Phil Bishop Posted December 17, 2002 Share Posted December 17, 2002 The inlet trumpets in my carburettors do not sit tightly and rotate with the vibration of the engine. I remember reading somewhere that this can eventually cause wear to the body of the carburettor, which is made of softer metal. Apparently, you can get retaining plates with lips on that solve this problem, but a couple of places I rang seemed to think I'd just dropped off of Venus or something. Any help on this one? Link to comment Share on other sites More sharing options...
DAVID L Posted December 17, 2002 Share Posted December 17, 2002 Aren't they supposed to be held in by grub screws that are then secured by wires? BTW anyone tried getting rid of the K&Ns and putting some trumpets on instead: simply for cosmetic reasons (and to make MORE noise!!) I think a louder car is a safer car.....join the DIN (Department for the Increase of Noise) Hee Hee! Link to comment Share on other sites More sharing options...
Phil Bishop Posted December 17, 2002 Author Share Posted December 17, 2002 Christ! You must camp next to your computer. No, mate - not so simple. They are retained by a couple of little plates each on the front face of the carb, and the trumpets spin and wobble like good 'uns. Link to comment Share on other sites More sharing options...
R2D2 Posted December 17, 2002 Share Posted December 17, 2002 The air horns should have a slight step on the outside diameter just as they enter the bore of the carburettor. There should be a shaped washer (see item 20 at : http://www.webcon.co.uk/weber/40dcoe.htm) that locates against this step and presses the air horn lightly against against the choke. This slight clamp force should stop any rotation. It is the choke that is located by a grub screw and lock nut. If you have 40DCOE 151s that are made in spain they may be a poor fit. Edited by - chris flavell on 17 Dec 2002 17:24:21 Link to comment Share on other sites More sharing options...
Allan Haighton Posted December 17, 2002 Share Posted December 17, 2002 Chris - my trumpets rattled/rotated from new. Drove me nuts. So I fitted a thin aluminium shim strip behind each of the trumpet locating/clamp plates bolted to the air filter backplate. Job done. Link to comment Share on other sites More sharing options...
stevefoster Posted December 17, 2002 Share Posted December 17, 2002 Simplest fix is to wrap and twist off some thin wire around each trumpet and then bolt up the clips as normal. That'll fix it. /Steve My racing pics, 7 DIY, race prep. Updated often here Photo's of the year here Hants (North) and Berkshire Area club site here Link to comment Share on other sites More sharing options...
Phil Bishop Posted December 17, 2002 Author Share Posted December 17, 2002 Thanks for the suggestions - glad to see it wasn't just me being picky. What if any of these bits of ally or wire break loose and end up getting blown through the carbs - am I going to do harm to the inside of the cylinders or begger up the valves? That's what the filters are there for, to stop stuff like that getting in. Link to comment Share on other sites More sharing options...
I.Mupferit Posted December 18, 2002 Share Posted December 18, 2002 When mine had the same problem (Made in Spain!), I stripped about 12mm of PVC insulator from a piece of wire and fitted that behind each of the retaining plates. I too was concerned that a piece of wire might work loose and get ingested into the inlets, so figured that a small piece of PVC wouldn't do any irreparable damage if that happened. Worked a treat! Brent Link to comment Share on other sites More sharing options...
Phil Bishop Posted December 18, 2002 Author Share Posted December 18, 2002 You're a star Brent. Only been a Seven Club member since yesterday, and logged on to the club site for the first time. I can't get over all the helpful ideas that have come in for this little problem. For someone who's chief claim to engineering fame was to (badly) mechanic a couple of karts for his kids ten years ago, building a car from bits was a bit of a lonely experience. I'm only sorry I didn't find you all sooner. Link to comment Share on other sites More sharing options...
Klaus Loske Posted December 18, 2002 Share Posted December 18, 2002 Hi, the bolt down trumpets are used on Dellorto carbs David. On my Webers, I had the same problem. I noticed though, that the shaped washers are also slightly bend so that they push down on the step of the trumped. So they have to be the right way around. What also happens is that they are flattend out over time since they are bolted down. I used some pliers to bend them again to get them to press on the trumpet again. All in all a not so nice and cheap design. Probably best to get some nice Pipercross alloy rampipes. Klaus 1700+ X-flow Combustion is not a secret Link to comment Share on other sites More sharing options...
stevefoster Posted December 18, 2002 Share Posted December 18, 2002 Twisted steel wire is not going to break loose. It is trapped by the taper of the trumpet even if there were no clamps. Worry more about the nut vibrating loose and being ingested! I always used Nyloc on them! /Steve My racing pics, 7 DIY, race prep. Updated often here Photo's of the year here Hants (North) and Berkshire Area club site here Edited by - stevefoster on 18 Dec 2002 12:42:27 Link to comment Share on other sites More sharing options...
puremalt Posted December 18, 2002 Share Posted December 18, 2002 There was a thread recently ref removing the K&Ns and using longer trumpets. Don't take the filters off as dirt/stones in your carbs etc will not be fun. ITG filters are worth a look, but take ages to reply to emails, or Pipercross. Someone suggested a F3 airbox too. MMnn nice. Get it out, the weather's dry Link to comment Share on other sites More sharing options...
Noel Mclaughlin Posted December 19, 2002 Share Posted December 19, 2002 www.hi-flow.com Have fitted these integral ram tube type filters to 2 cars now, Sprite with 1-5'" S.U, xflow with Webers on my Seven. K and N elements, good power boost and still "got the noise" Highly recommended *thumbup* Link to comment Share on other sites More sharing options...
AJC Posted December 19, 2002 Share Posted December 19, 2002 Pop em out and run a ring of silicone sealant or blue hylomar ...leave a bit and Roberts your relative. Link to comment Share on other sites More sharing options...
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