what is the grove at the bottom for? just a shear spot to save the pump?

why do the seals go both directions?

do you plan on making the barring race into the shaft or tuning the shaft down to press a bearing on?

and what kind of material are these made from? 4340 steel?

 

4340 isn't hard enough, its 8620

 

Exactly... Treated 4340 has a Rockwell in the 40-44rc range. 8620 only has a Rockwell in the low 30's when untreated, but when case hardened, forms a .020" thick layer that is in the low 60rc range. What this does is leave the middle soft enough to take shock loading, but makes the outside hard enough to dull a file. Basically one of the best shaft materials.

 

exactly.

That's why transfer case and ring gear/pinions are usually made from 8620.

You can surface harden it to around 62rc, but retains its ductility

 

Hey there have been a few guys that have built and experimented with Db2s on Chevy 6.2 diesels over at the diesel place. You might try to get ahold of them over there and pick their brains a bit. Also you might call and talk to Schied and Unique Diesel. Schied makes a 300 crank horsepower pump and Unique makes a 375 crank horsepower pump. They might be able to help a bit to if you talk to them.

 

so wehn you get this all done and what not ill send you both of my pumps for ya to mess with one will be the one that is done dont know why guessing wore out the other will be the one that is still on my truck well kinda so let me know because well im severly interested in what the differences are in a i guess stock pump and a rebuilt pump

 

Ive researched all there is on the net as far as The DB (And even DS pumps for that matter) pumps are concerned. There is companies that claim these numbers, but problem is, there is no proof, the only high powered pumps out there with documentation are the Heath DS4 (500hp supposedly), the 300hp Swb chevy on YT (300whp), and NMB2's DB4 (300whp). Plus, I already was running a 300 crank hp pump, the Turbo cal. These pumps are pretty simple if you understand their functions, and once you understand their functions, its apparent what modifications need to be done. I will get the delivery I want, that is not an issue at all, its making the pump reliable with the related delivery. I have some good ideas though. VE pumps can put a ton of fuel out, and as far as im concerned, the DB pumps have a better design, and should be able to surpass a VE as far as flow is concerned, its just a matter of building them to handle the stresses.

 

It would be neat if like the ve pumps you can just buy the hard parts and swap them into an existing pump. From what I've read the db2 is better. Just the having a cold idle solenoid and cold advance helps a bunch. I've seen cummins guys that have to sit in their truck while its cold until it warms up so it will stay running. The idi just engage the high idle and enjoy the warmth of your house.

 

Subcribing. I have a DB2 pump also.

Chet

 

the only place it could get grit is from the engine oil no? are these pumps that sensitive?

i was kinda thinking you would turn the bearing location to a lower diameter and then fit a cartage needle bearing on in a press fit, but i guess you would have to watch out for it to shear off at that point due to the force of the gear.

how much more do you think that tang can take? and if not that the slot it fits into on the rotor.

"Tempering of carburized parts is done at 250 to 300 F and this will result in the alloy having a core strength of approximately 135 ksi minimum with Rockwell C case hardness of 90. Tempering of heat treated and water quenched parts (not carburized) is done at 400 F to 1300 F with greater hardness the lower the tempering temperature."

you guys are really putting a lot of thought into this, i am interested to see where it goes.

do you have any good sources that i can read up on these pumps?

 

The factory pump (At least the turbo pump, and Im going to assume at least all 92.5+ Torque screw pumps) have a roller bearing on the input shaft, but I dont think the gain is all that huge in any manner. As far as pump info, you just have to read, there is a lot of info out there, and if you can get your hands on a spare clapped out pump to tear apart, go for it. Like I said, Ive read just about everything there is on the net about these pumps, and now I have had a couple completely blown apart to analyze, I fully get how they work, and what their restrictions are now, and why the obvious upgrade from a 2 plunger pump is DB4 parts, and that the DS4 pumping mechanism works backward from the DB pumps as far as delivery goes, and why the parts arent interchangable. I know where the DB2 pumps faults lie, and how to fix them, as well as the capability to do so... Im not sure too many people have had all three, or if they have, to care that much to put the time into it. I know Ken from DPS has had some gnarly 2 plunger pumps, and know the Super Moose is supposed to be along the same lines, but never been realized, and That the chevy guys have tinkered a bit too, but it doesnt seem too many of them are intelligent enough to really make this thing work, or it could be that Im just thinking over my head, but I highly doubt it, I wouldnt go this far out on a limb if I didnt think something could be done, its just a matter of how much work is it going to take... Luckily my time is paid for...

 

i'd figure that the roller bearing is just for gain on life and maybe a little more stability for the input shaft.

i just don't see how your going to get past the fuel : torque ratio that is the limiting factor right now besides removing the fuse and maybe using a higher grade material.

i kinda wonder if putting a roller bearing on the plungers instead of just a roller would help out.

other than that i could only see revising the timing helping by unloading the pistons more correctly.

 

The bearing and the bushing both support the shaft over the same distance, so there is no support to be gained... Longevity, Its possible, there had to be some reason they went that way. The shaft issue will be solved with a new input shaft, and the new shaft will take just about anything you can throw at it, you will grenade other stuff before the shaft. A roller bearing on the plungers wont add anything substantial, and might add more parts to fail, especially with the forces experienced on the pressure side of the pump.

Timing is something I was thinking a lot about yesterday, And I know Ken does some stuff with the Turbo cal (Dont know what exactly, Ill have to check things out a little bit more to see) to adjust the timing advance to help with a turbo setup more, like more initial timing, and less max timing or something along those lines (At least thats the way it would make sense), Im sure such things can be adjusted out with the trim screw and transfer pump pressure. I know my truck makes the most power at 6* BTDC, so if you could get the curve to add more initial timing and take advantage of the efficiency down low, while still taking advantage of the peak torque and HP up higher, that would be Ideal. Its going to take some tinkering on a tuning front after the pump is together.

 

Im just stoked to know someone, somewhere that has the tools, skills and knowledge who is going to figure this out, and most importantly, is willing to talk about it, answer questions and offer some explaining. I hate when people come up with this great pump, or perfect trubo config, or tune or whatever and its a big secret and they dont tell anyone.

Example: was out at the track friday, there was a street trimmed 66 charger with an iron headed 440 running 12s on street slicks, i asked him about his engine and suspension, and he told me theyre special....

On a side note, I just thought of something, Racin you planning on any kind of dyno run with the NA pump on there? Would be interesting to know what it makes compared to the turbo cal. and would give you a baseline to go off of for your pump youre building. Then you could compare that later on to NMB2s DB4 if youre still going to get it from him.

 

I dont care if people know how this stuff works, and what I figure out with these things. If somebody can do it themselves, let them do it. Hypothetically If I was ever to build and sell these pumps, its the work that would be being paid for anyway, not the "secrets". It doesnt mean much anyway if somebody can just tear apart something you build, and discover it for themselves anyway. If I can build a successful HO DB2, that completely turns around the way the IDI is looked at performance wise than that is satisfaction enough for me, nobody is going to get rich building IDI parts anyway.

I would just like to see some decent fuel delivery for these engines, I know they are never going to be powerhouses, but a solid 300whp with the potential for much more if one wanted to push it, would totally change the way these things are looked at.

As far as the dyno, yes Ive been kicking it around, just to compare to my previous numbers, and im sure its going to happen as soon as NMB2 gets his new turbo on.