Run and hide little cobra

[mr bruce]

http://www.youtube.com/watch?v=jY_Te...eature=related

[patrickt]

Originally Posted by mr bruce

http://www.youtube.com/watch?v=jY_Te...eature=related

But the truth of the matter is the Cheetah is a very unattractive car. Doesn't matter how she performs if you can't bear to look at her....

[jwd]

Originally Posted by patrickt

But the truth of the matter is the Cheetah is a very unattractive car. Doesn't matter how she performs if you can't bear to look at her....

I agree. But the same thing can be said about the Daytona coupe. They are both fugly and I wouldn't be seen in either.

Jim

[1985 CCX]

Sounds great however how did they fare in the day? Wasn't it more like "Here comes the Cobra", HIDE.....

[jwd]

Originally Posted by 1985 CCX

Sounds great however how did they fare in the day? Wasn't it more like "Here comes the Cobra", HIDE.....

They were 440 lbs. lighter and had 175 more HP than a Cobra. They had trouble meeting the 100 car minimum production to race with the Cobra so they were put in the same class as the Chaparral. They actually faired well against them winning 11 races but production was stopped after 2 years.

Still ugly though.

Jim

[mr bruce]

Weren't allowed to run against cobras, put in the same class as the rear engined Can-Am cars. Owned the track record at Road America at 185, stood for how many years. Run 215 at Daytona, cobras only ran 198. not too shabby a record for the few cars that were built. Imagine if they did the full 100 and tweeked them, this would be called ClubCheetah. Whatif?

[WildBill3]

[quote=jwd;963138]I agree. But the same thing can be said about the Daytona coupe. They are both fugly and I wouldn't be seen in either.

Jim[/QUOTE
To each his own,but you are FOS Jim
Beautiful and Fast

[patrickt]

There is not the slightest bit of similarity between a DC and a Cheetah.

[jwd]

Originally Posted by patrickt

There is not the slightest bit of similarity between a DC and a Cheetah.

I disagree. They are BOTH ugly as he!!.

[mr0077]

Very cool, Bruce. I think they look outstanding.

[jdean]

Yeah I kinda like the looks, it is the lack of comfort driving it I would worry about.

How about Mr. Bruce tell us the difference in driving between the two.

[John McMahon]

Love dat vid Bruce.

I've been seeing some of those Bill Thomas Continuation Cheetahs showing up on ebay. Some nice finished examples pulling down decent dollars.

I'd love to have one to flog.

This one sold for $55K....

http://cgi.ebay.com/ebaymotors/ws/eB...m=300318760335


This is sweet too, but the starting bid is way too high.....

http://cgi.ebay.com/ebaymotors/1965-...3A1%7C72%3A317

[mr bruce]

Them contunuation cars is nice , but I can't fit in one. The ones I build are made for larger people. I have had a few real live racecar drivers do hotlaps at BeaveRun and even my mouse motored car could whip a certain GT40 replica, according to one driver. Some freelance writer even did a track test and article write-up on my cars, but since the mag bizz is all but defunct he hasn't been able to sell the article to anyone. I have in car vid and the nitwhit that was editing it has it and won't give it up. As soon as he does I'll put up a link.

[John McMahon]

Originally Posted by mr bruce

Them contunuation cars is nice , but I can't fit in one. The ones I build are made for larger people. I have had a few real live racecar drivers do hotlaps at BeaveRun and even my mouse motored car could whip a certain GT40 replica, according to one driver. Some freelance writer even did a track test and article write-up on my cars, but since the mag bizz is all but defunct he hasn't been able to sell the article to anyone. I have in car vid and the nitwhit that was editing it has it and won't give it up. As soon as he does I'll put up a link.

cool, would be nice to see some action shots of that Turd. I'd love to see it run at BR. How many of dem have you guys built so far?

[mr bruce]

Yous guys is just me. The frame for number 5 is hangin' from the garage rafters. Number 4 ,the first big block car is close to being blown apart for paint, and then reassembly/fireup/track test. Number 4 will really make you pee yer pants.

[WildBill3]

Hmmm lets see the only American car to win a World championship hmmm wonder what it could be?And I like the Cheeta neat car but proofs in the puddin.Bring one to RunNGun and we can fight this out on track again

[mr bruce]

we was talkin' fastest, from back in the day, Cheetah's fastest. you got 1 with the cobra Wolrld Champ. Now today,r+g , kit cars, maybe next year.

[DMXF]

Bruce - The Cheetah was thought by it's developers to be more than a match for the Cobra when comparing to the small block cars: the small block Cobra power to weight ratio was 375hp/1950lb = .19 hp/lb. The high water mark of Cobra engine development, however, was the 427 high riser with 58mm downdraft webers. This engine, with all original 60's specification parts, will generate a solid 600hp. Competition big block Cobras with the lightweight engine were quoted in Shelby American documents to weigh as little as 2150 lb., resulting ratio of .279 hp/lb. I'm not sure about the Cheetah engine power, but I read that some of the cars came with 365 hp 327's and others ran a 377ci. I can't imagine the 377 would put out more than 450hp with cylinder head technology they had back then, but optimistically assuming output of 480hp for the best configuration yields a ratio of .27 hp/lb (I ran across a weight of 1780 lb on the internet). So the cars are quite comparable in that respect.

As far as top speed, the 215mph number sounds hokey and without solid evidence doesn't seem reasonable. Top speed is a function of HP, frontal area and coefficient of drag and 1) The Cobra made more power, 2) The frontal area of the Cheetah looks to be in the ballpark of a race-prepped Cobra, especially since the track width of the Cheetah is about the same as or slightly greater than the big block Cobra, and 3) The nose of the Cheetah looks to be about as bad as the Grand Sport Corvette, with the upward protrusion that scoops up air underneath and makes the car lift off the ground at speeds in excess of approx 150mph. There are also big open areas around the Cheetah wheelwells that grab air. I have fairly extensive empirically-based analysis that shows the big block Cobra in race trim requires 600hp to go 200mph, so how can a Cheetah with less power and similar if not worse aerodynamics go that much faster? Doesn't make sense. I recall hearing the '67 L88 Corvette reached a top speed at Daytona of about 185mph, so given the aerodynamics of that car are more in line with the Cheetah's, that sounds like more of a realistic ballpark.

You are rightfully proud of your car, the Cheetah must be one hell of a ride. You can imagine, however, that posting on a Cobra forum for Cobras to go run and hide would have it's repercussions!

[Cobra #3170]

I will undoubtably regret this but:

600 hp with Webers on a 427 in the 60's "the impossible dream"
Every dyno sheet I have ever seen and I have looked at quite a few show maximum power in the 550 range and that was a 427 Tunnel Port with 15 to 1 pistons with Daytona cam and dual 4 barrels on a single plane manifold. Certainly not a road race set up. The dyno sheets were from the Dearborn engine lab and thus accurate, as compared to other less reliable sources.

How did you get to 2150 for a Cobra with an all aluminum 390 vs a Cobra with a 427 iron block high riser probably more like 2250

Cheetah going 215 on a closed course, again how? Poor aero, not enough HP and poor exit speed because of handling issues.

I watched a Cheetah in a road race on the west coast (Santa Barbara Airport I think) a loooong time ago, it went like hell up the straight but was so bad in the corners that a 289 Cobra hammered it.

For the record I wanted to buy a Cheetah in the 60's because I was a died in the wool chevy guy, I could not get one, so went to the Cobra instead.

[DMXF]

Originally Posted by Cobra #3170

I will undoubtably regret this but:

600 hp with Webers on a 427 in the 60's "the impossible dream"
Every dyno sheet I have ever seen and I have looked at quite a few show maximum power in the 550 range and that was a 427 Tunnel Port with 15 to 1 pistons with Daytona cam and dual 4 barrels on a single plane manifold. Certainly not a road race set up. The dyno sheets were from the Dearborn engine lab and thus accurate, as compared to other less reliable sources.

How did you get to 2150 for a Cobra with an all aluminum 390 vs a Cobra with a 427 iron block high riser probably more like 2250.

Bruce, it seems whatever evidence anyone provides will not change your mind on things, but I’ll give this a shot. I may not have enough time to get into every detail, but the 600hp number is based on dyno testing, similar engine configurations and analysis. This also ignores the fact that the weber engine will make significantly more mid range torque than any of the Holley setups.

First, the following baseline dyno results from Ford's Engine and Foundry division show the 427 high riser 2x4 in top tune as having generated about 550hp. This work was done during the SOHC development period, as there are other graphs where the red curve was plotted against the various SOHC results for comparison.

Next, these results were duplicated/correlated with modern dyno testing done by the owner of CSX3191. His engine just had a bigger cam (around 270 deg duration) than was available back when the Ford testing was done, so he achieved 558 HP with the C4AE-F 2x4 intake and 569 HP with the taller C3AE-D 2x4 intake. The 58mm weber induction was then installed and tuned and he was ultimately able to achieve 600hp, which was documented in this article:

The cam in my engine is slightly less radical than the one in this testing, mine essentially falling in between the factory grinds SK38427 and SK42390, but with less overlap to minimize weber reversion. However, my engine has other period original power enhancing attributes, like the traditional longitudinal carb mount intake manifold with straighter, shorter more direct ports, shorter velocity stacks and slightly larger chokes, all for more top end tuning and peak HP, factory dry sump, better combustion chamber design of the factory aluminum HR race head, roller cam (used by SA on their top race engines) and original Shelby American works porting (relatively mild). As you may remember, a friend who works for one of the leading F1 teams also modeled my engine on their software, which predicted just over 600hp.

In addition, David Salkowski, who occasionally posts on this forum, has a modern Shelby aluminum engine at a higher state of tune with reproduction Berg 58mm webers and he has many dyno runs showing about 735 HP. David’s engine uses ported Edelbrock heads (ie, more cylinder head flow), a bigger cam and higher compression, but a similar layout intake to mine and the similarity makes sense that mine would probably be within about 100 HP of his. Also, I don't know if you ever met Jim O'Leary, but he was an engine builder at Shelby American in the 60's. He said that they were getting 635 HP out of the tunnel port engines with the IR injection that they were running in the Can Am cars. My heads flow within about 15 cfm of the tunnel ports and Ford's Indy car program in the 60's documented that when they replaced the 58mm webers with the fuel injection they had available at the time the HP didn't change, just fuel economy went up. At some point I may have mine dyno’d, but in the mean time all the evidence is quite overwhelming supporting the 600 HP.

The 2150 lb weight came from the comp car specifications sheet that Shelby American released in ’65. I’ve been a little skeptical of that number, but I’ve been able to come up with a weight more around 2250 lb for my car with the all aluminum works race engine by subtracting individual component weight deltas from the standard street car value (incl magnesium wheel savings, etc), so I figured a few more pounds could be found here or there (remove heater, etc, etc). Either way, it’s in the ballpark.