Dez
Club Retro Rides Member
And I won't sit down. And I won't shut up. And most of all I will not grow up.
Posts: 11,714
Club RR Member Number: 34
|
Weber DGAV jetting questions. Dez
@dez
Club Retro Rides Member 34
|
|
|
I bought a DGAV carb cos it was cheap, good nick and had a manual choke conversion fitted. Assuming it hasn’t been messed with, the numbers say it was for a 2l pinto from a Granada or Capri. I need it to be jetted for a 1600 pinto. It’s not actually going on a 1600 pinto but I’ve run this carb at that jetting on this engine (1500cc) and it worked perfectly, so I’m going with experience. The current setup is on the right and what I need to achieve is on the left.  As you can see major things like the chokes, venturis and emulsion tubes are the same, and I’ll obviously swap the main jets. (Isles appears to be the same). But what about the other bits? It appears air correctors are cheap and easy to get(£1.25), but pump jets are very expensive (£20), so would I get away with not changing that? I also can’t find any reference to ‘air idle jets’ for sale. Can they be changed? |
| |
|
|
|
|
melle
South West
It'll come out in the wash.
Posts: 1,984
|
|
|
|
|
I would change the mains and see what happens, can't be too far off. The air correctors are for fine tuning more than anything else one DGV type carbs iirc. Not sure about the air idle jets, may be just bores in the casting? If you PM me your email address I can send you the Weber Tuning Handbook.
|
| |
www.saabv4.com'70 Saab 96 V4 "The Devil's Own V4" '77 Saab 95 V4 van conversion project '88 Saab 900i 8V
|
|
Dez
Club Retro Rides Member
And I won't sit down. And I won't shut up. And most of all I will not grow up.
Posts: 11,714
Club RR Member Number: 34
|
Weber DGAV jetting questions. Dez
@dez
Club Retro Rides Member 34
|
|
|
I would change the mains and see what happens, can't be too far off. The air correctors are for fine tuning more than anything else one DGV type carbs iirc. Not sure about the air idle jets, may be just bores in the casting? If you PM me your email address I can send you the Weber Tuning Handbook. That’s pretty much what I thought. Especially the air idle jets actually. Wing guy drilling’s one the body, with them being referred to as ‘holes’ as well. PM on its way with email, I used to have it if it’s the Haynes one you mean but I assume it went in the fire. |
| |
|
|
melle
South West
It'll come out in the wash.
Posts: 1,984
|
|
|
|
|
Files sent. If you need anything else give me a shout and I'll have a more thorough root through my digital and physical libraries.
|
| |
www.saabv4.com'70 Saab 96 V4 "The Devil's Own V4" '77 Saab 95 V4 van conversion project '88 Saab 900i 8V
|
|
Darkspeed
Club Retro Rides Member
Posts: 4,711
Club RR Member Number: 39
|
Weber DGAV jetting questions. Darkspeed
@darkspeed
Club Retro Rides Member 39
|
Apr 10, 2020 10:19:17 GMT
|
I also can’t find any reference to ‘air idle jets’ for sale. Can they be changed? Idle air jets are usually holes drilled into the casting that feed into the Idle gallery so cannot be changed - some do have drilled bronze bushes pressed in that can be drilled out and replaced. 45/45 seems logical enough but they are very easy to change so if you find that the progression on the throttle is not smooth enough you can up the primary to a 50. Sure I do not need to tell you as its a progressive carb nothing on the secondary makes any difference to the running until you are 3/4 foot down so for initial tuning only change the primary jets to get that right and then move onto the Secondary if its not right during that stage of throttle opening. I would only be inclined to swap out the primary Main and air corrector initially and have a 50 Idle jet in the draw. |
| |
|
|
melle
South West
It'll come out in the wash.
Posts: 1,984
|
|
Apr 10, 2020 11:11:14 GMT
|
|
It's been a while since I overhauled a few DGAVs (the version with a manual choke is called DGV), been messing with 28/36 DCDs more recently. I've bought a handful of jets from fast Road Cars when I set one up a few years ago; the jets are cheap enough to get a few more than you need and you have to pay the postage anyway regardless of the number you buy.
|
| |
www.saabv4.com'70 Saab 96 V4 "The Devil's Own V4" '77 Saab 95 V4 van conversion project '88 Saab 900i 8V
|
|
Darkspeed
Club Retro Rides Member
Posts: 4,711
Club RR Member Number: 39
|
Weber DGAV jetting questions. Darkspeed
@darkspeed
Club Retro Rides Member 39
|
Apr 10, 2020 12:34:49 GMT
|
|
One thing to look out for on manual choke converted carbs is if the vac port that feeds the auto choke assembly has been blocked off. I have found quite a few that had idle issues due to the person that fitted the manual kit not blocking the vac port off.
|
| |
|
|
melle
South West
It'll come out in the wash.
Posts: 1,984
|
|
Apr 10, 2020 12:39:58 GMT
|
The DGAV ("aqua") has a choke assembly with coolant hoses and the DGEV an electric control assy; I wasn't aware of an extra vac port. Dez , is your carb converted to manual choke, or is it a factory DGV? |
| |
www.saabv4.com'70 Saab 96 V4 "The Devil's Own V4" '77 Saab 95 V4 van conversion project '88 Saab 900i 8V
|
|
Darkspeed
Club Retro Rides Member
Posts: 4,711
Club RR Member Number: 39
|
Weber DGAV jetting questions. Darkspeed
@darkspeed
Club Retro Rides Member 39
|
Apr 10, 2020 12:54:10 GMT
|
The DGAV ("aqua") has a choke assembly with coolant hoses and the DGEV an electric control assy; I wasn't aware of an extra vac port. Dez , is your carb converted to manual choke, or is it a factory DGV? Not many are aware of it which is why it constantly gets overlooked - When the choke is fully shut by the bi-metal the vac port is there to open it as soon as the engine fires. You can see the vacuum canister and diaphragm on the end of the "aqua" choke assembly - and some manual ones and kits depending on the conversion type. Vac pot and the linkage it connects to.  |
| |
Last Edit: Apr 10, 2020 12:57:51 GMT by Darkspeed
|
|
Dez
Club Retro Rides Member
And I won't sit down. And I won't shut up. And most of all I will not grow up.
Posts: 11,714
Club RR Member Number: 34
|
Weber DGAV jetting questions. Dez
@dez
Club Retro Rides Member 34
|
Apr 10, 2020 12:54:17 GMT
|
|
Yes it was originally a DGAV that has had the auto Choke removed and the manual conversion kit fitted. This suits my needs perfectly and was a bit of a score as the conversion kit is not cheap. I believe you can also get electric choke versions but they’re not that common.
I think I may also have a vac line I need to address because of it originally being for an auto application, as i think they used a vac kickdown, but I’ve not looked into that yet.
|
| |
|
|
|
|
Dez
Club Retro Rides Member
And I won't sit down. And I won't shut up. And most of all I will not grow up.
Posts: 11,714
Club RR Member Number: 34
|
Weber DGAV jetting questions. Dez
@dez
Club Retro Rides Member 34
|
Apr 10, 2020 13:02:32 GMT
|
As for vac lines it has 3 I can see. One is below the butterfly’s, one is right on the butterfly when they’re shut, other one is on a diaphragm off the side. I presume they’re dizzy vac advance, the one for the autochoke as mentioned, and then possibly autobox kickdown. I’ve not printed out what you’ve sent me yet and identified their jobs yet melle, that’ll be something for over the weekend.   |
| |
Last Edit: Apr 10, 2020 13:06:37 GMT by Dez
|
|
Dez
Club Retro Rides Member
And I won't sit down. And I won't shut up. And most of all I will not grow up.
Posts: 11,714
Club RR Member Number: 34
|
Weber DGAV jetting questions. Dez
@dez
Club Retro Rides Member 34
|
Apr 10, 2020 13:08:50 GMT
|
Actually I’ve just spied this that seems a little out of place, and would correspond with what Darkspeed is saying. Does that mean it’s been dealt with?  |
| |
|
|
melle
South West
It'll come out in the wash.
Posts: 1,984
|
|
Apr 10, 2020 13:36:41 GMT
|
I see what you mean now, it seems not all have this feature. I was only aware of the direct vacuum connection between the choke housing and the carb body (with an o-ring as a seal in between), I thought this was retained with a manual choke kit. I've never actually seen a manual conversion kit up close, the two I have are DGAVs with the original water choke still in place. I just looked through my photos; one doesn't have the diaphragm opposite the accelerator pump and only has a single vac port under the choke, which is used for the dizzy. The second one, which I've never had on a car, is like yours. Is there supposed to be a vac line between the carb base and the vac can on the choke assy? Actually I’ve just spied this that seems a little out of place, and would correspond with what Darkspeed is saying. Does that mean it’s been dealt with? One of mine has a screw in the middle (the one with the single vac port) and the other looks like it's blocked like yours.   |
| |
Last Edit: Apr 10, 2020 14:03:18 GMT by melle
www.saabv4.com'70 Saab 96 V4 "The Devil's Own V4" '77 Saab 95 V4 van conversion project '88 Saab 900i 8V
|
|
Dez
Club Retro Rides Member
And I won't sit down. And I won't shut up. And most of all I will not grow up.
Posts: 11,714
Club RR Member Number: 34
|
Weber DGAV jetting questions. Dez
@dez
Club Retro Rides Member 34
|
Apr 10, 2020 13:46:03 GMT
|
According to the Haynes excerpt you sent me, this carb has the ‘RS2000’ anti stall device. And it appears that the two smaller vac lines should be looped?  Which means that if I do that I’ve only got the one for the vac advance left, so the one darkspeed mentioned has presumably been dealt with, or was never there. I think that’s one of the issues with these carbs, there just SO many variants of them it’s hard to pick through what you do and don’t want when using them on non-standard applications. |
| |
Last Edit: Apr 10, 2020 13:50:48 GMT by Dez
|
|
melle
South West
It'll come out in the wash.
Posts: 1,984
|
|
Apr 10, 2020 13:54:06 GMT
|
|
Yes, looks like you're good to go. I just added a line to my previous post. As far as I remember the vacuum for the choke is via an "internal" connection, which is kept in your conversion so there's nothing that needs blocking it seems.
|
| |
Last Edit: Apr 10, 2020 13:54:45 GMT by melle
www.saabv4.com'70 Saab 96 V4 "The Devil's Own V4" '77 Saab 95 V4 van conversion project '88 Saab 900i 8V
|
|
Darkspeed
Club Retro Rides Member
Posts: 4,711
Club RR Member Number: 39
|
Weber DGAV jetting questions. Darkspeed
@darkspeed
Club Retro Rides Member 39
|
Apr 10, 2020 15:01:14 GMT
|
Yes, looks like you're good to go. I just added a line to my previous post. As far as I remember the vacuum for the choke is via an "internal" connection, which is kept in your conversion so there's nothing that needs blocking it seems. Yep - The kit you have Dez retains the vac system as melle states the port is an internal one and only gets uncovered in the kits that remove the complete Auto choke assembly. You will need to install a pipe between those two connections as the photo. My understanding is that a vac holds a diaphragm open when its running but when it starts to stall the vac is lost a spring on the other side of the diaphragm just like an accel pump squirts extra fuel into the engine to stop it stalling. Anti stall sounds like a good thing to have on an Auto so makes sense on that carb |
| |
Last Edit: Apr 10, 2020 15:04:05 GMT by Darkspeed
|
|
Dez
Club Retro Rides Member
And I won't sit down. And I won't shut up. And most of all I will not grow up.
Posts: 11,714
Club RR Member Number: 34
|
Weber DGAV jetting questions. Dez
@dez
Club Retro Rides Member 34
|
Apr 10, 2020 15:07:06 GMT
|
|
Ah Yes, that all makes sense now. I didn’t know they did manual conversions that totally did away with the auto choke body. This one just replaces the actual waxstat portion.
Sounds like bar a few different jets I’ve actually got the perfect setup.
|
| |
|
|
