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MG Midget and Sprite Technical - Triangular holes in front structure

Hi everybody.

the big triangular holes in the front structure - pros and cons of covering these over? My driver's side one was full to almost level with rocks and sand and road grot (probably from autotesting in a gravel swamp) A cover over it would stop this, but will I lose a lot of available 'out' for the air under the bonnet? It's rotted the bottom out a bit - there will be a mend done, but should there be a drain hole in it?

Any mileage in strengthening these up a bit? Car gets a proper pasting every trip out.
Rob Armstrong

If you put a drain hole in it, don't see any reason why it shouldn't be covered.
Jeremy T2

I have seen a photo of one blanked off both sides with triangular covers, held together sandwich-style by a single long bolt and nut. So easily removable for cleaning/ checking. Sometimes plates are welded on to increase strength.

I drilled a good sized drainage hole in mine at the extreme lower point, 5/8" diameter.
GuyW

Mine has a decent drain hole at the bottom and I treat with dinatrol every couple of years. All very solid. Can't really see the point in covering it up and it may make fiddling around with the oil filter, starter motor etc more difficult.
Bob Beaumont

I am with Bob on this one. It has a drain hole.
Alan
Alan Anstead

In the full scale wind tunnel when testing my Sprite it was interesting to see where the airflow that enters the grille, exits - mostly round the wheels. Not sure if any of my youtube clips show this - if not I think I can find some footage to make a short clip.

It would have been interesting then to see if a wire wheel car lets out more air than a steel wheel or alloy wheel car, noting that the original Minilite wheels were designed to extra hot air from the brakes.

So, fill in the triangles and ask yourself how does the air from the engine bay that entered via the grille and now heated by the rad(s), exhaust manifold etc leave the engine bay and does in increase lift and drag or reduce it?
Daniel

yep, where does that air go if not out of the big holes in the front. Has to get rammed out past the bellhousing and engine - more lift and more drag I'd imagine.

On the other hand, covering would stop it filling with stuff.

I can't cover the passenger side because the lambda sensor pokes through the hole; access requirements are slightly different with a K series installed.

Suspect the easiest solution is to get the drain holes in so that small grot drops out.
Rob Armstrong

Rob, ex-factory the drain holes are there. All that needs to be done is to keep them clear by regular poking with a screwdriver. Best to do the 2 either side in the front wing bottom flanges beneath the sidelights at the same time.
davidsmith

Spotted those ones and enlarged them so that small rocks can get out. Hasn't stopped the bottoms of the wings wanting to rot though.
Rob Armstrong

Those front wing holes get cleaned about monthly on my car. And l enlarged them. It still isn't enough though!
GuyW

Best check mine while the front suspension is in bits!

I guess you could always make a 'cap' for the holes? Like a triangular band to close it off. Depends how much it bothers you and if that would cause any other issues?
Karl Bielby

Rob,
I have had the same problem with classic rallies and dirty autotests. As a non engineer my solution was to insert a length of grey expanded pipe insulation (v light) to keep the majority of the mud and stones out when competing.Remove the insert for road use to allow to dry out.The insert just fits into the well with the curved side upwards and the triangular hole is completely open to allow air to go where it will.You can also insert a length up the vertical section to further stop ingress.With practice and full lock on they can be put in and removed in seconds.
John S
J Sloan

You could make covers and louver them... the air gets out and the muck stays...Well you get the idea

Prop
1 Paper

I think John S has the solution! Maybe using a more permanent material would enable the coverings to be left on.

Unless competing, is heat dissipation a problem for road cars? Ditto drag and lift, do standardish Spridgets get to the point where those become apparent or an issue? Daniel no doubt has the answers with his wind testing and I'l need to buy his new book to find out...

BTW has anyone else's page layout changed since yesterday?
J Tickle

This thread was discussed between 02/04/2017 and 04/04/2017

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