Huh quite interesting. I didn't know that inlet pressure on the pump affected/effected (hate those two damn words always get them wrong) the timing. I guess I need to understand better how the pump works because I'm having some difficulty wrapping my mind around why at the moment. Thewespaul do you have any good articles/books to recommend so that I can get a better grasp of how the pump works? I like to understand why something happens rather than just knowing it does. Very interesting. Christian9112 Thewespaul is a fountain of info on these engines so listening to his advice will not steer you wrong.
Why does is smoke black if I time the injection too advanced?
- Thread starter Christian9112
- Start date
Thanks chemgrad, the hydraulic advance on these pumps are unique to the dm/dB/ds series stanadyne pumps, which are all the same basic pump with main changes only to the governor assemblies and case designs. The db2 pumps in our trucks are even weirder because starting in 1981 the db2s got the “light load advance cam” this is the arm, face plate and pin on the drivers side of the pump, this is a mechanical timing curve that is actuated by the throttle arm on the passenger side, so it gives dynamic timing depending on throttle position, where the hydraulic advance on the cam ring inside the pump is dependant on rpm. It’s a weird mix, but gives a lot more adjustability than previous pumps and gives better overall fuel mileage. I could ramble for hours but to learn more your best bet is to get a junk pump and disassemble it. There’s some stanadyne literature online for these pumps, but it’s all pdf form which isn’t the best imo. You can get stanadyne manuals on eBay
reset2
Full Access Member
My experience was:
Turbo ed a NA motor. Had previously turned up the pump (stock original factory). Smoked when pulling up a hill (black) unless boost was at 4 psi or more Try to not go over 1000 degrees.
At the last rally had the motor re-timed and it was about 1-2 degrees advanced. Backed off the timing some. And now it smokes less all around. Feel to have slightly more power.
Turbo ed a NA motor. Had previously turned up the pump (stock original factory). Smoked when pulling up a hill (black) unless boost was at 4 psi or more Try to not go over 1000 degrees.
At the last rally had the motor re-timed and it was about 1-2 degrees advanced. Backed off the timing some. And now it smokes less all around. Feel to have slightly more power.
jetfly12
Registered User
Watch this video first
http://www.stanadyne.com/dealerportal/ssi/english/Product Manual/99834.pdf
It is not exactly the same as our pumps that are made for 8 cylinders, but its all the same concept. Before seeing these two sources, I had no idea how a rotatory pump worked, and now I have a pretty good understanding the system.
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then read the first 1st ten pages of this manualhttp://www.stanadyne.com/dealerportal/ssi/english/Product Manual/99834.pdf
It is not exactly the same as our pumps that are made for 8 cylinders, but its all the same concept. Before seeing these two sources, I had no idea how a rotatory pump worked, and now I have a pretty good understanding the system.
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