| Author | Message | ||
     08herobolt |
Hey everybody, I know that if I go with an XB9 piston in my S1 I need XB heads or 04+ Sportster heads. Do the sportster heads need to be a 1200 or can they be an 883 model? I have new rods and a crank coming so I've re-enforced the engine. JP | ||
| Phelan |
Heads have to be Xb/'04-up 1200 in order to have the right shape and not hit, as the XB9 dome is the shape of the combustion chamber. 883 heads not only have the wrong shape but are way too shallow. That said, XB9 pistons in XB heads give you over 12:1 static compression so you would need to run a cam with high overlap in order to make it useable on pump gas. | ||
| 08herobolt |
Thanks Phelan. One more question. Are the intake cams interchangable? Two of my cams have S on them and one has a B. | ||
| Phelan |
XB cams are backwards of X1/tuber cams. tuber cams are 1,2,3,4 whereas XB are 4,3,2,1. Also XB cams are high contact ratio pinion whereas your S1 should have the less tooth count pinion gear, which is actually stronger. | ||
| Phelan |
Also XB cams use different timing marks, and are not marked for correct timing in XL/tuber motors. | ||
| 08herobolt |
So is it possible to to use XB heads on an S1 as long as I time it differently or am I just wasting my time? They are going on an S1 race bike. | ||
| Phelan |
Yes you can, you just have to get a different front mount. Make sure to use flat top pistons or XB pistons to match. In other words don't use a thunderstorm piston unless you cat an angled squish band in the heads to match. | ||
| The4ork |
what kind of cams /w the proper overlap you talking about phelan? been thinking about doing the xb9 pistons if my 1250 kit gives me trouble. or getting the xb9 equivalent 1250 pistons | ||
| Phelan |
Because XB9 pistons adds quite a bit of compression, you need the heavy overlap to drop the dynamic compression to be useable with a carburetor on pump gas. | ||
| The4ork |
i get that part, im just asking what cam would suit that bill? | ||
| Buelliedan |
NRHS Cat 3 pistons would work very well. They are a bolt in cam if using XB/04 1200 heads (Message edited by buelliedan on March 18, 2015) | ||
| Shadowracerx1 |
I added an XB top end along with cams to my X1 back in 2008. I used the timing marks indicated. I've not had a problem in over 10,000 miles. If this is truly the incorrect setup, how would one go about rectifying it? | ||
| Buelliedan |
I do not know how you could have installed XB cams using the stock marks as they are 105 degrees off. The bike would not run. | ||
| Knuckleduster271 |
I found a cheap xb9 motor. Id like to pick it up for the heads and pistons and use them on my 97 s1- I see where Phelan says the heads have to be for a 1200- will the xb9 head, cylinder, piston combo not work in my s1? One other question- if this actually will work, should i use the stock tuber cam or the one from the xb9? |
