Supercars Annual '69

[dog ear]

I give you two Desk Top Dyno sheets I produced for the 1970 Chevrolet 454-450 HP LS-6. Check and compare both gross and net HP figures against Roger Huntington’s slide-rule calculations in above Post #150 (Chevies Hottest Musclecar Engines with net HP ratings) and that of Ronnie Kaplan’s dyno session. (attachments below) Pretty darn close eh?

http://www.ultimatecarpage.com/forum...9&d=1331617679
http://www.ultimatecarpage.com/forum...0&d=1331617791
http://www.ultimatecarpage.com/forum...1&d=1331617829

Admittedly, I originally calculated these on the first edition of the Mr. Gasket Desk Top Dyno program. Later, I had re-done them on the Desktop Dyno 2003 edition. On that version, you have the option of entering net camshaft figures taken at .050’’ camshaft lift, which is more accurate than gross figures that are all based on theoretical instead of actuarial measurements.

My point is that if you use such a program and enter realistic data you can come pretty close to real-world net and gross horsepower figures for many engine combinations. In order to be really accurate within say 5 % you must enter factual head flow data, compression ratio, and camshaft measurements. Many times I came close to what you might expect from an engine actually measured on a dyno, or computed using the various cube root formulas for deriving such figures.

Although not foolproof it is a quick easy way to estimate raw numbers before you perform modifications to an engine. You may just want to verify horsepower numbers against magazine articles or what-have-you. It doesn’t really matter. What you glean from using the program is educational in itself. You can learn a lot and the information can be very beneficial when bench racing with your buddies. Dream baby!

See two attached scans

[dog ear]

So far, we have looked at the following Chevrolet big blocks in their various iterations tabulated below:

396-375 hp & (1965 Vette 425 hp) L-78
427-425 hp L-72
427-430 hp L-88
427-430 hp ZL-1
454-450 hp LS-6)

Now you might be wondering about the fabled 454 LS-7 that was supposed to be released in 1970. It was ultimately shelved at the last minute. Horsepower rating on this iconic beast was
supposed to be set at either 460 or 465 depending on the source. Basically the LS-7 was the 454 version of the 427 L-88.

The LS-7 has been marketed by Chevrolet since 1970 as a crate engine in various forms. In the following posted article you will see that it was a wild package to be sure. Imagine how it would have performed in a production car? About as well as the ZL-1 I am sure which is to say not very good considering the power it provides. It would not have been very tractable on the street.

Check out the numbers and see what you think.

[Fleet 500]

I am certainly interested in this June, 67 SS&DI test.

Here is the complete road test.

I checked my Hot Rod magazines. I have Dec., 1965 and Jan., 1966 (among others).

[Fleet 500]

Great info about the 454 LS-6 Chevy. There sure did make good power in stock form! One of the best classic muscle car engines.

[Fleet 500]

As promised here is an eye opener!

February, 1970 Car & Driver
Shelby Cobra takes on the competition
This test showed conclusively that you did not need a Shelby Cobra 427 to beat up on most musclecars. The ‘little’ Cobra 289 in an unmolested state of tune without any of the factory phase kits offered by Shelby and Ford would usually annihilate the competition, including the vaunted Hemi.
If you think differently than by all means post your data and let's bench-race. LOL!

See last page on next post.

A 289 Cobra wouldn't necessarily outrun a Hemi Mopar. Some of the tests I posted show Hemi Mopars running better than the 13.73 1/4 mile which is what the Car & Driver test Cobra ran.

Also, being a 2-seater weighing only about 2,300 lbs, it's not really comparable with a 3,800-4,100-lb 4-6 passenger mid-sized muscle car.

[dog ear]

A 289 Cobra wouldn't necessarily outrun a Hemi Mopar. Some of the tests I posted show Hemi Mopars running better than the 13.73 1/4 mile which is what the Car & Driver test Cobra ran.

Also, being a 2-seater weighing only about 2,300 lbs, it's not really comparable with a 3,800-4,100-lb 4-6 passenger mid-sized muscle car.

I knew that comment would get your blood up, Fleet. Just checking to see if you are still with us. Yes, the Cobra is in a different class as it should be, but, on the street it's run what you brung. In the C&D test, it would have taken a very good running Hemi (just like the LS-6 Chevelle) to out-run that little Cobra.

As I pointed out, that Cobra was the basic model with only 271 gross HP. You could have ordered the Cobra with upwards of 375 gross HP. Most people did not find the need to do so. However, adding headers, and a different Ford-Shelby camshaft would certainly put the Cobra 289 into the low-mid 13s. I actually drove in such a car back in the 70s. Man, what a ride!

Performance vrs dollars, the Hemi would have been the way to go. You would have comparable times (or better) for less money, and be able to cruise with your buddies, or girlfriend in alot more comfort. Some would also say ''style.''

[dog ear]

Here is the complete road test.

I checked my Hot Rod magazines. I have Dec., 1965 and Jan., 1966 (among others).

Thanks for the Fairlane article, Fleet. It was cool to read about the 427 Low Riser package as a prototype. In 1968, it was rated at 390 HP, and was only available for a short period of time, before the 428 Cobra Jet debut in April, 1968.

428 CJs proved to be superior street machines and cheaper to produce and thus buy at the dealership. Regualr 427s were bears to drive especially with the 2x4V setup and ultra high (11.0-11.6 compression).

Ford 427 Low Riser and Medium Riser dual four barrel setups were very spikey and were known to be hard on driveline parts. Best intakes were the Tunnel-Port Wedge (1x4V and 2x4V) designed for NASCAR and road racing. It was never a street production intake but was very popular among racers on and off the street.

Tunnel Port Wedge intakes used the Medium Riser intake port face and the Tunnel Port runner configuration for the best flow of any street oriented intake on the market. Problem was it's true high rise design. TP Wedges were at least 4'' taller than most other intakes which caused underhood clearance problems on cars with stock production hood-lines. However, they made lots of power.

[Simi]

I think it was great time for you to being a part to Supercars Annual '69... I want to be part of that type of Super cars Annual show..........

[Fleet 500]

It's not a '69 but here is a photo of a '67 Camaro taking a turn in a track at 110 mph. Not bad, especially that it has the standard suspension.

2nd photo shows a '67 Chevy Impala SS 427 taking a turn at "high speed."

Magazine is Motor Trend, Oct., 1966, covering the 1967 cars. I just got this magazine a few weeks ago.

[Fleet 500]

Here is a recent video I made. My '66 383 Plymouth accelerating and me shifting manually. Speedometer view.

It almost sounds like it has a manual transmission, doesn't it?

[ame="http://www.youtube.com/watch?v=7_qDi4UUVAg"]http://www.youtube.com/watch?v=7_qDi4UUVAg[/ame]

[dog ear]

Here is a recent video I made. My '66 383 Plymouth accelerating and me shifting manually. Speedometer view.

It almost sounds like it has a manual transmission, doesn't it?

http://www.youtube.com/watch?v=7_qDi4UUVAg

Sounds nice, Fleet. Those old 383s were really good runners. I remember driving a 1969 W? or D-200? 3/4 ton pickup with a nice running 383-4V. It was baby-shit brown in color with tannish interior. Ugly muthas but brutally trackable in their element. True work horses.

Aside from Road Runners and Bees, perhaps the best running 383s were the 67-69 Darts. Light and quick but no very good handlers. I drove a 68 GTS and loved it.

[Fleet 500]

Sounds nice, Fleet. Those old 383s were really good runners. I remember driving a 1969 W? or D-200? 3/4 ton pickup with a nice running 383-4V. It was baby-shit brown in color with tannish interior. Ugly muthas but brutally trackable in their element. True work horses.

Aside from Road Runners and Bees, perhaps the best running 383s were the 67-69 Darts. Light and quick but no very good handlers. I drove a 68 GTS and loved it.

Yes, I do like the 383 engine. Did that '68 GTS you drive have a traction problem? It most likely did!

Just got another magazine... Car Life, Oct., 1968 showcasing the 1969 cars. Reading through a magazine from that era is always a treat for me, since I find classic cars more interesting than modern ones.

[dog ear]

[QUOTE=Fleet 500;987434]Yes, I do like the 383 engine. Did that '68 GTS you drive have a traction problem? It most likely did!

I drove several different Darts (GTS and Swingers) back in the day. All were pretty good cars.

The 68 GTS was a 383 automatic and 3.23.1 posi. It had pretty good traction if you did not punch it violently to the floor. Tires were non-stock G70-14 (White Side Wall) Firestone Wide Ovals. Everything else was completely stock including tune-up. It was a mid-to-high-14-sec car with good (on-the-street) traction. Color was medium green with matching green interior. No mag wheels; just factory hubcaps.

I drove lots of 340s including a 68 GTS 340 4-spd / 3.91.1 posi, 69 Swinger 340 auto / 3.23.1, 70 Swinger 340 auto / 3.55.1 , and a 72 Swinger 340 auto / 3.23.1, and a few Duster 340s as well. All ran about the same except the 72 Swinger 340. It was the low compression engine with 235-240 net horsepower (depending on which source you read) and it definately was not up to par compared to the earlier models. Then again, every other car was in the same vote except for the late model 455 Firebirds; they did not seem to lose as much power because of the big engines inherent low speed torque.

1971-72 351 HO / CJ Mustangs were quite abit faster than the standard 1970-71 351 Cleveland 4-Barrell engines in turn. 1972 351 HO was basically the detuned 1971 Boss 351 with lower compression and a different cam. The mid-year 351 CJ and the resultant 72 CJ versions of the 351 4-V Cleveland engine were much more performance oriented than the earlier models. They had more carburetion, hotter cams and better intake manifolding. 73s were a diffeernt story. They had the same equipment but the cams were actually retarded eight degrees from the factory for emission purposes. Result: doggy off-the-line performance and emasculated top-end.

Getting back to the 340s. They were fantastic little machines. Light, powerful, and good looking. Like all Mopar products they were easy to work on and tune. Just put on some headers, rejet, or better still, bolt on a 650-780 Holley. If you had enough beans left, purchase the Edelbrock LD-4 intake and go beat up the stock big blocks on the street scene. Remember this was early to mid seventies...

With enough traction (better tires, trac bars, pinion snubbers, or Super Stock leafs) you could really ET with mid-high 13-sec runs.

With all things being equal, the little 340 would whip ass off the 383s of the era, and make the 440 boys take notice, particularly if they were napping at the traffic light. LOL! Big block Darts were certainly harder to lauch successfully but you never seen that many anyway. Most 383s were in the Road Runner and Super Bees.

Now if you had a modified 383 Dart then you could easily get down into the low 13s. 440s were in the 12s if done right. There was such a beast in Toronto at the time. A real 1969 factory 440 GTS auto / 4.10.1 gears modified and running high 12-secs with street tires. It used a big Mopar hydrualic cam & valvetrain; the ''real'' 440 Six-Pack unit that was supposedly never installed in the majority of factory Six Pack / 6-BLL cars. Other mods inluded Hooker Headers, 780 Holley on Edelbrock C-440 intake, multi-angle valvejob, and a super tune with an electronic Mallory ignition setup. It was a real bear. LOL!

[dog ear]

[QUOTE=Fleet 500;987434]Yes, I do like the 383 engine. Did that '68 GTS you drive have a traction problem? It most likely did!

Hey Fleet; Just to recap; all high performance cars back in the 60s / 70s had traction problems if you really punched them to the floor on take off. Most guys would nail it softly on initial lauinch, then once they got going (say 20feet out) pet the pedal to the metal and then go for it. LOL!

I do the same thing with my 1998 Buick Regal GS with 3.8L supercharged engine. I got it modified now with a cold air induction kit, smaller (3.4'') supercharger pulley (creates more boost and quicker spool-up), colder 180 thermostat, complete 2.5'' ZZP exhaust system with high-flow cat installed, front tubular ''ramlog'' exhaust (header) pipe, hi-temp coated crossover pipe (connects both head pipes together), new programmed computer, and one range colder spark plugs. Car really hauls ass now. Will easily smoke tires at least 75 feet. Car is low 14, high 13 sec beast now. LOL!

Check out two scans below dealing with the 340s.

[dog ear]

Here is a 68 Dart GTS 340 road test from April 68 Hot Rod.