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zachpc2
09-16-2017, 12:31 PM
So i was thinking about doing one of these conversions and a thought occured to me. The benefit of the conversion is you get the gearing ratio of the 883 and the top end power of the 1200 right? Wouldnt it make sense to just throw the 883's gears into a 1200?
Possible? Maybe cheaper? Thoughts?

BadMonkeyMW
09-16-2017, 3:52 PM
The only gearing difference between 883 and 1200 is the number of teeth on the transmission pulley. The transmission gears themselves are exactly the same. The gain is in the old, but time proven notion that there's no replacement for displacement. Punching your cylinders out from 883cc of displacement to 1200cc is an almost 50% increase.......that's nothing to sneeze at.

If you put a stock 883 next to a stock 1200, you have two bikes that weigh the same but one has a whole lot more power than the other, regardless of gearing. That's why guys make the conversion.

farmall
09-16-2017, 5:25 PM
883 was produced for insurance and product differentiation reasons. The engine was designed for the larger displacement then produced in a neutered 883 version.

It's like offering two types of hooker, one without a pussy, while making subsequent pussy retrofit easy and reasonably priced.

I personally prefer tall gearing to drop highway revs.

You can also compare kit costs (parts plus any machining) to good used 1200 engines from dismantlers. 1991 was the year for the alternator move to the crankshaft instead of the mongtarded clutch hub version, and of the five speed transmission. Sidestand reposition is required to upgrade an old frame with the later engine, but that's easy.

http://www.baggersmag.com/sportster-enginetransmission-swap-hrbw-tech-dr-frankenstein-i-presume#page-4

If you do a swap you can sell your old engine (perform compression test on both cylinders and take a video of it running) to recoup a good bit of cash.

Cotton1
09-18-2017, 6:00 PM
You can play with the gearing via numbers on pulley teeth on ether go motor. If you want more power the upgrade is a no brainier.

I'd suggest Hammer Performance. They know enough about the Sporty engines. I think they offer a 1275 kit that is bolt on now.

Don't take my word for it though, visit their website or give them a call.

Fwiw I am going to convert to chain drive on my project 883 and likely play with different gearing ratios. Weird stuff like that is interesting to me. Just to know what performance can be had at what fuel economy etc.

I own and ride both 883 and 1200 carby bikes. The 1200 is a beast compared to it's little sister the 883. That said, each has enough power for typical daily riding. Factory air cleaner is a bad deal, the breathing don't need recycling and some other things can be corrected to help things along. My un professional 2 cents.

Cotton1

zachpc2
09-18-2017, 6:48 PM
I had always heard that the 883 was Harleys race bike, it had a lot of low end power, and that doin the kit conversion made a beast of a bike. Did i hear wrong? Is the 883 just harleys low baller?

Tattooo
09-18-2017, 7:28 PM
I had always heard that the 883 was Harleys race bike, it had a lot of low end power, and that doin the kit conversion made a beast of a bike. Did i hear wrong? Is the 883 just harleys low baller?

Yep you heard wrong...... It was just a cheap bike intended for the first time intro people..........

zachpc2
09-18-2017, 7:58 PM
Well shit ok. Maybe i just save another grand and get the 1200. Bummer, i am new to harleys and that did seem way more affordable but i want a more long term bike.

Dragstews
09-18-2017, 8:18 PM
A bit of info on doing the 1200cc from a 883cc ....

78848

This photo is of a 3-5/8" bore on a Ironhead ....

When ya take the bore to 3-1/2" bore of the 1200cc motors. your boring a full half inch out of the 833 jugs....
Now that will get the cubes far up from 55 cubies to 74 cubes.... But now that you got much larger lungs to feed you still have those 833 heads that have super small valves....

The trick set up for big time muscle is to bore your 833 jugs out to the 1200cc specs and install pistons and heads from the Buell Thunderstorm era ......

Tattooo
09-18-2017, 8:28 PM
Well shit ok. Maybe i just save another grand and get the 1200. Bummer, i am new to harleys and that did seem way more affordable but i want a more long term bike.


What you need to do is save up some more coin and buy a bigger bike that you like..... Not much need in buying a bike then wasting money making it bigger more CC as it won't make that bike worth any more money.....

Plus listen to Jesse he knows his shit on Sportys............

Dragstews
09-18-2017, 8:48 PM
Oh .... Don't listen to me....
I'll have ya installing a Turbo and turning it into a beast that will make ya soil your knickers ...!!!!

https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcSOXImFGimDDN4hzH9iP_Q3inoPiN09e nSCVn0REiStzfR4Bzlp

That me and my Buell ...
It will power up the wheel at a buck thirty and keep it there as long as my nerve holds out... Or until I shit me drawers .....!!!

Whichever come first ....

WillSCB
09-18-2017, 10:34 PM
Or until the oil leak on the exhaust catches it on fire (with your bosses ol' lady on the back.) Right? By the way, how close are you to getting that beast back on the road. Shame about all the bullshit with the company making the fiberglass for it.

Dragstews
09-18-2017, 10:38 PM
I think she was digging it until the oil filter came loose ....
Ya know I thought Blues would fire my ass over that .... But he was cool with it cause I got it to a stop with no harm to his Lady or me...

That was a movie shoot in Vegas .... Too bad they couldn't keep up,,,!!!

Say Willber ya got a clip of you and the crew in the ad ....
Can't think of the Girl's name that was from Czechoslovakia...
She was a wild one ... I'm here to tell ya.....

Did I tell ya about the party at the Hot Rod Cafe in Henderson.....

https://s3-media1.fl.yelpcdn.com/bphoto/-a_NINvQwgChSkRWyHdmKg/ls.jpg

Same night as the fire .... She got toasted and rode her bike to the Sand Dollar ...
Scare the crap out of me... I was behind her all the way on the horn....

I was trying to tell her that she was in no shape to be riding. but being she was bigger than me ... !!!

Now I recall her name.... Marketa, heard she gave up selling insurance and got a job on Union Pacific Railroad as a conductor ....

https://s-media-cache-ak0.pinimg.com/originals/7c/b3/e2/7cb3e2d1729fbc1bfac156a139f4ad3d.jpg

WillSCB
09-19-2017, 4:36 AM
Somewhere I have a VHS copy of the commercial you are talking about. Yeah, Marketa. Still run into her now and then.

tzienlee
09-19-2017, 4:38 AM
Dragstew....Tattoo.......... you may know,..

I don't work on anything newer than 1984,... all far too modern for me,
But I was told that an 883 bored to 1200 was faster than a factory 1200 if you used the 883 heads.
as the smaller combustion chamber of the 883 upped the compression ratio,...any truth to this???....
(I have also heard the thunderheads from a Buell are the way to go but if ya cant afford a set)

Dragstews
09-19-2017, 5:50 AM
The 883 heads used on the 1200 bore with flat top pistons will jump the compression up around 12:1 ......
With pump gas being 91 octane falls short for a street bike, a dish piston (Or modified the combustion chamber) would get the numbers down to where as pump gas will keep detonation from killing the motor...

Valve size:
Here's where it gets a bit problematic ... The swallow chambers of the 883 heads requires longer stems than what the 1200 valves have going on, in turn kinda limits high lifts cam profiles. Ports also necks down into the bowl area, oversize valves are available with the longer stems....
Be some seat and port work to do....
The Buell (TS) heads have monster valves, same size as the Oem 80" Evo big twins, chambers are also matched to the (TS) pistons ...

tzienlee
09-19-2017, 6:35 AM
thanks for that, it makes sense written out like that........had to ask,.... now back to me Shovels !!

thecarfarmer
10-19-2017, 5:24 PM
The 883 heads used on the 1200 bore with flat top pistons will jump the compression up around 12:1 ......
With pump gas being 91 octane falls short for a street bike, a dish piston (Or modified the combustion chamber) would get the numbers down to where as pump gas will keep detonation from killing the motor...

Valve size:
Here's where it gets a bit problematic ... The swallow chambers of the 883 heads requires longer stems than what the 1200 valves have going on, in turn kinda limits high lifts cam profiles. *snip*

Another issue to be cognizant of when you get greedy for more power is that the 883 - length valves get close to each other during overlap with big cams.

My .02: if you want to make power, the best bet is heads with some cleanup & a high quality valve job. NHRS, Hammer, Baisley, Jesse 'Dragstews', are among the good shops. A set of cylinders that have been honed with torque plates are another critical part. Raising the compression (maybe not to 12:1) is a major help with performance when upgrading the cams

Buying a 1200/1250/1275 conversion kit can accomplish all of the above.

Once you go down that road, the engine doesn't know or care whether it started as an 883 or 1200.

Also, I ended up putting a larger rear sprocket on my bike (883 w/ N4 cams) so it'd rev higher. But I rarely went over 50-100 miles away from home

Dougtheinternetannoyance123
10-20-2017, 1:37 AM
Uhhh, a bit of misinformation? All due respect but there is multiple ways of going about this from of course just buying a 1200 to begin with, But many people recomend that the 883 is the best bang for the buck and then follow 1-2-3-4 stage tuning over the HD tax.
Depends on what you want to end up with.
But a ton of build articles along with dyno print outs, parts used and different combinations on the XL forum.
Some go with the monster 1250 conversions too..
But some sound economics of using the special conversion kits, and still using the 883 heads, Its not the top HP combo but its cheap and adds a ton of power.
I have multiple Buells myself,, Tubers and XB so big bias to those, but you can affordably build a nice 883 that will run rings around most big twins and with a few tweaks is more cost effective than a 1200.

The S&S Hooligan kits are nice (And a site sponsor here) Is Zippers still around? They used to be popular and heavily promoted in the Sportster performance book.

But this is typical and cheap!!!! ,,See: http://www.nrhsperformance.com/ekit8831200.shtml

The famous NRHS 1250 kit is now available in a conversion package! This kit takes your 883 to the largest displacement that will fit into the stock cases without the hassle and expense of case boring. These kits are available in your choice of colors: silver, black or black-highlighted. The iron-lined aluminum construction offers excellent heat dissipation together with the structural integrity and ring seal of a thick ductile iron liner that wears much less than the factory cylinder. Coupled with premium NRHS Hurricane Forged pistons, Total Seal rings, and Cometic gaskets, we feel this is the ultimate kit for your Sportster!

These kits work on all EVO Sportsters 1986 and up to include the newest fuel injected models.

Note: all of our kits use the 2003 and older style cylinders. They bolt up just like the newer cylinders but the fins are slightly smaller. In our experience this does not cause any extra heat and most folks cannot tell the difference when installed. Pictured below is a NRHS 1250 kit with 2007 XL 1200 heads.


This kit includes:
- One set of premium Hurricane reverse-dome conversion pistons in 3-9/16 bore
these provide a 10:1 compression ratio with your stock 883 cylinder heads
- One set of new Axtell cast-iron cylinders, or NRHS iron lined aluminum cylinders
- Rings, pins, locks, and circlips
- Cometic EST head/base gasket set

Actual results obtained in the NRHS shop from our 2004 Sportster XL 883:

Or more:

NRHS 1250 PACKAGE WITH MATCHING CAMSHAFTS

Want even more power? NRHS has packages that include both the NRHS 1250 kit, gasket kit and matching camshafts that are proven on the dyno and on the street to work exceptionally well together. Buying a matched package takes the guesswork and error out of your project!

Note: This is for use with all 1986 and up 883 cylinder heads


Description
Black w/Highlighted Fins
Black
Silver
NRHS 1250cc package:
3.563" bore iron lined aluminum cylinders
CP 10.5:1 pistons, pins, clips, rings
Andrews N4 Camshafts
Cometic Top end gasket kit
Ring gapping
004-NAIL3563XL883PKG-BH
$950.00
Make payments with PayPal - it's fast, free and secure!

004-NAIL3563XL883PKG-B
$950.00
Make payments with PayPal - it's fast, free and secure!

004-NAIL3563XL883PKG-S

Dougtheinternetannoyance123
10-20-2017, 1:50 AM
This makes a compelling case for a lot for a little, and a Lot more $$$$ for just a little.


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