| Author | Message | ||
     Leftcoastal |
A buddy of mine has a set of Screamin' Eagle heads for 91 up Sportsters that he wants me to sell on ebay. I was wondering if any of you guys know if they are of any use to tuber owners. If they are, I'll list them for XL and Buell models. I'm thinking the Buell heads are better, but I'm not certain. Anybody got any info they could send my way? Thanks! AL | ||
| S2pengy |
From what I remember there are the same as Lightening heads.. | ||
| Puddlepirate |
From NHRS... 96-03 LIGHTNING HEADS: This is a head that came out in 1996 on the Buell S1 Lightning model, as well as the 1200S Sportster Sport model. The 1200S version is black with polished fins and has dual plugs, the second plug being accessible through the hole in the top of the rocker box. The Buell S1 version is silver and has a single spark plug. Versions of this head were also sold in the Screaming Eagle catalog. Early versions were silver and carried the "Lightning" script above the pushrod area. A version was sold in black polished with no script. And finally, a black polished version was sold with the "Screamin Eagle" script and dual plugs. Also, the Buell Blast comes with a version of this head. The valve sizes are 1.715" intake and 1.480" exhaust, identical to the 88-03 XLH1200 head. The same seats are used, so Stage 2 Lightning heads get 1.760" intakes and 1.530" exhausts. The ports are also identical to the 88-03 XLH1200 head. Later SE versions were advertised as having 8% higher flow than stock XLH1200 heads, but as someone who's flow tested lots of them, I just haven't seen it. the range of numbers I get has been the same. This only place this head is different from the 88-03 head is in the chamber. Extra material was added, as well as a 10 degree squish shelf, bringing the volume down to about 62cc. This gives around 10:1 when paired with flat top pistons. The squish band though does nothing with a flat top. So the performance increase from this head comes entirely from an extra point in compression ratio. This extra material in the chamber somewhat shrouds the valves, however, hurting low lift flow. It gets especially bad when oversize valves are fitted. When putting larger valves into Lightning heads, we always unshroud the chamber around the valve heavily to improve flow. This of course raises the chamber volume and requires us to deck the head significantly to get the volume back to 62cc | ||
| Leftcoastal |
Thanks! I'll probably just list them for XL models, as they have the dual plug set-up. He only has big twins and a bunch of 'Giz-machi's' & I can't use them on my RS (the turbo isn't all that fond of the resultant compression ratio) AL |
