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running an engine without manifolds
redscamp - 16/7/17 at 01:52 AM

Pointless maybe, but its something ive wanted to try for a while.
Interesting most of the start up/cold running smoke comes from cylinder 3.
look mum, no manifolds


LBMEFM - 16/7/17 at 06:02 AM

I like it, I would suggest that number three smoke is oil smoke probably from a worn bore, broken piston ring or worn valve stems/seal.


craigdiver - 16/7/17 at 06:16 AM

I like that, you can actually see the pulses of cylinders firing at lower RPM


Angel Acevedo - 17/7/17 at 04:45 PM

Loong time ago I heard that running without manifolds may bend valve stems upon shut-off due to uneven cooling.
I think that was the reason Big V12 engines in planes had short exhaust stubs.
I may be wrong (Or the guy that told me so)


motorcycle_mayhem - 17/7/17 at 05:14 PM

Difficult to tell from the video, but the smoke looks white on my CRT screen device. From experience with old LR engines (the 2286 that powered the Ark) and dodgy injector pumps/timing/pre-combustion chamber dropouts/clogged injectors/etc. etc., it looks to me like diesel fuel smoke, it isn't burning whatever is available to it at low rpm.


MikeRJ - 17/7/17 at 09:13 PM

It'll almost certainly be a tired injector.


nick205 - 18/7/17 at 10:14 AM

Nice!

One of those activities others may ask - why?

I say - why not?


Mr Whippy - 18/7/17 at 11:18 AM

quote:
Originally posted by Angel Acevedo
Loong time ago I heard that running without manifolds may bend valve stems upon shut-off due to uneven cooling.
I think that was the reason Big V12 engines in planes had short exhaust stubs.
I may be wrong (Or the guy that told me so)


I think that would be more the engine was narrower than the plane and more to avoid gassing ones self or setting the plane on fire other reasons I've heard are directing exhaust for more thrust hmmm..., hiding the flames during night flights hmmmmm.... and giving some back pressure to help scavenging (the most likely)

I have ran various 4 and 6 cylinders with no manifolds and the noise is spectacular


Angel Acevedo - 18/7/17 at 02:55 PM

quote:
Originally posted by Mr Whippy
quote:
Originally posted by Angel Acevedo
Loong time ago I heard that running without manifolds may bend valve stems upon shut-off due to uneven cooling.
I think that was the reason Big V12 engines in planes had short exhaust stubs.
I may be wrong (Or the guy that told me so)


I think that would be more the engine was narrower than the plane and more to avoid gassing ones self or setting the plane on fire other reasons I've heard are directing exhaust for more thrust hmmm..., hiding the flames during night flights hmmmmm.... and giving some back pressure to help scavenging (the most likely)

I have ran various 4 and 6 cylinders with no manifolds and the noise is spectacular


Ha!
You are very right...
My english composing skills are rubbish...
I think my statement should have been...
Loong time ago I heard that running without manifolds may bend valve stems upon shut-off due to uneven cooling.
I may be wrong (Or the guy that told me so)

And...

I think that was the reason Big V12 engines in planes had short exhaust stubs. (which is a very unaccurate assumption also)

I would like to hear a BMW Inline six without manifolds...