(first posted 12/18/11) This Sorrell-Manning Roadster from 1954 is utterly stunning, and if someone had told me it was a special-bodied Aston from Italy, I’d have been convinced. Bob Sorrell was an exceptionally talented designer/builder during the fiberglass golden era, and his SR-100 roadster was not only his earliest, but quite possibly the finest. Only seven were built, and this particular restored one has a period-correct 331 Chrysler hemi under the hood. But the first one he built especially for a Car Craft cover article, had what has to be my favorite vintage six, a 302 GMC bored out to 320 inches, and sporting an aluminum head and six carbs. Straight six porn indeed.
But before we get to that engine, let’s just savor what Bob Sorrell created here. Truly stunning, especially for 1954.
Here’s another angle. These two shots are from conceptcarz, that has a full gallery.
Now to the original and the Jimmy six. forgottenfiberglass has the full article, a reprint from the 1955 Car Craft magazine. The six exhaust pipes are already somewhat visible form this shot.
Here it is fully revealed. The GMC truck sixes were very popular hot rod material in the early fifties for a couple of very compelling reasons: they had over head valves, large displacement, and very easy to come by, having powered untold thousands of WW2 trucks as well as civilian versions. The new ohv V8s were just coming out, and not easy to come by. A Jimmy six easily put out more power than a Ford flathead, especially in the state of modification this one was in.
This one is sporting a Fisher-Horning twelve port aluminum head, a one-eight inch overbore for a full 320 cubic inches, 8.5:1 compression, McGurk billet cam, etc. And hanging on to the intake side are no less than six Amal carburetors. The engine was never dyno tested, but the owner said “It really scares you when you get on it”.
BTW, this gem sits on a Kurtiss roadster chassis, very similar to those used for Indy cars at the time. Ditto for the magnesium Halibrand wheels. Vintage perfection.
The featured car doesn’t seem to have the cutlines needed to tilt the hood, making it even prettier.
But do you think the whole body tilts for engine access???
I noticed that too. Here’s how:
There don’t seem to be doors either.
Here’s how you get in…
Yeah I’ll bet it really screams, on the rare occasion all the carburetors are in adjustment!
Party pooper. How about one with five carbs:
It was a GMC engine that gave Fangio his start in a Chevy coupe.
Too many carbs for me, Amigo. I thought tri-carb set ups were bad enough.
I’ve had VWs with the two carb setup, that was trouble enough. Twice the trouble for 5 more horsepower. I can’t imagine tuning 6 of them! But…what about putting a ‘modern’ Ford 300 with the fuel injection under there?
My FIL who is 72 now, was a pretty serious hot rodder before his daughter (my wife) was born. He’s regaled me with stories of his 1947 Chevy with 292(?) Jimmy six, and three two barrel carbs. Truck six, truck trans, truck wheels & rear axle, it was apparently pretty stout. He was pretty dismissive of the flathead Ford hotrods, thought they were mostly fragile junk.
He had it all the way through high school, and upon graduation enlisted in the Coast Guard and with the sale of his 1947 Chevy and money from graduation, bought a new 1957 Chevy 150 two door with 283 & power pack.
I’ve never had the pleasure of one of these Jimmy motors myself, but would love to try one. Another possible replacement for a motor in the SR-100 would be the Pontiac OHC motor. Or a BMW…
This car’s designer was obviously influenced heavily by the C-type Jaguar.
Plopping the dizzy atop the exhaust seems odd to me. Every other early cross-flow I6 engine I’m familiar with has the distributor on the intake side.
That’s an aftermarket 12 port cross-flow head. The original head ported both exhaust and intake on the current intake side. That didn’t leave much choice for the distributor.
What the corvette could have been.
I don’t think you need six carbs. a single big 4bbl or three twos could have flowed enough to do the job with a lot less complexity.
This car was built when 4bbl carbs were just emerging, and I wonder if they would have flowed enough. Going to 6 Amals was not an uncommon practice at this time, when you wanted to go beyond what could be done with 3 twins, for things like speedway cars.
Six carbs! Much respect.
That reminds me of a time in high school, I went to pick up a girl for a date, and her dad was working on a Buick straight 8 that had a log manifold. He’d built the manifold himself from a piece of about 2×4-inch rectangular steel tubing, and mounted three 2-barrel carbs on it. I never did find out how it worked but it looked pretty impressive to me.
Reading all the previous comments, I don’t know much about what you guys are discussing and I really only log into this site for the fun of it all…..but I’ll tell ya, that is one sexy beast. If one of the car companies actually built that today (I guess Jaguar comes closest in my mind….NOT their current stuff that looks like a warmed up Camry), they would sell a gazzillion of them.
I have a ’52 Chevy Bel Air Hardtop with a 302 GMC bored to 320 c.i.. It has Hicson headers and an Edelbrock 4 bbl. It has 3″ exhaust, 700 R4 trans with a 9″ Ford rearend. I would take on any flathead out there.
You sir, have the type of hot rod that was frequently featured in Hot Rod mag when I was barely old enough to understand what they were talking about. The 4bbl was exactly the type of simple answer I was discussing in my comments above. If your gearing is right, I think it would take on more than a flathead. The last one I saw that really got me to lusting had a turbo on a rig like yours. An old coupe IIRC. Smooth sailing.
It gets a lot of comments at car shows. Most of the younger crowd have never seen a 302 GMC inline six. Most are 350/350 combinatins.. I get asked all the time if I am running a big block when they hear it idle. I had a 40 Ford Coupe and this car gets a lot more thumbs up than the 40 ever did. It is black with Weld wheels and I love it.
Big block six.
Very interesting how modern it looks despite being built almost 60 years ago, you could slip that into the Aston showroom and aside from the Halibrand wheels nobody would know.
That being said, my favorite home built fibreglass car remains the Bosley Mk1
I will take that green Bentley coupe in the background of the first photo.
Who cares about MPG? I`m drooling!
Looks neat, but the cockpit is very small considering how wide the body is, especially considering that there isn’t any thickness required to contain door hardware. The sides are also very tall to step over. The body sides are higher than the shoulders of the guys sitting in it. The bodywork could really use a dip to assist with ingress and egress.
I would’ve guessed that the body hides a full space frame chassis, but judging from the pics with the body flipped up to show the engine, it appears not. I looked up the Kurtis chassis used under this car, and in the passenger area there are no frame members higher than floorpan level.
I love my 302 six and I have long dreamed of what I would like to transplant it in to, as it currently resides in the original 1952 GMC / Carpenter bus. One nitpick though; the 302 didn’t come out until 1952 and was gone by 1960. It did power thousands of military trucks, just not in WW2. I originally logged in to say what a beautiful car this is, and thanks for doing the story!
I said that Jimmy sixes were used in WW2, but not specifically the 302. One of these days, I need to do a more in-depth story on these big sixes.
So you did! My apologies, Good Sir!
Paul,looking forward when you do. If I came into a stack of money I would put one of those big GMC six cylinders in a “54” or early “55′ Chevy bullnose P/U.
Sweet looking car.
Wow, when I 1st started coming to this website it was, and I expected it to remain, about cars 75 years old to about 10 years old….but it’s the articles like this that blow me away.
I completely agree that this car could easily pass as a Aston Martin design by way of an Italian coachbuilder. Then there’s that engine….OMG!!!
As a showcar the 6 carbs are impressive, but I would imagine 3 two barrels, or if “necessary” one 4 barrel would be easier to live with.
I do love I-6s, and this one is sweet! There’s a guy in my area who has an Atlas 6 in a mid-30s Chevy street rod.
I dont understand the aversion to multi-carb setups. Sure, they’re a little fussy to set up, and 6 of them is probably a pain. Up until fuel injection started to become the norm on small engines, motorcycles have pretty much always had one carb per cylinder. I have never had any particular issues with multiple carbs, including 3 on an E-Type Jag, 2 on MGs, Triumphs, and Jensen-Healeys, and 2 or 3 on my bikes. You have to own a Uni-Syn.
Nice, but I’ll take the Continental in the background.
I’ll take the green Tucker.
It’s a deal. No wait, there’s a Cunningham!
That’s the one-off coupe built for Carl Kiekhaefer. He apparently didn’t like it.
Although I’ve never driven it (as if!!) I can say it’s an awkward looking car next to the other Cunninghams.
_VERY_ nice and way ahead of it’s time styling wise .
InLine 6 Bangers offer tremendous bang for your buck and the GMC versions stand head & shoulders above the old Chevy 235 & 261’s I know and love so well .
Even the earlier 228 C.I.D. Jimmy i6 is quite powerful and hig revving right out of the box , adding three carbys (one for each intake port) and opening up the restrictive stock exhaust makes them real screamers .
The exhaust note on InLiners is great and not overly nasty / loud unless you add some specific noise maker muffler .
BTW : multiple carbys are a bit of a PIA yes , but they _DO_NOT_ go out of adjustment ! the popping and banging they do is always caused by ignition failures or tight valves .
I no longer have the good hearing necessary to properly set up multi – carbys sad to say .
-Nate
So many of those fifties fiberglass specials did not age well. But this is certainly the exception!
At our local quarter mile dirt track one night there was a car with a big GMC inline six that was winning the feature race against a bunch of flathead Fords when it threw a rod. It seemed to be geared “too low” as it would walk off from the Fords coming out of the turns and they would pull up closer at the end of the straights. You could hear it over all the Fords and the rod knocking a hole in the block was audible over all the noise! It made me want to put a “Jimmy” in my ’39 Chevy. The guy at a local Chevy dealer’s parts counter told me I could put the gears from the Corvette’s close ration 3 speed in my transmission. I had already put the top off a ’38 transmission on mine to convert it to a floor shift. How many old Chevy rear axles could I have destroyed if I had had the money to do this?