SAAB V4 Forum
SAAB V4 Forum
Home | Profile | Register | Active Topics | Members | Search | FAQ
Username:
Password:
Save Password
Forgot your Password?

 All Forums
 Technical
 General Technical
 Fuel pump/ carburettor membrane material
 New Topic  Reply to Topic 
 Printer Friendly 
AuthorPrevious Topic Topic Next Topic 

melle
V4 Guru

United Kingdom
2831 Posts

Posted - 26 Sep 2014 :  23:46:19 Show Profile Visit melle's Homepage Reply with Quote
Where do I buy material to cut new membranes for fuel pumps and carburettors? I'm too thrifty to buy new Weber choke and power valve diaphragms whilst it's easy enough to replace the membranes.




Same for fuel pumps, why throw good pump bodies away instead of simply replacing the membrane? Seems to be a very uncommon idea these days...

1970 96V4 "The Devil's Own V4"
1977 95V4 van conversion project
1988 900i 8V

dansp1
V4 Beginner

51 Posts

Posted - 27 Sep 2014 :  08:39:28 Show Profile Reply with Quote
http://www.ebay.co.uk/itm/VITON-RUBBER-SHEET-GRADE-A-A4-SIZE-0-5mm-1mm-2mm-3mm-4mm-5mm-and-6mmthk-/231010911840?pt=LH_DefaultDomain_3&var=&hash=item35c952c660
Go to Top of Page

melle
V4 Guru

United Kingdom
2831 Posts

Posted - 27 Sep 2014 :  13:41:21 Show Profile Visit melle's Homepage Reply with Quote
That was in my eBay watch list already. Thanks!

1970 96V4 "The Devil's Own V4"
1977 95V4 van conversion project
1988 900i 8V
Go to Top of Page

melle
V4 Guru

United Kingdom
2831 Posts

Posted - 27 Sep 2014 :  13:49:39 Show Profile Visit melle's Homepage Reply with Quote
Does anyone know what thickness I should buy for a fuel pump? I don't have one here to measure the membrane... 0.5mm should do for the carb diaphragms.

1970 96V4 "The Devil's Own V4"
1977 95V4 van conversion project
1988 900i 8V
Go to Top of Page

melle
V4 Guru

United Kingdom
2831 Posts

Posted - 28 Sep 2014 :  14:38:03 Show Profile Visit melle's Homepage Reply with Quote
Hmm, the Weber membranes measure 0.1mm, so 0.5 Viton seems a bit too much. Might just try it though if I can't find thinner stuff. If it doesn't work I can always revert and buy new parts.

1970 96V4 "The Devil's Own V4"
1977 95V4 van conversion project
1988 900i 8V
Go to Top of Page

melle
V4 Guru

United Kingdom
2831 Posts

Posted - 11 Jan 2015 :  18:59:36 Show Profile Visit melle's Homepage Reply with Quote
Result! Laser cut out of (imitation) Viton I bought off eBay:


The others are paper gaskets for a Weber 32/36 DGAV.

1970 96V4 "The Devil's Own V4"
1977 95V4 van conversion project
1988 900i 8V
Go to Top of Page

beta
V4 Fanatic

Ireland
278 Posts

Posted - 11 Jan 2015 :  20:02:28 Show Profile Reply with Quote
Well done Melle !!
Go to Top of Page

Derek
V4 Guru

United Kingdom
1872 Posts

Posted - 11 Jan 2015 :  22:32:17 Show Profile Reply with Quote
How are you going to fit them? Drill out and then use some sort of blind rivet?
Go to Top of Page

melle
V4 Guru

United Kingdom
2831 Posts

Posted - 12 Jan 2015 :  07:17:41 Show Profile Visit melle's Homepage Reply with Quote
I'm using an M2 bolt with a countersunk head.

1970 96V4 "The Devil's Own V4"
1977 95V4 van conversion project
1988 900i 8V
Go to Top of Page

Derek
V4 Guru

United Kingdom
1872 Posts

Posted - 12 Jan 2015 :  13:41:35 Show Profile Reply with Quote
Accelerator pump diaphragm has an easy life but the fuel pump is bashing away continuously at a pretty high rate, more like a vibration, so I'd think that some very high lock Loctite, which can stand up to oil and petrol, would be a very good idea.
Go to Top of Page

beta
V4 Fanatic

Ireland
278 Posts

Posted - 12 Jan 2015 :  14:14:04 Show Profile Reply with Quote
Hi Melle
Did you make many of those intermediate plate gaskets - I could offer my car as a test bed for the first batch !!

Go to Top of Page

melle
V4 Guru

United Kingdom
2831 Posts

Posted - 12 Jan 2015 :  17:30:03 Show Profile Visit melle's Homepage Reply with Quote
Paul, I anticipated on your question, come pick some up at your nearest leisure.

Derek: the membranes you see in the photo are for the power valve and the choke of a Weber 32/36DGAV carb, those will be installed using an M2 bolt and medium strength thread lock. I haven't cut a fuel pump membrane yet, but you're absolutely right that this will be under significant stress during its life. Luckily I can use a bigger diameter and longer bolt there, now with a stronger type Loctite/ PermaBond. Using a blind rivet might be an even better alternative though, any opinions?

1970 96V4 "The Devil's Own V4"
1977 95V4 van conversion project
1988 900i 8V
Go to Top of Page
 Previous Topic Topic Next Topic 
 New Topic  Reply to Topic 
 Printer Friendly 
Jump To: 
Snitz Forums 2000
SAAB V4 Forum© 2000-04 Snitz CommunicationsGo To Top Of Page