160+?

[No Cents]

Walk in the park to see 150/150 from a 124" on dynos from Fla, to Calif, to NY,........160 hp is yet something altogather different.
The higher you climb, the harder it is, to climb higher.
I know at one time, there was an individual on this site, that laid claim to a Mikuni carb equipped, 160hp with a 124", using a .640 "stick"......along with a White Bros. E series pipe.....I was born at night....just not last night...


      100%

[build it]

Is there a specific reason why it is so difficult to get a HD to 1.3 per ci and so easy to get a V8 there?

To many to list.

[02roadcling]

Is there a specific reason why it is so difficult to get a HD to 1.3 per ci and so easy to get a V8 there?

To many to list.

45 degrees.

   cling

[Hossamania]

Is there a specific reason why it is so difficult to get a HD to 1.3 per ci and so easy to get a V8 there?

To many to list.

45 degrees.

   cling

One simple way to think of it, in a 2 cylinder motor, each piston must perform 50% of the work, in a V8, each piston only has to perform 12.5% of the work, plus many other factors. Maybe I'm not looking at that correctly, but I'm trying.

[Ohio HD]

Is there a specific reason why it is so difficult to get a HD to 1.3 per ci and so easy to get a V8 there?

To many to list.

45 degrees.

   cling

Yes, 405° firing interval doesn't help much.

[Ray G]

Finally a post with some brimstone & fire. Lots of opinions but as mentioned would like to see some builders adding accurate & tested comments. This post is just fascinating, I eagerly wait till we see some factual results.  I haven't seen a post that kept me so interested since the beginnings of the Barn Build which is a classic by anyone's standards.  Not intending to step on anyone's toes just interested in all the replies.   

[gordonr]

Is there a specific reason why it is so difficult to get a HD to 1.3 per ci and so easy to get a V8 there?

There are a few reasons. 1st is HD's having a siamese intake manifold, its a hp killer. 2nd being intake manifold volume is way to small. Est 20 sq inches and should be the volume of both cylinders combined for reserve cylinder fill (consequently the reasoning behind large TBs for 2 cylinders). 3rd is the intake runner length. Estimate 3.5" on an HD, should be at least 12''. There a couple more but its dinner time

[Ohio HD]

Finally a post with some brimstone & fire. Lots of opinions but as mentioned would like to see some builders adding accurate & tested comments. This post is just fascinating, I eagerly wait till we see some factual results.  I haven't seen a post that kept me so interested since the beginnings of the Barn Build which is a classic by anyone's standards.  Not intending to step on anyone's toes just interested in all the replies.   

I posted two members dyno results that have made the HP. The scope of their builds are listed on their post.

[Matt C]

Is there a specific reason why it is so difficult to get a HD to 1.3 per ci and so easy to get a V8 there?

There are a few reasons. 1st is HD's having a siamese intake manifold, its a hp killer. 2nd being intake manifold volume is way to small. Est 20 sq inches and should be the volume of both cylinders combined for reserve cylinder fill (consequently the reasoning behind large TBs for 2 cylinders). 3rd is the intake runner length. Estimate 3.5" on an HD, should be at least 12''. There a couple more but its dinner time

That pretty much nails it. (The induction system is total crap by any standards)

[1workinman]

Walk in the park to see 150/150 from a 124" on dynos from Fla, to Calif, to NY,........160 hp is yet something altogather different.
The higher you climb, the harder it is, to climb higher.
I know at one time, there was an individual on this site, that laid claim to a Mikuni carb equipped, 160hp with a 124", using a .640 "stick"......along with a White Bros. E series pipe.....I was born at night....just not last night...


      100%

Well it has not been that long ago that 150 hp daily drivers were the talk that was repeatable on the dyno lol .

[Hillside Motorcycle]

Is there a specific reason why it is so difficult to get a HD to 1.3 per ci and so easy to get a V8 there?

There are a few reasons. 1st is HD's having a siamese intake manifold, its a hp killer. 2nd being intake manifold volume is way to small. Est 20 sq inches and should be the volume of both cylinders combined for reserve cylinder fill (consequently the reasoning behind large TBs for 2 cylinders). 3rd is the intake runner length. Estimate 3.5" on an HD, should be at least 12''. There a couple more but its dinner time

One of the reasons our "Cross Ram" manifold, with either B or D series S&S carbs worked so well.
Paul Morris knows.

[ecir50]

That's just a tease without pics.

[TheDog]

I have S&S T124 with b2 heads. I have dynoed bike several times. It makes app 160 rwhp. I´m going to "uppgrade" motor
with S&S G extreme kit this winter and better exhaust.

http://harleytechtalk.com/htt/index.php?topic=88026.0

[pwmorris]

That's just a tease without pics.

Here ya go...
Warming up the tire using the cross ram-


And in the winners circle-







And what I run now on my street bike-
I cant stand the crap HD solution splitting into the heads....Plenum works great for me on the street...




And here is J Shaheens 124" that makes 200 HP using a hand made plenum and intake by SA Racing (who ported and redid my plenum on my street bike as well as my race bike)


Made 189 at the shootout but after further testing nailed 200-   https://goo.gl/4QdTCJ

[ecir50]

Awesome pics Paul but was thinking pics of the just the intake not on bike to get a visual of the cross ram. Was thinking cross ram had individual runners but now see they have a common plenum from the pics above.

[1FSTRK]

 But it was nice that he included the trophy pic form the Pinup Models bike show.

[Hillside Motorcycle]

That's just a tease without pics.

Here ya go...
Warming up the tire using the cross ram-


And in the winners circle-







And what I run now on my street bike-
I cant stand the crap HD solution splitting into the heads....Plenum works great for me on the street...




And here is J Shaheens 124" that makes 200 HP using a hand made plenum and intake by SA Racing (who ported and redid my plenum on my street bike as well as my race bike)


Made 189 at the shootout but after further testing nailed 200-   https://goo.gl/4QdTCJ

Thanks for posting those photos, Paul.

[ken6217]

Well since we know 160+ is not easily doable, can we now move this thread to Earl's Place and discuss those Blondes in the photo? 

[joelp34252]

That does not look like any AHDRA winners circle photo I have ever seen. Which race was that at. I'm curious.


Joel 2001 FLHT

[pwmorris]

That does not look like any AHDRA winners circle photo I have ever seen. Which race was that at. I'm curious.


Joel 2001 FLHT

Dyno Shootout/bike show winner
I only raced AHDRA a few times, as it was mostly East Coast.

[08flstf]

So could a custom intake with longer runners be made to work with an HPI throttle body, and if so would you reep the same benefits you would with a carbed bike?

[No Cents]

So could a custom intake with longer runners be made to work with an HPI throttle body, and if so would you reep the same benefits you would with a carbed bike?

  I ended up making an intake for my throttle body. I played with the lengths of the intake tube to find what worked best for me. My t/body is a S&S 66mm T/Hog and the intake tubes ID is the same size as the ID of the t/body...so the incoming air has an unrestricted flow directly into the throat of the t/body. Once your moving it's like a ram air.
This was the initial intake mock up.
[attach=0]

  After a little testing I shortened the intake tube length some. At the length it is at right now my engine has never lost one horsepower with the K&N air filter on it...or off it...according to Jim Kennedy on his dyno.
The final length of the intake I made.
[attach=1]

[Hillside Motorcycle]

So could a custom intake with longer runners be made to work with an HPI throttle body, and if so would you reep the same benefits you would with a carbed bike?

Have manufactured, and have had HPI manufacture 1" spacers for their 2 pc intake systems, to increase plenum volume.
We have also fooled around with the idea of manufacturing a 2-throated EFI, using either our Cross Ram, or something similar to the S&S Extreme G, common plenum.
Would not be difficult, but have so much else going here, that has taken a back seat now for quite some time.

[louloupa]

why are the tb never separated on each cylinder?  Normally, it gives more power .

[No Cents]

 Gregg Dahl has ran a "dual efi t/body" set up that he made a few years ago and he runs it on his drag bike...pretty cool looking rig.
I think he pretty much dominates the class he runs in with that bike.