Sparks from the Exhaust!!!

Post by **croft** » Sat Oct 11, 2008 8:49 pm

Hi all, unusual question this but I was wondering what would make sparks come out of the exhaust of a Minor?
I was travelling to Edinburgh yesterday (not in my Minor!) when I was overtaken by a very shabby looking blue with a white roof Morris Minor van! As i was doing 65-70 uphill at the time! I thought it must have a different engine in it. It continued in front of me doing about 70 for a few miles when suddenly I noticed sparks coming from it, I first thought it was something dragging along the ground but on closer inspection the sparks where coming out of the exhaust! They got worse and worse and eventually it slowed and pulled off into a lay-by. As I was running a bit late for my meeting I was unable to stop and see if they needed help. On my way home a few hours later the van had gone and no sign of any oil slick in the lay-by! There wasnt any smoke before the sparks started and it didnt stop straight away.
Anyone any Idear what could have caused it? Or does anyone on here own it? I think it was an H reg, sort of faded french blue with a white roof and lots of rusty patches showing through!

Post by **rayofleamington** » Sat Oct 11, 2008 9:39 pm

A badly failed exhaust valve, or head gasket failure can give an excess of burning fuel/air into the exhaust.
The soot particles in the exhaust can get dislodged and travel down the exhaust glowing red from the heat - a standard exhaust will have a well baffled exhaust so you won't see them.
If it had a sports silencer (straight through) they stand a chance of coming out the end. It's rather like when you have newspaper on a bonfire - the red glowing soot embers can travel around on the wind.

It'c certainly not what I'd expect to see though!

Post by **8009STEVE** » Sat Oct 11, 2008 10:31 pm

Ray, you have covered it all , AFASIK.

Post by **bmcecosse** » Sun Oct 12, 2008 7:13 pm

Seriously overheating engine - head gasket letting go - piston burning up - and all the items Ray has covered. It's usually serious !

Post by **Alec** » Mon Oct 13, 2008 5:44 pm

hello all,

the less serious reason is an Italian tune up. An engine that has had a lot of slow and short journeys can build up a lot of carbon in the head and exhaust. Giving it a good thrash will clear it out with the evidence you witnessed.

Alec

Post by **croft** » Tue Oct 14, 2008 8:11 pm

Thanks guys, I thought it must be serious when I saw it but reading the replys I'm tempted to think it could have been the Italian Tune Up! As I said there was no smoke or sign of any oil and it didnt slow straight away. I'm wondering if it had just been bought and was getting a good run at speed. It looked very tatty to be in everyday use. Be interesting to see if the owner turns up on here! It was pulling off into a lay-by just before Dalkieth when I last saw it. Anyway thanks again guys.

Post by **MarkyB** » Wed Oct 15, 2008 9:49 am

Maybe I'm more pessimistic but if I see sparks coming out of some ones exhaust I put it down to metal melting somewhere in the engine.
The scenario you describe sounds like some one felt the engine slow down a bit and so gave it some more wellie to get back up to speed

Post by **Alec** » Wed Oct 15, 2008 6:01 pm

Hello marky,

engines with metal hot enough to melt don't run. Aluminium, by the way doesn't change colour when molten either.

Alec

Post by **Mogwai** » Wed Oct 15, 2008 8:49 pm

Dosnt sound very healthy ether way

A bit off topic but I had to prepare some vehicles for an oil refinery once & the diesels due to high soot levels had to have spark arresters fitted in the exhast basicly a big swirlpot made a great whooshing noise when revved

Post by **rayofleamington** » Wed Oct 15, 2008 8:51 pm

engines with metal hot enough to melt don't run.

ermm.. just being picky but 2 strokers will run until the piston is nicley melted.
A-series will normally stop before it gets that far although will get hot enough to burn the paint of the block (been there done that

)

Post by **MarkyB** » Thu Oct 16, 2008 8:51 am

engines with metal hot enough to melt don't run

So exhaust valves don't get burned away?
That's odd, I've seen some that have

3 cylinders can be running quite happily while all kinds of devastation is going on in the 4th.

Post by **Alec** » Thu Oct 16, 2008 5:16 pm

Hello Marky,

yes they do, but would be very short duration as the lack of compression also eliminates any heat as there is no combustion?

Alec

Post by **MarkyB** » Thu Oct 16, 2008 5:41 pm

In practice the compression doesn't disappear that quickly.
A running engine is a different proposition to doing a compression test.
I would guess ignition might still take place down to a 6 to 1 ratio.
I only wish I'd kept some of the burnt exhaust valves I've replaced.
At least one of them looked like a gas axe had been taken to it.

Post by **bmcecosse** » Thu Oct 16, 2008 5:53 pm

The fact this van slowed and pulled off after a while tells it's own stoiry I think! However - some of the Mini lads do install a device that pumps extra fuel into the exhaust and ignites a spark plug near the exhaust tip - just so they can make a stab of flame spurt from the exhaust pipe at will! This however is an obvious flame - and not just sparks.

Post by **rayofleamington** » Thu Oct 16, 2008 6:29 pm

some of the Mini lads do install a device that...

AFAIK 'Afterburners' started in the US custom scene - donkeys years ago,

Post by **bmcecosse** » Thu Oct 16, 2008 6:54 pm

Indeed - just not seen one on a Minor. But no doubt someone will do it now!