Optimal engine tilt/angle

[motor puzzle]

Hi all. I've noticed that most engines are tilted forward. Is that the best way for the engine to sit? It seems that the carburator is tilted forward as well. Shouldn't the engine be mounted in such a way where the carburator and float are parallel to the ground for optimal performance or is it better for the carburator to be tilted forward.

I noticed that this guy (attached picture) mounted his engine straight up and down which will make the carburator tilt away from the engine. Is he going to have problems getting gas into the engine or possbily with engine lubrication?

I'm in the process of putting my engine in and still deciding the best place for it. Searched for anwer but couldn't find any. Thanks

 

[drimpact]

I try to make the Carb as parallel to the ground as possible. Really that and exhaust clearance are the two things I look at most when finding the right angle to mount at. Usually if the mounts are perpendicular to your bars the angles are correct. IMHO!!

 

[just for kicks]

Well I've only done one so far so I'm still a big time noob but I tried to get the best fit on the engine mounts/frame as possible so that the engine would stay put, then I considered the carb and exhaust.

My main concern was to have the engine as secured to the frame as possible.My reasoning is "if the engine shifts and moves the rest wont matter anyway"

A slight carb angle wasn't much of a concern because I knew it would be close enough and the exhaust can be tweaked/bent slightly if needed.
Actually mine went together very easily and works very well.

 

[azbill]

Usually if the mounts are perpendicular to your bars the angles are correct. IMHO!!

I agree...if they are both square (90degrees)to the frame , that is the best angle
if the mounts are not square to the frame, only one side of the mount touches frame, increasing vibrations and could cause frame failure (cracking)
it is possible to cut and weld the manifold if you have to (it has been done by people here)
I, personally, have seen some severe angles (seems to be mostly cruisers with curved downtubes), and they all ran when I saw them !