Hi Jeff,

I'll give you a call tomorrow.

Hi all

During the past two days I was able to get some work done on my 289 and did add some nice parts on to it.
One of them was the WEBER LINKAGE John (CompClassics) did manufacture for me.

It looks awesome and is working perfect!:)
MANY Thanks to John!

http://www.clubcobra.com/forums/pict...ictureid=17774

http://www.clubcobra.com/forums/pict...ictureid=17775

http://www.clubcobra.com/forums/pict...ictureid=17776

If I may, on my 48s I found two very critical things that needed attention.

1. linkage - your linkage can look great, but function poorly. Make sure it will repeat and travel WITHOUT BINDING.

2. Position - make sure the throttle rests at the same point each pedal let-off and make sure it gives you FULL THROTTLE when the pedal is all the way down.

I offer these as checks to assist in your setup.

I hope this helps - I did not read all of the comments as it was clear there are several ways to do this.

Tru

Hi Bill thanks for your reply.
Not to worry on pt. 1. The linkage is not only looking great it is perfect for adjustment and from my point if view the best you can add to your 48 IDA's.

http://www.clubcobra.com/forums/pict...ictureid=17777

There are a couple of different ways to look at the opposed and parallel descriptions, one is the way the carburetor throttle plates move, parallel = the same direction, opposed = away from each other. The other way to identify with the descriptions is the way the fuel inlets are positioned for each bank of carburetors, opposed = the inlets are opposite of each side, parallel = the inlets are all facing the same side.

Trularin brings up a very good point, the throttle linkage is the key for a Weber carburetor system. If you have even one flaw in the system your Weber system will not function properly. All to often poor Weber performance or operation is blamed on the carburetors when in fact it is a poorly executed throttle linkage. You must pay attention to geometries and distances from one bank of carburetors to the other bank of carburetors. Having mismatched components, levers, rod ends, hex shafts, etc will leave you with an untunable system. Having rod ends that have to much slop in the pivot bearing will leave you with an untunable system. In short you have payed a premium for a carburetor system to improve the performance of your engine, don't cut corners by investing in cheap linkage components or a poorly designed linkage. Aircraft specification rod ends are a must for these applications.

Nice work John, looks great!

Jim

Thank you Jim!

Just an FYI,

We reproduce both linkage types using period correct aircraft rod ends and SAI carburetor lavers. We can also provide period correct hardware for the complete Weber installation with all variants of the carburetor to manifold nuts and washers.

Just curious.

Where does the center pivot linkage system fall into the discussion relative to adjustability and performance (repeatability, return, full throttle etc).

Cheers
Greg

my427cobra,

Are you referring to a small block linkage or a big block linkage?

Not to add to confusion, but I will add; once you are down to turning screws, do not put restrictive "air filters" over your pipes.

Some can change the mixture a lot.

I recommend covers when in storage, open when running.

Just my opinion.

Tru

Hi CompClassics. Since the thread is small block related I was wondering because I've seen center pivots on small blocks.

Not sure about big blocks.

Cheers
Greg

If an air filter is a concern for idle mixture trimming, then it surely is a restriction to high rpm.

I run a large filter around the whole lot, more than enough filter area.

my427cobra,

I have not used or even tinkered with the linkage type that sits above the center of the driver's side valve cover. So I can not answer your question regarding the qualities or short comings of that system. I can say that it looks like an additional step or two might be required when having to make a valve adjustment. I am sort of a originality geek when it comes to Cobras and installing anything on them.

Hi CompClassics. Here is a pic of the linkage set-up I was referring to. Perhaps I'm using the term "center pivot" incorrectly.
http://www.clubcobra.com/photopost/d...nter_pivot.JPG

Cheers
Greg

That's the type I like, easy to sync. :)

my427cobra,

That is like the currently available FE Weber linkage systems, I have used them but not on a small block application. It is a very simple linkage compared to a period opposed system.

I recognize that driveway and manifold. That's my Father's car. Here are pics I have taken for those in need. If interested, this center pivot setup is from Pierce Manifolds in Gilroy, CA. https://www.piercemanifolds.com (ask for Mike).

http://www.clubcobra.com/photopost/d...thumbs/346.jpg

http://www.clubcobra.com/photopost/d...humbs/1104.jpg

http://www.clubcobra.com/photopost/d...thumbs/250.jpg

So it looks like this linkage is using a cable between the throttle pedal and the linkage mounted on the intake manifold, although no where near original it would make the linkage easier to get from point “A” to point “C”.
I noticed that there is only one adjusting screw for the idle, you should have one on each bank of carburetors if for no other reason to use as a throttle stop when the engine is at idle. By not having that throttle stop the carburetors on that bank do not have a positive stop and therefore on returning to idle the linkage sort of floats (as will the idle on that bank) for lack of a better term whereas the side with the adjuster screw has a stop to rest on and cannot deviate lower than that stoped position. I know you are probably saying to yourself that I am nuts and that the “floating” can not happen but it does and it can affect the engines idle and can possibly create premature wear on the linkage rod ends on that bank.

Yes, that is correct.

Any V8 of quad weber config should have the linkage set up with a positive stop on each bank.
Any amount of sudden throttle closure can cause the bank to bank balance to go out.
It also places more stress on all the interconnecting joints.

Gary