quickster
Full Access Member
Where can you find the HP rating on your motor? There are no stickers on the valve covers. From what I read , there are 3 different ratings, 155,165,185. This is for my '87 6.9. My pump is a DB2829 4746. Thanks
HP rating
- Thread starter quickster
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bbjordan
Snow Monkey
That injection pump was used in the 1984-1987 6.9 diesels in Ford F Series Trucks / E Vans. These engines were rated 170 HP. This pump has the smaller 29 mm plungers. The "29" in the DB2829.
quickster
Full Access Member
Thanks. I knew about the year and what model, I couldn't find hp.
I wish they were 29mm, a db2829 has .029” plungers
quickster
Full Access Member
Yeah didn't pick that up. 29mm is like an inch. Sent you a pm Wes
There’s a ton of differences between the 6.9 and 7.3 db2 the more I’ve cut them open and figured out what holds back the 6.9 pumps as far as performance, at some point I would like to make a tech article for it, there’s many advantages in performance and fuel economy to running a 7.3 pump over the 6.9 pump.
Jack, I got your pm I’ll be back at the shop soon and I’ll put together your parts and send you some pics.
Jack, I got your pm I’ll be back at the shop soon and I’ll put together your parts and send you some pics.
bbjordan
Snow Monkey
Oops, my bad. Not 29 mm. Not .029" either.
Let's try .290"
Let's try .290"
IDIBRONCO
IDIBRONCO
Funny. All I can remember seeing on the valve cover stickers was 155 and 165 for a 6.9. 185 for a 7.3. 195 for a 7.3T. Maybe I missed seeing a number?
IDIBRONCO
IDIBRONCO
I had forgotten about the 166 HP. I guess it was a California thing? I don't ever remember seeing a 7.3 with that spot punched out. That's why I can remember the 185 HP.
I've got an '86 that says 175 on the valve cover. Always wondered about all the various ratings on those things.
My stickers are gone. It says " void" where they were. Is that what happens when someone pulls them off?
I assume that the smaller 6.9 pump is enough for a N/A engine and swapping to the 7.3 pump would just make more smoke.
I assume that the smaller 6.9 pump is enough for a N/A engine and swapping to the 7.3 pump would just make more smoke.
quickster
Full Access Member
I was thinking the same thing. I have a pump off my '91 7.3 that's still in good shape. I was wondering how it would work on my'87 6.9 project. If it smoked a bit, maybe turn it down a flat? Wes posted above that it would have some positive effect on the truck. Maybe Wes can chime in a little more about the subject?
This sticker above tells it all, each engine has a low and high altitude calibration. 52cc for a high altitude 166hp setting, and 185hp for a 58cc setting at low altitudes. You can see on Jason’s sticker the 185 is punched out, so he has a 185hp setting from the factory.
The 6.9 and 7.3 pumps are not just different from the plunger size and fuel output, but Stanadyne really improved how that fuel is being moved which translates to better performance and fuel economy. The design of the rotors in the 7.3 pumps have a much lower fill port angle than the 6.9s, this means there is more time or overlap when the fill port lines up with the passage in the head, allowing more time to completely fill the plungers, as well as increasing the volume of the ports, since if you think back to middle school math and the Pythagorean Therom, a smaller angle creates a larger hypotenuse, or a longer ramp. The longer ramp (fill passage) acts like a longer syringe filling the plungers.
Also, the 7.3 rotor has a 25% larger discharge port, so the fuel can be injected quicker, which lends itself to better atomization of the fuel as opposed to taking more time to slowly deliver the same quantity of fuel. Think again of the syringe, if you are slowly pushing all the fuel out of the syringe it is not going to carry the same velocity out the nozzle as smacking the syringe with your fist and quickly ejecting the fuel.
They also dramatically improved the design of the delivery valve and delivery valve passage, advance system, governor, cam ring, metering valve, I could go on and on. Bottom line, a 6.9 putting out X fuel will make less power than a 7.3 pump making the same fuel.
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