Cobra weber intake

[kjspeed]

++1

[zray]

addendum:

I experimented with cams a little with my Weber set up.  I had a special cam made up  with a little more lobe separation angle than the stock HiPo cam has. It was different in the lift also. 

I came away thinking I should've stuck with the stock HiPo cam.  The 289 HiPo doesn't have an abundance of low rpm torque anyway. When you start putting custom cams in it, the usual result is the high rpm power is increased , YEA !!!  But the flip side is the low rpm torque and horsepower is diminished.  BOO !!!

That won't matter if you are going to be on the track all the time, but it's a real buzzkill for street driving. There no free lunch when it comes to cam design, what bonus you get on the top end, you will have an equal negative effect on the low end.  Unless you modify the motor to have variable cam timing. And I haven't seen a huge aftermarket need for that yet.

Think hard and long before  putting in a whiz-bang cam  that gives you a lot of top end. You will hate it when driving in the real world.

Z

[deathsled]

Thanks for your input zray.  I shall consider it.

Richard E.

[JD]

I have 48 IDA's (fourth casting release version) on COBRA Intake (fuel line on the outsides) setup with linkage etc., that was bought new from Inglese in the '80's.  I did get some info from Dan Case (Thanks Dan) on these and they could be available.

[shelbydoug]

Very seductive and difficult to resist. 

[mygt350]

Do Webers "like" higher or lower compression engines? Part 2 of the question is what constitutes hign and low compression as it relates to Webers?

[Greg]

The only thing that bothers me with running Webers is the lack of a filter.  Sucking crap in the engine is troublesome and risky IMO. 

[mygt350]

For cars requiring vacuum for things like brakes, will plumbing the cobra weber intake provide enough vacuum for the brakes?

[terlingua11]

If anyone has an early "opposed" original intake I am in need of one and will pay up for it if you are willing to part with it knowing it will end up on 2122.
Thanks-
Jeff

[shelbydoug]

Do Webers "like" higher or lower compression engines? Part 2 of the question is what constitutes hign and low compression as it relates to Webers?

The higher the compression, the "crisper" they run.  Don't go under about 9.5:1 with them.

Running with any open carbs is a risk. Some sort of a screen on the street is really minimal but if you have the room you can do more with the screens. The greater the surface area the less of a flow drop you will have BUT it isn't a direct proportion. Consult with a Professional Engineer for flow characteristics calculations.

There are those who think they can run power brakes off of the vacuum of one cylinder. I disagree.
There are many vacuum reservoir/manifold designs around but I find that it's the nature of an independent runner manifold more then the carbs not to be able to supply the volume of vacuum necessary and after years of trying to discover a solution I finally gave up and went to a Compcams vacuum pump.

It's a little annoying because it's a mini-compressor and sounds like it but with the noise of the headers, solid lifter cam, etc., the sound just gets lost in there anyway.

For those reading this that are going to disagree with the comment about "lack of volume of vacuum" because they are running electronic fuel injection and they do get enough vacuum, carbs and fi set ups are not equal in this respect.

[JD]

The only thing that bothers me with running Webers is the lack of a filter.  Sucking crap in the engine is troublesome and risky IMO. 

Not sure what the performance help/hurt is on these but K&N does make a filter unit for these, others will know better.  It doesn't have filter material above where reversion flame and fuel can burn/soak it has metal.  Does take-away some of the wow factor.

[zray]

Do Webers "like" higher or lower compression engines? Part 2 of the question is what constitutes hign and low compression as it relates to Webers?

The K code engine I had the. Webers on had a measured CR of 10.0:1.  Detuning a car by lowering  the CR would be shooting yourself the foot. The Webers do more than just provide eye candy. Properly set up you will see improvements in torque and horsepower. Lowering the CR will only serve to minimize or negate those gains?

The following chart may interest you, it was copied from the 1965 Ford High Performance Catalog (for ordering thru Ford dealers)
Quote from the catalog:

"Horsepower Figures were obtained from actual dynometer test programs by Shelby-American Inc."

Stock 289 w/ one 4V 232 @ 5,500 rpm (A code I'm supposing)
289 Performance 4v kit 286 @ 6,500 rpm (I think the carb is a Holley 715 w/ the Cobra Hi Rise manifold.
289 w/ two 4V carbs kit. 276 @ 6,000 rpm
289 w/ three 2V carbs kit 314 @. 6,500 rpm
289 w/ four 2V carbs (Weber 48 IDA carbs) kit 345 @ 6,500 rpm

The only thing that bothers me with running Webers is the lack of a filter.  Sucking crap in the engine is troublesome and risky IMO.

I ran my 48 IDA set for 2 1/2 years, and over 20,000 miles. Most of time I used some screens that Jim Inglese sells.  They are not just  the just plain mesh, they filter down to 10 microns or some ridiculously small number.  I tried running without them on occasion and really couldn't tell a difference in performance. I was using two AEM a/f meters, and their readings didn't change whether the screens were in or not. So I'd question Jim and try those same filters.  I had occasion to drop the oil pan to fix a leak, and also changed a head gasket..  After 20,000+ miles, no measurable wear. I took that car a few long-ish trips of 1,000 miles round trip. It performed great on the highway with the Webers. The torque improvement made passing slower cars a real treat.

For cars requiring vacuum for things like brakes, will plumbing the cobra weber intake provide enough vacuum for the brakes?

You can either get an electric vacuum, or  use a Weber manifold that has a sealed off plenum, in which all 8 cylinders are connected to via a small drilled hole in the runner.  I used that type of manifold so I could run a PCV valve.   I wasn't too keen on all the cylinders having a connective plenum, as it seemed that was negating the benefits of a IR manifold. So I did experiment with plugging up the connecting holes and shutting off the plenum, and just having an open breather w/o a PCV valve. I couldn't really feel  any performance difference, and the a/f meters displays were unchanged one way or the other,  I so unplugged the holes and went  back to using the plenum acting as a vacuum source for the PCV system. 

I don't think you can  get a plenum manifold in  the dual waterneck style, not sure about that.


Z

PS. BTW, I had a permanently installed vacuum gauge, and   had 10" vacuum with my Webers.

[2112]

If those filter tops and bottoms were cast like Valve covers they would look right in place.

Miniature oval air cleaners but with no script. Shot peened billet pieces may look close, then any machine shop could make them.

[zray]

With a stock 65 or 66 hood I think you would need to use shorter (not optimal) stacks to use any air filter.

I barely had enough room above  the rear stacks, and eventually went to a set of Ron Morris 1/2" lowering engine mounts.


Z

[mygt350]

Have seen a Weber manifold with stainless hard lines connected to a fitting drilled in each runner just below each stack. All eight lines ran to a block with a single vacuum port. Would that be adequate for power brakes? Where would PCV be plumbed to?