FH Engine Breather

[simon.holyfield]

The plan is to replace this mangled breather pipe with something with a similar swan neck but which is long enough to drop below the frame rails.

Any pearls of wisdom before I anneal and bend the pipe? Is it better routed somewhere else?

[pete.collings]

A word of caution, I once extended the breather pipe with a bit of fuel tubing to exit just above ground level, to avoid previous problems of oil mist making its way onto the back tyre. This was after an engine rebuild, when the internal breather setup had been renewed with new parts.
Unfortunalely, the breather worked too well, and negative pressure when the rotating sleeve holes were closed resulted in sand and road muck being sucked into the engine, so my rebuilt engine didn't last very long!
Lesson learnt, the engine was again rebuilt, but without the extended breather. An engine with some bore wear and crankcase pressurisation would be less likely to have the same problem. I think I redirected the breather onto the rear chain (1955 frame setup).

[Mick D]

hi

This is my breather, which I have no reason to believe is not original:

beaether.png (192.02 KiB) Viewed 402 times

Regards Mick

[simon.holyfield]

According to the picture in the parts book, this is more or less what Ariel intended. Given that my gearbox is in the forward-most position, I can't see that this routing is very effective if indeed they intended for the router to contribute chain oiling?

I think I will route it downwards, but not too far.

[Mick D]

Hi Simon

Is there enough room to direct the breather onto the inner face of the sprocket? There's no other obvious access to the inside of the FERC that I can see.

Regards Mick

[simon.holyfield]

Yes, with the pipe a bit longer and with some fancy bends!

[pete.collings]

The 1954/5 inner primary cases had a cutaway to enable the breather to blow directly on the gearbox sprocket. With the introduction of the FERC and oil drip feed from the tank, the protrusion on the back of the inner chaincase (and cutaway) to shield muck being thrown off the sprocket disappeared.

[simon.holyfield]

The 1954/5 inner primary cases had a cutaway to enable the breather to blow directly on the gearbox sprocket. With the introduction of the FERC and oil drip feed from the tank, the protrusion on the back of the inner chaincase (and cutaway) to shield muck being thrown off the sprocket disappeared.

That makes sense, thanks.

I guess they didn't change the routing of the breather pipe.

[simon.holyfield]

Should I expect to see much discharge from the breather?