Over Sq Harley - Real World results ?

afterburn 549 · 08-30-2015, 09:30 AM

I should not ever think..but it happens
Now that i got this thing running real good...
I want to change.....
Does anyone know of results of stock stroke and a big bore on the EVO platform?
Your thoughts?

asphaltgambler · 08-30-2015, 10:22 AM

It has been done over the years - but only perfected when S&S partnered with Star Racing to engineer a real world street engine that makes 150HP / 145TQ at the rear wheel on pump gas...........it's been out since 2009 ......................

G2 Motorsports | Star Racing

afterburn 549 · 08-30-2015, 10:28 AM

Thanx for the link!
What are the caveats ?
Seems pretty straight fwd.
What am I am missing ?
They did it with the twin cam it looks like, a Evo ought to lend itself or a "after market engine case.

asphaltgambler · 08-30-2015, 10:38 AM

Actually, there is no comparison with anybody else. Rock solid and proven. S&S partnership resulted in having truckloads of cash and other resources to develop this. Of course, there are a few options where you can add more power (like cam and compression) but it makes a ***** load of usable street power as it is.

They engineered it from the beginning as street engine based on the geometry of the current HD twin cam, which is very good btw. The biggest difference is the cam chest is offset to allow for the large bore and the oiling system is designed to handle that displacement efficiently.

Lastly, the B-2 heads have large, raised high volume ports, "D" to almost oval shape to move the amount of air that engine requires @6500+ RPM's

Assembled and out the door minus induction / ignition is @$10K+

afterburn 549 · 08-30-2015, 10:41 AM

Thanx!

asphaltgambler · 08-30-2015, 10:44 AM

It is a lot of money, but a pump gas 150HP dead nutz relaible street engine is no effin joke. That's almost Hayabusa territory...................but with almost the torque as HP that is 1 serious contender!

afterburn 549 · 08-30-2015, 10:52 AM

I was thinking the biggest bore cylinders I could get on a evo style case (fly cut of course ) ...I am not up to speed what is even out there.

afterburn 549 · 08-30-2015, 01:45 PM

To Pursue this I need after market cases with some huge spigot bores.
Ideas?

Chocaholic · 04:05 PM

Obviously not in your plans, but for about $3k less than the engine alone, you could buy a nice BMW K1200S with 167HP and 300 lbs lighter. Use your HD for its intended purpose and your K12S for its intended purpose. And the K12S is built to handle and brake commensurate with that power, unlike your HD. And in the end, you won't lose your shirt on resale.

Different tools made for different jobs. Just a thought.

afterburn 549 · 08-30-2015, 04:07 PM

Hay thanx!
I just do not see two up on that..
I have considered the F6
But it comes dwn to - i am fixer upper kind of guy, of stuff.
It is not ever good enough no matter how good it is! LOL

Chocaholic · 08-30-2015, 04:14 PM

It's considered a sport touring rig. I've owned two and may go back to the well again. My wife has ridden with me on my K12S and, not as roomy as my HD, it is certainly very, very well designed for two up.

But I can certainly understand the joy of the project! Dig in and have fun. In the mean time...

BMW K Series | eBay

afterburn 549 · 08-30-2015, 04:19 PM

I have nothing but respect for BMW and a lot of others.
But i love a carb and simplicity .
The HD supports two people rather well for 500 Miles a day.
If i was alone, I would maybe consider something else.

sammyg2 · 08-31-2015, 05:45 AM

afterburn 549 · 08-31-2015, 05:48 AM

Yea........I know........

asphaltgambler · 07:02 AM

Some of the problems with the older EVO / single cam design was the awful valve train geometry especially on the front exhaust pushrod / rocker set-up. As soon as you start adding camshaft lift / duration and then, or course, added spring seat pressures - valve train noise and stress go up exponentially. My lest EVO 117" street engine was total bad@ss but when hot and idling at a stop light it emitted sounds from the rocker covers like someone had thrown in a handful of gravel inside.

Also while the EVO was a good step forward from the extremely outdated / long past due retirement Shovel, it lacked structural strength and too many gasketed 'things' to move around and leak oil when really pushed to make HP/TQ.

The Twin cam design was / is a huge step forward by eliminating a lot of bolt-together-things like casting the cases and lifter blocks as one piece, adding material in the deck and crank bearing area. Star-Racing / S&S then further engineered their own engine based on the already proven piece.

BTW, HD already knew this even as their first twin engines were in production in the late teens / early twenties. For their racing engines (board track)they did a twin-cam version that was very proved very successful. Unfortunately, it proved to costly too manufacture in 'street' engines at that time.

afterburn 549 · 08-31-2015, 08:57 AM

I think if HD had all their pickles in one jar they have just copied the K or sportster 4 cam configuration.
SO..your saying start off with TC cases , Like S&S and a welded crank unit right?
I hate the looks of them.......but will do as i have to do.
When at Sturgis couple weeks ago I was wandering the pit areas.
Besides looking kool I did not see any representation of TC stuff.
Those things were going dwn the 1/4 under 5 SEC!

asphaltgambler · 08-31-2015, 10:56 AM

Well if I were considering a serious upgrade, I would just buy the engine. Buying and assembling parts from various manufacturers gets very expensive and time consuming when Star racing has done that already. They do sell it un assembled for reduced price.....

afterburn 549 · 08-31-2015, 11:09 AM

I will look into it
Thanx!
No use i reinventing the wheel