A few questions; maybe I missed it from previous posts, but what transmission/s did they run? Does anyone happen to know the compression ratio and cam specs? And not trying to be a smart-ass, just truly want to know, were they Jahns pistons?
The motor literally wasn't available to the general public when he first started the project. Think about that... Tom was a talented engineer for sure, but he had no historical knowledge or testing to fall back on and yet he still hit a first pitch homerun. It's crazy.
Come on man, you’re killing us with this stuff. And while the engine was not in any production vehicles Chevrolet, undoubtedly through Duntov’s****istance, made sure they were available to speed merchants for development.
Huh, I didn't even think about the engine not being available yet. I just****umed the Edelbrock tri-power intake he used was for small block Chevys. Was it not? Was it adapted from an Oldsmobile or similar one? Or did Vic Edelbrock get to work with it in advance as well?
I have no clue. Vic and Tom were bitter rivals, so I doubt they helped each other much. I've read a couple of things: "Tom Cobbs took early delivery of a 265" Chevrolet sometime in 1954." "Cobbs was able to double the horsepower of the then new Chevrolet with less than a year of development time." I don't know how he got the motor or who helped him if anyone get the power out of it... I do know that I have scans of Tom's shop notebook and some of the answers might be within. I guess we will find out when we get there?
After seeing how he took pictures, I can only imagine what kind of mad scientist level of notes are hiding in those notebook scans.
I was thinking about this earlier… Tom’s color work is unreal - easily on par with, and often better than, the best stuff printed in Hot Rod Magazine or anywhere else at the time. None of their big-name photographers could touch what he was doing with Kodachrome. But when you flip through his black and white shots, they feel looser, almost casual... like quick snapshots grabbed between real frames. And what’s wild is that many of those were taken during the same era as the color work. Then it hit me... color film was expensive as hell back then. Black and white? Practically pocket change. These weren’t “art shots.” These were Tom’s iPhone photos... cheap, quick, and disposable. Document.
Thinking that Edelbrock intake manifold was their first 3/2 intakes (355), the 265 Tom screwed together was pretty innovative, he had to have been really well connected.
I have nothing to back this up with, but we do know that Stu Hilborn was one of Tom's best pals. So, I would imagine that Stu helped him a lot with intake stuff when he supplied the injection setup.
@DDDenny I enlarged one of the photos and sure enough it looks to be an Edelbrock C355. Had to have been one of the very first ones; if not pre-production. Apparently those were for just the 265ci motors.
Fantastic thought to do that... I'm an idiot. Tom and Vic must have had a complicated relationship. The first real legal drag race was spawned because Tom was talking***** about Vic... or maybe Vic was talking***** about Tom. Either way, there was beef and it was settled on the first ever real drag strip in Goleta, CA. I think it was Robert Genat that wrote about how they gained respect for each other after that, but I always chalked that up as*********. Kids don't typically like each other after a fist fight, right? And they were kids... But maybe they found a common enemy and worked together to beat it... Maybe they were more mature than me.
Truly magnificent, this realm of Tom Cobb's, that is being revealed, through this element of the H.A.M.B. We are all so fortunate, to be able to see and learn about his world! Thanks @Ryan
Ironic the last photo shows a flathead similarly equipped, put aside but destined by many in various configurations to rise again for decades in the future.
Wow 1954, wonder when Chevy started developing the small block, and who all was involved. They wouldn’t give just anyone an engine in the development stage. WOW
I'm guessing Cobbs got the motor through Stu Hilborn. That would make the most sense to me... As for the SBC, it was designed under Ed Cole at GM, but lots of engineers had a hand in it... One of my favorites is a guy named John Dolza. He developed the "green" sand casting method that allowed the engine to have thinner wall construction thus saving a ton of weight. Don McPherson too... He developed the heads... and its basics are still in use today.
Ed Kelly was the head of Chevrolet Engineering in 1951 when design work was begun. Cole came on board as the new chief engineer in ‘52 and the work changed dramatically, he wanted the engine to be economical to produce, simple to work on and especially lightweight. In effect it was to be the antithesis of the Caddy V8 he had developed earlier with Harry Barr.
I was curious about the de-stroke and after seeing the large round exhaust ports in the head I guessed that Tom used larger valves and, since the engine is supercharged , he opened up the combustion chambers to improve flow. a 3.810 bore with a 2.900 stroke gives about 264 Cubic in. I'd love to see a pic of the bottom and intake side of those heads.
To this day, there is a massive aftermarket that is riding on the shoulders of all of the guys mentioned and as much as I respect guys like Yunick, Jenkins, Lingenfelter and everyone between and after it's those GM engineers, the Edelbrocks, Hilborns, Cobbs, Duntovs, etc. that we salute, otherwise we might all still be driving around in 6 cylinder powered cars. And all the guys that still worship the the "six poppers", please send no cards and letters, I'll be kept busy with the Caddy, Olds and flathead guys!
damn I'm interested in the crank driven adapter, looks welded up, were there similar set ups for the flatheads?
Yeah, one of the first things I noticed too was the hogged-out exhaust ports. And also the casting marks on the heads; these were I suppose essentially the same heads that the later low-performance 2-barrel small blocks used. So there had to be a bunch of cylinder head work involved. And it's doubly amazing to me that Tom Cobbs documented all this stuff through his photos. How many people back then would have thought about doing that? Every one of these Tom Cobbs photo posts is an absolute historical treasure. I'll be waiting for a forthcoming book. Seriously.
I just hope your Will and Testament has your superior collection going to Peterson or some noteworthy museum to be kept forever. You have an amazing collection of really cool history. Thanks, keep those posts coming.
I wonder how welded up the intake was. Those nozzles look a bit vertical. The fuel pump and tach driven off the mag shaft, too kool. Flathead trans pattern surely didn't mean a walnut shell Ford trans, likely a popular pattern for racing parts. The whole engine seems to exude something akin to superior aircraft engineering simplified.
Simply amazing! The gift that just keeps giving! Thanks again! Thank you @theHIGHLANDER for pointing out the fuel pump driven off the mag. I was wondering about fuel delivery.
The Jalopy Journal
