the same my problem. please help

[goitoibayvoi]

To get my motor to fit the MA shroud (stratus kit) I, like others had to mill the head of the motor to fit. It is impossible to get shroud to fit with the bottom bolts without doing so, inside clear width of shroud =49.8mm, and motor head width outside dim=56mm. I tried the heating trick on a sample I cut off and that seemed like it would have been difficult to do and end up with something I would look at. Out of curiousity, I asked OS their opinion about this

OS reply:

Thank you for your recent e-mail.

This could affect the cooling characteristics which could cause the
engine to overheat.Doing so would void the warranty on the engine.
The only tooling on the side of the crankcase should be the embossed
logos.

[Gary O]

That's about the only response you could expect from OS. They can't endorse cutting the head. This is one of the reasons I run Viper Heads on all my OS engines.

[DavidH]

I have the OS Cspec PS heads on my motors. The blue ones. I milled 4mm off each side and cut one layer of fin off the top. Been running it like that for a while. It has not ran any hotter than it would with complete head area.

A belt sander works great for milling the sides of the head <G>.

David

[EricLarson]

http://www.ericlarsonrc.com/Heli/Equipment/StratusLandingGear/Prototype%20Landing%20Gear%20Close.jpg

This is what I do. No problems. The rubbing was when I use to run the shroud over the top of the head. The method in the pic cools much better.