Fuel Vapourisation

Post by **Scott** » Wed Jun 30, 2004 4:26 am

4 blade fans are standard here & fuel vapourisation is still an issue sometimes. Mind you, on 40+degC days, some of the modern cars can't even handle the heat.
Fitting a mechanical fuel pump is often done in Aust. to get the fuel line lower down & away from the exhaust.

Post by **Cam** » Wed Jun 30, 2004 8:32 am

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

Yes and no. In that order!

Post by **Kevin** » Wed Jun 30, 2004 10:14 am

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

But that one is for the pipe line area and not a shield for the carb as Willie mentioned.
If the main area causing the problem is the pipework to the pump and the pump itself maybe a heat shield like the Grumpies one with a heat deflector of the type Willie mentioned on the outside as I think the Grumpies one is just an alloy plate with no deflector + using a pipe insulator (a heat deflecting type would be good if it exisits) of the type mentioned by Ben.
Willie does the MG one have the asbestos type material fitted exhaust side or carb side as there seem to be some modern ones made of stainless but without the material fitted.

Post by **rayofleamington** » Wed Jun 30, 2004 11:22 am

But that one is for the pipe line area and not a shield for the carb as Willie mentioned.

Ah - I read it differently the first time as I thought is was a shild mounted to the manifold to protect the fuel pipe, but on a second read of the post I see what you mean.

Post by **57traveller** » Wed Jun 30, 2004 11:29 am

The Grumpies kit comprises two parts, as follows.

The first screws to float chamber lid and the second utilises two redundant holes near the damper. It extends further down than shown. The copper fuel pump suct. pipe is on the right, the black is speedo cable.

Post by **nick_h** » Wed Jun 30, 2004 1:46 pm

This only seems to affect 1098 Engines

Martin

I was in the stop-start queue coming through Castle Donington village and heard my pump racing to supply my 803cc engine. I wondered what the cause of this was. This post has explained what was happening. Fortunately I didn't konk out, but was visualising all sorts of horror scenes going on under the bonnet. Nothing untoward was noted when the bonnet was raised on arrival. Is this more common with unleaded fuel?
I am on unleaded.

BTW
I have some photos of the rally but just need the time (and know-how) to post a few of them. Will try later, but don't hold your breath!

Nick

Post by **Kevin** » Wed Jun 30, 2004 2:03 pm

Thanks for that 57 I didnt realise is was a 2 part kit, the float chamber one looks a good idea but could do with some form of insulation material I wonder which would be the best side to fit some, did you find the kit eliminated the problem.
And yes Nick the problem is worse with unleaded although for the exact reason someone like Ray will have to explain.

Post by **57traveller** » Wed Jun 30, 2004 2:23 pm

There was quite a long discussion about this subject some time ago and some were and some weren't troubled with fuel vapourisation. I was one of the unaffected - not to date anyway

There were a couple of times last summer when stuck in a slow queue on one of the hotter days that the pump in my saloon would tick much faster but the engine never stopped. I fitted the Grumpy kit as an added precaution but have not experienced the same conditions in the saloon, so cannot comment as yet.
The Traveller has been in slow/stopped traffic for prolonged periods on very hot days (isn't the M6 wonderful around Sandbach?) and has never given any signs of vapourisation whatsoever. Both cars have the same engine set up so it's a mystery.
I suppose it's 6 and two 3's as to which side some form of insulation material could be fixed. The float chamber side would allow better clearance between deflector and manifold and allow for thicker material. You can buy heat resistant pads (asbestos free) that plumbers use to protect walls/paintwork when using a gas torch for soldering one of these cut to suit would probably do the job.

Post by **Willie** » Wed Jun 30, 2004 6:38 pm

My heat shield kit from Mr Grumpy was of a completely different
construction to those illustrations! KEVIN, the asbestos was
on the exhaust manifold side of the plate. I suppose that ,these days,
the asbestos could be replaced by a reflective foil such as used
behind radiators?

Post by **custommartin** » Wed Jun 30, 2004 8:23 pm

The kit in the pics, supplied by 57Traveller (thanks by the way), doesn't look quite the same as the one I bought and fitted, to another mog, many years ago.

Maybe this is an up-dated version??

However, seeing the pics reminded me that the 2 screws holding the shield onto the float chamber kept shaking loose!

You just can't win, can you?

A spot of Loctite or similar, kept them in place, in the end.

BTW
I've just had a look at the placement of the Pick-Ups main fuel pipe.
It's in the 'normal' position, behind the metal tag, but then has an un-necessarily large loop that takes it back towards the manifold before connecting to the pump.
Room for improvement there me thinks!

Post by **s.richardson** » Wed Jun 30, 2004 9:04 pm

MARTIN ,your rite wat u say about getting rid of the hot air,i had a scimitar for 6 years ,major overheating probs, i put cosworth bonnet vents in bonnet ,on a hot day in traffic the heat escaping was amazing, i posted a while ago under fuel pump,i realise now i was suffering from vapuorisation,im going to try and re route a longer fuel pipe and get some exhaust wrap or similar,steve p.s. bumpers still looking good mate

Post by **custommartin** » Wed Jun 30, 2004 9:17 pm

Hi Steve,

Where were you sunday, you could have joined our convoy?!

Glad to hear about the bumper!

I will be altering the pipe this week-end, and fitting some heat reflecting stuff (If it's good enough for NASA it's good enough for the Pick-Up!)

BTW

My Pick-Up is in the club's Donington photo gallery - Page 2.
(Teal blue Pick-Up - KUC....) - Excellent!!!

I had just arrived and was more than a bit peeved at breaking down!!

NOTE - the bonnet un-latched to aid air flow!

I didn't even notice the photographer!

Post by **s.richardson** » Wed Jun 30, 2004 9:19 pm

too far for me martin ,how long did it take u at wat speed . ill have a look now

Post by **custommartin** » Wed Jun 30, 2004 9:27 pm

About 3 hours + queue

50-55 mph!

Dennis went there from Eastbourne.

He did stay all weekend though.

Cheers.

Martin

Post by **s.richardson** » Wed Jun 30, 2004 9:31 pm

pick up looks great mate,i went to southern rally in tilford ,that took me nearly 3 hours at 55/60mph including stopping at clacket lane and getting lost near rally, ill let u know wat happens wen i sort fuel pipe,steve

Post by **dennis** » Wed Jun 30, 2004 9:35 pm

yes i travelled a round trip of about 450 miles.
so come on steve your mog can do it, so you should be able to, we will see you at longleat next year we hope
dennis

Post by **dennis** » Wed Jun 30, 2004 9:56 pm

where are the photos of the donnington rally

Post by **s.richardson** » Wed Jun 30, 2004 10:31 pm

i had a job finding em dennis, i think new members site,club gallery,,reckon ill make next year den

Post by **MrA.Series** » Thu Jul 01, 2004 12:00 pm

57traveller wrote:The Grumpies kit comprises two parts, as follows.

Sorry, just going back to this thread, but if the heat shields are painted black, as they are in the pictures above, surely they're just going to absorb the heat, and not reflect much, leaving all of the heat collected to be dumped to the carb and floatbowl, much like using the carb as a heat sink for the 'shield'!

Post by **Kevin** » Thu Jul 01, 2004 1:29 pm

Thats a good point Rob and explains why the MG ones are made in Stainless.