PDA

View Full Version : 883 to 1200 conversion (parts and kits)



33anda3rdreich
11-10-2011, 7:43 AM
So I want to make my 883 sporty into a 1200. there are quite a few kits out there. I have been directed by a few people to NRHS, everyone says they are the best which is fine but I dont have the $$$ for the best.http://www.nrhsperformance.com/ekit8831200.shtml

The lowbrow conversion kits are a little closer to my budget. The lowbrow kits use "wisco" parts etc. Which I hear are 50/50 on quality. kits usually run around $500

Now I find this Wisco kit for $230. But you only get the pistons. http://www.amazon.com/Wiseco-Piston-1200cc-Conversion-Reverse/dp/B000WJCQ2Y


So whats the difference? Will the kits with just the pistons really work? and if so, how well?



Thoughts please

mindthreat44
11-10-2011, 8:19 AM
I think the kit with the just the pistons will require you to bore out your stock cylinders to except the bigger pistons. The other two are completely bolt in. I can't comment on quality of either one though since my bike is still an 883

Bonsai
11-10-2011, 9:22 AM
The kits are.. well kits... "bolt on" as one can get... as opposed to just buying the jugs and then having to machine it- which sounds like you will have to farm out...

So add a few $100's for that work by the time you get done. Know a guy that just had this done to his 883 by NRHS and dumped about $1200 into it- he added some mild upgrades- cam, etc.- he says it's a pretty sick ride now.

My nature says the "bolt on" is not entirely tru- would love to hear frmo someone that's actually done it and what all else ends up needing to be done as I have an 89 sitting here that is just screaming for it..

azmotorhead
11-10-2011, 9:49 AM
wiseco quality is fine, they make pistons for s&s. cheaper just to bore your cyclinders and buy a set of pistons.

AfterHours
11-10-2011, 10:06 AM
You may as well have a local shop bore out the cylinders that you have 'cause the bolt on ones are mass produced and you really want to hone them to each piston anyways. Wiseco pistons are alright, not great, but you're not building a $10,000 motor so it'll be fine. I think you want to hone on the tight side with Wiseco's, talk to the local shop and they should know better.

Now is also the time to have your heads ported. This is the best money you can spend for performance aside from the 1200 conversion.

CRFyou
11-10-2011, 10:11 AM
when i get cylinders bored, i take the pistons to the machine shop so there's no guessing in their machine work.

it's def more affordable if you do the leg work yourself. i, personally, wouldn't bore an air cooled motor on the tight side. pistons swell faster than the cylinder walls expand.

VonMisfit
11-10-2011, 10:16 AM
i was looking at this guy. same price as some of the cheap china V-twin kits (these are the one you can find everywhere) but he uses harley jugs. planes all the mating surfaces too.
http://www.ebay.com/itm/150550732998?_trksid=p3984.m1436.l2649&item=150550732998&viewitem=&sspagename=STRK:MESINDXX:IT&vxp=mtr

just have to send him your old 883 jugs

Shovelzilla
11-10-2011, 10:37 AM
wiseco quality is fine, they make pistons for s&s. cheaper just to bore your cyclinders and buy a set of pistons.

True that,ive rebuilt alot of my dirtbikes with Wiseco pistons/cranks,good quality!

33anda3rdreich
11-10-2011, 11:13 AM
Talked to local shop. He said it would be cheaper to buy bolt on kit vs have my current parts bored out. he also said go with reverse domed pistons and might have to go up to a larger valve in order to make a real difference in power.

his opinion on porting and head polishing is that there are better things to spend $ on.

LDNCLR
11-10-2011, 1:02 PM
sounds to me like he wants to sell you a bunch of stuff. Port the heads.

33anda3rdreich
11-10-2011, 5:15 PM
I would have thought that but the guy doesn't sell any of the kits, parts, or services mentioned. he told me to keep researching and make the best decision.



as far as porting I have heard arguments for both sides. I am no expert so I will leave it at that

bigdaddy
11-10-2011, 5:39 PM
let's get a bunch of guys from indiana together and see if we can get a shop discount for having the jugs punched out!

GO4TH
11-10-2011, 5:56 PM
Call Dan At Hammer Performance 970 344 7120 ....He knows more about Sportster performance,big bore kits,and porting,than anyone I know.:cheersmate:

azmotorhead
11-10-2011, 6:38 PM
could always buy some used 1200 cylinders off of flea bay and a set of buell heads. just happens to be a set on classifieds right now.

rackball
11-05-2015, 6:24 PM
sorry to bring this up being so old. but can you take a stock 883 and put same year 1200 heads jugs and pistons on it? without fukkkering the bottom end up? keep hearing contradictions.. weight of pistons on the crank and what not..

jmattsen
11-06-2015, 12:24 AM
since you allready bumped the thread il throw in my question also.

would going from a 1200 to a 1250 be possible by boring my cylinders out like the 883 to 1200?

and did we decide it would even be worth it cost wise?

Dragstews
11-06-2015, 3:53 AM
since you allready bumped the thread il throw in my question also.

would going from a 1200 to a 1250 be possible by boring my cylinders out like the 883 to 1200?

and did we decide it would even be worth it cost wise?


To give y'all an idea of how much meat is bored out of a 883 jug are these photos...

http://i279.photobucket.com/albums/kk140/dragstews/transXL017.jpg (http://s279.photobucket.com/user/dragstews/media/transXL017.jpg.html)

The 883 jugs has a standard bore of 3"

http://i279.photobucket.com/albums/kk140/dragstews/transXL019.jpg (http://s279.photobucket.com/user/dragstews/media/transXL019.jpg.html)

Taking them to 3-1/2" which is the standard bore of the 1200cc

http://i279.photobucket.com/albums/kk140/dragstews/transXL024.jpg (http://s279.photobucket.com/user/dragstews/media/transXL024.jpg.html)


At the 1200cc bore the liner gets pretty thin... Three more bores can be done to them at .010 a wack .... Alot of manufacturers makes a .040 over... With that bore the liner turns into an eggshell.....

http://i279.photobucket.com/albums/kk140/dragstews/transXL021.jpg (http://s279.photobucket.com/user/dragstews/media/transXL021.jpg.html)

This pile of cutting is 1/2" of meat out of each jug....
Just went from 55 cubic inch to 74 cubes... By bore alone.

Want more....???
Could build it into a stoker....
That would require longer rods and taller jugs...

Have done a few larger bores and keeping the short rods in play..... This will take the cubes to 84 inches.
Requires boring the cases for 3-5/8" Big Bore jugs, then bore out the jugs to 3-3/4"
This is a one time shot being "NO" oversize pistons are offered...

docmel
11-06-2015, 10:36 AM
Been there, done that. Frankly, just going with a bigger bore from 883 - 1200, you will not see much of a power increase. To get a power increase, you need to add a slightly hotter cam (nothing crazy needed), another carb other than OEM, with some good head flow work to take advantage of the bigger bore. Otherwise, you wont get a power increase that was worth the cost of just going with a bigger bore

Dragstews
11-06-2015, 12:02 PM
The 883cc heads won't make much power being the chamber design is a problem ..
They have a raise chamber, meaning the valve stems are longer.
Super small valve heads, seats and ports.... Just don't cut it...
Mega rework to get them up to snuff...

Next step up to feed these new numbers in cubes would be 1200cc heads and flat-top pistons...

Up from that would be a set of Buell Thunderheads and matching pistons....
Now were'll taking horsepower.... Nice set of cams, carb and pipes would be icing on the cake..

guiltyview
11-06-2015, 12:25 PM
when i get cylinders bored, i take the pistons to the machine shop so there's no guessing in their machine work.

it's def more affordable if you do the leg work yourself. i, personally, wouldn't bore an air cooled motor on the tight side. pistons swell faster than the cylinder walls expand.

different material piston vs different material cylinders vs different material liners all require different fitment. there is no set in stone method. some like it tight some don't

Dougtheinternetannoyance123
11-06-2015, 1:28 PM
Please DO NOT part out any Buells for your Sportster project, that being said, there are a ton of articles on the web on doing these convesions.
Or buy the Sportster perf. handbook (although the newest version is spendy) read up on stage tuning 1,2,3, 4 and relative costs vs benefits.
I disagree with the other poster about it not being effective. After you completed stage 1 (Air cleaner, carb tune and exhaust,,,,NOTE Use CV Performance see their website) then Stage 2 is 883 to 1200cc,, and for the dollars is a very good investment. Yes,,, buying the kit makes sense. And Lowbrow are good people (ive known Tyler since he started in his garage, say Hi to Todd as well) well worth spending your pesos there.
I would recomend 1200 heads,,, or send in your heads to NRHS and have a basic clean up and rework. Both Hammer Perf and NRHS are good. (Some issues over the years but been addressed)
YES,, you CAN buy a big bore kit that will fit in cases,,, but thats overkill for most and too big requires case machining. Read up on NRHS and Hammer performance and their tech pages. Google various topics. Some good write ups out there or buy the Sporty perf book as well.
Of course CAMs are a big help, a big bore alone WILL produce a measurable diff. but its the TOTAL package and it can be done affordably. But power isnt cheap and once you start that road,,,,,,,, it can add up. Do your research first. best investment you can make. I own a bunch of Sportys and Buells, including a 1450cc hot rodded monster. (Axtell cyls, The whole menu of NRHS goodies, RedShift cams, blah blah blah,,, 140hp and 112 ftlbs torque if you believe the dyno sheets.)