How stout are the old mechanil injection systems ?? Im thinking about swapping over to the mech injection set up. Im thinking and have been told that with the modifications I have made, the electronic set up will be harder to work with. Heres what I got. 96 td, 18:1 pistons, Power stroke intercooler, Ats turbo pulled from a wrecked 12v dodge. Custom headers. Center mounted turbo. sitting in place of my old fuel filter assy. Im not real sure what to expect from this engine since It has not ran yet. I wanted to do something wild and see how I came out. Worst case, and nothing works out that great im going to drop in a 24v cummins that I have. So if i go to mechanical injection will it be able to out perform the electronic set up ?? Im wanting to get up to the 400 hp area. Been told its not really realistic on a 6.5, but Im hoping I can get close.

Probably in neighborhood of 240 is what you have, I have reflash PCM, hi Pop inj, lots of other mods see below; but no 18:1 yet. I'm in that 240 Hp ball park, with 18:1 & mods I have 300 HP is what several have gotten, which is about safe limit of 6.5 mech or electronic, maybe twin turbos and some other strengthening mods would better that for 400 Hp goal, the Cummins swap might be better spent money/effort as a properly tweaked Cummins can go 400+ which is near end of rainbow for a 6.5.Edited by: Turbine Doc

The cummis is comming soon, but still would like to see what I can push out of a 6.5 first. I have about all the strength you can get out of the bottom end. Arp studs. Main cap girdle. phazer gear drive. Heads have been ported and polished in the same fashion as gasser heads. Lower intake has been extrude honed, port matched. The upper manifold is getting axed for a custom elbow for the 3 inch intercooler pipe. Garret turbo with ats 88mm wheel and ported shroud upgrade. Powerstroke inter cooler and 18:1 pistons. Thats about all there is for the 6.5 out there. The turbo I have, ats says can put out up to 45 psi. The truck over on the 6.2-6.5 page was only using 18 psi of boost if im correct, maybe im not though. Im thinking maybe if I go with orings as well and I am able to bump the boost up some more, I can get close to over 400 mark, or past it. Im just concered about a feeding it fuel. I can only find a few companies that can calibrate injectors for our engines and they all say 300hp is close to all they can deliver with this style injector. I have an email in at pennisular diesel to see injectors they use on there 400hp 6.5, but yet to hear back. Worst case, It will be a total flop, and I can return it to somewhat stock and drop it in my boat and drop the cummins in my truck. I just want to see what this thing can do before that.

The 6.5 EFI system would be a bit more of a challange, but with the proper reflash it should out perform the mechanical.


How is that?


The EFI system can advance timing, increase fuel delivery and boost if wg controlled on the fly based on programming while the mechanical is a set it and drive system.

everything you have is fine and dandy........but the only thing that will make more power is fuel. What you have added will only help you burn the extra fuel. my 250 hp pump was calibrated to have 81 cc's of fuel per stroke......so go from there on how much fuel you need. My stock, 130 hp 6.2 called for 46cc's.

Bill Heath's new Flash gives ~83mm fuel for the DS-4 electronic IP - so far, everyone is raving about it.


JK's EFI 6.5 truck had something similar, and it was reportedly the baddest 18:1 6.5 at every hill climb event - a 2500 Z-71.


The DP Project 18:1 mech inj 6.5 had set the original bar, tho.


Bill Heath's twin turbo 6.2l swb truck was setting 11.62\116mph numbers back in 1993.


As Grape sez - run it, and see what you got......

easier to get more fuel out of your mechanical DB2 pump than the Electronic DS4. If you have the pump out of it, just remove the side plate, rotate the pump until the leaf spring adjusting screw is visible and give her a good 1/4 turn or more (5/32 allen), with the setup you've got you can afford to be pretty liberal. If you want to do it in the engine, remove the top cover and governor guide stud just below the top cover at the back, roll the engine until its visible and give her a good crank...just be careful to watch how everything goes back together, noting the space between the locknut and guide stud head in the back of the pump too, that controls your high idle setting.

my stock DB2 pump has been bumped im guessing 5/8 turn+, I think there is still more to go on the pump if I wanted, right now with my setup (see sig) Im overfuelled with about 21 lbs boost max.


So, given your setup with the intercooler I think you could get pretty much all the fuel you could use out of the DB2.


IIRC there is a big version of the DB2 called a DB4, Penninsular uses them.

good luck finding an 8cyl db4, and one one that doesnt have the mounting bolts upside down (2 on top, one on the bottom) The DB4s are for off highway uses, you wont see one on a GM. If peninsular says they're selling GM automotive pumps with 8cyl DB4 heads....well I sure wouldnt be buying one. your 2 31mil plungers, assuming it is an 831 head, not an 829 and has the faster ramp 27833 cam ring inside not the 23119, will put up plenty of fuel, even with the setup you have.Edited by: Texas Diesel Guy

My pump shop and I finally found the two part numbers for the 250 hp and the 300 hp pumps, both of which are 831 two roller pumps. Nothing on the four roller, they said more than likely he is swapping head parts from something else to do it. I'm also not sure how thrilled I'd be to want two fuel screw adjustments inside the pump instead of just one.

veeeeewy interesting...texas diesel, question about the 23119 cam ring: I have no idea which one I have, but assuming I have the faster ramping 27833, if I replace it with the 23119 would I get less smoke at lower RPM but the same at higher RPM? I ask because with the bigger turbo I have now not much happens until 2200 RPM, no point dumping fuel in.

I think you might be trying to relate the ramp angle of the cam lobes to the actual fuel curve...


the 23119 just doesnt make as much fuel as the 27833, lobes are smaller overall height, the ramp angle just makes for a slightly quicker injection event than a 23119 at the same fuel delivery. reguardless, your getting smoke below 2200 because your pump has no way of matching fuel delivery to boost pressure (such as an aneroid), it just puts up XXcc and you will get black smoke until you get enough air to make it all burn, or take your foot out of it.

The 23119 camring was the early 6.2 pumps. The 27833 is the -4911 ring, and has been put in the early 6.2 pumps to 'make 'em run like a -4911'.


Not much chance of that due to housing flex, imo. -4911 pumps got stiffer, braced housings.


The early camrings could be operated either direction, for reverse rotation DB pumps, as in the Ford\Navstar engines. Or, maybe the 6.2 series were the reverse rotation pumps.....


Those camrings are marked both sides as to direction. Match the arrow to the direction for proper ramping and timing.


The 27833 ring is unidirectional, with specific marking for that direction, only. Mechanics are specific to rotation to meet advance specs.


Marine camrings, in the hi-output pumps Pen offers, get different specs for boat-drive use.


I also saw an oddball ring, out of an '88 6.2L pump, marked 27833, stamped for both directions, but the ramps were between the 23119 and the 27833 in angle and heighth.


Wow...who knows what wonders Stanadyne wrought?


Corrections????Edited by: gmctd

is it possible/cost effective to have a marine cam ring put in place of the 27833 ring? What is required to do that?

Marine Cam Rings? 27833 unidirectional???? just about as many Fords (Clockwise pumps) have these cams as Chevys (Counter-Clockwise pumps). I'll check the Test Plans and see if there is a different cam ring for marine 6.5 applications (never built one for a boat) but I dont think there is... I'll let you know though.

Chevy 6.5L 27833 camring is marked arrow to ccw.


Ford (Navstar) 7.3L 27833 camring is marked arrow to cw.


Neither has 'reverse' direction arrow marked on opposite side.


23119 (and other) camrings have cw arrow on front side, ccw arrow on back side, can be 'flipped' to suit app.


I've worked with the Chevy versions only, but a Stanadyne guy showed me the 'Ford' versions for reference.


Has to do with the degree'd location of the advance pivot bore, I do believe.


Camring replacement is by remove pump from engine, disassemble throttle and governor components in top, remove distributor 'head'\rotor assembly, disassembly of advance mech, R&R camring, new silicone\nitrile o'ring set, make sure drive shaft is 'timed' to rotor upon assembly.


Be 180deg out, if not, requiring complete routine again.


Could be done of a Saturday, if you're good with that stuff.


'Course, I'm sorta assuming, on the marine pump info - timing can be altered merely by changing the end caps in the advance piston bore, or the cam on the throttle shaft, etc.


Heard about 'em, but was not shown one to observe - TDG should be able to get the deep skinny on it.

you know what I remembered to check on the 8cyl DB4s (which do not exist) but I forgot about checking the marine pump cam ring. I'm also assuming the marine specs will have different end plugs for greater advance travel but I forgot all about it and I will try to look into that tomorrow.