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Opeler
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6 Posts
Discussion Starter · #1 ·
Guys and Gals,
I need some help. Could you provide the make and part numbers of a complete cold intake. My Opel GT keeps shutting down after a highway drive from gas flash off. Any direction you can give me would be great. My carb is a Weber top air filter. I’m using a thick gasket on the manifold. I’ll be installing a heat shield from Opel GT Source.
 

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Super Moderator
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5,947 Posts
MODERATOR's NOTE: I have moved this thread to a different, hopefully more relevant Forum

Wow, a member since Sep 6, 2004, and this seems to be your first ever post!


If you are having "heat soak" issues, which are common for these engines due to the intake and exhaust being on the same side, and especially due to the direct-coupling of the manifolds, the heat shield is the first thing to try.

There are a number of other suggestions:

The fuel inlet into the Weber should enter from the outboard side; many Weber DGV's and DGS's come with the nipple facing the engine block. Often not too difficult to plug that entry and install a nipple on the other side.

Ensure that the fuel line around the front of the engine is insulated to avoid it becoming excessively hot.

Re-route the fuel line around the front of the radiator, down low.

Install an electric fuel pump, back at the outlet of the fuel tank. Ditch the mechanical pump and plug the hole.

Replace the stock exhaust manifold with a header or a "Sprint" exhaust manifold. That is the best way to minimize heat soak into the intake manifold and carb.

Replace the downdraft Weber and factory intake with a single or dual DCOE side draft intake and carb(s).

HTH
 
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Opeler
Joined
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6 Posts
Discussion Starter · #3 ·
MODERATOR's NOTE: I have moved this thread to a different, hopefully more relevant Forum

Wow, a member since Sep 6, 2004, and this seems to be your first ever post!


If you are having "heat soak" issues, which are common for these engines due to the intake and exhaust being on the same side, and especially due to the direct-coupling of the manifolds, the heat shield is the first thing to try.

There are a number of other suggestions:

The fuel inlet into the Weber should enter from the outboard side; many Weber DGV's and DGS's come with the nipple facing the engine block. Often not too difficult to plug that entry and install a nipple on the other side.

Ensure that the fuel line around the front of the engine is insulated to avoid it becoming excessively hot.

Re-route the fuel line around the front of the radiator, down low.

Install an electric fuel pump, back at the outlet of the fuel tank. Ditch the mechanical pump and plug the hole.

Replace the stock exhaust manifold with a header or a "Sprint" exhaust manifold. That is the best way to minimize heat soak into the intake manifold and carb.

Replace the downdraft Weber and factory intake with a single or dual DCOE side draft intake and carb(s).

HTH
Thanks for the reply. I’ll work on this today.
 

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Just Some Dude in Jersey
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15,349 Posts
After 40 years and trying all that stuff, an electric fuel pump works the best. I did a series of video tests of the most used types: Diaphragm, old school Carter, and new school Edelbrock. The red Edelbrock 3-5psi is the quietist and most modern and I'm very happy with it. Re-routing and insulating the fuel line helps. A phenolic spacer between the carb and intake manifold is pretty effective. I'm not a fan of the heat shield.

Your problem is that, when your car is fully warmed up, heat is soaking into the intake manifold and carb and boiling the fuel out of your carb's fuel bowl. There's virtually no way to stop this from happening. The oem mechanical pump requires you to crank the engine so that the pump can replenish the fuel bowl, so that the carb can start squirting fuel. You waste spark and starter power and induce starter wear and tear during those first dry cranking attempts as a result. An electric pump kicks on as soon as you turn the key to Run, no cranking or spark usage, and refills the fuel bowl in a jiffy. Generally, you wait 3-5 seconds and you'll hear the fuel pump change pitch, that's when you know that the fuel bowl has been refilled. THEN crank the engine. This set up has worked the best for me. Here's the video of the Edelbrock:

 

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Opeler
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6 Posts
Discussion Starter · #5 ·
After 40 years and trying all that stuff, an electric fuel pump works the best. I did a series of video tests of the most used types: Diaphragm, old school Carter, and new school Edelbrock. The red Edelbrock 3-5psi is the quietist and most modern and I'm very happy with it. Re-routing and insulating the fuel line helps. A phenolic spacer between the carb and intake manifold is pretty effective. I'm not a fan of the heat shield.

Your problem is that, when your car is fully warmed up, heat is soaking into the intake manifold and carb and boiling the fuel out of your carb's fuel bowl. There's virtually no way to stop this from happening. The oem mechanical pump requires you to crank the engine so that the pump can replenish the fuel bowl, so that the carb can start squirting fuel. You waste spark and starter power and induce starter wear and tear during those first dry cranking attempts as a result. An electric pump kicks on as soon as you turn the key to Run, no cranking or spark usage, and refills the fuel bowl in a jiffy. Generally, you wait 3-5 seconds and you'll hear the fuel pump change pitch, that's when you know that the fuel bowl has been refilled. THEN crank the engine. This set up has worked the best for me. Here's the video of the Edelbrock:


Thank you so much for your time and explanation. I’ll try doing this next.
 

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Just Some Dude in Jersey
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15,349 Posts
I guess I would suggest the #17303 one:


At 30 gallons per hour it can pump WAY more fuel than your car will ever use. It's rated at 2-3.5psi. I'm currently using the higher pressure #17301 and haven't had any issues with it overpowering the fuel bowl valve, but I was using it on a single side draft on a 2.4 engine and I'm now using it as the main delivery pump on a 2-pump returnless FI fuel pump system I bought when I switched to FI. I'm building a new car that will get the side draft set up and I will probably buy the lower pressure #17303 for that car. Get the #17303 one.
 
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