| Author | Message | ||
     Johnnylunchbox |
This is just a what if scenario. Could someone easily fit a stock 1200 sportster motor into a later model ('99 - '02) tube frame like an S3T? Would it be more trouble than it's worth? | ||
| Purpony |
from my understanding the stock sporty motor does not have the necessary spot to bolt the rear buell swingarm/rear engine mount to. Also, the sportster stock heads do not have the mounts for the front buell engine mount, would need buell heads. | ||
| Johnnylunchbox |
Interesting. Thanks for your insight. | ||
| Blks1l |
I think that information is incorrect, I believe there is a difference in hole sizes on the aft engine mount, sportsters mount their engines to the same spot, same goes for the head, at least the S2 head is a stock sportster head but it has 2 different bolt sizes in the front mount bosses. | ||
| Purpony |
I could be wrong ... so if I am... please someone set me straight!!! | ||
| Xldevil |
The rigid mount Sportster 5 gear engine until 2003 will fit. Only modi would be the upper front engine mount. Bolts instead of srews.No big deal to change that. I did it the other way round,using Thunderstorm heads on my Sporty.If you go with Thunderstorm heads,you would have to change nothing. The swingarm mounting block of tubers is only bolted to the original Sportster engine case,instead of the lower engine mount on rigid Sportsters. The engine case is identical. Cheers,Ralph | ||
| Rick_a |
It's the rear engine to swingarm mount bolts...bigger sizes for Buell...easily rectified. The front tie bar may be another concern. | ||
| Johnnylunchbox |
Great info here. Thanks. The reason I ask is that I have my S3T just sitting for years. It ran when I put it away, but had a rocker box leak (again). I'm wondering if in the future when parts are not easy to find, can I just keep it going with a sportster motor if I have to. I'd like to get the S3T back on the road. | ||
| Harleyelf |
Just change the rocker covers over to Blast or Firebolt PCV style. Parts will always be available for the XL motor. Your 2001 S3T shares most engine parts with the Sportster; no need to change the case if it is intact. | ||
| Hootowl |
"can I just keep it going with a sportster motor if I have to" You should be able to rebuild indefinitely. The cases don't wear out. All the wear items are HD/screaming eagle parts, or easily obtained in the aftermarket. | ||
| Upthemaiden |
Does the same go for all 3 years of S1 models? I'd assume the older the buell, the easier it would be to swap a motor because it'd be closer to the sportster motor it started with. Would it be easier to swap an S1 vs an S1W, the other way around, or all the same? I'm looking to pick up an S1 when I find a good deal on one, and even though I know the S1Ws are the ones to have, I feel like sportster interchangeability would be higher on my list than a few extra HP. | ||
| Hybridmomentspass |
its all the same bro The later tubers had better heads on them some bikes/models had different cams than others but outside of that - its all the same to my knowledge | ||
| Hootowl |
Heads are all the same casting though, yeah? Just different levels of work? | ||
| Phelan |
No. There are 3 different castings that came on tubers. Standard 1200 heads (S2), Lightning heads ('96-'98 tubers except S2, S3T and S1W), and Thunderstorm heads ('98 S1W and S3T, '99-'02 tubers). The 1200 and lightning heads are essentially the same, except the Lightning heads have extra material in the combustion chamber with a cast 10* squish band, though the factory never utilized the squish band because all bikes that came with these heads had flat top pistons, which netted 10:1 CR (1200 heads and flat tops net 9:1 CR). Thunderstorm heads have better ports, bigger valves and valve seats, and they have a cast 15* squish band in the combustion chamber with matching pistons, netting 10:1 CR. Stock squish clearance with stock gaskets on these bikes is .060-.080" though, not overly useful as a squish band. We general prep heads with squish bands to net ~.030" squish with the right gaskets. (Message edited by phelan on May 21, 2015) | ||
| 1313 |
Theoretically that would work for 1995-1996 S2 and 1996 S2T and prior Buell's as they had standard Sportster 1200 engines in them, and with the Buell intake and exhaust got the increased power. The 1996-1998 S1 and 1997 S3 had lightened flywheels, Lightning heads and Lightning cams. All could be swapped out, of course, to bring a stock Sportster motor to a Buell configuration. 1997-1998 M2's were the same except for the cams. The 1998 S1W and 1998 S3/S3T had Thunderstorm heads and pistons in addition to the lightened flywheels and Lightning cams. 1999-2002 X1 and 1999-2002 S3/S3T had the same equipment noted above (for 1998 S1W and 1998 S3/S3T) except with DDFI. 1999-2002 M2 was basically a X1 or S3/S3T motor with a carb instead of DDFI and 'stock Sportster cams'. But all of the 'unique components' could be swapped to update a stock Sportster motor into any desired Buell configuration... 1313 | ||
| Hootowl |
As ever, Ross and Brankin are fonts of knowledge. If you didn't know, one is a current employee of NHRS, a high performance head shop, and the other a former Buell employee. You'd be wise to heed their advise. And ignore mine. Except for this.  | ||
| Phelan |
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| Upthemaiden |
I love knowing these engines are swappable. Even if it comes down to dropping a stock sportster motor in there and losing the HP, it's nice to know you can keep these bikes running forever. |
