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-   94-98 2nd Gen. 12V (http://www.competitiondiesel.com/forums/forumdisplay.php?f=87)
-   -   2001 12v swap (http://www.competitiondiesel.com/forums/showthread.php?t=197385)

79powerwagon 08-13-2017 03:05 PM

2001 12v swap
 
I recently swapped my 2001 24v out for a 160hp ppump 12v out of a FedEx truck. This is my first PPump truck.

Looking for some advice specific to my application

Truck has a NV5600 and 35's, south bend OFE,60 lb springs, Allen headbolts

Daily driver and occasional hauler. Nothing crazy.

Hoping to be around 400hp maybe a bit more without pushing limits of the clutch.

I have ground the plate, afc barrel. Full forward. Piston pump at 20-30 psi. Stretched ofv spring. Throttle arm is hitting plate flush. 16* timing. 4k gsk.

Just got it on the road and have nearly no smoke.

Power is OK feels about like the VP did but less low end torque and a bit more top end.

Guess I expected more. Thinking I may have a boost leak and it's not moving Afc. Sound right??

Thanks

BigPapa 08-13-2017 03:33 PM

Injectors and DV's will get you closer. A set of 215's and some 181 DV's are readily available used and won't break your wallet for a decent boost you'll definitely notice.

79powerwagon 08-13-2017 05:07 PM

Sounds good, thank you.

Does it sound right that this thing will not smoke with the current mods?

Here's a few photos of the truck

https://i.imgur.com/F9uenmq_d.jpg?ma...&fidelity=high
https://i.imgur.com/XSP1kOR_d.jpg?ma...&fidelity=high

79powerwagon 08-14-2017 10:05 AM

Also getting a bit of a hard start after sitting along with a fluttering fuel pressure gauge. Ordered a Tork tek ofv020 hopefully that solves it.

BigPapa 08-14-2017 10:39 AM

If you're running the mechanical lift pump it's going to "spike" of "flutter" as you called it. It's not steady like an electric pump. You'll need a snubber to calm it down. The OFV won't help with that.

Describe the hard start and when it happens.

79powerwagon 08-14-2017 10:53 AM

I do have a snubber. I can almost hear the change when I watch the gauge flutter while criuising.

Starts up fine initially and after a few seconds sounds like it starves for fuel and either dies or picks back up. Starts again with some throttle and runs fine.

Seems to happen after it sits for any period of time. Not any worse overnight.

BigPapa 08-14-2017 11:00 AM

The rubber hose in the return line between the OFV to the tank are known to deteriorate and suck air causing the lift pump to lose prime.

Also, not sure on your engine, but on our trucks there is a fuel heater between the pre-filter bowl and the base that also causes problems. Most remove it and throw it away.

79powerwagon 08-14-2017 11:07 AM

I am going to have to inspect the return line. I did replace a large section of it from the OFV to the factory plastic line.

Truck already had 3/8 rubber line from tank to VP. I got rid of all the factory crap on the engine,3/8 line the whole way with larger banjos.

I did mount the 24v fuel bowl (new Baldwin filter) on the frame until I can get a dual base for cat filters.

79powerwagon 08-15-2017 06:53 AM

I changed out the return line section from ofv-plastic line for some clear tubing. Looks like I have air going through it.

I'd guess most likely place for a leak is at the fuel bowl or the factory fuel pickup in tank.


Now, is the piston pump OK pulling fuel through a filter or better off pushing?

95cummins5.9 08-15-2017 08:43 AM

It works best pushing.

BigPapa 08-15-2017 10:45 AM

Pushing.

79powerwagon 08-18-2017 07:25 AM

Thanks guys.

The tork tek ofv did help a bit, gauge does not jump around like it did.

Still have the sputter on startup, I ran a hose right off the lift pump into a can of fuel and still looked like I had air, I don't see any bubbles in the return at idle but when it's revved there is a rush of what looks like bubbles.

I've got over 400 miles on the clutch now so I have been rolling into throttle a bit harder and it definitely feels better.

The way my throttle linkage is set up it takes a lot more pedal input than original. It's hard to say if the pump is just not fueling down low or what but it takes much more throttle to get into the torque than the VP did. (Which with the smarty was right off idle)

Is this a characteristic of the ppump and 16* timing or do I just need to keep increasing preboost? I have the starwheel all the way forward and have been increasing preboost in small amounts on every drive. Still have a ways left to go.

The top end power is much better than the VP but I'd like to have that grunt off the line of possible.

79powerwagon 08-25-2017 07:15 PM

So I finally found the air leak. Pressurized the tank and waited, started dripping out of the steel JIC fitting I have on the suction side of the lift pump. Cleaned up the flare surface and no more air.

Also went in a good bit with the preboost. Woke it right up.

I'm very impressed with this engine. I have had a few common rails and VE trucks, this seems to be the best combo of both. And no worries about an over sensitive fuel system.

Looking at injectors, for those that have ran them, would a 5x12 set over power my south bend OFE?

Thanks for the help.

Sam

79powerwagon 08-29-2017 07:26 AM

So it seems to be running pretty well but I am still wondering about the low end.

I never ran this engine while it was stock so I have nothing to compare it to.

The vp/24v was able to pretty much idle off in 2nd gear, with a strong start from a stop.

Should this 12v be able to do the same? It seems to 'fall under itself' while taking off in 2nd, with a good amount of throttle to get it going, and from ~1/4-3/8 throttle and up it takes off strong. If I lay into it harder it does fuel. ( good puff of smoke)

I'm wondering if I need to tweak the gov springs, I used a TST kit and the stud protrusion was in spec. Has anyone ran into this before?

badbowtie 08-29-2017 08:07 AM

It is in your gov spring setup, try backing both sides off 1 or 2 clicks. I don't know much about tst springs but some others the seat is too thick and must have .020 machined off the be able to obtain a strong idle. I ended up spending the money for a good set of bosch springs, made life much better. A grabby dual disk and weak idle are not a fun combo. You will find most guys who have issues are running a manual transmission.

Sent from my SAMSUNG-SM-G900A using Tapatalk

79powerwagon 08-29-2017 11:03 AM

Thanks.

Supposedly TST makes a good gsk so that's why I bought them.

Ill try adjusting them and report back.

79powerwagon 08-29-2017 06:46 PM

Found the power :)

I went one click tighter, throttle response improved.

Went another click, even better. It raised the idle a good bit so I brought the low idle screw down. It now takes a touch of throttle to fire off. Tempted to try another click.

It's still a bit tricky off the line but much less effort. Cruises with less throttle and lower egts. Damn near bangs gears like my old CR with a smarty though.

Now I have to re-relearn how to drive it. And add a throttle return spring.

Bodacious 08-29-2017 09:02 PM

Don't know much about pumps but I do like your avatar.

79powerwagon 08-30-2017 05:30 AM

Yeah. That's my 79 warlock/12v budget beater.

Currently down with a grenaded steering box.

79powerwagon 08-31-2017 03:16 PM

About push/pull filtering....

I would like to keep my filters mounted in a spot that is easy to access. Currently I have a filter mounted right behind the cab under the flatbed.

I just made a dual base for a Cat 1r0750 and Water separator. I'd like to have the fuel push through it but there's not much room left in the engine bay.

Thinking about running the fuel supply from the LP back to the filters mounted behind the cab, and then back to the IP.

Anyone done something like this? Too much fuel line to travel through?


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