Were those pump mods tried before or something? If so it would still be worth a shot...

 

Yeah basically what I grasped from Ken and Justin's convo was that Ken builds 200cc DB2's all the time for pullers, but they dont last, he just waits for the call when the pump dies. He has built as big as a 250cc DB2 before... And apparently with 250cc, 700hp in an IDI is possible, and there is proof of it... When Justin mentioned the 120cc stock pump he just sort of shrugged it off like it was nothing new, and actually gave some tips on how to do it without a marine leaf. The shocker is, up to this point, we thought that 100+cc DB2's were just Voodoo, and not to be attempted, that anything north of 90cc's is running the ragged edge... Obviously that is not the case... I thought it was kind of weird when the Local shop said that they got 120cc no problem, like they werent even shocked....

Needless to say I feel a little "naived" right now... Im guessing the real reason we dont see more 120cc pumps is the fact that nobody (Short of comp pullers) has pushed the Airflow capacities of these engines until now... Fuel has always been an issue to make power, but up until now, the stock setup didnt allow the engine to surpass the stock fuel... Well we've done that now... Now we need the fuel...

Another thing I learned that was interesting, and totally contrary to what has been said on the other site and passed through IDI hearsay, is that the same truck that got the 120cc pump from the local builder, also has 7.3PSD rods in it. They told me that they milled the big end to fit the IDI, and that there was still enough meat for the bolts... The engine has 50k on it now like that... Now with that said, he doesnt seem to think the truck has seen any substantial RPM/Boost to put a serious load on the rods. Either way PSD rods WILL work in an IDI, run and last for thousands of miles, the real question is whether or not they will take serious abuse.

 

So I'm guessing you still plan on doing your pump correct? I'm still interested in what you do with it.
Also is there any info on the truck with the 120cc pump? I never heard of it before...

 

Oh absolutely... I have $250 into that thing already... I will probably have $500 into it before Im done... And thats if I dont have anybody assemble it for me...

Plus I want it to work...

Thats ok, my next rendition of the pump will be rediculous... I think even Ken will have the deer in headlights look... I gotta rough out the details on paper first, then I will draw it up in AutoCAD... Then I will reveal it... and then I will build it...

The truck with the 120cc pump is just a local guy that worked at the local shop, I dont think he is on any of the forums. Hell I dont think he is taking advantage of the pump by any means, they said he is running less boost than Justin and I are...

 

ken said high output DB2's don't fuel very high.... maybe 2400-2500rpms tops... so it would be kind of hard to get high HP numbers from one, but you could get the low end torque....

He mentioned pulling the vane pump out of the inside, and force feeding them with a powersteering pump. 50psi at idle, 270psi of housing pressure WOT, then you float the metering valve and things get fun.

 

A question if you could have some rods macined and cut for lets say 1800$ out of any metal you wanted would it not be worth it to know they are no longer the possible weak link. Afterall raccinnanddrumin could probably do most of it and what he couldnt the shop near him could. I could see some nice extreme hd rods and stronger wrist pins being in demand if people see that the idi has the parts out now to make any power level. I got a thread im gunna post up its a great read for this thread this guy did what the idi guys are gunna have to do machine there own hard parts. My latest homemade parts - Dodge Cummins Diesel Forum

 

if high end fueling is a problem, then the extra holes he poked into the rotor should help. between that an increase in the transfer pump and the larger pistons it should put out.
if that doesn't get the high rpm fueling back(even if you switch to the ps pump) then it is time to start checking passages on the lp side

just have to make sure that the pistons don't have too much side force and that all of the ports line up so that there is no hydraulic lock. that is kinda my point of getting in there and putting a probe into certain passageways to see what was the most restrictive.
obviously there will be at least 1800 psi on the piston (or whatever the injectors are set at) but from what i have seen inside an injector, once it hits that point, there should be no more pressure than that in the ip unless there is a flow restriction.

 

What kind of end do these pumps come to? I could live with a rebuild every 30-50k for 200cc

 

Not a chance.

We're talking maybe a season of pulling..... you would be lucky to get 1000-2000 miles from one on the street.

 

Peak injection pressure on a stock DB2 WOT and stock injectors is around 3500psi.

Peak injection pressure on my DB4, WOT is between 11,500-12,000

 

Ok, thought it might be a scenario where if you drove it normal and didnt push it, it would live about as long as a typical pump.

 

why so high? once the injector pops, there should be more surface area there for the injector should open up more and allow more to flow in return decreasing the pressure.

where was the measurement taken on the pump?

 

Because, Injection pressure atomizes fuel better, and gives you more power capabilities because it promotes auto-ignition.

Injection pressure is affected by Volume, vs time, vs restriction.

Your injector essentially controls restriction, and the pump is volume and time.


When I was talking to Ken about why my truck smokes so much worse with the DB2 on it, than my DB4, his answer was injection pressure, and this is the example he gave me.

He knows what the flows and pressures are, because he has a bench to measure it all..... so for instance.... my DB4 when cruising down the street didn't smoke, this DB2 basically smokes all of the time...... no matter how little of throttle I give it, and it smokes like a freight train under WOT.

So lets talk about WOT. Under WOT the DB2 maxed out is capable of about 72cc's, and about 3000psi Injection pressure with a stage 1.

It takes that DB2 about 4 milliseconds to inject 72cc's.

Everything exactly the same, except for my DB4.

My DB4 can inject 72cc's more than twice as fast as a DB2, but to keep it easy we'll say 2 milliseconds. There is a loss somewhere in there that I didn't quite understand, but for the DB4 injecting the same fuel 100% faster than the DB2 @ the same volume, it increases the injection pressure approx 70%.

My DB4's IP @ 75cc's is roughly 5500-6000psi. WOT Ken said he tunes them between 11,500-12,000.

That being said, now that I have had a DB2 on my truck, I would highly recommend against decompressing if you're going to run a DB2. Smoke haze constantly, very poor mileage.

 

i bet you love havin that DB2 on there lol i know im off topic, but what can you hit for boost with it?

 

I only laid into it a few times when I first started driving it, just to see what it would do... I refrain now because the smoke is embarrassing..... but I hit like 24-25psi WOT. Very sluggish but it'll get to there... max EGT I've seen is about 850*