883/1200 power, fact or fiction

[01norcalsporty]

Originally Posted by ttopbandit

My 883 hangs "just fine" with my buddy's 1200 S, that is, until we get to the upper end of 5th, the he starts pulling on me. Mine? A 98 883 Hugger, with a Screamin Eagle 1200 pistons and jugs, stock heads and cams. Add my screamin eagle exhaust and she scoots fine. The gearing helps alot, but I am thinkin about changin pulleys for mor highway...maybe....

How many teeth are you considering going up and on which pully? I understand you can change either the sprocket on the output of the motor or the pully/sprocket on the rear wheel.

[camcarvin]

No way hes doin 140 mph with his 1250 build if hes runnin the 28 tooth 883 pulley !

[Flamin883]

One thing that no one has mentioned, is the fact that you can actually have a better preforming longer lasting engine after the upgrade if you have it done correctly. all the OEM parts meet the factory specs and are just pulled from a bin, so it is possible that you end up with a rear jug on the outer/upper limit of specs a rear piston on the lower end of spec. while the front is exactly the opposite so you end up with kinde of a missmatch. but when you have a quality shop set things up for you you can come out with exactly .002 clearance on both. same goes with the chambers of the heads there can and probably will be slight differances, but I know both of mine are just shy of 56 cc's and identical, this makes for a much smoother running engine I still run the 883 gearing and can see out of the mirrors at 85+ in 4th gear. But it's not anywhere near a fair comparison to a stck 1200

[Scrapper]

The stock 883 crank shaft has a lighter balance weight on it due to the smaller 883 pistons so 883 conversion pistons are normally lighter than stock 1200 pistons(as well as having a reverse dome for dropping compression)
So technically an 883 /1200 conversion should spin up faster and have better throttle response than a stock 1200.
Now this is where people fall down,
Not installing bigger 1200 sized valves.
Installing 1200 heads and normal 1200 weighted pistons in an 883 bottom end.
And as mentioned the gearing of your front pulley is 1 tooth smaller in the 883 which will hurt you on the highway against your 1200 buddy.
hopes this makes some sense.

[Big_Baazzoo]

yeah, it's that front pulley that needs changing.

[aswracing]

Originally Posted by Scrapper

The stock 883 crank shaft has a lighter balance weight on it due to the smaller 883 pistons

No it doesn't. The Motor Co went to a common flywheel assembly in the mid 90's.

[Scrapper]

Originally Posted by aswracing

No it doesn't. The Motor Co went to a common flywheel assembly in the mid 90's.

I stand corrected so is that why the new 1200s vibrate like hell, is the crank balance factor matched for 883s ?

[Turbo Sporty 48]

Scrapper,
Mine does not vibrate that bad at all. Unless you compared it to a ricer, which I am not.
When looking I checked out the non-rubbermounts.
Maybe you are seeing bad tunes?

Originally Posted by Scrapper

I stand corrected so is that why the new 1200s vibrate like hell, is the crank balance factor matched for 883s ?

[Scrapper]

Compare it to a new 883 they vibrate, unless somehow magically HD have managed to perfectly split the difference with their common flywheel assy.

[Turbo Sporty 48]

Lots of good things to say about the 883, now that is one of them that I did not know.

Originally Posted by Scrapper

Compare it to a new 883 they vibrate, unless somehow magically HD have managed to perfectly split the difference with their common flywheel assy.