883 to 1200

[northbrun]

I have a chance to pick up a set of 1200 cylinders cheepo and have a few questions. I would like to change to 1200 heads but money being tight i would like to wait to do that. I would also like to find a set of buell heads if i can.
do i need to use conversion pistons if i don't change the heads right away? Is there a difference between the pistons for use with 883, 1200, or buel heads?
I know carb and cam issues will have to be dealt with as i make these changes, but my main concern right now is piston fit. Any info appreciated.

[Panzer]

North,
Your 1200 cylinders has a larger bore then the 883, hence you need larger pistons & rings to fit.
You can't just install 1200 jugs and say I'll do the rest later.
With one advancement others follow.
Buy the jugs now if the're a good price, but know full well you will need other parts later.
Hope this answers your main question.

Panzer

[northbrun]

thanks panzer.. I know i need new pistons to fit. my question is this... does the heads i am using have any impact (other than compression ratio) on the pistons i buy? I would like to set it up for the 1200 heads but run the 883 heads till i get the heads, then change them out
i guess i am wondering if there would be nay clearence problems  etc.

[14Frisco]

Yes, depending on the heads you are going to use, you will use different pistions.
The XB heads, for example, use flat-top pistons.

What year is your bike?  I have a set of used 883-1200 heads that I would sell cheap.  They are 883 heads that were relieved for a 1200 conversion I did several years ago, very common to do before, and they use flat-top pistons too.  I ran them for several years and took them off when I upgraded to the XB heads.

[northbrun]

99 xl. I might be interested in the heads.. tell me what has been done to them?

[BONERACIN]

Can you bore to 1200 and still use stock 883 heads? I apoligize if this has already been answered.

[14Frisco]

northbrun,

There are several ways to do the 883-1200 conversion.  With regards to cylinders, you can either bore the stock 883 ones or buy new 1200 ones.  With regards to heads and pistons here are some common options:
- modified 883 heads (combustion relieved), standard flat-top 1200 pistons
- unmodified 883 heads, reverse domed pistons
- Buell Thunderstorm heads, domed Thunderstorm pistons
- Buell XB heads, standard flat-top 1200 pistons

If you use 883 heads you must bring the compression down, either by relieving the heads (enlarging chamber) or using reverse domed pistons.  Back in the days, I think relieving the heads was the most common method - and that is the route I took when I converted my 1993 XL to a 1200 in the mid-90s.
Then, Buell came out with new heads, first the Lightning and then the  Thunderstorm heads and in particular the Thunderstorm heads became very popular to use when doing a 883-1200 conversion.  And still is.  The Thunderstorm heads require you to use a domed piston though.
Then, Buell came out with the XB heads which in many's judgement are the best heads.  And with the XB heads you use standard flat-top 1200 pistons.

Perhaps the cheapest way to go is to use your stock 883 heads and get reverse-dome pistons.  It might not be the ultimate performance buster (compared to using Thunderstorm or XB heads), but it is a huge kick compared to an 883.

The heads I have are the stock 883 that have been relieved so they are used with standard flat-top 1200 pistons.  I ran them for several years on my XL and took them off when I did a top-end rebuild and got XB heads.

By the way - the above is for pre-rubbermounted XLs.  I haven't really followed the changes for the rubbermounted Sportys and whether the conversion options still apply.

[neale]

I converted my 02 883 to 1200 using KB pistons, reverse dome, and keeping the standard heads......ran sweet and I wish I still had it in my shed, you wont be disappointed at the performance for the dollar.