throttle butterfly seal.

throttle butterfly seal.

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Discussion

garagewidow

Original Poster:

1,502 posts

169 months

Wednesday 2nd April 2014
quotequote all
hello all.

in the process of reconditioning some old throttle bodies I stupidly cleaned up the bore and now have some daylight visible around the butterfly when closed.i've re adjusted them but to no avail.is there a hard setting spray or coating I can apply to establish a good seal,i was pondering a thin smear of 'chemical metal' resin compound around the bore then seating the plates while it is still pliable,or is there danger of it coming off and being sucked into the engine.
I could probably get the idle down by messing with the ign timing by retarding it but its not really ideal.

TIA.

CrutyRammers

13,735 posts

197 months

Wednesday 2nd April 2014
quotequote all
Not sure if there are any compounds like that that are petrol/oil resistant. I've used stuff like "araldite metal" and I daresay it'd be mechanically ok, but I'd worry about chemical attack. JB weld always gets good reviews.

Limuweld would work (like solder for aluminium), but it's hard as hell so would be a pain to grind/file it back down; but it wouldn't come off. Otherwise you could get someone to build it up with a tig welder and machine it back. Probably easier just to buy a new tb though if you're getting into remachining.

Have an hour or so's google - I quickly found maxbore.com who are in the states, but say they do rebooring and repairing of tbs, so there's probably some company somewhere who can do it.

Pumaracing

2,089 posts

206 months

Thursday 3rd April 2014
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If by cleaning up the bores you mean you gave them a good hammering with a flapwheel or similar then for all practical cost effective purposes I suspect they're toast. Butterflies are oval and should still seat at a slightly steeper angle on the long axis but if there's clearance at the sides there's no easy fix.

spitfire4v8

3,990 posts

180 months

Thursday 3rd April 2014
quotequote all
You could bore them up a size and fit sleeves but as puma says if youve taken metal out then your tbs are likely beyond economical repair.
Golden rule is never touch the bore where the throttle plates are.

garagewidow

Original Poster:

1,502 posts

169 months

Sunday 6th April 2014
quotequote all
thanks all.

I decided to try smearing some 'super steel' around the bores and seated the plates,it seems to have worked and it idles ok.
they are heavily worked lucas bodies so replacing will involve more work.if it lasts all well and good,otherwise I will have to bore and sleeve as suggested.