Correct Manifold for Comp Cars with Hi Rise Heads?

[Cobra #3170]

Originally Posted by Byots

Tunnel Port heads and inductions only came into use near the end of Cobra production and had nothing to do with the Cobra. Bruce, I don't dispute that your monster cubic inch modern fuel injected engine would outdo my old technology, my interest is just more into the nostalgia, as the big weber inductions were a part of the development and history of the big block car and were optional race pieces for them. Webers were integral to the heart and soul of Ken Miles and Shelby American and that philosophy was being carried over from the small block to the big block cars, just ultimately not fully exploited, as with many other aspects of the 427 car. The big block Supercoupe is probably the best example of the pinnacle of Cobra withdevelopment that didn't get its fair opportunity in "combat", but that does not take away from its special place in the history of these cars.

Here is how the first big block car prototype engine came into SA from Ford by June of '64, equipped with an 850 Holley: http://www.clubcobra.com/photopost/s...=47517&cat=500 This was the aluminum 390 with aluminum high riser heads that were cast special just for Shelby.

Shelby American still had substantial control over its racing development activities at that point and, like the small block race engines, did some of their own development on the big block. It is believed the two styles of high riser weber intakes were specially made for the Cobra during this development period (the inline carb one to maximize hood clearance under the crown of the Cobra hood). Guys like ex Ford employee Ernie McCune (sp?) involved with racing activities said a batch of the 58mm webers were specially made for Shelby American in early '64 to use on the Cobra, which they installed on this prototype engine in place of the Holley: http://www.clubcobra.com/photopost/s...=47518&cat=500

This configuration notably outperformed the Holley, making reportedly over 500hp from only 390 cubic inches and tiny 390 sized valves. SA decided this was the optimal setup to run and went on to install this engine into the big block configured coupe (http://www.clubcobra.com/photopost/s...=47492&cat=500) for an assault on Lemans in '64 - it was to be Shelby's "secret weapon". The car was damaged in a transporter accident on the way to Lemans and returned to the shop, but SA employees were in awe of its potential. This engine, with webers, was later run in the flip top car.

Documentation from Ray Geddes to SA around August of '64 specified several big block race cars that were to receive these engines for the '65 season. Another Geddes memo dated about October of '64 (I haven't looked at these in some time) specified cast iron 427 blocks to be used in the race cars instead of aluminum, although Shelby would have probably still used the two aluminum ones he already had, as evidenced by the subsequent use of one in the flip top car in December at Nassau. Even after Ford changed the block specification from aluminum to cast iron, the 58mm webers were still planned on being used, as they were included in the FIA homologation paperwork at the end of '64/early '65. Early documentation just specified aluminum for the cylinder head material, leaving the option open of using MR or HR castings (the 58mm intake manifolds were only made for the HR head), whereas later in '65 just the MR P/N was specifically called out.

By the end of '64, Ford had taken much more control of SA's activities and all emphasis and key employees were diverted to the GT40 effort. With all the emphasis taken off the Cobra, the big block Supercoupe was starting to experience delays and problems. The writing was on the wall and finally when Shelby American was refused homologation around March or April of '65, the big block Cobra became a still born race car and many of the trick things the key SA race team members developed, like the big webers and big block coupes never had their chance at ultimate glory.

From the point Ford started having major influence over SA's operations in '65, SA employees became notably limited in what they could do with many of the engines. Race engines came in pre-assembled from Ford Engine and Foundry and SA employees in large part were not allowed to take them apart, including changing inductions. Bean counters and other Ford influence made the big block Cobras go out the door with more cost oversight than how SA had previously approached the small block cars (just look at the SA invoices....big block cars almost always had no options vs small block cars were often loaded with different equipment), also driven by Shelby's attention shifted to the GT effort. CSX3005 (a comp car) was a good example of this changing philosophy - it was being "optimized" by the factory, but when it came time to deciding who was paying, the car ended up being disassembled and the parts sold off or used in various ways. Earlier on, SA would likely have footed the bill just to get the visibility and promote Cobra racing success - now they figured they achieved what they wanted with the car.

The coil spring Cobras, including the comp cars, ended up being delivered in more basic form, with SA not as receptive to do as many add ons at the factory as they did with leaf spring cars. This was dictated from Ford's Ray Geddes mandate that the 427 just be a "customer car". Many things needed to optimize the cars for racing were left up to the owner to incorporate, with Shelby American offering most of the necessary items (including the webers) over the counter - although in many instances such specialty items were in short supply and SA would only freely "open up" availability to prominent racers. The 427 Cobra was being sold under a different mandate than modern supercars such as the Z06, etc. On the street, the Cobra in it's day was so fast relative to everything else, that SA employees had commented in discussions about parts outfitting that all the bells and whistles were not necessary and if someone wanted such trick parts they were available separately.

So, I hope this provides a fair picture of how special hardware like the webers fit in with the big block cars.

More weber comparative and sizing data to follow when time permits.

Note:
I was referring to my naturally aspirated 1967 dual 4-barrel tunnel port cast iron 425 CID engine vs. your Weber carb titanium rod "period engine" although they didn't have titanium rods for big blocks in 1967. I would be glad to compare dyno sheets. You would be at least 200 horsepower shy of my "monster cubic inch modern fuel injected engine" with those Webers and that comparison was certainly was not my intent.

My point is that because they offered something in a speed catalog, it doesn't make it period correct unless the car came with it, and none did. Any that actually had Webers had them added after delivery. If someone had a car that had a 1960's race history with them I suppose it would be fall in the realm of the Shelby Paxton cars but just putting them on a 3000 or 3100 series car after the fact is not period correct. You could only race them in an unlimited class and I suspect those instances were very few, and related to specific cars modified by their owners. 289s could race in production class with Webers, 427's could not. What racing customer would want to go out and get beat by a bunch of lighter mid-engine cars Webers or not. Essex wire is one exception based on your history lesson. There might be others, and again if they had a history of racing with them in the 60's it would make them sort of period correct. There were several cars that were chopped up to install 427 SOHC engines in 1967, does it make them period correct because some one did it?
I am waiting for that Weber powered dyno sheet. My car with the tunnel port engine and road race tires was timed at 11.20 @ 128 miles an hour at Detroit Dragway.
You could also provide a time slip for your Weber engine magic cam car if you don't want to dyno it.
I suppose you will be telling everyone how well 427 Cobra's handled
next if only the cars were equipped with all the options that were thought about and never released.

[Michael4yah]

[IMG]10262shelbyintakeadd-me[/IMG]The Cobra was a work in Progress, Not many were delivered exactly the same way. Ive talked to original owners and comapred notes. If Shelby sold the manifolds to the general public you can bet they were installing some of them on new ordered cars. Stop the nitpicking and pi$$ing contest. If Carroll Shelby himself cant tell you what every car came with who can?

[Cobra #3170]

OK got the message, since I actually had one of the very first orders for a 427 and lived through many of the problems associated with purchasing and owning these cars I thought that you might be interested in first hand experience, with engines and chassis, apparently not.

[Byots]

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[Michael4yah]

3170, your not the only one to have owned an original. Ive have a friend who owned his orginal till just a few years ago. His was 3282. A street cobra. It showed up with a 428 instead of the 427 and no top! Putting all that aside Id like to remind you that people come here to relax and lose their troubles talking about the cars they love. Lets leave all the angst at the door. We all experience enough of that in our day to day lives.

By the way here is what YOU posted on the orange 3050 thread when talking about his car.

"""" dual 4-barrels
They all did unless ordered differently""""

Cobra # 3170, THIS IS EXACTLY WHAT WE ARE TALKING ABOUT. People did put in special orders and they were period correct. To say they werent bastardizes all those owners who went the xtra mile with their new original Cobra.
Michael

[computerworks]

OK...enough of the tit-for-tat.

This is a good thread with quality facts bring posted...let's keep the dialog running without side trips.

Thanks
ron
ClubCobra Moderator

[Anthony]

I was looking through Sports Car Graphic, 11/65, and it lists the comp engine as having aluminum Hi-Riser heads / intake, and a 780 cfm carb, not an 850 like was stated before. The comp car in the article appears to have a carb with mechanical secondaries, as there is no vacuum dashpot for the secondaries.

If I remember correctly, I had thought that I heard that Holley designed the 850 carb, with bigger throttle bores, for the '67 L88 vette. Like you said, maybe the 850 carb was out in 1964/65.




Anyways, here's the graph from weber I was eluding to earlier..

427 has about 875 cc per cylinder.

[Byots]

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[Byots]

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[Anthony]

Originally Posted by Byots

There is a red/white Fomoco dealer document from '64 that has the parts breakdown for the high riser engine - that's where they list the 780 std and 850 for 7000 rpm kit. Many of the Cobra racers from the 60's & 70's do recall running 850's, although some were added after delivery.

If you run across the Holley List # on the 850 carb, I'd be very interested to know the specific carb. Thanks.

[Byots]

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[Michael4yah]

Z_427_LEMANS_CARB_C5AF-9510-BV_NEW

Byots, can you tell which carb this is?
Michael

[Michael4yah]

[img]z_427_lemans_carb_c5af-9510-bv_new[/img]

[Byots]

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[Michael4yah]

This is the carb. It's on Carls Fords Parts website.

[Byots]

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[Anthony]

Originally Posted by Michael4yah

427_LEMANS_CARB_C5AF-9510-BV

Byots, can you tell which carb this is?
Michael

Holley lists that carb as for a 65-67 427 Hi-Riser race engine, # 3255-1.

C5AF-9510-BE is listed by Holley as for a 65 427 Hi-Perf engine , # 3255

Originally Posted by Michael4yah

This is the carb. It's on Carls Fords Parts website.

Here is the carb stamping on the carb on my engine.

[Anthony]

Originally Posted by Byots

Here is a picture of a high riser equipped engine in CSX3002 at Silverstone in late '64: http://www.clubcobra.com/photopost/s...0&ppuser=18204 The carb was an 850, as evident from the different shape of the airhorn relative to the 780. Period Ford documents list the 850 for the "7000 rpm" high riser.
.

Well, obviously the air horn has been modified, as well as the choke plate removed. I believe a 850 holley carb has bigger throttle bores and plates compared to a 780, and I am wondering if the carb pictured is a "true" 850, with larger throttle bores/plates, or simply a modified 780 for greater airflow, being labeled as a 850, which would then not be a true 850, and probably not flow like a true 850.


I'll do alittle investigating.

[Byots]

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[Anthony]

Originally Posted by Byots

The choke plate was removed, as was on all comp car carbs, but that is not how the choke towers were milled when the carbs were modified. Here is an original period 850 comp car carburetor airhorn:







You can see how the original plating is still on the top edge of the airhorn, so it was not machined after original manufacture.

Nice close up shot. Obviously the carb was modified from a vacuum secondary to a mechanical secondary.

You wouldn't have a close up shot of the front of the carb? Showing the list #, date of manufacture ?