Differences
This shows you the differences between two versions of the page.
| Both sides previous revision Previous revision Next revision | Previous revision Last revision Both sides next revision | ||
|
techtalk:ref:svcproc26 [2020/03/04 05:10] hippysmack [Lightning Heads] |
techtalk:ref:svcproc26 [2020/03/04 05:59] hippysmack [Thunderstorm Heads] |
||
|---|---|---|---|
| Line 140: | Line 140: | ||
| They also improved the ports and went to larger valve sizes (1.810" / 1.575"). This setup is head and shoulders better than the Lightning setup. \\ | They also improved the ports and went to larger valve sizes (1.810" / 1.575"). This setup is head and shoulders better than the Lightning setup. \\ | ||
| - | The angled squish bands direct the fuel being squeezed out of the squish bands more directly at the flame front. \\ | + | The angled squish bands direct the fuel being squeezed out of the squish bands more directly at the flame front. ((aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=2206)) \\ |
| But the way it's done in the Thunderstorm, it's really rough. Since it's cast in, it's uneven. \\ | But the way it's done in the Thunderstorm, it's really rough. Since it's cast in, it's uneven. \\ | ||
| Typically from the factory the clearance is .050" or more, and that makes the squish band largely ineffective anyway. \\ | Typically from the factory the clearance is .050" or more, and that makes the squish band largely ineffective anyway. \\ | ||
| + | |||
| + | Thunderstorm heads are obsolete now. \\ | ||
| + | They could be machined nice and even, but there's a huge overhang around the perimeter. \\ | ||
| + | So to machine it, typically .035"-.045" had to be taken off the deck, sometimes more. \\ | ||
| + | |||
| + | Below is an example of before and after machining. This is much better with a nice even and consistent squish clearance. \\ | ||
| + | But cutting the deck this much has some side effects, like less valve to piston clearance. \\ | ||
| + | As well as potentially forcing the customer into short or adjustable pushrods. \\ | ||
| + | It also typically makes the chamber too small, forcing us to open it up in other areas. \\ | ||
| + | |||
| + | Also notice how there's not a whole lot of surface area. This squish band is effective up to about a .125" tall dome. \\ | ||
| + | Anything higher than that and the dome goes past the squish band. \\ | ||
| + | |||
| + | | Stock Thunderstorm Heads ((photo by aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=2206)) | Thunderstorms as Machined ((photo by aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=2206)) | | ||
| + | |{{:techtalk:ref:svcproc:thunderstom_chamber_by_aswracing.jpg?direct&300|}}|{{:techtalk:ref:svcproc:thunderstorm_as_machined_by_aswracing.jpg?direct&300|}}| | ||
| + | |||
| + | |||
| + | |||
| + | |||
| + | |||
| + | ====== Buell XB/04XL Heads ====== | ||
| + | |||
| + | As delivered, they have flat squish bands with a 62cc chamber. ((aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=2206)) \\ | ||
| + | This lets you toss them on over flat tops and have a squish band with lots of area and 10:1 compression. Not a bad way to do it. \\ | ||
| + | If you want to angle it, it's not a problem, you've got lots of material to work with. \\ | ||
| + | You can make the squish band as big or small as you want. \\ | ||
| + | You can make it match the piston you're using exactly, do relief cuts with the rest of the material to help overlap flow if you want. \\ | ||
| + | You can do all this without excessive deck milling and all the problems that come with it. \\ | ||
| + | |||
| + | The stock valves are the same sizes as the Thunderstorms, 1.810" intake and 1.575" exhaust. \\ | ||
| + | The springs and guides can support up to .550" lift safely, though, versus .500" for the Thunderstorms. \\ | ||
| + | The ports are actually a little better than the Thunderstorms. \\ | ||
| + | The Thunderstorms were a major step forward from the Lightning/Screaming Eagle heads, but the XB/04 XL1200 heads are even better. \\ | ||
| + | |||
| + | | Stock Buell XB Heads ((photo by aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=2206)) | Machined XB Heads ((photo by aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=2206)) | | ||
| + | |{{:techtalk:ref:svcproc:buell_xb_heads_by_aswracing.jpg?direct&300|}}|{{:techtalk:ref:svcproc:buell_xb_heads_as_machined_by_aswracing.jpg?direct&300|}}| | ||
| + | |||
| + | |||
| + | |||
| + | |||
| + | |||
| ====== Compression Ratio ====== | ====== Compression Ratio ====== | ||
