Hey guys. Im about to fire up a shovel that my father and i built. I have the S&S super e tuning guide. I was just wondering what a good baseline would be. The build is as follows:
1980 FXWG
4.75 Stroke 80 inch .020 over
9:1 Comp Ratio
Dual plugged heads
Dyna single fire ignition
Sifton 117 cam
Velva touch lifters
Supertrapp 2-1
Super E
I was thinking a 31 on the pilot and 72 on the main. To start off anyway. Thanks in advance!
Many think they have to add fuel for a big motor.
I think a big motor sucks harder so will draw the fuel it needs.
Also an 80" motor is not big and 9:1 is not considered high compression (from a performance view).
I don't have a bore stroke chart in front of me but I think a 4.75 stroke should make a bigger motor than 80"?
Weren't the 74's 4.25" and 80's 4.5"?
With a somewhat elevated compression ratio (for a Shovel) I'd want to look closely at the cam choice especially with a stroker.
This will also depend on how it is loaded and how it is ridden.
The 31 will work but have a 29.5 handy because I think that is where you will wind up.
The 72 will likely blubber when you back out of WFO so I would use a 70 and a ThunderJet.
Quote from: TornadOH on October 25, 2019, 01:00:12 PM
Hey guys. Im about to fire up a shovel that my father and i built. I have the S&S super e tuning guide. I was just wondering what a good baseline would be. The build is as follows:
1980 FXWG
4.75 Stroke 80 inch .020 over
9:1 Comp Ratio
Dual plugged heads
Dyna single fire ignition
Sifton 117 cam
Velva touch lifters
Supertrapp 2-1
Super E
I was thinking a 31 on the pilot and 72 on the main. To start off anyway. Thanks in advance!
Search. This subject has been discussed several times. The information is already here.
Stock 74" are 3-7/16 x 3-31/32.
Stock 80" are 3-1/2 x 4-1/4, just like an Evo.
An 80" with 4-3/4 stroke & stock bore is going to be about 92".
Agree with Burnout, don't just throw big jets in because the cubes are more. Look at the S&S instructions for Super E, has the basic info you need.
-JW
In the end there is no "magic" jet for any particular motor.
Install the carb and see what it wants, make some changes and see if it gets better.
It usually takes me quite some time to settle on a certain jetting on my own bikes, usually with many changes, and sometimes even different carbs.
It also depends on your goal, fuel mileage or power.... That is why I use a ThunderJet on an S&S carb, you can bring the gap between mileage and power much closer.
I played with 2 different E carbs on my stocker and the 93" I have in it now. As I recall they come out of the box pretty fat.