S&S Carb on BIG Flathead

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Frankenstein
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Re: S&S Carb on BIG Flathead

#16

Post by Frankenstein » Tue Jul 17, 2018 2:50 am

O.K, can't find a pic of the S&S flathead heads, one question, do they have the shelf between the piston area and the valve area? such as the K model heads are patterned?
I found that this a was a big performance boost, and it also helps keep the pistons from overheating. I"m using the "ULR" heads from Finland, and they are a definite "seat of the Pants dyno" improvement.
My engine is currently an 88", Paul F. built up the cams from stock cams and also added K model intakes with ports to suit to Cylinders that are "Indian" (subcontinent) at .010 over . His theory on BTSV's is enlarge the inlet tract as large a possible. In his words, this area acts as a "plenum" and the larger the volume, the better the power.
I run a 38MM VM carb, and have recently added a wideband O2 sensor and air/fuel ratio gauge. It was eye opening.
It verifies your accel pump findings. The VM carb delivers a fairly consistent fuel mixture throughout the rpm range, even when the throttle is rolled on, no lean out in mixture. This is a very simple carb, but then, so is the S&S.
I suspect the increase in performance you're seeing is the larger throat of the S&S adding to plenum area available on roll on.
Currently my machine is running about 3/16" popup utilizing the stock type pistons that Vtwin sells, the heads are relieved to give the pistons clearance. Compression ratio is approx 7.9:1. This is not achieved by head milling, but the much larger swept displacement into the original combustion chamber.
Currently running an electronic ignition by "Power ARC", fits into the stock timer with a couple of minor modifications and delivers a "triple spark", single fire ignition with programmable electronic advance curves. It also provides for a VOES switch input which eliminated a "pinging" problem I had earlier with mechanical advance. For whatever reason, it has added to engine performance, as measured previously with the S.O.T. dynometer. :D
It's not in the league with your 101 incher, but by far it outpaces a stock 80, and gives my 80 knuck a run for the money.
DD



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Re: S&S Carb on BIG Flathead

#17

Post by Buddhahoodvatoloco » Tue Jul 17, 2018 2:27 pm

Radical scoot.

flatheadmatt
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Re: S&S Carb on BIG Flathead

#18

Post by flatheadmatt » Wed Jul 18, 2018 4:34 am

I have to ask...have some more pics of the bike?

Frankenstein
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Re: S&S Carb on BIG Flathead

#19

Post by Frankenstein » Thu Jul 19, 2018 3:29 am

[img]http://dicky_linn.webs.com/Misc-Pics/37ULH_iron.jpg[/img]
Here's a shot of the bike.
and one of the ignition module. It requires 2 small air core coils as opposed to the standard big black dual fire one.

[image]http://dicky_linn.webs.com/Misc-Pics/ULH_Pwr_timer.jpg[/image]
DD
Well, that didn't work, we'll try again tomorrow.

Frankenstein
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Re: S&S Carb on BIG Flathead

#20

Post by Frankenstein » Thu Jul 19, 2018 11:04 am

37ULH_iron.jpg
37ULH_iron.jpg (131.49 KiB) Viewed 305 times
ULH_Pwr_timer.jpg
ULH_Pwr_timer.jpg (136.3 KiB) Viewed 294 times
[img]http://dicky_linn.webs.com/frankiemainshaft.htm[/img]
Panhead, thanks for your efforts, I agree, my website is acting wierdly, If you'd be kind enough to get the ignition module pic to load, I'd much appreciate it.
DD
Last edited by Frankenstein on Thu Jul 19, 2018 11:26 am, edited 4 times in total.

panhead
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Re: S&S Carb on BIG Flathead

#21

Post by panhead » Thu Jul 19, 2018 11:14 am

Well, that didn't work, we'll try again tomorrow.
Your site is acting strange. I downloaded and added the first pic.

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Re: S&S Carb on BIG Flathead

#22

Post by panhead » Thu Jul 19, 2018 1:19 pm

Both visible now.

flatheadmatt
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Re: S&S Carb on BIG Flathead

#23

Post by flatheadmatt » Sun Jul 22, 2018 6:03 pm

beautiful bike and looks completely road ready. Nice work!

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Re: S&S Carb on BIG Flathead

#24

Post by tomo256 » Wed Jul 25, 2018 12:22 pm

Blind Melon. PM sent.
Thanks

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