From experience - the HD published numbers are significantly pessimistic. In example, here's HD's chart for the 585 cam in a 103HO:



But - with the cams installed and a dyno run, my actual curve looks just like this, only at 110 ft-lbs and 92 HP.

Many poo-poo the idea of keeping your Harley 100% HD. Yes, you may find a cam that will perform slightly better, but don't be fooled - you will LOVE the tire shredder kit. And no one is going to walk away from you with similar kits.

 

The quality of the components is what HarleyD is dropping the ball with. They've succumbed to the bean counters and shareholders. (Make more profits by using cheaper, substandard products.)
S & S hasn't started to "cheapen" their products as of yet. AAFAIK.
It's like buying a large pizza with the works, getting home opening the box and there's a personal sized cheese pizza that's burned inside the box...

 

In your quest for added performance, there are different methods for reaching your goal:
1) You can stick with the factory enhancements that probably should have been on the bike when it was originally sold (and are still somewhat limited).
2) You can just get a new engine from S&S that has it all done for you.
3) You can try to find the right combination of aftermarket parts that compliment each other. This method gets you the most bang for your buck, but requires a fair amount of knowledge to do it properly.

At any rate, real performance gains will not be realized with the factory, and quite possibly still void your warranty, so it's your decision.

 

The bonus to using HD parts - my ESP is still in effect.

 

don't confuse HP and torque

You can get massive torque with low HP (Harley V Twins) and massive HP with carppy torque (rice rocket inline 4's)

There are a lot of things that go into it, bore and stroke ratios ( under square, square, over square) but if you are comparing apples to apples ( same displacement, bore and stroke) it is going to come down to the cam profile, and how the rest of the components ( heads, exhaust, compression ratio) are matched so they all have the same characteristics ( works well for torque, or works well for HP, or a compromise to get some of both)

 

S&S cranks are 100x better. Cam chest is better design as is oil pump. Cases are beefier. The list goes on and on.

Unless you do significant head work you might want to consider a 55mm throttle body and match the injectors to the flow through the heads.

My "little" S&S T111 left the dyno at 130/131 with 9.5 compression and plain old S&S superstock heads. It's about matching QUALITY components for the build not, just throwing a big bore kit at it.

 

Well it is a good thing the O.P. has an esp. He is likely going to need it once the Harley coolaide runs out

 

you should read this all the way thur ....this build is all you need ...unless you ride at 5-6000 rpm's all the time ..!!!
this thing will get you there very, very quickly ...ask me how i know ...!!!

https://www.hdforums.com/forum/engin...-lbs-pics.html

thanks to Dave and the guys at Hill Side !!!!