"People who say this often fail to realize that a larger displacement engine makes more power everywhere than a smaller one, all else equal. There is no replacement for displacement."

People who say this often fail to realise that 3-4ci on this type size of build.. (128vs131, 139vs143) Is going to mean little on a street engine that fails to keep ring seal and wears out before it had to. On top of that the HP difference can safely be made back through rpm. The airflow IE HP choke point is generally the same as its the same intake heads exhaust. If when the airflow is not the choke point having more safe rpm range is a good thing. To not only peak HP but average HP in the shift to recovery range. All else equal we all like more displacement. The thing is in that scenario its not all equal. Last didn't I start out with "personally I prefer" then even shared why. You are entitled to your preference and to make your case as to why. Discussion is what forums are for and it can be done without put downs.


At this point we now know this type build is not relevant to the OP. He is not interested in the type performance I gathered from his first descriptions but rather in a bump up from stock. And there is nothing wrong with that. If he is happy at that level I am happy for him. Many times over the years I wish I did not suffer from gofast-itis. Cheers all.

 

FLTRI117, it's a lot more than 10 of anything, see my dyno in the M8 section. or you can believe me at 110HP and 118Tq. That is with a 114 "big Bore" from Harley (it's in the Screaming Eagle Catalog). with a 22X Woods Cam and a Fuel-Moto canned map. The bike was run on a dyno (no tune) before and after parts were added. All under IIRC $2500 and has over 25k on the build and 44K on the bike. Yes it is a blast to ride and drive!!

 

I'm sure FLTRI17 is well aware of what those kits can do. He is one of the pre-eminent Harley tuners in the country.

The 114 vs the 107 is about 8-10 hp and ft/lbs, without changing the camshaft. Doing the Harley Stage III on a 107 involves a lot more than just increasing the displacement, so yeah, much bigger gains.

 

The 107 to 114 and now the 107 to 119 both great cost effective regular street riding type kits. Like h7009 I did the 107 to 114 over 3 years ago. SE AC & intake, SE tuner & S&S pipe with cat for a warranty compliant build. 118 HP 122 TQ on a softail. 37k on that build zero issues. On a long pipe bagger the torque number would climb. Today building a used bike no warranty concerns i'd do the 119 with appropriate aftermarket cam & tuner and as FLTRI17 said hold on.

 

Do the 107 SGS's have RDRS?

 

shows as an available option on the pricing sheets for the Touring bikes with 107s on the HD website...I don't know I have seen one equipped with it though...but it seems pretty standard on the Specials

 

Last year for a 107 in a SGS was 2018. RDRS was not available that year.

 

Thanks Dynamick!

 

Bore on 107 and 114 so close the same difference is very slight increase in stroke that makes it a 114.
I have owned both.
114 seems to have long legs. 107 stronger on the low end .

107 3.937 X4.375
114 4.0 X4.5

 

Here are Harley's published dyno charts of a stock 107 and a stock 114, overlaid into one graph.


The 114 is stronger everywhere, as you'd expect from the increased displacement.

(Original post and supporting data here)