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Discussion Starter · #1 · (Edited)
First of all, hello to all of you. I was following the forum but I was not a member. Super information is shared. So thank you all..
Now as for the problem I'm having.
I was using varejet carburetors before. Then I got solex addhe 40 carburetors. However, after installing these parts,

Problems
1-I did not see a big difference in terms of performance
. Except for the sound :)
2-4000-5000rpm problems,
3-Exhaust 3000 -4000rpm exploid blupp blupp.(carb no spit)idle performance its ok.
Possibilities
1-fuel jets (Is there a measure I should use?) as if the car is running rich and float problems..
2-injection problems (use old series bosch blue coil 3ohm)
3-Use stock mechanical fuel pump.
4-vacuum problems.

Is there any other possibility you can suggest?


Motor vehicle Car Automotive design Auto part Vehicle


 

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Just Some Dude in Jersey
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16,258 Posts
My records have this jetting scenario for an Irmscher modified 2.0 with dual 40's(I presume that means Weber DCOE's, but it may refer to the Solex side drafts). This information came to me from Opeldean.:

115 Mains
190 Airs
f11 Emulsions
40 pump jets
30mm chokes
4.5 Aux Venturies
45 F9 Idles

Another very respected and talented Opeler was PJRomano, who died not too long ago, and my records have this jetting scenario for dual 40's on a 2.0:

34mm chokes
135 Mains
190 Airs
F16 Emulsions
55 F9 Idles

The Chokes and the Mains, possibly the Emulsions, seem to have the largest part to play and if you compare the two scenarios above you'll see that there is some disparity between the size of the chokes and the size of the Mains. The bigger the chokes the bigger the Mains in seems. I'm no expert on side drafts, but I did a little reading while I was setting up a single side draft on a 2.4. I was not very successful. In the end I was fortunate enough to find a side draft tuner with a dyno near me in Philadelphia and he got me running. I have since moved on to FI. "Knorm" on this site seems to have a better grasp of side draft tuning than anyone else on this site at this time.

I've been told that jetting is mainly based on displacement, so cam specs, exhaust size, etc. shouldn't change the jetting scenario much, if at all.

For the most part, we are only familiar with Weber DCOE's, so any nuances that are specific to other carburetor brands and styles are mostly beyond us. It sounds like your problems are at higher rpms and that could mean too small venturies or too small mains.

Absolutely make sure that you don't have vacuum leaks, they are the bane of all Opel CIH engines. Any vacuum leak can radically throw off any jetting or tuning attempts.

You need to find out the size of your venturies and give us more jetting sizes.

You may have better luck posting this problem on one of the Facebook Opel Groups. Hardly anyone knows a dang thing about side draft tuning here in the US anymore, but they were and are used a lot more in Europe. The Facebook groups tap into all the Opelers worldwide and some guy in, say, Romania, might have exactly the info you need. The facebook groups that I administer is called "For the Love of Opel and Chrome" and caters to Opelers who modify their cars, so it might be a good place to start. There are a handful of other Opel groups that cater to racers.

Short of that, you're going to have to dig into research and try to find books or manuals on Varajet side draft set up for your size engine. But it all starts with knowing all the jet and venturi sizes you have in your carbs.
 

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Discussion Starter · #6 · (Edited)
My records have this jetting scenario for an Irmscher modified 2.0 with dual 40's(I presume that means Weber DCOE's, but it may refer to the Solex side drafts). This information came to me from Opeldean.:

115 Mains
190 Airs
f11 Emulsions
40 pump jets
30mm chokes
4.5 Aux Venturies
45 F9 Idles

Another very respected and talented Opeler was PJRomano, who died not too long ago, and my records have this jetting scenario for dual 40's on a 2.0:

34mm chokes
135 Mains
190 Airs
F16 Emulsions
55 F9 Idles

The Chokes and the Mains, possibly the Emulsions, seem to have the largest part to play and if you compare the two scenarios above you'll see that there is some disparity between the size of the chokes and the size of the Mains. The bigger the chokes the bigger the Mains in seems. I'm no expert on side drafts, but I did a little reading while I was setting up a single side draft on a 2.4. I was not very successful. In the end I was fortunate enough to find a side draft tuner with a dyno near me in Philadelphia and he got me running. I have since moved on to FI. "Knorm" on this site seems to have a better grasp of side draft tuning than anyone else on this site at this time.

I've been told that jetting is mainly based on displacement, so cam specs, exhaust size, etc. shouldn't change the jetting scenario much, if at all.

For the most part, we are only familiar with Weber DCOE's, so any nuances that are specific to other carburetor brands and styles are mostly beyond us. It sounds like your problems are at higher rpms and that could mean too small venturies or too small mains.

Absolutely make sure that you don't have vacuum leaks, they are the bane of all Opel CIH engines. Any vacuum leak can radically throw off any jetting or tuning attempts.

You need to find out the size of your venturies and give us more jetting sizes.

You may have better luck posting this problem on one of the Facebook Opel Groups. Hardly anyone knows a dang thing about side draft tuning here in the US anymore, but they were and are used a lot more in Europe. The Facebook groups tap into all the Opelers worldwide and some guy in, say, Romania, might have exactly the info you need. The facebook groups that I administer is called "For the Love of Opel and Chrome" and caters to Opelers who modify their cars, so it might be a good place to start. There are a handful of other Opel groups that cater to racers.

Short of that, you're going to have to dig into research and try to find books or manuals on Varajet side draft set up for your size engine. But it all starts with knowing all the jet and venturi sizes you have in your carbs.


I will be able to give all the information as soon as possible. I didn't have much time today.

brake booster may also leak. I'm having trouble with brakes.
Thank you very much for the information.
 

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Just Some Dude in Jersey
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16,258 Posts
Are you Turkish? Is that the language I'm seeing? You should try to get on the European Opel groups to get more information. There are very, very, few people here in the US who know anything about side draft tuning.
 

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Certified Opelholic
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1,504 Posts
Mikuni bought solex years ago
for the most part Weber and Dellorto carbs go together (similar)
Solex and Mikuni go together

when I got my Mikuni's the first thing I did was get the manual
now its on line

with 30MM chokes you probably would not see much of a performance gain
but have a look at the book


HTHs
 

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