Cobra weber intake

[shelbydoug]

Red lasagna better than white.

(pssst!...Bud Light!) 

[SFM5S000]

shelbydoug,

You're right when Cobras and GT40's "Raced" back in the day, they did run without filters. They "raced" with racing cam profiles. That same cam profile does not work well on the street then or now.

I think I can safely say, most people who run Weber's today do it for the esthetic  reasons because of their potential and lore of being the ultimate carburetion system of the day which it was.
There's something about the 8 velocity stacks and the symmetry of the carburetor bodies, fuel line and nuts that are visually attractive from a mechanical point of view, heck  Ferrari's had Weber's.

To me Weber's look best without screens or filters ( I actually drive with screens) standing still. And yes you are right again people that ran with a form of filter system got vapor fume soaked and had a propensity to catch fire when re-starting, and in doing so very easily turning the car into a Car-B-Que, you best have or carry a fire extinguisher.

Funny shelbydoug  I'm not really a fan of Lasagna, I'll eat it though but my preference is more for a meaty Bolognese style spaghetti sauce over a  Rotini pasta because with spaghetti noodles you end up wearing sauce on your shirt and I've never found it fashionable to tuck the dinner napkin into the collar of my shirt. White wine (Pinot Grigio) with Lasagna? Seriously? Don't get me going on wine, remember I'm from NorCal (Napa, Sonoma, Alexandria, Tri Valley, Coastal, Paso Robles etc. ) NorCal does red wine, and white too.

Back to Weber Manifolds

~E

[SFM5S000]

I suppose to further the questioning Richard (OP) might ask:   I notice there are two types of intake manifolds for the sbf, for Webers.  One
has two water exits and the other looks like normal one (with thermostat housing).    Any advantage / disadvantage to either?

Greg,

You're opening a can of worms by asking that. Not only are there different (Modern version) thermostat/ (original configuration) no thermostat with "Y" water neck. There is also orientation of carburetors butterflies and which way they swing open noted by the way the fuel line passes to the outside vs fuel line up the middle.  As well as the "Cobra" castings from OECO (Offenhauser Engineering Co) and the FoMoCo E&F (Engineering and Foundry) both very different in appearance and spacing. Then the reproduction pieces from Blue Thunder and whomever else over the years.
I'll let others elaborate on the variations of manifolds.
I own examples of both OECO and E&F.

Cheers,
~Earl J

[shelbydoug]

Jim Cowles ran for 30 some odd years on the street with CSX2138(?). Ask him what he thinks.

Lots of comp cars ran with just the stock 289hp camshaft.

I would say that if you are going to take the "cam" out of it, you might as well cut down the size of the chokes to 30 to 32mm? Those would be a street setting.

You see, it's not just the cam that is involved in this. It is the entire induction system. That includes the flow of the heads, the flow of the exhaust manifolds, the flow of the carbs.

Heck, you might even be able to put a cam and mufflers on this thing so you can cruise around town and play a nice stereo with lots of violins and children's choirs and be able to have a conversation with your passenger without yelling? It could be a very relaxing experience I suppose?

Yes, Pinot Grigio. Comon'. Walk on the wild side. If you wanna' talk the talk, you gotta' walk the walk, otherwise just make a coffee table out of them. They are industrial art. You can sit around with your friends drinking a Merlot, put the a/c on high and get plastered playing with the throttle. 

[acman63]

between 2122 and 2138  it was about 25 years.   I ran no screens and 42 chokes.  dyno shows when you run screens it loses about 40 HP  if I recall.   On a small block thats a ton.   I didnt want any of the chebby big blocks to get the best of me

[shelbydoug]

between 2122 and 2138  it was about 25 years.   I ran no screens and 42 chokes.  dyno shows when you run screens it loses about 40 HP  if I recall.   On a small block thats a ton.   I didnt want any of the chebby big blocks to get the best of me

What cam Jim?

[mygt350]

What factors enter into the equation to determine proper choke on a 48IDA?

[shelbydoug]

Closing down the chokes would have the same effect as putting a smaller Holley on an engine.

For instance if you took the 715 off of your '65 and put a 1848 on it. You would get an immediate torque response to it at the expense of loosing upper rpm.

The Cobras ran 42mm "chokes" as Weber refers to them and in these carbs they are changeable.

A new IDA now, and for a long time now would come with a 37mm choke.

So what you really are seeing is the large "tuning" capability. That includes the engine displacement as part of the tuning.

Most are not that used to this kind of flexibility.

Probably a street small block is better off with a 37mm choke.

It isn't just the size of the choke that matters, the bore of the carb, i.e., in this case 48mm is significant also.

A 351 really needs a 51mm and a 427 a 58mm.

[CSX2259]

There are at least three different Weber manifolds and multiple variants of each for the 289 Ford application....

1) Early Cobra opposed

2) Later Cobra parallel

3) Ford produced parallel, GT40 application

None of which have a built in thermostat housing.

[deathsled]

There are at least three different Weber manifolds and multiple variants of each for the 289 Ford application....

1) Early Cobra opposed

2) Later Cobra parallel

3) Ford produced parallel, GT40 application

None of which have a built in thermostat housing.

That Cobra in your avatar is pretty damned hot!

[CSX2259]

deathsled,

Thank you, it has Weber's too!

[acman63]

between 2122 and 2138  it was about 25 years.   I ran no screens and 42 chokes.  dyno shows when you run screens it loses about 40 HP  if I recall.   On a small block thats a ton.   I didnt want any of the chebby big blocks to get the best of me

What cam Jim?

No idea.  I never cracked the engine open.  Im guessing it was similar to Lemans grind. same cam that Murray ran at road atlanta/  could rev this as high as the gasoline would let me. nothing like webers for instant response

[CSX2259]

Jim,

Did 2138 have 48 IDMs on it?

[zray]

if you don't have a good deal of experience with carburetors in general , I'l suggest ponying up the extra $$ and have Jim Inglese provide and set up the Webers for you.  His set-up's are  always right in the ballbark, if not spot on for any given application.  more than likely you will not have to do much in the way of tuning besides a very basic synchronization when you first put them on. After that, just enjoy them

Z.

https://www.jiminglese.com/

[shelbydoug]

if you don't have a good deal of experience with carburetors in general , I'l suggest ponying up the extra $$ and have Jim Inglese provide and set up the Webers for you.  His set-up sare always right in the ballbark, if not stop on for an y given application.  more than likely you will not have to do much in the way of tuning besides a very basic synchronization when you first put them on. After that, just enjoy them

Z.

https://www.jiminglese.com/

Excellent advice. +1.