Weber Airbox retaining bolts spec?

PostPost by: l10tus » Sun May 31, 2015 11:15 pm

Just planning on fixing the original air box - help needed please?

Q) Can anyone confirm the screw thread size and type of the 3 retaining bolts, on the air box cover for a Sprint please?

Q) Seems to be some discussion as to it being either:- 1/4" UNC or UNF ?

Q) What are the length of each of the 3 no. bolts?

Q) Is there a rubber gasket around the air box between the metal and fibreglass joint? - does Anybody have a picture please?

Many thanks in anticipation !

Regards,

Phil.
Philip.

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Sometimes my Lotus makes me cry.
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PostPost by: mbell » Mon Jun 01, 2015 1:21 am

Bolts are 1/4 unf. On my plus two I have one 1 1/2" and 2 2". I think the standard gasket is cork if there is one.
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PostPost by: Elanconvert » Mon Jun 01, 2015 7:39 am

also have two bolts on my s4......
obtained a gasket from sue miller [u-shaped] but when fitted it was too fat, so don't use anything....I suspect
a bit of foam strip would do.....
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PostPost by: TroonSprint » Mon Jun 01, 2015 8:06 am

I too couldn't make the "official" gasket rubber work so have used self-adhesive draught excluder on mine. My air box also has only two bolts. I bought some wing nuts from B&Q and welded them onto the bolt heads so that the box is easy to remove without tools.

Mike
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PostPost by: ericbushby » Mon Jun 01, 2015 8:07 am

Hi Phil,
My Weber airbox is the three bolt fixing type.
Bolt lengths are :- 1,1/8" 1?" and 1,7/8" not including the bolt head.
No gasket on mine yet. Waiting to decide what to do, if anything. It does seem quite a snug fit without.
Eric in Burnley
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PostPost by: l10tus » Mon Jun 01, 2015 10:07 am

Thanks for the replies Gents, much appreciated.

I too have tried the Sue Miller rubber U shaped gasket, but find it too thick and bulky, so have decided to use draught excluder foam, if possible.(Don't suppose it's the end of the World if one isn't fitted !)

Regards,

Phil.
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PostPost by: Europatc » Mon Jun 01, 2015 5:16 pm

Hello Phil,
with the U gasket I just ran silicone around it with my finger. It wanted to pop out at first but with a tad of perseverance it will go in. Once it has been on a while refitting is no problem. Just my experience
good luck
Stuart
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PostPost by: jono » Mon Jun 01, 2015 7:12 pm

For the gasket I used some U shaped thin rubber profile from Woolies, this one:

http://www.woolies-trim.co.uk/p-1772-ru ... usion.aspx

Bond it around the flange of the airbox on both faces - I used Tigerseal (light smear, leave to go tacky and then stick).

Leave the rubber trim with the bottom of the U sticking about 6mm from the lip of the airbox flange. When it's tightened up it all compresses beautifully to give and airtight seal.

This work really well, I was dead chuffed with it and it's good as new 3 years later and should last as long as the airbox.

Jon
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PostPost by: jono » Mon Jun 01, 2015 7:14 pm

PS: I used rubber penny washers under 20mm stainless penny washers to create and airtight seal where the box bolts through to the back plate
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PostPost by: l10tus » Wed Jun 03, 2015 8:10 pm

Jon,

Great answer!

And thanks to all others who replied!

I knew someone would come up with away of fitting it - as they say " where there's a will, there's a way" !

So, when you say it is 6mm short of the "bottom" - do you mean it's not effectively pushed onto the tin flange of the air box backing plate completely? (Although glued in place? - Just fixed onto the first bit of Tinware, before the first shaped bend ?

Because, as you know, there appears to be too much rubber there, so that when the bottom IS fully seated onto the tin, it's far too large, and 'spills' out further than the tin shape. - as if the sides of the 'U' shape rubber section is too long or too big?

My issue is there just doesn't seem enough clearance or sufficient gap between the fibreglass part and the shaped opening of the metal back plate ?

Did you have to 'relieve' the fibreglass a little, to generate enough of a gap for the rubber to fit snugly between ?

Photo's ??

RSVP.
Regards,
Phil.
Philip.

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Sometimes my Lotus makes me cry.
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