- Joined
- Mar 9, 2010
- Messages
- 464
hobot said:I had look at shaft with a cut out method to press exhaust rocker down a tad.
Looks like its possible to do. Rocker arms stand above the cover gasket surface ~1/4" where the tallest part of rocker ach is. So shaft would have to cross rocker boxes about .8" below the top cover stud. Actuating lever would go rotate along side of head, lifting up sticking forward to press on valve then flopped forward to lay down almost vertical tucked in close to head for a tiddy device.
No oil passage on valve side of rocker so some metal could be removed if needed.
Main issue I ponder is if the two small studs and ridgidity of the rocker covers could take the spring force to hold valve open slightly and still seal or not break.
Space for shaft must be made, either just drilled through cover or by a half nip out of head and cover. Don't know how to seal shaft ports. Advice accepted.
Wonder if valve gap can be diddled to both lower kick force yet still start and run long enough to lower releases in time. May be able to kick engine over with the long duration over lapped cam, but don't think it'll be much help going by the starting efforts of racers with similar aggressive cams and CR.
Would have to start with too much gap to run then file and try file and try file and try till either works as hoped or becomes too hard to kick and start, ugh.
The Husaberg (and the KTM since its a copy ) one is only used to hold the valve (well actually both) open so you can push the engine just past TDC/compression and get a full intake/compression/fire from the kickstart . Im not sure how it would work with the twin, maybe it would run ok on one pot, allowing the exhaust to be held open on the second giving the required amount of time to close/flip lever. A second thought and Im not sure how it works but a 2cylinder yanmar marine engine has two compression release levers on the tappet cover, each two position, both pushed pully over and you can crank it by hand until its spinning fast then flick one to the intermediate position and it will fire, once it fires a coupleof times the other lever will also go to the intermediate position by itself, both positions lower the compression but it will run in the second position. To make it run properly flick both levers right across. Ill see if I can have alook at a manual for one this week and get back to you on it