sigma pump

zstroken said:
You got it. People can get more fuel out of a 12 mm pump, than I get out of my 13, but I chose the 13 for the ability to deliver it faster! We know that duration builds heat. Get the fuel in there as fast as possible.
Click to expand...

Kinda off track, but once maxed out don't all 12mm pumps flow the same about of cc's, just it would ba a matter of delivery time due to the different cam profiles for the 160 vs. the 215 pump?
 
No there are different cut's on the plungers among other things.They will not flow the same.
 
Last edited:
Yea its real funny picked up enough hp on a dyno to warrent the change.
Wonder what all the top SuperStocks and alot of the top Pros are running for pumps??? I can tell you,Its further out I 70 then Ohio.
 
nwpadmax said:
Ah, dumb question....

If you go with a significantly larger plunger, then it would take less lift to deliver the same volume of fuel (assuming a similar cam profile).

So whereas a pump with a small plunger needs more lift (and that takes some time to accomplish), a larger plunger with the same type of cam profile would be "quicker" because it takes less travel (and thus less time on a similar cam profile). You wind up getting the same fuel with less duration....and this is what makes power, better spooling, etc.

Am I following that right or am I screwing it all up?
Click to expand...

I was doing some math. If a 16mm Sigma plunger travels 4mm a 13mm P-pump needs to 6mm. It roughly needs roughly 2/3s the travel to move the same fuel.:rockwoot:
 
JOHNBOY said:
I was doing some math. If a 16mm Sigma plunger travels 4mm a 13mm P-pump needs to 6mm. It roughly needs roughly 2/3s the travel to move the same fuel.:rockwoot:
Click to expand...

Yeah, I'd like to know what the travel is on these things.

16mm plunger @ 4mm lift:
pi * r squared * L
3.14 * 8 * 8 * 4
= 804 mm^3

??? That's obviously entirely too much...???
 
nwpadmax said:
Yeah, I'd like to know what the travel is on these things.

16mm plunger @ 4mm lift:
pi * r squared * L
3.14 * 8 * 8 * 4
= 804 mm^3

??? That's obviously entirely too much...???
Click to expand...


From what i understand they flow them through an orfice. Kinda like a fire hose, the end determines how much fuel you get.
 
nwpadmax said:
Yeah, I'd like to know what the travel is on these things.

16mm plunger @ 4mm lift:
pi * r squared * L
3.14 * 8 * 8 * 4
= 804 mm^3

??? That's obviously entirely too much...???
Click to expand...

That is assuming 100% fill though.
 
nwpadmax said:
Yeah, I'd like to know what the travel is on these things.

16mm plunger @ 4mm lift:
pi * r squared * L
3.14 * 8 * 8 * 4
= 804 mm^3

??? That's obviously entirely too much...???
Click to expand...


Should that not 6? Also 804mm3 = 80.4cc
 
http://www.cumminsdatabase.com/read.php?id=171

I am going out on a limb here from what i see in the above links.

From what i see with no actual numbers on the pics. Here goes. The total diameter of the barrel is 16mm but not the inside diameter. For instance my barrel is a 12mm but if you look at the delivery valve i can tell you for a fact it is not 12mm in diameter. Maybe 5 -7 if i remember right. You can see this from the pics. But flow is also dependent on other variables such as rack travel and the orfice which the fuel flow through. That is atleast if a sigma is fundamentaly the same a a p7100.

But i could be completely wrong.:pop:
 
You go by the plunger size because it's size and length of travel equals displacement of the fuel. Like nwpadmax posted [3.14*(R*R) * L= displacment] * number of plungers.


Correct?
 
JOHNBOY said:
You go by the plunger size because it's size and length of travel equals displacement of the fuel. Like nwpadmax posted [3.14*(R*R) * L= displacment] * number of plungers.


Correct?
Click to expand...


Wow i feel stupid i just remembered what my plungers actually look like. :poke: , only after i hit submit. They are that width. But can you flow that much fuel through the valve? Out of 80.4 cc per barrel how much really gets through?
 
JOHNBOY said:
Should that not 6? Also 804mm3 = 80.4cc
Click to expand...

Um, with my old-skool math, 16mm / 2 still = 8mm

And, 804mm^3 = 0.804cm^3. Divide by 10^3.

You been ....:owned:
 
Last edited:
nwpadmax said:
Um, with my old-skool math, 16mm / 2 still = 8mm

And, 804mm^3 = 0.804cm^3. Divide by 10^3.

You been ....:owned:
Click to expand...

Yes I have:hehe: :kick:

I new that would bite me!

Divide by 10^3. Learn something new everyday.:rockwoot:
 
LMAO! There has already been a Sigma on a Cummins 5.9 for nearly 3 years that was built for drag racing.

Rumor has it the new owner always said it wouldnt even start up. :hehe:
 
:nopics:
Soup Nazi said:
LMAO! There has already been a Sigma on a Cummins 5.9 for nearly 3 years that was built for drag racing.

Rumor has it the new owner always said it wouldnt even start up. :hehe:
Click to expand...
 
GSM-01 said:
I disagree. "How Do You Like Me Now" did not have a Sigma or 12cyl pump the whole season. Only after Corey Bought the truck was a Sigma Pump placed on the truck. You can even look in the September 2007 issue of DieselPower to see this.
Click to expand...


Corey's truck was not competitive at all untill he put a sigma on and then it started to run good but i still wouldnt call it competitive.

As for BBD I dont think it pulled against the midwest trucks this season so thier is no real comparison. he has no real competition on the other coast

Travis
 
Soup Nazi said:
LMAO! There has already been a Sigma on a Cummins 5.9 for nearly 3 years that was built for drag racing.

Rumor has it the new owner always said it wouldnt even start up. :hehe:
Click to expand...

yes even video of it making a half pass.

And as far as starting..... A sigma equipped engine will start easier than a P-pump
 
You must log in or register to reply here.
Back
Top