Screaming Eagle heads
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I got a set too - same valves, ports were CNC machined by Wegner automotive a pretty damn nice job ! They need a little transition porting from the different CNC angles where they come together and general cleanup with a dremel tool but overall very good. 1250 heads are more restrictive but still work fine in most cases on stock engines. CNC heads have been used in engines to 165 Hp+ with no problem. If you look at S/E CNC and late model 1250 as cast heads side by side it's pretty evident which is more open. At some point valve diameter is the restriction, I'm putting AV&V valves in mine and for what I do with the bike they will be close to a full port and +1MM seat job. Comb. chamber should be the same, but watch out for valve seats that protrude from the dome surface, I got 3 CNC heads and one is terrible in this regard, I rejected it at first glance.
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127 Posts
Supposedly the differences from the 'normal' 1250cc heads are minimal and of no real consequence performance wise in reality. Cool to have perhaps but little more than that and not worth much of a premium price wise.
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the only difference to the std sand cast heads versus sand cast se heads i found were the height of the valve seats .the se heads i have ,the seats projected into the combustion chamber more than stock,and i believe this would allow better flow when valve first opens.just a theory.
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Alone we fall, together we rise ( in Hp and Tq. )
Yes, higher valve seats will help eliminate the "shrouding" effects of valve seats that have been enlarged and set deeper in relation to the roof of the combustion chamber. Gotta be careful though, go too high and you have a new restriction of exhaust gasses trying to ride up over the edge of an otherwise flush valve seat surface. Once you get over that the S/E Heads are like a lot of high performance parts - not worth as much alone as they are in the train of a coupled system. In other words S/E heads on a stock 1130 will help, on a stock 1250 compared to stock '08 and up heads will help but if you go big bore pistons, cams and high flow valves with a nice 2-1 pipe they will come into their own and allow the additional flow they provide to enhance the other changes so as to breath as a tuned system and really produce Tq. and Hp. Just a piece in a puzzle - not to be discounted in value by what alone they offer, but to be judged together with other engine mods because that's just how you build engines to be absolutely outstanding, using off the shelf parts. :blahblah:
Yes, higher valve seats will help eliminate the "shrouding" effects of valve seats that have been enlarged and set deeper in relation to the roof of the combustion chamber. Gotta be careful though, go too high and you have a new restriction of exhaust gasses trying to ride up over the edge of an otherwise flush valve seat surface. Once you get over that the S/E Heads are like a lot of high performance parts - not worth as much alone as they are in the train of a coupled system. In other words S/E heads on a stock 1130 will help, on a stock 1250 compared to stock '08 and up heads will help but if you go big bore pistons, cams and high flow valves with a nice 2-1 pipe they will come into their own and allow the additional flow they provide to enhance the other changes so as to breath as a tuned system and really produce Tq. and Hp. Just a piece in a puzzle - not to be discounted in value by what alone they offer, but to be judged together with other engine mods because that's just how you build engines to be absolutely outstanding, using off the shelf parts. :blahblah:
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Now that makes sense. Completely understand the interconnection of all the relationships. That being said, by larger pistons are you referring to 1350's? And i LOVE the look of the duals ('15 muscle) and i have no plans to go to 2 into 1. So, those heads offer me, with my setup, no real gains, except the cool sticker.
I call that "trading stock" then.
Thanks for your response. ?
I call that "trading stock" then.
Thanks for your response. ?
All this time, I didn't realize you had a Muscle with duals.
Ron
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Yea, like 4.250" CP pistons, with Advanced Sleeves liners like Vreelands sells for a 1/4" stroker crank. I do like the dual exhaust setup but not the stock muffler automotive side pipe look. I envision more of a TL1000 upswept 2 muffler C/F muffler exhaust style system on my R Model. Probably will not work with the front cylinder exhaust studs on the S/E heads for Rt. exit, so I'll probably not torture myself with that mod. And, yes trading them is always a great idea, they still have value - not the $ 2200 they originally asked for the head only kit 10 years ago but $ 350 - $ 1200 depending on who wants 'em. Good Luck !!
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