we have interference engines - would assume it will keep the valve from dropping too? Some might be concerned about valve damage? Not sure I see it as an issue since the t-belt is still in place and valve dropping to hit piston would only be a very small downward force....
Downside is manually needing to advance the engine to get things into position...
PS - Folks who have tried the rope method say it's a total pain getting it into the cylinder.