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P400 in the Burb install

n8in8or

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One thing I would like to add that is kinda weird is that even though I know I have valve seat issues on #2 cylinder when I ran both of the pumps that Chris loaned me the #2 hole was clearly firing, no smoke out of the exhaust port and it would burn my hand if I held my hand in front of the exhaust port, (remember, I'm running it without an exhaust mani on the PS side) when I crack open the injection line it would kill that cylinder. But when I ran the Conestoga pump the #2 hole smoked and would not burn my hand but there was a little difference in the running when I cracked open the injector line. I know, I need to add H20 and run it some more which I defiantly intend on doing before I pull the motor.
I’m glad to hear you’re finally on what sounds like a path forward, even though you need to yank it. What are the chances one of the valves in the #2 cylinder was hanging open when the engine was dormant and the humidity in Florida rusted the valve and or seat so now it won’t seal?

Regarding the difference in #2 between the 2 pumps I have 2 thoughts: 1. Were both pumps timed the same? I don’t mean by the line on the front cover, but by a Ferret or luminosity probe. With the lower compression of that cylinder it’s not generating as much heat so that along with a timing issue could make it more difficult for that cylinder to light (at least when the engine is cold). 2. Again with the lower compression, the Conestoga pump is putting out more fuel at idle and could actually be snuffing the flame out - almost like running rich in a gassr.

Either way, it seems like too much of a coincidence for that cylinder to have low compression and it’s also acting funny. I’m glad Chris was able to use his experience to get you over that hump. I have no idea about that cam key.......
 

Twisted Steel Performance

Anything worth doing is worth overdoing.
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Sorry if this was covered earlier in the thread, but what was the intention/ purpose behind 6.2 valves in the P400 head?
Peter, all 6.2 valves aren't larger, only a certain few years were.. The ones in question are .125thou or 1/8" bigger thus allowing more flow through the heads.. My set also have the bigger valves, and I went one step further with the unshrouding around the seat area..

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DieselAmateur

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Thanks for the lesson, learn something new every day here :)

1/8" seems pretty significant, wonder why it wasn't kept that way if it indeed gives better performance? Out of curiosity, which years specifically had the larger valves?

I remember from one of Chris' threads on P400 heads that the valves are noticeably different in the seating area, didn't think other valves would interchange so easily.

@spdgofast sorry the engine is giving you so much trouble, hope this is rock bottom and it can only go up from here!
 

FellowTraveler

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Did Fellow Traveler do his Cummins conversion with the OEM independent suspension or did he go to a straight axle in the front? I feel that going to a straight axle totally looses the factory ride that I like on my Burb. If I was going for a jacked up on 38 or 40 inch tire rig then I would throw away the IFS ride and do a straight axle conversion. Just talking about options for others out there, like I said, I'm to invested in the P400 with the OEM IFS ride at this time so I just have to put my head down and move forward. So it looks like I'll be pulling my 100 mile P400 engine out pretty soon.
I an w/the IFS but in 2wd for shakedown now building a full manual Dodge 47RH/48 4x4 hybrid transmission using a Dodge NP241 DLD front case and a GM NP 241c rear case so far its looking like I will not have to move the IFS x-member from the stock location.

I was going to lower the front IFS diff 2" but that required grinding off lots of reinforcement on the IFS case on drivers side so I'm going to shave upper rightside IFS case in the area of the top 3 bolts it is real close to the Cummins oil pan edge.
 

Twisted Steel Performance

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1/8" seems pretty significant, wonder why it wasn't kept that way if it indeed gives better performance? Out of curiosity, which years specifically had the larger valves?
82-87 6.2's... The valves were canted slightly different in the heads...

And the p400 heads do have more metal under the seats and are able to safely have the bigger seats installed, other heads I won't even attempt it...
 

spdgofast

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I an w/the IFS but in 2wd for shakedown now building a full manual Dodge 47RH/48 4x4 hybrid transmission using a Dodge NP241 DLD front case and a GM NP 241c rear case so far its looking like I will not have to move the IFS x-member from the stock location.

I was going to lower the front IFS diff 2" but that required grinding off lots of reinforcement on the IFS case on drivers side so I'm going to shave upper rightside IFS case in the area of the top 3 bolts it is real close to the Cummins oil pan edge.
So your conversion is on a 4x4 with IFS you just haven't completed the T case and drive shaft configuration yet, correct?

I had a 12 valve Cummins from a 96 5spd manual with the 215HP pump that I was going to install before I went with the P400, I didn't want the added expense of a built 48RE trans with a stand alone computer and a 271 T case which I figured would be like 8 to 10 k plus the engine mods and install, you know how that hindsight is right? 20/20 I still think the shit would be a 06 Cummins EFI live 5.9 twin turbo 48RE and a 271 t case. But then a fully deleted 6.7 with the same setup would work. It's a freaking viscous cycle! If I could only win the Lotto and get all of this shit done!
 

FellowTraveler

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So your conversion is on a 4x4 with IFS you just haven't completed the T case and drive shaft configuration yet, correct?

I had a 12 valve Cummins from a 96 5spd manual with the 215HP pump that I was going to install before I went with the P400, I didn't want the added expense of a built 48RE trans with a stand alone computer and a 271 T case which I figured would be like 8 to 10 k plus the engine mods and install, you know how that hindsight is right? 20/20 I still think the shit would be a 06 Cummins EFI live 5.9 twin turbo 48RE and a 271 t case. But then a fully deleted 6.7 with the same setup would work. It's a freaking viscous cycle! If I could only win the Lotto and get all of this shit done!
Yes to your question.

Since I started with a 47RH which I had already owned from my Ram Cummins I was concerned about the 4L80e braking ability so I built the 47RH hybrid using all 48RE components that fit too include all 6 pinion planets etc....this Dodge series transmission is perhaps the easiest to work on and costs for building are greatly reduced by doing it yourself more like 2.5 to 3k drag racing add another 3k to that figure. Yes there is a DIY learning curve with the valve bodies and the many variations from full manual to simple control or expensive track controllers. I don't race my diesel if I want speed I jump on my Busa for the Adrenalin rush it always gives.

My full manual valve body is the only way to combine both the 47RH/48RE components so they work the shifter has a thumb switch to shut off lockup when downshifting "no shutdown say goodby to trans..."

A word on the stock input intermeadiate and output shafts they are claimed to generally good too 450 HP level that's crazy torque and that is what breaks thing quickly behind any Cummins.
 
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