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Converting a 1.6 weber carb to a 1.8

Posted: Wed May 13, 2015 6:14 pm
by Macc
Probably get laughed at but Ive very little mechanical experience (thats changing every day thanks to my mk2!) But in the boxes of parts I obtained with the car theres a 1.6 weber with a manual choke, its the choke i really want so i can replace the "mind of its own" auto!

Anyway, just wondered if it were possible because it looks an exact fit!

Re: Converting a 1.6 weber carb to a 1.8

Posted: Wed May 13, 2015 11:15 pm
by Nate
Is it a 32/34 dmtl? Usually stamped near the base, or on a little metal flag somewhere. If so, iit is the correct carb, you'd just need to get the appropriate jets for the larger engine from webcon.

If not, the carb might be a tad small. But you could still do it with the right jets, it just would have as much enthusiasm

Re: Converting a 1.6 weber carb to a 1.8

Posted: Thu May 14, 2015 12:18 pm
by Macc
Hi Nate yes its a 32/34 dmtl carb, went on Webcon and im a bit unsure what to get, for instance this but it doesnt say 1.8, 1.6 or anything (but im probably missing it to be honest!) http://www.webcon.co.uk/shopexd.asp?id=15164

Re: Converting a 1.6 weber carb to a 1.8

Posted: Thu May 14, 2015 3:08 pm
by Nate
Ring them ;)

Re: Converting a 1.6 weber carb to a 1.8

Posted: Thu May 14, 2015 8:00 pm
by bengould
As Nate said. Ring them and they will just send you a bag with all the right bits in. After £'s have changed hands of course. :-).


Ben.

Re: Converting a 1.6 weber carb to a 1.8

Posted: Thu May 14, 2015 9:51 pm
by Macc
Rang em up, thoroughly nice chap on the phone, he emailed me the pdf of the instruction manual with all the part numbers required etc so thats one main jet, one air corrector and a gasket (because if I dont order that it will "definitely" need one!)

Part numbers for anyone else doing this are;

73405 (117) Main Jet(Primary), 73405 (127) (Secondary)
77501 (145) Air Corr, 77501 (200)
Primary same as 1.6, Emulsion Tube secondary 61450231 (F33)
9990046200 Gasket

Heres a link to the instructions in case anyone else needs them

https://www.dropbox.com/s/y204um0tq2edc ... 5.pdf?dl=0

Re: Converting a 1.6 weber carb to a 1.8

Posted: Mon Jun 08, 2015 1:58 pm
by Macc
Aaand not forgetting the base plate conversion and gasket as I did and have just been told by the garage! 99900896 and 99901168

Re: Converting a 1.6 weber carb to a 1.8

Posted: Fri Jul 31, 2015 6:19 pm
by james butler
have a look at the link in this post on how to tune these carbs.
it will teach you how and why the car behaves the way it does as you tweak bits.
viewtopic.php?f=12&t=18055

Re: Converting a 1.6 weber carb to a 1.8

Posted: Mon Aug 03, 2015 9:07 pm
by 110%
Thanks for posting the pdf. I've been baffled by my 1.8GTII for a while as I couldn't work out which parts were standard and which were from the weber carb modification that I bought the car with.

My carb flange is knackered, and know I recognise the weber mod, I think I need this 1.6 flange (even though ive got a 1.8) and just add the convertion plates over the top.

https://www.dropbox.com/s/ijvamaiozpda5 ... 7.jpg?dl=0

https://vwheritage.mobi/GB/productDetai ... D=47475232

Could anyone confirm this is correct??

Re: Converting a 1.6 weber carb to a 1.8

Posted: Mon Aug 03, 2015 9:17 pm
by mark1gls
Looking at your picture it looks like the right part.
I've not got a 1.8 mk2 but a 1.6 mk1 with a FR engine and yours does look the same.

Re: Converting a 1.6 weber carb to a 1.8

Posted: Mon Aug 03, 2015 9:53 pm
by 110%
Apparently it's an EX engine which would look like this:
http://www.partsbase.org/vw/scirocco-sc ... ke-system/

But the intake looks more like this:
http://www.partsbase.org/vw/scirocco-sc ... arburetor/

Re: Converting a 1.6 weber carb to a 1.8

Posted: Mon Aug 03, 2015 10:29 pm
by 110%
Actually, is this the flange I need:
https://vwheritage.mobi/GB/productDetai ... D=34024104
And then the two small hex bolts fit into the diagonal holes of this flange with the weber plate over the top. (It says it's for the 1.8 with the 2E2 Pierburg carb which would have once been on it.)
I will have to try and remove the top plate tomorrow to see if this is correct.

Re: Converting a 1.6 weber carb to a 1.8

Posted: Tue Aug 04, 2015 7:34 pm
by 110%
Just to help anyone else who has a 1.8 GTII weber conversion, this car flange is the one that sits beneath the weber bracket:

https://vwheritage.mobi/GB/productDetai ... D=34024104

And this is the two separated:

https://www.dropbox.com/s/nf6zqjp44ouv9 ... 7.jpg?dl=0

My replacement car flange should arrive tomorrow and then I'm back on the road.

Re: Converting a 1.6 weber carb to a 1.8

Posted: Tue Aug 04, 2015 10:23 pm
by mark1gls
Glad you have found out which one you need, just make sure when fitting the new one that the carb is not putting extra strain on the flange by sitting at a funny angle and is fixed down properly, there should be a bracket on rocker cover with a grove in it to hold the front of the air box and I think the mk2 may need an extra bit to hold the carb at the right angle but perhaps someone else could confirm this?

Re: Converting a 1.6 weber carb to a 1.8

Posted: Tue Aug 04, 2015 10:45 pm
by bengould
Yes, the air box mount needs to be raised about 10-15mm. I welded a bit to the top of the original bracket but there is a bit in the weber kit that does the job.

Ben.