Failed 26 year old original db2, what’s inside? What goes wrong?

Clb

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Small linear actuators???
Seems like a LOT of work when the answers allways gunna be a different eng.:sorry:
 

nelstomlinson

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The torque screw basically is an adjustable stop for the metering valve, limiting how much fuel can get through the mv and into the charging ports in the head.

So this let's you turn the fuel up or down? Is there a reason not to set it high and leave it there? We could come up with a sane way to control that screw from inside the cab, but I'm not sure why we'd want to.
 

hacked89

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The lock nut has to stay to retain the o ring against the housing and seal the torque screw. Y’all can experiment with electric control if you like, but I plan to keep electronics off my db2s indefinitely. It would be more difficult to do with the smaller pumps like 90 and 110s because of the retained light load advance but locked timing pumps I have external controls available for anyone who wants to have the ability to adjust power on the fly with my 130 and larger pumps, all done mechanically with control in the cab. We are going to be showcasing it on a project I’ll be making a thread for once it hits the dyno.
I'm looking forward to that thread [emoji6]
Very curious to see now that the N/A rods are established as the weak point. Whether the turbo rods or pistons are gonna be next. It would be nice if it's not the turbo rods cause otherwise that means we would have to work with machine shops and use PSD rods. Ive read the dimensional comparisons.

Also thanks for the rotary pump explanations and Q&A in this thread. I read a bunch of literature and training video to keep my questions to a minimum and think I have an OK grasp now.

I realize now what it looks like and means with the advance piston so my pump is essentially like locking out the vacuum advance to max in gas distributor world + your secret sauce to get it to peak 160cc on factory spec plungers.

Sent from my SM-G955U using Tapatalk
 

Laine D

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Small linear actuators???
Seems like a LOT of work when the answers allways gunna be a different eng.:sorry:
I wasn’t saying anything electronically controlled at all. I think I should’ve explained that better. I mean like a literal mechanically controlled rotary thing so you can just turn the screw from in the cab LOL.
 

Thewespaul

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So this let's you turn the fuel up or down? Is there a reason not to set it high and leave it there? We could come up with a sane way to control that screw from inside the cab, but I'm not sure why we'd want to.
Yes, and the adjustment is good for hot pumps where daily driving with 400+cc is not warranted, but needed when the Cummins bros need a lesson.
 

Clb

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I wasn’t saying anything electronically controlled at all. I think I should’ve explained that better. I mean like a literal mechanically controlled rotary thing so you can just turn the screw from in the cab LOL.

No worries, even a camloc type fitting and hand wheel sort of get up could work.

My point was more to the point of, harvester made dozers once tryin to chase cat.....
There is a reason they succumbed to the venerable catarpiller drive.
I think navistar picked the cheap was out with the 6.9/7.3.
We will NEVER compleatly overcome the inhearent (sp) shortcomings of this platform (my .02).
 

Clb

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Wes
Question
Would there be any reason to crack open a low mile ip other than leakage?

Are there componnents that break down with age?


Eg. 1993 idi, (093 added 1993). <60 K FACTORY miles, no leaks, starts right up, pulls smooth, idles smooth, great drivability, just sucks fuel.
 

bilbo

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That’s very good, although turning the pumps fuel delivery up won’t have any negative affects for reliability, in fact you can often cheat a bit more life out of a worn pump by turning the fuel up. Your high idle issue is likely unrelated to the pump, it’s probably an issue with your high idle solenoid, if it’s getting erratic I sell them on my website.

Thanks for this post, I’ve been looking for this solenoid for a while as mines shot and only was finding them for 200-ish. None of my local yards had them. I just put in an order for one from your website. My searching never turned up your store for whatever reason; I was using both Ford and International part numbers.

Sorry for the hijack.
 

Thewespaul

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I’m a believer in, if it ain’t broke don’t try to fix it, but if you’ve noticed a drop in mpgs when you previously saw better numbers you’re probably loosing some of your advance curve and not making as efficient power at part throttle. If it gets bad enough and you travel a lot it may warrant a replacement eventually, but it’s by no means something that is going to strand you or suddenly have problems. These pumps are very well designed for their purpose, and really quite reliable if you keep them in regular use and maintenance.

I do not offer any DS4 pumps for the 6.5s but I have built a few db2s for the 6.5 crowd up in the 260cc range. It’s fairly straightforward to swap a 6.5 to a 6.2 timing set and run them all mechanical.
 

nelstomlinson

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I wasn’t saying anything electronically controlled at all. I think I should’ve explained that better. I mean like a literal mechanically controlled rotary thing so you can just turn the screw from in the cab LOL.
Put a big toothed wheel on the end of the screw, turn it with a worm that is twisted by a cable or linkage with the other end mounted on the dash. From what Wes is saying, we'd have to come up with some other way to seal that penetration, and that would be the difficult bit.

Maybe drill a bigger hole in the housing, thread in a tube, and pass a polished shaft through the tube to do the job of the screw? Some packing and a valve bonnet to seal, and the shaft moves in or out as you turn it, just like a plumber's valve stem.
 

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