Exhaust Burbling/Farting

[chrisryder]

We all know and love the burble, fart, call it what you will, that a minor makes on gearchanges, or when going down hill on the 'back of the engine'. but what causes it?

I notice that my minor even with its 1.5 inch exhaust still tries to do it. running down hills at about 20 in 2nd, you can just hear a faint attempt at a fart. so it must be in the engine rather than the exhaust design.

could it be a phenomena of the 5 port head, or the constant fuelling of a carburettor rather than the 'only on when you need it' of injection?

[bmcecosse]

Not in the engine - or even in the exhaust manifold - Minis never do it and they share the engine and manifold..... So it's all down to the exhaust system - mainly the location of the silencer.

[chrisryder]

i wasn't sure if mini's did or not. good point.

the only other vehicle i've ever heard making similar noises are LDV Pilot vans. the number of times i've turned around expecting to see a moggy and actually see one of them instead!

[brucek]

948's seem to do it best in my experience. I remember heading down a long hill in France with a 948 in my convertible and managing to keep the burble going for ages - well over a minute travlelling about 20mph in third i think. Just the right amount of exhaust gases at the right speed I guess. How come we've never had a competition to see who can keep the burble going the longest!!

[chrisryder]

living at the top of a hill that goes down hill for about a mile one way and 2 the other... my sisters 948 with its shiny new stainless (extra resonant) exhaust would fart all the way

i think people of a certain age fear it's a doodle-bug though.

[chrisd87]

It's definitely down to the exhaust system. The old exhaust on maggie (which was pretty loud anyway) used to let out wonderful crisp farts at pretty much every gearchange, and would do them all the way down long hills if you got the revs right. When that fell apart I fitted a Bosal system, which is much quieter and only gives the faintest hint of a fart when provoked.

[brucek]

So, it seems like we have a venue for the 1st National Morris Minor Open exhaust burbling championships. Best of three runs on the 2 mile course. Marshals every so often to verify a continuous burble. Run what you brung. Practice saturday afternoon - beer Saturday night/Sunday morning, championships on Sunday. I'll see if Eddie Jordan is available and a good laugh will be had by all. Just trying to imagine how it would sound/look on you tube

"Here comes Jonny Fartpants(apologiesto Viz) and Windy Miller in their normally aspirated Morris Minors!" Gotta be worth a go hasn't it?

[chrisryder]

an event for MOT2012 perhaps? not that my Bluey would be a contender. But my flatulent sister should be there!

[brucek]

Mine should be 1275 by then so unlikely that the honours would be coming my way but like the idea of an international round of the championships. I might offer to fly in BMCecosse as my technical guru cos i think he probably knows how to get a burble out of any A series engine! There should be some excellent hills in SW France! Before long we could sell TV rights and haggle with Sky and the BBC for who gets to televise it.

Don't forget - we thought of it and we were here first!

[DAVIDMCCULLOUGH]

Chris, I think my traveller would win!! Its got a £40 stainless exhaust bought from MGM some years ago that is very loud and can fart for Ulster

[KatiePotatie]

I was worried that the combination of new exhaust & engine would get rid of the fart...but no. I think Martha & I would win :p

[brucek]

Well - good to see a few hardy souls are up for it! We could do with some entries from Wales and Scotland to ensure a true UK representation. What about our friends from Holland, France etc..... or am I taking this a bit too seriously!

[mbo145]

Mine is much more farty with the new exhaust! On the way from the top of Portland it farts all the way down! The exhaust was a bit loose on the join to the manifold and it farted even more!

[Neil MG]

Mine struggles to make a little farty burble, almost drowned out by the gearbox. Is that typical for an 803? Compared with a friends 1098 traveller with stainless exhaust - now that couldn't be drowned out by an earthquake!

[stevey]

my2 door you can hear 2 streets away, and its got the same stainless steel exhaust as davids traveller!!

[mike.perry]

I was wondering if removing the rear silencer would restore the fart to my 1275 LCB system?
I think that the 6 inch tail pipe extension does not help the fart on my Series MM
From casual observation or whatever you do with ears, travellers and vans seem louder than cars

[chrisryder]

i think if you removed the rear box on a large bore system, you might find it excessively loud at high rpm. whether it'll fart or not, i've no idea.

i imagine vans and travs would be louder for the occupants as there is less to absorb/block the sound coming from the rear. i certainly notice my saloon to be much louder to me when the rear seats are down.

[56minor948]

I can do Morris Minor impressions.

[ian.mcdougall]

My sister gave me a bithday card a few years back that was in the shape of a motorbike and when you pressed a button there was a recording on a chip of a bike accelerating into the distance. Maybe the club could investigate having cards made in the shape of a Minor with the farting minor sound on it for sale to club members

['61Morris]

I'm definitely up for the farting competition with Bluebell! Her current farty exhaust has a bit of a potted history. When I first bought her, the mild steel exhaust did fart but not as loudly as the one on my 2-door. I swapped them over before selling the saloon but then disaster struck - a van drove into the back of Bluebell and, amongst other horrendous things, broke off the end of the exhaust. My Morris specialist welded a new end onto the exhaust but it was never as loud as before.

I then heard a terrific farty exhaust on a Morris courtesy car that's owned by King Street Motor Servies in Kent, whilst following it on the Kent Branches Hop one year. I enquired about purchasing the exhaust for my car and they agreed! What's more, it's stainless so Bluebell now has (I think) the loudest exhuast fart in the South East!

I've heard loud mild exhausts and loud stainless exhausts. I've heard quiet mild exhausts and quiet stainless. I wish somebody would do an experiment to find out exactly what causes that characteristic Minor sound. The LCVs always seem to be the loudest - maybe the way their exhaust system is set up to come out the side has something to do with it?