RE: 325ci Cobra small block

[shelbydoug]

As I recall, at some point, Shelby had Gurney driving "the rabbit". It was thought to have been a 325ci.

It was used to over stress the competition by being unrealistically fast and was not expected to finish the race.

Although I have seen those pictures of the offset connecting rod caps, I believe that it was small block Chevy connecting rods that were being used at least at some point in the developement.

The Boss 302 heads were intended to solve the issue of intake restrictions on the 289 heads.

The intake flow numbers as stated are really the hp restrictions with the 289 head flowing stock around 180cfm, race ported about 220.

The GT40 heads something like 240cfm and the stock B302 around 250cfm.


Current aftermarket heads for the inline valves are showing around 300cfm on the intakes and complimentary exhaust numbers.

A couple of years ago, a member here, built a 325 with AFR heads, a .528" solid lifter cam, a single Cobra intake, tri-y headers and a 715 carb and it dynoed right at 425hp.

Several involved in that build thought there was more power to be had there with better cam selection and maybe a better exhaust design that would bring it closer to 500hp?

So the thought of more power by larger displacements on the SB Ford has been kicking around for decades and you can make significantly more with modern tech.

Using old tech will result in old numbers since there is no hidden magic in the old castings.

[pbf777]

Interesting that no real bore and stroke numbers come up... my guess at the different crank journal size is a welded stroker effort, which likely reduced the rod journal diameter.

    I'm guessing that this engine subject must have fallen under the "need to know" basis, as the available information seems limited; but with consideration, I'm betting on the 3.25" stroke crankshaft with a standard 4" bore.   
 
    Now, the crankshaft makeup otherwise would be interesting!  Again I'm guessing, but I doubt the 325's crankshaft was of a 289 cast piece with weld build-up to allow for the offset stroke grinding.  It is probable that the otherwise intended to be 289 "raw" casting core could be turned out to the 325's dimensions or that the the casting boxes could be readily modified to permit such; but I'm more inclined to think that instead, they borrowed raw steel forgings from the "Indy 255" project and had those finish machined to the requirements? 

    Again guessing, but I'd bet the connecting rods, at least the raw forgings, also came from the Indy 255 program? 

    But the documentation just doesn't seem to be available, nor does it seem the participants have ever voiced much in the way of factual information on this topic?  All of which is interesting in itself!   

    Scott.

    P.S.  I would highly doubt that "Chevy" rods were ever actually utilized, the engineers probably had "looked" at such, just as they often studied the product of the competition in establishing what they were doing, not only in engine development, but everything else also; but I'd be concerned for my job at Ford Motor Co., if it were ever established that as an engineer I had just substituted in a set of Chevy rods and Henry Ford II ever found out!   

[JohnSlack]

Interesting that no real bore and stroke numbers come up... my guess at the different crank journal size is a welded stroker effort, which likely reduced the rod journal diameter.

    I'm guessing that this engine subject must have fallen under the "need to know" basis, as the available information seems limited; but with consideration, I'm betting on the 3.25" stroke crankshaft with a standard 4" bore.   
 
    Now, the crankshaft makeup otherwise would be interesting!  Again I'm guessing, but I doubt the 325's crankshaft was of a 289 cast piece with weld build-up to allow for the offset stroke grinding.  It is probable that the otherwise intended to be 289 "raw" casting core could be turned out to the 325's dimensions or that the the casting boxes could be readily modified to permit such; but I'm more inclined to think that instead, they borrowed raw steel forgings from the "Indy 255" project and had those finish machined to the requirements? 

    Again guessing, but I'd bet the connecting rods, at least the raw forgings, also came from the Indy 255 program? 

    But the documentation just doesn't seem to be available, nor does it seem the participants have ever voiced much in the way of factual information on this topic?  All of which is interesting in itself!   

    Scott.

    P.S.  I would highly doubt that "Chevy" rods were ever actually utilized, the engineers probably had "looked" at such, just as they often studied the product of the competition in establishing what they were doing, not only in engine development, but everything else also; but I'd be concerned for my job at Ford Motor Co., if it were ever established that as an engineer I had just substituted in a set of Chevy rods and Henry Ford II ever found out!   

Scott,

As I said regarding the actual 325 parts that Wayne Richards actually had at his shop the crank, rods were 255 Indy parts. The crank had no evidence of welding, we assumed that it had started out as a raw forging and was ground for the purpose of being used in that specific build. The block was an XE block with deck oiling similar to the tunnelport 302, however was not a "Dry Deck" block. The main bearings were not a standard size.Wayne bought the parts at the Shelby LAX sale.


John

[gt350shelb]

Yea  this has raised my interest in  how they did this . I understand why they did it to even the 327 chevy playing field  . would really like to see the actual parts used .   

[pbf777]

    Yep, seems Ford was more "reactive" than "proactive" in this arena of engine packages, this example where they figured out that the Chevy guys had a 327 as of '62, and then when GM crammed their "big-block" in the Corvette in '65 (396/427), so then Henry decided the Cobra would have the "427" too! 

    Surprisingly, the exception was when Mercury in '58, and when at the time was Fords' performance arm, just blew everybody else out of the water with the introduction of the MEL 430 cu. in. "Bulldozer" engine w/ single 4-barrel was at 350/360 H.P., 490 ft. lbs. of torque and w/ the "Super Marauder" "Tri-Power" set-up was at "400 H.P. and claimed to be 500-510 ft. lbs! 

    In comparison:
      Cadillac was only at 365 cu. in. and w/ three 2-barrels was at 335 H.P.,
      Chevy's new big-block "Porcupine" engine was at 348 cu.in. and with 3-duces @ 315 H.P.,
      Olds was 371 cu.in. w/ the "J-2 Rocket" option was at 312 H.P.,
      Pontiac was at 370 cu. in. w/ the tri-power was at 300 H.P. and w/ F.I. was 310-330 H.P.,
      Chrysler who receives all of the accolades for performance in the period with the 392 cu. in. w/ dual 4-barrels was at 380 H.P, and w/ F.I. 390 H.P.; but the greatest torque was about 450 ft. lbs. w/ a single 4-barrel, but then dropped to 435 ft. lbs. with dual 4-barrels etc..

      But after '58 Ford abandoned the performance efforts for the MEL and Mercury for the most part, so few know or have even heard of the "M.E.L."!   

      Scott.

      P.S. O.K. I got sidetracked!    

[roddster]

"Back in the day".  Long time reader of Hot Rod Magazine.  You could buy a Chevy stroker right out of the magazine.  But Ford stuff?  Always some kind of NASA shop "could" make it for you at a price.

[slither]

Interesting that no real bore and stroke numbers come up... my guess at the different crank journal size is a welded stroker effort, which likely reduced the rod journal diameter.

    I'm guessing that this engine subject must have fallen under the "need to know" basis, as the available information seems limited; but with consideration, I'm betting on the 3.25" stroke crankshaft with a standard 4" bore. 
 
    Now, the crankshaft makeup otherwise would be interesting!  Again I'm guessing, but I doubt the 325's crankshaft was of a 289 cast piece with weld build-up to allow for the offset stroke grinding.  It is probable that the otherwise intended to be 289 "raw" casting core could be turned out to the 325's dimensions or that the the casting boxes could be readily modified to permit such; but I'm more inclined to think that instead, they borrowed raw steel forgings from the "Indy 255" project and had those finish machined to the requirements? 

    Again guessing, but I'd bet the connecting rods, at least the raw forgings, also came from the Indy 255 program? 

    But the documentation just doesn't seem to be available, nor does it seem the participants have ever voiced much in the way of factual information on this topic?  All of which is interesting in itself! 

    Scott. 

Seems odd that the info has never really seen the light of day...

[TA Coupe]

There was an article published. I believe in late 70s to early 80s. I also remember seeing the rod with the angled cap on it.But couldn't swear that that was for a ford or what Engine it was for. If memory serves me, which is questionable, I think the article said that Ford put three of the engines into cars for testing. I remember after reading it that I wondered if a guy at work had one of those engines in a car he had because it ran a lot stronger than it should have and it was totally stock,As far as he or anybody else knew. My Mustang had a built engine, and we would run basically head to head. So that made me wonder if he might have one of those cars that got out of ford. There's a good chance that I still have the magazine or engine annual that had a write up on that engine.But with close 5 thousand magazines, it's really going to be hard to ever locate it. Here's a picture of about 4000 magazines. And a few dozen catalogs and other odds and ends of ephemera, for those that probably don't believe i've got that many. There are hundreds more in each of the man caves,one in the house And one in the garage. I will keep my eye open for the article, As there are some things, I need to look up and some of the magazines.
Part of the possible engine problems
Could have been the angled caps because bolts are not made for side strength.They are made to be stretched and have strength in that plane.So they might have given away due to the angle of the rod bolts.

      Roy

[gt350shelb]

offset grinding a 289 stock crank to a 3.230 stroke makes the big end of the rod really  small.   this would not ad reliabilty in a race engine . but would reduce friction and  increase hp  (for a short time) I do not see any 255 indy parts that would  interchange with this project . 


Requires a rod with a
1.77 bore

[JohnSlack]

offset grinding a 289 stock crank to a 3.230 stroke makes the big end of the rod really  small.   this would not ad reliabilty in a race engine . but would reduce friction and  increase hp  (for a short time) I do not see any 255 indy parts that would  interchange with this project . 


Requires a rod with a
1.77 bore

There are many things that are said on the Internet that because they are not actually said in a conversational environment don't come off with the respect intended, so please understand that what I am saying is from the highest mutual respect.

In the parts that Wayne had from Shelby the crankshaft was an XE forging, (I'm aware of the difference between a forging and a casting) the rods were Indy 255 rods and the block was an XE block. Other than that I can not tell you anything else. I know that from what I have seen and touched in my FoMoCo adventures over the years not everything is cataloged.

[98SVT - was 06GT]

As I recall, at some point, Shelby had Gurney driving "the rabbit". It was thought to have been a 325ci.

The Lotus 19B and/or 19J. Gurney had been running the Arcerio Brothers Lotus 19 with an aluminum Buick (Traco?). John Klug of Pacesetter homes sponsored the one off 19B  designed by Len Terry for Lotus with a 289. All the Lotus 19s had reliability problems - mainly gearbox. The famous Gurney win by stopping his failed car just short of the finish line until time ran out was the Arciero car not the 19B. Gurney's All American Racers partnered with CS for 2 1965 races in the much modified 19B listed as a 19J running Shelby colors - and undoubtably a SA supplied engine. It had 2 DNFs both engine failure. The car was later found by Wayne Lyndon under a pile of used tires at Caldwell Tire company in Pasadena. He was a fireman and owned part of a model train store. He opened a store in Sacramento and that's when Gordon Gimbal bought the car from him for his wife Nancy to race. It was well known here in CA having been restored to it's Pacesetter paint scheme. The Arciero 19 continued racing  with a different driver and Chevy. These little V8 Sport Racers are considered to be the genesis of the CanAm cars.

[gt350shelb]

[q
[/quote]

There are many things that are said on the Internet that because they are not actually said in a conversational environment don't come off with the respect intended, so please understand that what I am saying is from the highest mutual respect.

In the parts that Wayne had from Shelby the crankshaft was an XE forging, (I'm aware of the difference between a forging and a casting) the rods were Indy 255 rods and the block was an XE block. Other than that I can not tell you anything else. I know that from what I have seen and touched in my FoMoCo adventures over the years not everything is cataloged.
[/quote]

totally agree  with XE parts anything is possible  back then

[98SVT - was 06GT]

I must agree often Ford is late to the party. But the 427 FE R code (dual quad) was in 1963 Galaxies. The Flip Top Cobra was built in 1964 as a big block test bed. Arnig was already developing the coil spring chassis. GMs 396 came out in 1965 and wasn't a 427 until 1966. Then Ford did copy it's porcupine valve layout for the Cleveland.

[pbf777]

. . . . . offset grinding a 289 stock crank to a 3.230 stroke makes the big end of the rod really  small.  this would not ad reliabilty in a race engine . . . . .

    I believe you looking at this from the perspective of us, as the end-user in the performance aftermarket, this being post O.E.M. production.  But a an O.E.M., they had access to the "raw" castings/forgings which could accommodate reasonable stroke adjustments without the "need" to be of a smaller journal diameter. 

   

There was an article published. I believe in late 70s to early 80s. I also remember seeing the rod with the angled cap on it.But couldn't swear that that was for a ford or what Engine it was for.

    Yeah, I'm in the same boat; kinda remember, but I just couldn't bet a lot on it!      Besides, it was a "magazine article", and I'm not sure I'd bet my life on anything printed there any more than that on the inter-net today!   

Part of the possible engine problems could have been the angled caps because bolts are not made for side strength.They are made to be stretched and have strength in that plane.So they might have given away due to the angle of the rod bolts.

    The "angled cap" or "parting-line" connecting rod isn't really terribly unique, often practiced on smaller bore engines or particularly heavy duty industrial examples where they might be quite under-square with "generously sized" journals and "meaty" rods are utilized, this where the rod big end wouldn't fit down the bore otherwise.   

    Now, the "angled parting line" rod, if was as utilized in the "325", doesn't really make sense on the 4.00" bore, after all we're familiar with the BOSS 302 "TA" rod and as meaty as that thing is, it drops-in with the standard horizontal parting line; but if in the process of looking for a better/meatier example than that of the 289, preferably something that was already in the pipe-line, and the rod had been borrowed from the 255 cu. in. "Indy" project, well the 255's bore was only 3.76"! 

    Hmm . . . . . 

    I would agree that the bolt being placed in even a scenario of a partial "shear" probably isn't really a positive, but the idea is that the heft and draw on the fastener for the tightening torque is to be far greater than the shear influence.

    And this is just another example of one of those "compromises" the the engineers must wrestle with in creating the total package of an engine.   

    Scott.