Fuel Vapourisation

Post by **custommartin** » Sun Jun 27, 2004 7:29 pm

Hi All,

After being stuck in THAT queue outside Donington

and having to pull over, off the road

Has anyone come up with a solution to the problem of fuel vapourisation???

I know I can buy a kit from Grumpies.
BUT is there another, simpler, way.
Tin foil around the supply pipe and float chamber, for example??

BTW.
This only seems to affect 1098 Engines (doesn't it Ian!

),

Cheers.

Martin

Post by **rayofleamington** » Sun Jun 27, 2004 9:23 pm

After being stuck in THAT queue outside Donington and having to pull over, off the road

I got a phot of you broken down - unless it was someone else...

the kit from grumpies is just a heat shield so if you can pick up some sheet ally then it can't be too hard to replicate.

Post by **Kevin** » Mon Jun 28, 2004 11:53 am

Hope you got home OK martin, I know a couple of people who have fitted the Grumpies kit and it does not eliminate the problems fully.

BUT is there another, simpler, way.

Well personally I think there is and it costs very little, on my 1275cc engine I fitted an alloy inlet to allow a larger carb but wanted to keep the original exhaust note, and this was done by getting an old mini 1000 manifold and cutting off the inlet section and reprofiling the centre section to the same as the 2 end sections, this gave a space between the manifolds that I could squeeze an index finger through, so if you get another manifold Minor or Mini (if you use the Mini you should only use the exhauct side as the carb is bigger) and seperate them this eliminates quite a hot spot between the manifolds, I was in the same queue in front of you as you know and in spite of overheating

troubles I did not get the fuel evaporation problems you experienced although my pump was clicking quite a bit faster than normal, its worth trying as a second hand manifold is not going to cost much more than £5 - £10.

Post by **Benjy** » Mon Jun 28, 2004 4:07 pm

I've often considered putting some foam pipe insulation, the sort you get for microbore radiator pipes, over the rising fuel pipe, but I rather suspect most of the problem comes from the float chamber and carb getting too warm, in which case Kevin's suggestion is far more effective - and apparently good for a few bhp too!

Ben

Post by **rayofleamington** » Mon Jun 28, 2004 5:49 pm

Well if you can hear the petrol pump ticking there are 2 possibilities
1) fuel has vapourised in the pipe and the pump is running (badly) on fumes
2) fuel has vapourised in the carb (and the pump would be chucking new stuff in). If it is vapourising at that rate in the carb then there would be a stink of petrol

The overheated carb is certainly a good theory but I would guess most of the problem is the hot fuel pipe. The heatshield kit will work well up to a point but it is only going to add a delay and isn't a magic cure to keep the pipe cool in a very very long jam on a hot day.

Post by **Chris Morley** » Mon Jun 28, 2004 6:13 pm

I've only suffered this once (last summer when it was 99F) - luckily I wasn't caught in traffic long so no breakdown. You could always try my solution - pull over, open the bonnet, pour loads of water on the affected area. It worked a treat !

Post by **Arfron** » Mon Jun 28, 2004 7:57 pm

I thought that vapourisation happened mostly to Ford 100E ( my other car is a Ford Prefec 100E 1956 ) The main reason is that after a long run the little fan on the M.M . cannot diplace the heat build - up in the rad.and engine bay . The Ford solution seems to be ; either a 4 blade fan , or , fit an electric fan - which in my case ( Ford )was a 'push' electic rather than pull fan e.g Kenlowe , or there are fans advertised in the Vehicle Wiring Products catalogue ( Ask Jeeves for www ( good products and prompt delivery )
I also seem to remember reading that the petrol set-up, in ye old days of leaded juice ,was somewhat differnt than the modern stuff and now contributes to the vapours !! Can't remember the technical details !!

Hope this helps a bit ??

Arfron

Post by **custommartin** » Mon Jun 28, 2004 8:17 pm

Hi All,
As usual thanks for all the helpful advice.

I was really after a very easy and cheap option to get me through to the end of the rally season, after which time things will change slightly

.
Thanks Kevin

Ray
The pump starting pumping erratically (gasping, I guess). This got worse until the engine spluttered and died.

I had thought of pouring water (like Chris) over the pipes etc., but didn't want to create more problems.

I left it to cool for half an hour , topped up the water (didn't need any) and re-joined the queue. I left the bonnet on the swan neck, not completely shut, to aid air flow (we weren't going to go fast were we!!!)and crept along with the engine revving higher than usual. This seemed to over-come the problem BUT the slight puffing of smoke from the exhaust didn,t help!!
Apologies to anyone around me for the noise and pollution

Erm.......Yeh, that was probably me!!! M1 junction 23a, 50 yards up the slip-road buried in the gravel trap!!! Just after the traveller with the same problem. (I beat them into Donington)

I think mine was the only blue Pick-Up there! Apologies if not.

Was there anyone with the Pick-Up??
I spent most of the time sitting on the crash barrier next to the traveller.

I may regret asking this, but, was it a digital pic??
Can you put it on here???
I'd/we'd love to see it!! (seriously)

I didn't think to take my own pics!!.

To be fair I have fitted one of Grumpies kits before and it did seem to help a bit. It was a while ago though!
I had thought of making a guard of some sort but thought I would ask you first.

BTW
I never had this trouble with my Twin-Cam Mog.

Thanks Again (Pic Ray??).

Cheers

Custom 'See you on the hard shoulder' Martin.

BTW2
Apparently un-leaded IS more volatile and susceptible to vapourisation than the old 4 star.
The other question is;- how come I suffered and no-one else?? (traveller excepted)

Post by **Matt** » Mon Jun 28, 2004 8:45 pm

Midgets have a heatshield, and so do metros and minis... you could get one from a scrappy...

Post by **rayofleamington** » Mon Jun 28, 2004 8:56 pm

Erm.......Yeh, that was probably me!!!

Unfortunately it wasn't you - it was a blue saloon and it was only a mile away from Donnington and it was after 12:00 . I guess dozens of moggies died in the heat so rest assured that you weren't a one off.
And embarrassment by Ray when he only found a picture of the steering wheel. At least the rest came out ok.

Post by **Kevin** » Tue Jun 29, 2004 10:28 am

Well if you can hear the petrol pump ticking there are 2 possibilities
1) fuel has vapourised in the pipe and the pump is running (badly) on fumes
2) fuel has vapourised in the carb (and the pump would be chucking new stuff in). If it is vapourising at that rate in the carb then there would be a stink of petrol

Ray my pump was also ticking like the clappers in that jam but kept going so although I was convinced I was suffering from some sort of fuel evaporation having the seperate manifolds obviously helped enough to keep it going, Its a shame I did not think to check if any of the pipework was hotter

than normal to try and pinpoint the area/parts that were suffering.

Post by **salty_monk** » Tue Jun 29, 2004 10:33 am

The Ford solution seems to be ; either a 4 blade fan , or , fit an electric fan

The four blade fan would be a very simple mod to try, I'm sure someone must have a spare on here.... Just undo the bolts & double it up at 90 degrees, we've talked about it before & aside from the 2 bhp or so you might loose driving it we couldn't think of any other drawbacks...

Post by **rayofleamington** » Tue Jun 29, 2004 10:45 am

The four blade fan would be a very simple mod to try

I had twin blades (4) on my first mog but it would still get fuel vapourisation in really bad traffic on a hot day. I needed a thick skin on some days as when you get to the roundabout the car struggled on slower than walking pace as i tried to keep it running. I'm sure everyone else was rather unimpressed after such a long time in a jam to find someone half blocking up the roundabout

Post by **pskipper** » Tue Jun 29, 2004 11:02 am

I must have just missed breaking down then in THE QUEUE

I noticed that the pump was sounding a bit funny so I stopped the engine whenever I was stationary, bad experiences of overheating back when I had my old polo had taught me what to do (such as adding coolant to the water in the radiator

).

Post by **rayofleamington** » Tue Jun 29, 2004 11:45 am

so I stopped the engine whenever I was stationary

On a moggy you don't gain much but on a Eurobox that will overheat it more quickly.
This is used on hot testing by vehicle manufacturers - turning off the engine when it is very hot usually causes a 20 degree rise in temperature as the cooling system is turned off and all the energy from the hot internalls (normally cooled by the water jacket) spreads to all the other components.
The electric fan will cool the radiator but that water doesn't get back to the engine quickly enough to make a big difference, so on a few cars where it couldn't take the additional heat they have to have an electric water pump to circulate water after key off!

Post by **custommartin** » Tue Jun 29, 2004 6:06 pm

Are there two different problems here?

1) Adding an extra blade to the fan, or fitting an aftermarket fan, will keep the engine, as a whole, cooler.
This air needs to escape though!
Probably the large holes in the floor plates (forgotten their correct name for now) are where most of the hot air comes out. But ideally you need a vent up top. I have vents in the bonnet of my convertible and the amount of heat that comes out is impressive!

2) The fuel vapourisation problem I had was caused by the proximity of the main fuel pipe, and possibly other related bits, to the exhaust manifold.
The noise the fuel pump was making suggests to me that the fuel being SUCKED IN was affected ie in the main pipe.

Making the engine run slightly cooler might not necessary cure the vapourisation problems.
Moving the main fuel pipe away from the manifold might be a better idea.

I guess, moving the pipe, improving the fan efficiency and providing some better means of getting the hot air out, would be the ideal situation!

Post by **Willie** » Tue Jun 29, 2004 6:49 pm

I've said it before but it's worth repeating. The MGBs have a
thin metal plate lined with asbestos(dirty word) fitted between
the carbs and the manifold. This plate is the length of the exhaust
manifold so it deflects/absorbs the heat and works very efficiently.
In these days of unleaded fuel which is more prone to vapourisation
problems I am amazed that someone like Mr Grumpy hasn't made
and marketed such an accessory. The other,probably vital, point
is that the MGBs fuel pump is NOT in the engine compartment!

Post by **Cam** » Tue Jun 29, 2004 9:43 pm

the MGBs fuel pump is NOT in the engine compartment!

No, it's under a daft metal shield in the boot which if it comes undone one side chafes though the feed wire and melts your entire wiring loom! That weekend was fun!!

Post by **Gareth** » Tue Jun 29, 2004 10:33 pm

Speaking from experience again, Cam? Don't have much luck, do you mate?

;)

Post by **rayofleamington** » Wed Jun 30, 2004 12:03 am

I am amazed that someone like Mr Grumpy hasn't made
and marketed such an accessory.

Oh! I thought they have been doing a heat shield for years.

custommartin
not 2 different problems as far as i can tell - I think the 4 balded fan was mentioned as a way of getting increased airflow underbonnet - At least that's the way I took it, rather than to prevent engine overheating. Regarding the engine overheating it may give a benefit but in the UK climate a well maintained moggy shouldn't overheat anyway.