[cumminsbandit]

Don't wast money on injectors. They most likely wouldn't change anything unless you turned up the pump. I'm sure you could achieve 500+hp with stock injectors. And the allison wouldn't like that...

 

[nevrenufhp]

The MW pumps alone cant make that kind of power without serious $$,$$$. They can only be had with 10mm plungers, and Bosch doesnt have listings for anything bigger(not that I found anyway). The 10mm plungers dont make very big power. Adding marine injectors will gain a little bit on a stock pump setting. Adding 350hp injectors(modded for an MW pump), with adjusting the pump, can get you to the 300+hp range. Actual hp will vary due to all the variables(pump setting, engine condition, etc.). One truck may make 280hp, while one may make 360hp.

 

[MtnSnow]

Well I have to say I am totally happy that I went with the Pakbrake 3-4k GSK # hp10029. I used just the 3k set of spring and set it exactly like they suggested (.040-.050) I ended up with .042 and .046 for my settings) and my idle is perfect and my RPM hits 2800 spot on!

Here is a short vid of it running/reving...sorry for the parking brake alarm in the background

So final setup at this time is 3.5 turns on the top fuel screw and the PacBrake GSK

 

[panzerwillie]

Very good info hooping to get a A2 zoom will turn up the fuel and maybe do the GSK , i have the tool for the governor springs some where from my 5.9 PT days will look for it thank you for all the postings ...

 

[MO MV man]

Thanks for the info and video!
When you're used to stock RPM's, 2800 sounds impressive to say the least!

I did my straight pipe/stack yesterday and can't wait to adjust the top fuel screw.
I'm sure a governor adjustment or spring install will follow.

So the HP10029 kit fits the MW pump? I went to Pakbrake's instructions and it says "P pump".

Thanks again!

Well I have to say I am totally happy that I went with the Pakbrake 3-4k GSK # hp10029. I used just the 3k set of spring and set it exactly like they suggested (.040-.050) I ended up with .042 and .046 for my settings) and my idle is perfect and my RPM hits 2800 spot on!

Here is a short vid of it running/reving...sorry for the parking brake alarm in the background

So final setup at this time is 3.5 turns on the top fuel screw and the PacBrake GSK

 

[MtnSnow]

Yes the HP10029 GSK is the one to use with our MW pumps.

 

[wreckerman893]

Okay...this ain't funny anymore. I recovered a M936A2 for a fellow member a while back and had to drive it home with an auxiliary fuel tank on the toolbox because it would not pull fuel from either tank. He is allowing me to work it like a rented mule while awaiting transport to his AO.

Once I got it home and had my way with it I got the issue resolved with a lot of wringing of hands and gnashing of teeth.
It started fine the other day (other than having to slave it off due to dead batteries) and I'm using it to reverse engineer a deuce for a buddy of mine.

This morning I desperately needed to use the wretched invention of the devil to lift the frame of the deuce up and remove the axles. It would not start for anything.

I have fuel to the small spin on filter (there is no big filter on the frame), I have fuel to the injector pump, I have the electric shut off solenoid removed so I can manually shut off the engine and the lever is in the correct location for the engine to run.

When I pump the primer pump I do not hear the "squishy, squishy" (technical term) sound that I hear when I prime my M927A2. When I loosen the fuel line into the IP fuel sprays out like it is under pressure. I cracked the rear injector line on top of the pump and there is no fuel squirting out when the engine is turned over.

I disconnected the fuel line where it goes into the primer pump and blew into it and heard air bubbling in the fuel tanks so I assume that the fuel level is above the bottom of the pickup tube. The fuel gage shows almost half a tank.

Other than using it to dismantle it smaller brethren I can't imagine what I have done to the beast to piss it off.

Any ideas before I call my local diesel doctor to do a house call (after applying a generous amount of lube to my anal orifice)?

 

[Jeepsinker]

Crack open the bleeder on the IP and put some air pressure to whichever tank it is set to draw fuel from. I have a fuel cap with a schrader valve on it for this because these trucks have such notoriously crappy fuel systems. Pressurize the tank until fuel drips out on the ground from the bleeder in a steady stream. Of course, use your common sense and don't blow the tank up.

 

[JxxxOxxxE]

Seems like the wrong thread, but when mine loses prime I usually have to pump it manually 90 to 100 times... Yes, I've done it enough that I've actually counted it...

 

[wreckerman893]

Seems like the wrong thread, but when mine loses prime I usually have to pump it manually 90 to 100 times... Yes, I've done it enough that I've actually counted it...

I have a blister on my palm from pumping the %^%*&$% thing. When I crack the line into the IP fuel sprays out. Is it that hard to get fuel from the pump to the injectors? I even gave it a shot of ether (applied very sparingly) in an attempt to get it to prime. This situation is making me nuttier than squirrel turds.