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MG Midget and Sprite Technical - Fumes, urgh!

Went out with the hard top on this afternoon for the first time and was half gassed to death by exhaust fumes.
Any ideas as to why?
The screen top seal is brand new but the rear seal is old and rather flat. Is this the problem?
I don't think there is a problem with the hood up but that is a very rare occurrence.
Clive Berry

Could be that it is sucking fumes in through the rear seal. This is a common problem with estate cars when driven with the rear window open and the side windows closed. Something about the aerodynamics that causes this effect. An open side window prevents this from happening. Willy mentioned that about a B with the rear window open in the zip out window thread a few weeks ago.
Martin

First and obvious question is why are you bothering with a hard-top on such a good soft-top car unless you are doing high-speed (in a Spridget?) roundy-roundy racing?

Aren't the hard-tops supposed to be more aerodynamic putting the exhaust fumes more behind the car?

He who can not be mentioned had possible problems with carbon monoxide coming into the cockpit with the hood down. Now this may have been to to do with the length and position of the tailpipe but I can't remember.

I do know, as I told he who can't be mention, that I've been told by a reliable source that those that go by carbon monoxide are not a pleasant sight for those that find them, and those that survive I know can have life long problems from it.

Fumes can be very serious, get it sorted for your sake and your passenger's.
Nigel Atkins

How is the gasket between your manifold and downpipe?
Or do you have a LCB manifold.

Flip
Flip Brühl

Nigel, long term plan involving winter use. My midget motoring is usually alfresco year round.
Carbon monoxide poisoning is not nice and best avoided.
Flip, it has an lcb bit I'll be checking all joints.
Clive Berry

Clive-
""Went out with the hard top on this afternoon for the first time and was half gassed to death by exhaust fumes. ""
and
"Carbon monoxide poisoning is not nice and best avoided."

Bit of an understatement--
Carbon monoxide poisoning is very very dangerous---and it builds up in you
Doesn't have to be exhaust either, barbecues gas burners, propane torches and some chemicals like the fumes from paint stripper
It's odourless, you smell exhaust fumes cos they smell but the actual carbon monoxide is odourless,-a later car with a cat converter is more of a trap as it doesn't stink as much but the co is still there
Please be carefull and always remember, what goes in with your breathing stays in there, it doesn't come back out---
William Revit

Clive,
I'm a mgb roadster driver - some years ago i found fumes getting in the cockpit when the hood was up. I eventually found the grommet surrounding the choke cable where it passed through the inner fire wall had become dislodged. Once reinserted, the problem went away. Have you checked for any similar problem with your Midget / Sprite?
(I have recently helped restore a Mini Moke where we had the same problem - there were no noticeable fumes with the hood dowen,but evident with the hood up which required sealing any holes /gaps in the firewall).
Cheers, Charles
Charles9

Holes in the firewall shouldn't be a problem. In a perfect world the only poisonous fumes should exit the tail pipe. As others have said, CO is a deadly gas. It isn't poisonous per se, but what it does is bind with the haemoglobin in your red cells and so prevents them from carrying oxygen. In the final stage you technically suffocate because not enough oxygen reaches your organs and particularly your brain. However, as long as it hasn't gone too far it is reversible and getting back into clean air will allow the process to be reversed, albeit slowly.
Mike Howlett

"In a perfect world the only poisonous fumes should exit the tail pipe."

Absolutely Mike. But I can't help thinking future generations will look back at us and say " What were they thinking, using transport which vented known poisons and carcinogens straight into the air they breathed?"
A bit like us looking askance at the Victorian practice of 'night soil'. That was never going to end well.

I love the sight, sound and smell of ICEs but we have to move onto an alternative which doesn't poison us. If there was a kit to convert the Midget to electric, I'd be in the queue!





Jeremy MkIII

Thanks for the comments. Some investigation to do.
Jeremy, electric vehicles simply poison other people somewhere else in the world.
Clive Berry

Clive,
from a source I can't name, see image below, also this thread - MG Midget and Sprite Technical - CO poisoning. MGF seats. Huh? I kid you not. (in the Archives) - http://www.mg-cars.net/mg-midget-sprite-technical-bbs/co-poisoningmgf-seats-huh-i-kid-you-not-2014100518442717599.htm



Nigel Atkins

I was once surprised when something went BANG!, hit the inside of the windscreen and landed in my lap. It was the plastic boot badge.
Jonathan Severn

gunson GasTester is a good bit of kit for keeping the CO emissions down, and keeping the carbs on tune.
Works well if you follow the instructions.
Dave Barrow

This thread was discussed between 07/09/2019 and 16/09/2019

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