Stupid weber twin 40s question..

[novathere]

Sound like a retard asking this but I'm stuck with the gaskets. I bought some from eBay for weber twin 40s dcoe which is what I have. They don't fit but I'm struggling to find anything that does?

Do the rubber o-rings go between the carb and the trumpet? If not then where?

And I take it there should be some sort of foam/card/cork gasket between the carb and inlet manifold? (This is the one I've bought but doesn't fit)

If I can't find anything would making some from thick card be ok? Is it ok to use gasket sealent?

Thanks in advance just want to hear them roar!!

[Novasport]

You need to fit Misab plates between the carbs and manifold

http://espimages.biz/2386/I/121/50/CSP001.jpg

[paul james]

Yep thats what I use too. You might want to use these rubber washers and metal cups between the studs and bolts to absorb vibration:

http://i.ebayimg.com/00/s/NjkwWDE2MDA=/z/bJcAAOSwYH5WB-Mk/$_57.JPG

heres a pic of mine:

http://i1159.photobucket.com/albums/p638/pauljames14/nova056_zpsgtxelzur.jpg (http://s1159.photobucket.com/user/pauljames14/media/nova056_zpsgtxelzur.jpg.html)

[Southie]

Not sure if you've seen this but it's quite helpful regarding twin 40's:
http://cnx.org/contents/oKbaEWQ3@2/Selection-and-Tuning-of-Weber-

[slimtater]

I bought this kit:

http://www.ebay.co.uk/itm/Weber-40-45-48-DCOE-Twin-Carb-Kit-/351662428999?

[wwinstanley]

http://www.ebay.co.uk/itm/WEBER-DCOE-40-45-48-MISAB-O-RING-PLATES-SET-OF-4-/201280095749?hash=item2edd3a8605:g:x4MAAOSwWnFWB7-K

These go between the manifold and the carb.
As someone mentioned earlier its best to use the rubber washer set too otherwise you could suffer issues with the fuel foaming up in the floats due to vibration :thumb:

[wwinstanley]

Oh and its a good idea to replace the misab plates and rubber mounts periodically as the rubber has been known to vulcanise and break down.
I used to do mine annually on the rally car before I went to throttle bodies but that's probably over the top for a road car.

[novathere]

Thanks for the help guys really appreciate it stuff I've bought is proper shite. I'll be ordering one of those kits today. Thanks

[novathere]

Bought it, Paul James from looking at your picture I can see the misab plate goes between the carb and manifold and then is it
washer-rubber-washer-bolt
On the studs?

Thanks can't wait to get this running again.

[novathere]

Also what size trumpets are those? Need to replace mine.http://uploads.tapatalk-cdn.com/20160309/6c66b3b6bfe41b841e9cb32390291cb9.jpg

[paul james]

Bought it, Paul James from looking at your picture I can see the misab plate goes between the carb and manifold and then is it
washer-rubber-washer-bolt
On the studs?

Thanks can't wait to get this running again.

Yep that's the right order. I would use nyloc nuts and as you can probably make out from the photo you don't need to go overboard with tightening them on. Obviously don't do them up loose so fuel leaks out, but you don't want to crush the misab plates either.

Can't remember what size trumpets are on mine, I will check and report back later.

[novathere]

Thanks I'd appreciate that, I've had a quick look online, 40-50mm looks best but seen slot in trumpets? Are they for specific carbs? Never seen them before. Was going to go for thesehttp://uploads.tapatalk-cdn.com/20160309/8314a54959b74752ab57b36a73affd7f.jpg

[paul james]

Checked and I have 48mm trumpets on mine

[slimtater]

Trumpets on road cars?

[Jonesfach]

Trumpets on road cars?

Do you disapprove?

[novathere]

ive never seen carbs without trumpets. thanks for the sizing paul james :thumb:


got all the gaskets and fitted it, it starts but its revving/idieling at 4k! anyway to restart or reset the idle? I know the jets are under the cap on top but just not sure which ones are which. also took the throttle cable of just incase it was pulling.

got a brand new filter king on it pressure is set at 3.2 ish psi but keeping reading different things. what psi is best?

lastly... what alternator belt is best? standard one is too big. thanks

[paul james]

Can't see why having trumpets is an issue, as long as some kind of filter(s) are used on them.

Have a look here: http://www.novasportregister.com/history/the-sport-pack/installation-instructions/

The throttle stop screw as its called on there will affect the idle speed, give it a small turn with the engine running and check the rev counter. I have previously got through an MOT emissions test by turning the idle speed up with that screw, as it had failed on a lower idle.

I think 3psi is what most people go for.

I believe the alternator belt I've got is a 850mm length 9.5mm width
http://www.ebay.co.uk/itm/360440438675?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT


(http://www.ebay.co.uk/itm/360440438675?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT)

[slimtater]

Do you disapprove?

Not so much disapprove, more interested in running without filters and the risks.

[Royston]

Not so much disapprove, more interested in running without filters and the risks.

increase in power output, with the risk of dirt ingress leading to engine wear/damage (for a few HP)

Each to their own, fine for race engines that are rebuilt regularly, plenty of free flow air filtration options available

Just my opinion..........

[slimtater]

increase in power output, with the risk of dirt ingress leading to engine wear/damage (for a few HP)

Each to their own, fine for race engines that are rebuilt regularly, plenty of free flow air filtration options available

Just my opinion..........

That's what I was thinking and had been told - by John Noble in 1990! I had been toying with going to trumpets for my Sport but ended up with K&Ns. John said that one of the best options was the Sport airbox base with a filter element cable tied in place. The view was filtration of some sort was a must - I did live in Derbyshire and work in a former quarry though! lol

[Jonesfach]

That's what I was thinking and had been told - by John Noble in 1990! I had been toying with going to trumpets for my Sport but ended up with K&Ns. John said that one of the best options was the Sport airbox base with a filter element cable tied in place. The view was filtration of some sort was a must - I did live in Derbyshire and work in a former quarry though! lol

You can fit trumpets and filters - K and N types. I have them on mine!

you are right about the airbox set up. Used to run without the lid on as much better air flow. I had some cables with crimped connections, that you could secure using the existing round Allen head bolt threads, on the airbox.

however ended up with trumpets and filters and been so ever since.

[wwinstanley]

Not sure where you would find it but there is a measurement for the gap between the two washers either side of the rubber. You can measure it with a feeler gauge to ensure they are the correct tightness.