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Marine Injectors

Be careful in putting too much in what TDG had to say, Mike aka Diesel Pro is spot on; but TDG disappeared after he hosed over a couple members & messed up IPs they sent him. If you will remember he was also the one that first proposed chrome valve cover breathers for making more Hp,
 
Turbine Doc said:
Be careful in putting too much in what TDG had to say, Mike aka Diesel Pro is spot on; but TDG disappeared after he hosed over a couple members & messed up IPs they sent him. If you will remember he was also the one that first proposed chrome valve cover breathers for making more Hp,
Click to expand...

You should know me better than that TD, I need confirmation from a recognized source before acceptance of information!

;)
 
FWIW - In April, I swapped from truck nozzle rebuilt injectors set to ~ 2200 psi to marine nozzles set to 2250 (also from Barry). It felt like there might have been a small, noticeable power increase, but nothing remotely as dramatic as the +40 hp or more some vendors claim.

Barry checked pop pressure & pattern on my old injectors - the patterns were fine. 7 popped around 2200 & one at 2000. The engine now runs a bit smoother & would suppose the lower popping injector could explain this.

I do think there is slightly more fuel flowing at WOT at rpms above 2500 as there was a small but again notable decrease in WOT fuel pressure (read just before the inj pump). Something on the order of maybe 1/2 psi lower. Tough to really correlate that to a quantifiable volume of increased fueling. Just thought I'd mention it as this is at least a bit more objective that "feels like it makes a bit more power."

So far I've put about 25k miles on my engine since building it & have diligently recorded all fuel fills/mileage since. I've put around 3500 miles on since the swap to marine nozzle injectors - going to/from work w/ pretty consistent route/speed etc. There appears to be a small improvement in fuel economy compared to the same timeframe the previous two years - possibly around 0.5 mpg. It's gonna take more mileage before I'd say this fuel economy bump is real but 'ya can't complain about a positive trend.

So far, my opinion is that paying a significant premium for marine injectors wouldn't be a great value. That said, if you can get marine nozzles for similar cost & you have a pump that's fueling a little more than stock, there might well be a small benefit.
 
SmithvilleD said:
FWIW - In April, I swapped from truck nozzle rebuilt injectors set to ~ 2200 psi to marine nozzles set to 2250 (also from Barry). It felt like there might have been a small, noticeable power increase, but nothing remotely as dramatic as the +40 hp or more some vendors claim.

Barry checked pop pressure & pattern on my old injectors - the patterns were fine. 7 popped around 2200 & one at 2000. The engine now runs a bit smoother & would suppose the lower popping injector could explain this.

I do think there is slightly more fuel flowing at WOT at rpms above 2500 as there was a small but again notable decrease in WOT fuel pressure (read just before the inj pump). Something on the order of maybe 1/2 psi lower. Tough to really correlate that to a quantifiable volume of increased fueling. Just thought I'd mention it as this is at least a bit more objective that "feels like it makes a bit more power."

So far I've put about 25k miles on my engine since building it & have diligently recorded all fuel fills/mileage since. I've put around 3500 miles on since the swap to marine nozzle injectors - going to/from work w/ pretty consistent route/speed etc. There appears to be a small improvement in fuel economy compared to the same timeframe the previous two years - possibly around 0.5 mpg. It's gonna take more mileage before I'd say this fuel economy bump is real but 'ya can't complain about a positive trend.

So far, my opinion is that paying a significant premium for marine injectors wouldn't be a great value. That said, if you can get marine nozzles for similar cost & you have a pump that's fueling a little more than stock, there might well be a small benefit.
Click to expand...

Well my original pump is a 4911 rated at 200 hp, the pump I'm gonna be running once this engine is completed and installed is a 310 hp DB4.... I would think that there would be a bit more fueling then stock, otherwise I would have had my injectors rebuilt using standard automotive bosch nozzles with higher pop pressures.
 
It will be interesting to see how you make out trying a DB4 in a truck.

It's been a while back, but there was an article on another 6.5 forum that quoted calibrating specs for the 3 common 6.5 pumps: DB2, DS-4, and the less common DB-4. The specs suggested that the the DB-2 & DS-4 pumps volume capabilities tapered off more at higher rpms than the DB-4.

The article claimed Stanadyne's inj pump calibrated flow rates were:

DB-2 (DB2833-4974) - max fuel rate of 81.5 mm3 @2000 rpm & 68.5 - 73.5 mm3 @3600 rpm

DB-4 (DB4831-5722) - max fuel rate of 79.0 mm3 @ 2600 rpm & 73-77 mm3 @ 3500 rpm

DS-4 (DS4831-5521) - max fuel rate of 89.9 mm3 @ 2000 rpm & 65.2 - 75.2 mm3 @ 3400 rpm

I'm not certain what to make of the higher rpm spec's volume range?

As a comparison point, the article noted the original 2001 LB7 Duramax made 300 flywheel hp with a fuel rate of 91.7 mm3
 
I obtained the pump from a buddy of mine.. I had asked him how the drive-ability was, he said it was fine, ran great with no problems... until he pushed 35 - 40 psi to it.
 
I can't answer much.. I'm kinda diesel dumb. I'm hear to learn from you all that have way more experience then I.
I just happened to be lucky enough to come across some goodies from a buddy of mine for a hella good price.

However, my buddy did tell me that when he bought this pump (new) that the fueling screw was turned in quite a ways from the get go, and that he turned it up all the way, which was maybe 1/8th - 1/4 turn. Stock this is supposed to be a 310 hp pump, I'm kinda wondering what it would push turned up and or with a better turbo maybe such as the ATT...
 
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