I'm keeping it.

This.

 

what would happen if you were to make the cam ring "deeper" aka longer stroke?

 

Its already too deep. The rollers dont contact the whole cam ring, only the tips, and how much of the tips is regulated by the leaf spring. If You simply removed the leaf spring and let the plungers extend the whole cam ring, you would have over a 100cc DB2 even on a N/A pump, but the thing probably wouldnt last long, there isnt a whole lot of support for the rollers/saddles with that much stroke. This is one of the things im going to experiment with on rotor design... Getting the most amount of stroke with the most amount of support possible.

 

Off topic here, but, why are you keeping the pump and replacing your turbo? I thought you got the comp wheel to make the turbo work better for when you got the bigger pump? Apparently im behind the times.

 

No, I'm changing turbo all together.... current charger is 62/65/.80, and I'm going to an Engineered Diesel - 63/68/.70. Turns out my power was limited by exhaust side of these chargers Racin' and I got. They weren't nearly as high performance as we thought, and was my issue with having to run such narrow timing. (6* BTDC)

our current compressors can support about 400-450rwhp w/ the "tractor" covers. The small .80 housings and 65mm wheels can only support about 350 crank power though on their intended applications, which are C7's and 3126's.

 

like you guys said the cam is the key to these engines, guess it's not just the valve train cam. lol

how close to a bearing race is 8620?

 

Hey I found this guy a while back and idk if you have talked to him Racin but I figured he might be a good point of contact cus he has torn into those IPs quite a bit and experimented with um a lot. His name over there is 6.2 Turbo. Anyway here is his first post in a thread he started over at The Truck Stop. He even talked about a few of the things he has done to the pumps too.

"Modified 6.2 turbo diesel

I have a 92 chevy truck 4x4 5sp. Im building it for sled pulling.

Its a 85 6.2 out of a chevy van.

The motor has main bearing girdle homemade with angle iron, dished pistons, chambered heads, turbo precups , z28 sbc valve springs no rotators, head studs ,tried felpro 6.5- 10 over headgaskets they blew @ 60 psi boost, with stock bolts ,tried cometics and with studs constantly seeping,curently running victor rienz stock 6.2.

The turbo is wh1c holset 12cm welded waste gate. Im try to build power with high boost low compression and over fueling .

Ive tried lots of pump mods ,even 1/2 plungers wich worked fine for half way around the block,then snapped the cam pin. Currently the pump cam is locked solid.

Ive gotten enuff fuel from .310 plungers for 50 psi boost a turned up pump gives about 35 psi boost.

The 60 psi was with my big pump.Tonight i finely got running again with my new victor rienz head gaskets.

Ive only gotten 45 psi boost .IT does not run very well.

It wont start hot without cold water on the pump head .

My big pump is pretty much to loose, also the plungers seized one time so they are also loose. The head and rotor siezed one time also and i managed to cut them apart so head and rotor are not matched.

I can get a 4 plunger head and rotor from the central penn pump co. for less than $400 . So far im not very impressed with my combination . It ran best with the big plunger pump when it was new and marine injector tips .

I could pull out in 2nd gear and spin the whole way through when the turbo lit . Currently running 6.5 turbo nozzles that i modified .

Tonight it was cutting out a higher rpms. Not shore if its just the injector pump, my timing might be to far retarted.

It is hard to set when your cam ring is locked.

Also i dont think the wh1c is the right turbo for this combo ,the exhaust wheel is pretty restrictive , on a free rev it will boost 30 psi.

If any body thinks a 6.2 can really run im willing to try anything as long as it dont cost to much."

Also here is the link to the thread. It might be of interest too.

http://www.thetruckstop.us/forum/sho...2-turbo-diesel

 

I quit reading @ angle iron stud girdle.

Where do you find these clowns?

 

I didn't say everything they did was correct. Lol. I just was saying they tore into the IP. Haha

 

when do you plan to have this fella done?

 

Ya I thought the angle iron bit was little odd, but them chevs need any help they can get lol... anyway, i read it, sounds like he had the heart to do it, just not the brains. I can only assume he was hitting the dead ends that Racin is attempting to solve. Some very intersting info on the DB's as well about how they start defueling around 2100 as they just cant fill the chamber at those speeds.

I call BS on hitting 60lbs with a H1C and a modified DB2, and 35lbs free reving?? I dont know much about turbos but thats...not believable.

 

ditto. i wonder what kind of boost it makes at idle lol.

 

well the de-fueling issue could be solved by stream lining the passages and running a little more inlet pressure i am sure.

lift pump:transfer pump:high pressure pump right?

 

I saw that post some time back, and it is definately an interesting read, if not for entertainment value at least.

Increasing the fuel pumping capability is the easy part, its the little stuff like port opening duration, and cross section that make for a pump that can deliver the fuel effectively. I think a lot of what he had going, while being well intentioned, was haphazard at best.

He seems to be under the impression that the metering valve is a big restriction in the supply side (Hence the external metering valve bypass), and while under certain circumstances (IE: blueprinting, porting, etc...Well get to that later), I could see it being a restriction, but not in any way is it a restriction in stock form, the galleries to and out of the metering valve, as well as the valve itself are bigger than other aspects of the supply side of the hydraulic head.

So far the biggest restriction (In real terms, obviously pressure has a different effect on things) I can see in all of the pump, is the distribution ports on the head itself. They measure out at .088". This is coming from the bore that the rotor rotates in, and the holes that the fuel is delivered through there, are are .114"... Thats a big difference on the supply side of things. The rotor itself necks down before that though, before it is distributed to the cylinders, the ports on the rotor themselves, are .090"x.100" (Because they are drilled at an angle). Upstream from there, the next restriction is the delivery valve, which (I need to check again) is 2 holes at .073" each, which isnt the smallest cross section wise. After that is the orifice into the pumping chamber, and that is the biggest opening on the line. Thats the pressure side of the pump...

I havent measured the supply side of things yet, so ill update that front when I get there.

As far as the blueprinting mentioned above, this is what i have found. First of all, this pump was meant for one thing, and thats to pump fuel into a diesel engine in the narrowest of RPM ranges (Maybe not as narrow as a P-pump, or other non-advancing pump) and delivering the fuel to an engine that isnt in high demand for it. The ports in the hydraulic head are simply drilled holes without any sort of smoothing of action, nor timing allowance in the function of their fuel delivery. There is a lot of work that can be done to help this out...

First of all being an 8 cylinder pump, the cylinders are divided in 45* increments, and those are divided in half between the filling and pumping action. That means that the plungers have 22.5* of rotor movement to fill the pumping chamber, and 22.5* to pump the chamber into the heads of the engine. One issue I have found so far is that the rotor bore (Larger orifice) gallery diameter of .114" is only 14* of the rotor rotation, that leaves 8.5* of improvement to be had, or Opening the holes up to .160" (To solve the duration problem, and open the cross section for more fuel) If one part of the equation is opened up, Than the rest should be as well, So I am going for a gallery diameter of .160" all the way through the pumping side of the pump. This should smooth the pump action out significantly, at least on the pressure end.

Like I said, I still have to work out the supply end, and Im sure there is a bunch of stuff I have missed here tonight, but its late, and im tired, and Im going to bed...

So more when I feel like it... Lol.

 

^^^mind blown