69427

Just curious. Did you, or anyone there, remind Duntov that "the market" paid his salary every two weeks? It doesn't matter what he liked or disliked. Without "the market" handing over their money to Chevrolet, Duntov would have been looking for work elsewhere.

Chrysler and Ford were selling lots of cars with 406 to 440 CID engines in them. Given the popularity of drag racing in the sixties, the Corvette's "reputation" would have been pretty poor from getting its *** kicked by a bunch of Ford and Chrysler sedans with big engines. Like they say, run with the big dogs, or stay on the porch.

In engineering, it doesn't matter what you like. All that matters is that you come up with a solution to the latest "problem/need".

Little Mouse

1963 farrari 250 P mid engine won 24 hours lemans and 12 hours sebring and everything else. 62 last year of a front engine car winning in all out competition, front engine car became an antique car by 63. Lol.they still raced them in lessor GT class racing still to this day just in the way on the track. You can read the drivers mind coming up on a gt car. Please get that damn snail out of my way have serious cars i have to race.

jb78L-82

Karsten, your comments are spot on and my experience over the years as well with BB C3's versus the SBC C3's and, of course, my own 78 L-82 4 speed over the last 40 years.

The BB crowd "family Secret" is putting a 150-175 lbs BB motor in a C3 (it is NOT 100 lbs difference between the BB and SB, which is part of the family secret) Does effect the handling significantly, not just in street driving since the BB engines DOES make the C3's feel nose heavy, do not even mention autocross or road racing. Now why is that?

Again, BB weight distribution is generally 54% Front;46% rear in a BB C3 (SBC C3 like my 78 L-82 is 48% Front:52% Rear), the BB engine is 150-175 lbs heavier overall, the BB sits slightly forward of the front axle center line (versus the SBC C3 sitting more mid engine to the chassis), AND the BB engine sits MUCH higher in the engine bay for a much higher center of gravity overall.

This nonsense comes up periodically mostly by the BB myth that the giant engine has tons more power and torque (which it does) but with a significant handling penalty, that is often denied vehemently by some.....the nay sayers....

ignatz

Why does a BB "feel" heavier? I would suggest it is steering feel and seat of the pants as to which end of the car is doing all the work. Been a long time since I've driven a big block, so the following is only notional, but I would suggest it has to do with tire "slip angle". Tire slip angle is of course what generates the cornering force.

I halfway remembered a video I once saw where slip angle was derived from basic physical parameters. Video below. I went and crunched some numbers for a 3400# big block and 3200# SB and jb78l's weight distribution. Came up with the conclusion that the big block in a turn has a roughly 17% greater slip angle at the front tires whereas the SB has roughly an 8% greater slip angle at the rear tires. That would surely translate into a different feel between the two cars.

Your conclusions may vary, just drinking the morning coffee and doing some "maths". Mostly equation 8 in the video and all else being equal. Willing to be proven wrong, just fooling around with the numbers as given.

v2racing

I'm a little hesitant to get into the chocolate vs vanilla argument, but here is my take anyway. Any weight added to a car, especially towards the front, will adversely affect handling. Was the effect between SB a BB extreme, no, but you could feel the difference. Could this effect be offset by lighter engine parts, better suspension and tires, of course. Could the SB cars keep up with the BB cars back when these cars were new, no they couldn't, not on the street, the drag strip or the road race tracks.

As far as what can be built in 2019, it has little to do with what was available to the OEM when these cars were built. Racers were also limited to what GM was building at the time too.

The simplest answer to the OP's original question is yes and no. In the original SB and BB cars with the same suspension, the SB cars handled better, but that does not mean the BB cars were sub par to cars of the time.

As far as what is better, whatever you like in your car is better, but that does not mean it is better for everyone! Run what you like and be happy, don't worry about what others think is best. I run a small block but it is because I bought a small block car and had small block parts to build an engine. If I had bought a big block car and had big block parts on my shelf, that's what I would have built.

Mike

jb78L-82

I think Mike's assessment above ^^^ pretty much summarizes the issues well....!!!!

Little Mouse

not even close to 54/46 on a bbc and a 70 LT1 no options is 49/51. All iron bbc in cluding iron manifold is 680 lbs same exact sbc is 520 lbs, 160 lbs difference. My 66 with the sbc with zero options i weighed it at 3150 lbs with the 331 i built for it 74, when i put the 396 in it same scales was 3310 lbs. Both engines iron except both had GM aluminum duel planes. Because all the stuff bigger when your start goi g aluminum on both engines the bbc starts realling the sbc in. 32 lbs saving on sbc head, 70 lb weight saving on bbc. The 78/79 heaviest vette made despite a sbc. My 69 camaro with nothing but power brakes sbc was 54/46 108 wheelbase with engine/ trans way away from rear axle. A bbc 68 camaro with an a/c system only 55/45 weight. Chevelle next bad with its 112 wheelbase. Then nobody want to know how bad your pickup is. Lol

69427

While I find the trivia about the 1963 Ferrari interesting, you're still wrong about the '62 being the last front engine car to win overall in an all out major professional sportscar race.

Little Mouse

all out expermintal class that was put in 1963 so car manufacture did not have to sell the car to the public run what you brung there was never a front engine car win it. A mid engine car is just a vastly superior design for road racing. Im 100 percent correct in my statement. they all knew this back then not only in road racing front engine car was finished in oval track indy racing probably about the same time. Would you be interested in showing me a picture of a 1983 front engine indy car or formula 1 car !!

jb78L-82

Not going to arguing semantics but I did say the BBC C3's are a range depending on the year, Front 52-54%:Rear 46-48%. My 78 L82 4 speed SBC 350 is 48% Front: 52% rear. All these numbers are reported in the literature at the time quoting the above numbers..............

jpatrick62

I should think that compared to other cars of the time (late 60's) the BB Corvette exhibited better handling and better f/r weight distribution, correct? I've driven BB ponycars (Mustangs/Camaros), and I thought the Camaros showed terrible understeer and felt very nose heavy. I would assume, for instance that BB Camaros and Mustangs would be more in the range of 47/53 (or worse!) for f/r weight distribution. Couple that with the fact that most ponycars had only front disc brakes at best and a live rear axle - you have a real handful there. Don't even get started on Mopars which my friend owned. I've only driven SB Chevelles, so I don't know how they handled.

7t9l82

I've had several of both, either one can be very fast but you drive them differently.
Nothing I mean nothing compares to driving my old 68 L-88 through the mountains of Virginia years ago a car with no radio no heater Stahl side pipes on a cool fall day with the top down I'm sorry nothing is as good.
On another note as Gkull said light reciprocating weight is a big advantage. I put a 9" 2800 convertor in my current car and it's amazing how much quicker the car responds.

leigh1322

I believe it is more about the overall handling balance. GM always designs a little too much understeer into their factory cars as a safety measure for the average driver. A "loose" tail can be very deadly, very quickly. Since the extra torque of a big block in and of itself increases rear slip angles, I am assuming the basic chassis had even more understeer built into it on a BBC car, in the interest of safety. The front springs and both sway bars front and rear were changed on BB cars. That's more than enough to dial-in some extra understeer for "safety". The increased diameter of the front bar would make way more of a difference than the tiny little rear bar that was added, hence more understeer.

BTW: the math says 160lbs extra only changes the front weight distribution by 2.2% So a 49% Front (SB) moves to 51.2% for (BB). Not really that big a deal.

Has anyone ever calculated the roll rate or the front handling balance on these cars? I could use a few more numbers. Anyone know the Center of gravity height?

Little Mouse

how is that a 70 LT 1 has the same 98.6 wheelbase same engine trans placement in chassis one with nothing on it but power brakes is 49/ 51. Yet you have A/C system, power steering and heavy front bumper system way the hell forward even in front of the front axle in the car and your 48/ 52 rear. Fact is the the 70 car i describe far lighter up front then your's. I had a new 78 for a short time period and a long time friend as all original 70 LT 1.

ignatz

jb78l says "the BB engine is 150-175 lbs heavier overall, the BB sits slightly forward of the front axle center line (versus the SBC C3 sitting more mid engine to the chassis)"

I don't know if that is true but if so that puts more weight on the front than just increasing the SB numbers.

Little Mouse

its mounted same location, if you measure a bbc bare block its 3 1/2 longer then sbc that 3 1/2 inch forward of the motor mount. So only very smal amount of weight forward not the whole engine/trans moved forward. If i buy another 78 im seriously considering moving the engine back and downward some. Of course ralf naders 5 mph bumber BS will be gone, that unsafe at any speed bastard still alive you would have thought someone would have killed his sorry *** by now.

jb78L-82

Can you stop debating this fact now? Thanks

Source: The Vette Net Any search from the era will come up with the same numbers: Road and Track, Car and Driver, etc

1978 Corvette Specifications

Dimensions

Wheelbase (in.)98.0

Track Frt/Rear (in)58.7 / 59.5

Length (in.)185.2

Width (in.)69.0

Height (in.)47.9

Frontal Area (in)NA

Ground Clearance (in.) (minimum)4.3 in.

Curb Weight (lbs)3500

Coefficient of DragNA

Weight Dist. F/R (%)47.6 / 52.4

Coolant Capacity (qt.)20.7

Fuel Capacity (gal.)24.0

Oil Capacity (qt.) (w/ filter)5.0

BTW-The BB engine C3's have a notch in the front cross member to accommodate the balancer since the BB engine sits further forward of the centerline. The SBC C3 engine sits MUCH farther back from the front centerline and BEHIND it...NOT even close.

Let's review again about the BB C3 family secret:

1. The BB engine is approximately 160 lbs heavier than the SBC engine in a C3.
2. The BB engine in a C3 sits just slightly forward of the C3 chassis front centerline versus the SBC engine which is much farther aft towards the middle of the car which is why my 78 weight distribution with a SBC is Front 48%:Rear 52% (see above documentation)
3. The BB engine is MUCH taller than the SBC engine and in a C3 chassis adversely effects the C3's center of gravity versus the SBC.

Facts folks^^^^^^^^^^^^^!!!!!!!!!!!

69427

Outside of the Can-Am series, I'm not aware of any "run what ya brung" professional racing series, so what's your point?

OBTW, you're still wrong about there not being a front engined car winning overall in a world class professional road race since 1962.

Metalhead140

Because '78+ cars have huge heavy rear glass! Better aero though... Don't get me wrong, I love my '79.

Metalhead140

Also, 47/53 is with 3 gallons of fuel - with a full tank they were pretty much bang on 50:50.