offenhauser dual port question...

[datzenmike]

I ended up using the same gasket ^^ and it works good. I dono what is in yalls coffee.. this thing shits n gits now! she pulls from a dead stop all the way to a buck! I also have been running around with an open exhaust manifold :w00t:

 

-mike

.

Put ear plugs in and try it. Bet it goes back to before the change. Noise does not mean power.

[thebucketslider]

I know iys not noise silly! Its the fact I can pull all the way to 100 on flat ground. I put up a good fight with my buddys toyota with a 38 and a five speed! Keep in mind im runnin napco slush box and a tired as fuck l20!

[Eriks]

Just bought a new Offenhauser from Summit Racing http://www.summitracing.com/parts/ofy-6138-dpw

 

Original gaskets look like this:

 

[K_trip]

- removed -

[KlassicMotion]

Did you guys re-jet the carb after swapping the manifold? 

 

 

I've also heard claims of efficiency and performance with this manifold.  It seems like a good design for a street motor, I'm wondering how well it would run with proper jetting.

 

 

For anyone reading this that hasn't seen the Weber instructions on tuning:

 

http://www.redlineweber.com/html/Tech/carburetor_set_up_and_lean_best_.htm

 

This made a big difference on my new-out-of-the-box carb.

 

Pay close attention to this part:

 

 

Simple Rules for low speed calibration

If the mixture screw is more than 2 1/2  turns out turns then the Idle jet is too lean (too Small). When the mixture screw is less than 1 1/2  then the Idle jet is too rich (too large). These assumptions are based on the fact that the speed screw setting is not opened more than 1 1/2 turns. If the speed screw has to be opened 2 or more turns then this is also an indication of a lean condition usually requiring greater change. At times it may appear to be showing signs of richness or flooding it is really a lean condition. See pictures and notes in the tech 2 article supplied in the kit instructions, view and please understand the need to keep throttle plate as near to closed as possible so as not to prematurely expose the transition holes. This is what causes the visible rich condition, and confirms the need to increase the jet size. JET KITS are available if needed.

EXAMPLE     With the speed screw set at no more than (1 1/2) turns in after contact with the stop lever; and the best idle occurring with the mixture screw set at  3 turns from bottom, indicates the need for a larger Idle jet. Achieving the best idle at under 2 turns indicates the need for a smaller idle jet.

The secret  to understanding the critical nature of the carburetor set up and the advantages of a WEBER over other carburetors is the Idle circuit. Referred to as the low speed circuit by Weber, this circuit is responsible for 80% of the driving operation. This is the reason that the Weber should give a fuel economy improvement over most factory carbs along with significant  performance gains. In the worst case you should not see a significant fuel economy loss over stock, while improving HP & Drivability.