Harley Sportster at Wilmington

[TurboCat]

What would be a reasonable expectation from a 1250 conversion Sportster with appropriate gearing making in the vicinity of 110hp? This '07 would have to run M/PP I'm guessing because some of the stock components have been upgraded (tires, wheels, forks, exhaust, ect.). I would like to make the trip this year to familiarize myself for a serious run next year in P/PP 1000 using the same bike.

[55chevr]

1250cc Sportster with a mild worked engine, good pipe, good carb set up, geared correctly should go mid to high 140-s mph in the paved mile. In order to run production, it has to be completely production appearing including belt drive.  I suggest you get a rule book and read it 3 times ... then read it again.   Production rules don't allow much deviation.


Joe

[TurboCat]

1250cc Sportster with a mild worked engine, good pipe, good carb set up, geared correctly should go mid to high 140-s mph in the paved mile. In order to run production, it has to be completely production appearing including belt drive.  I suggest you get a rule book and read it 3 times ... then read it again.   Production rules don't allow much deviation.


Joe

You misunderstand...if I come this year it will be with the 1250 and will have to run Modified...next year will be the real test when I return with the bike in Production trim in the 1000cc class. Yes I have the rulebook and understand it fairly well...that was the reasoning behind modifying the stock exhaust system I had lying around for next season. This bike is an '07 efi model with plans to run a 68T/32T combo gearing...calculators and theory say it should suffice, but we all know the real world sometimes dictates otherwise.

It's good to hear you think it capable...looking forward to giving it a go! 

[RansomT]

I'm not following?

How are you going to return 1250cc conversion back to a less than 1000cc engine?   Engine swap?

[55chevr]

You mentioned 110 HP. If you are going to run in 1000cc with that bottom end you have to go to barrels from an 883   ...  has to match up with 883 small valve heads. That is a tough combination to get any power out of.  With that combination running stock exhaust, I would think that it would come out in the 80 HP range.  The 1000cc production bike we ran awhile back was on an XB9 platform and used the short stroke crank. 


Joe

[wfojohn]

Hi Turbocat,

If you are ever near Lawrenceburg, TN stop in and say hi. We don't play in your league, we mess around with small bore 2 strokes.

Wilmington is everything its touted to be. Absolutely great track, town, restaurants and accomodations. The ECTA has its stuff together, only Bonneville surpasses it.

John Ritter

[TurboCat]

Thanks guys - Maybe I can clear this up...I'm in the process of converting the bike from 883 to 1250 atm which is my daily ride. Hammer Performance is doing the machine work on some extra cylinders/heads I sent and it will be a virtual clone of their '07 dyno mule. http://www.hammerperf.com/dynoroom.shtml

I missed the opportunity last year to attend Bonneville with my buddy Jason Sarratt who runs a turbocharged sidecar Sportster...



I so wanted to bring my turbo'd 883, but the trip proved to be just too much/far for me logistically. Not being much of a spectator I scrapped the trip entirely, but the itch remains.



Meanwhile, I have been talking with Dan and Aaron at Hammer about my plans for the 1000cc build. Wilmington is very doable for me distance wise and I decided to get the ball rolling while I still have my health. Aaron will be doing custom slugs which will bring displacement out to 997cc and will be machining the 883 heads to match the new bore size. Once completed this motor will not be in any fashion streetable...it will just appear to be so. Aaron was on the crew for a similar bike in 2002 at Bonneville and he has a good idea what will be needed. Horsepower levels of the 1000cc motor are unknown atm as this will be out of the realm of common builds, but I can tell you it will be pushing all it is capable of given the constraints we have to deal with. Just to be clear, yes I will be using the current bike for this venture...it will be using a different top-end and the chassis will be put back to production status.

@ John - I used to spend a great deal of time at Lawrenceburg at Jim Butler's dragstrip when he still operated it...good times.

[wfojohn]

We hit the track several Friday nights each summer for the test & tune sessions. Fun little track and real laid back.

Just a thought and maybe I am confusing classes with your bike. There are very strict new rules about overbore. Now understand, I don't know HD engine sizes but "if" I am correct (very possibly wrong) but a 883 can not be bored in production class. We use to be able to go to class size plus .020". If I am screwing up what applies to your application just ignore what I am saying.

John Ritter

[TurboCat]

We hit the track several Friday nights each summer for the test & tune sessions. Fun little track and real laid back.

Just a thought and maybe I am confusing classes with your bike. There are very strict new rules about overbore. Now understand, I don't know HD engine sizes but "if" I am correct (very possibly wrong) but a 883 can not be bored in production class. We use to be able to go to class size plus .020". If I am screwing up what applies to your application just ignore what I am saying.

John Ritter

I believe that '020" reference is for clean up purposes in those cases of cylinders being at the maximum class displacement. If an overbore is not allowed for Production bikes I would be shocked...this same type of bike set a P/PP 1000 record in 2001 at Bonneville @ 139mph and change...it was a 883 with XR1000 pistons. Maybe someone else can chime in on the subject. By rules a 883 has to compete in the 1000 class...it would have no chance against say a Buell if not for an equal displacement allowance. I can find no reference to overbore limitations for Production motorcycles in the rulebook, tho mine is a 2012. It just states "Any performance modifications must be out of view".

[wfojohn]

I think you are going to have to reread the rule book. They screwed it up good. You might use the search feature in Bonneville General Chat or maybe the Rules section. I only mentioned this in my last post because I thought you were thinking of doing it the old way. If I am passing along correct info as I think I am, you have time to rethink your project. We use to be able to go to class size plus .020" as you said but now Production cannot even be bored (I think)(??)

I hope what I an telling you is correct PLEASE triple check me, it is meant to help so if I'm wrong. I apologize.

John Ritter

[Stainless1]

OK guys, stop fretting... here is how I understand the rules.... any motor can be bored to the class limit... the rule change has to do with going past the class limit for a clean up overbore of .5mm or .020 inch.  The rule change says you can still go past the class limit only if your stock bore + the .020 puts you over.  If you bored it to the limit, you can't have the extra .020 that would put you past the class limit.
Production does not get the over the limit bore at all, but boring to the limit is allowed.
So bore your 883 to 1000, but don't let it measure 1001 or you will be in 1350 class.

[TurboCat]

That was my understanding as well, but the question un-asked is usually the one that bites you. 

[rouse]

The way I read it, the PP class rules make it clear.You can not increase the engine size beyond the class window it originally fits. So if you have a 883; it fits the 1000cc class, so do what you want on the bore as long as you don't violate the 1000cc limit for the class.

I agree with the .020 overbore rule as written; it only applies when original "OEM" is already at the class cc limit, but that has nothing to do with this engine, as far as I can tell.

139+ MPH for an open bike will be a tall order, the class record now is 144.626 MPH by a Buell. The aero advantage of the Buell makes one heck of a hill to climb for a open bike.

Rouse

 

[relaxedphit]

If you are planning on running the stock looking black/gray sportster in one of your pictures, the tach/speedo setup is just like the one I had on my late '99 FXDX. You will not be able to get anything close to a good tuck trying to see over the gauges. Since I was running modified, I got a flat bracket and cut that lying speedo off to see around the tach.

[rouse]

If you are planning on running the stock looking black/gray sportster in one of your pictures, the tach/speedo setup is just like the one I had on my late '99 FXDX. You will not be able to get anything close to a good tuck trying to see over the gauges. Since I was running modified, I got a flat bracket and cut that lying speedo off to see around the tach.

I thought he was talking about running P-PP, If so, the gauges have to be OEM and in the original location.

P-PP is tough on open bikes, especially if they are styled for looks and not aero.