I am getting ready to replace my injection pump came across this http://www.rubiconautoparts.com/wst_page7.html it
gives a good synopnis of how our pumps work.
john
gives a good synopnis of how our pumps work.
john
Db2 pump
- Thread starter 94johnh
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Diesel JD
Full Access Member
Good writeup by Rubicon. Thanks for sharing John.
dieseldummy
Lost in time
I beleive that is a GM DB2, the fellow is/was a member at thedieselpage.com.
Diesel JD
Full Access Member
Actually those pumps are teh same internally, only the Ford/IHversion rotates one way and teh GM/Detroit version rotates opposite. At least that was my understanding. Actually I think one of the mods that some folks did to their pumps was to switch out the 6.9 min max governor for the one from a GM 5.7 pump which allowed the RPMs to wind up to 4250
dieseldummy
Lost in time
Yeah, the insides are mostly the same. Some parts in the pump are actually interchangeable and can spin both ways, like camrings and such. Shimming the Gov spring or replacing it with a stiffer one is all that is required to get lots of RPM's. I've had mine upto 5000+ before... I've got a bunch of pics I need to sort out and a bunch of parts to take more pics of. they are a good addition to that article.
Diesel JD
Full Access Member
You're scary dude...a 6.2 at 5000 RPMs would be insane!! I bet its nowhere near stock?
dieseldummy
Lost in time
It was an accident to be honest... the trans shifts at 3400 under full throttle so it's not a problem usually, the free rev in neutral was an eye opener though... You are correct, it's nowhere near stock. I tried to attach some IP pics.
Attachments
Diesel JD
Full Access Member
Reminds me of teh time mine ran away when I took teh governor cover off. I' surprised teh engien survived. I learned my lesson about economy pump rebuilds though. Do you do your own pump work or do you have a rebuilder that does all that cool stuff for you? Although, honestly I can't tell exactly what you did do to it from the pics.
dieseldummy
Lost in time
The pics are of a stock 6.2 pump. The first pic is of the governor assy, gov guide stud, and fuel metering valve. The second pic is a side view of the head/rotor assembly removed from the housing. The leafspring/allen screw side facing the camera. The third pic is looking into the housing at the camring and driveshaft. The 4th pic is of the plungers, leafspring, and rollers. (from top to bottom) The last pic is a picuture of the rollers vs. the plungers size wise. (.38" vs .29") The main difference between a stock 6.9 or 6.2 pump and a 7.3 or 6.5 is the plungers size. (.29" for the little motors and .31" for the turbo motors) There are some timing differences between the two also. The holy grail, so to speak, is the marine head with .33" plungers. Or the DB4 with 4 plungers...
I do all the work on my pumps. I have some crude but effective tools that get me in the ballpark and final tuning is done on the engine. I have a few different things in the works right now and hopefully I can report about them tomorrow if things run correct...
I do all the work on my pumps. I have some crude but effective tools that get me in the ballpark and final tuning is done on the engine. I have a few different things in the works right now and hopefully I can report about them tomorrow if things run correct...
Gee ****... where were you last year? 
We've been looking for folks who have experience inside these pumps for a while. We finally got our own at the IDI Weekend last July, and 3 of us gave ourselves a crash course in the inards of these things. However, I don't think the 3 of us felt comfortable putting it back together and bolting it to our engines, so if your at that point..... 
We've been looking for folks who have experience inside these pumps for a while. We finally got our own at the IDI Weekend last July, and 3 of us gave ourselves a crash course in the inards of these things. However, I don't think the 3 of us felt comfortable putting it back together and bolting it to our engines, so if your at that point.....
dieseldummy
Lost in time
I did basicly the same thing as you guys. Got a pump off of ebay for $25 and tore into it. I started to get some ideas of how to modify them and experiementing started earlier this year as time permits. To be honest I've got a box of cheap ebay "learning experiences" at home...
TLBREWER
Windy B Ranch
Sounds like we may have another tech article (book) in the making. This could really be an eye opener for us "pump dummies". I would really like to be able to do my own instead of spending $400+ and not necessarily getting what you want.
Tom
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