Jay Leno's Take on the 426 Street Hemi

[dog ear]

Thanks for the info fleet. My buddy was trying to find out 0-60 mph times for the Hemi Challenger with no luck.

Do any of your old magazines have Muscle Car era contemporary Ferraris such as the 275, 330 and 365? I would be interested in seeing what they do the 0-60 mph and 1/4 mile in.

I think that I can dig up some quotes for you. I actually have an ongoing database with mos of the American and European figures from all the leading mags of the day. May take me a few days but I will post some for you.
Terry

[dog ear]

How do you know that it wasn't stock?

Wasn't the 350 SAE net hp based off the 425 gross hp which itself was underrated?

Chrysler and Chevrolet both released gross and net hp figures for 1971.

Chrylser rated their engines as follows:

426 Hemi as Follows: 425 Gross hp
350 SAE net

440+6 385 Gross hp
330 SAE net

440-4V Magnum 370 gross hp
305 SAE net

383-4V Magnum 300 gross hp
250 SAE net

340 Magnum 275 gross hp
I believe it was rated at 275 SAE net but I will look it up to be certain.


318-2V 150-155 SAE net


I do not believe that the 350 SAE net hp for the 426 Hemi was under-rated in any way, even though various sources claim that the gross 425 hp was ''under-rated.''

One thing to keep in mind here: Hemi cam specs were changed for the street engines through the years.

1966-1967 were solid lifter designs with less duration and lift than the later 1968-1971 versions.

Here is the rub: Even though the timing specs for the 426 Hemi cams were supposedly the same from 1968-1971, you should know that Chrysler installed a hydraulic cam in 1970, as opposed to a solid lifter design in 1968-1969.

I am no engineer but I have read in many camshaft articles that a solid lifter design will out perform a hydraulic design even with the exact same specs. It is claimed that the solid lifter version will out excellerate the hydraulic one and actually produce a faster rate of lift thus giving an advantage in engine excelleration.

I have an article that attempts to explain this phenomemon. I will try to find it and post it for everyone's perusal.

What this means is that an earlier (1970) model may actually slightly out-excellerate an otherwise identical 1971, even if there were no actual measurable hp diffference. Some racers I have talked to over the years feel that this is true. Who can say? At any rate, I hope thagt this info helps you.

[dog ear]

And has aftermarket dual exhaust, a shift kit and an unsilenced air cleaner.



I may do that someday. Even with its 39-year-old engine. When are you taking your car to the drag strip?



I'm not really "boasting." I am pointing out that it runs a better 1/4 mile than many would guess along with its passing times.
Where do you get 240 net hp? Is that from the magic formula you keep using? And is that with or without dual exhaust?



What are you talking about? That Tahoe you posted runs a 16.5 1/4 mile. The same as the '69 Cad in the Motor Trend test. Why wouldn't mine "keep up?"

And speaking of "boats," this '69 Pontiac Grand Prix would destroy that Tahoe:
(Car Life)
'69 Pontiac Grand Prix SJ
Engine/rated hp------------------ 428/390
Axle ratio------------------------ 3.55:1
Weight-------------------------- 4,180 lbs
Wheelbase/length---------------- 118"/210"
0-60 mph------------------------ 6.7 sec
1/4 mile-------------------------- 14.1 secs @ 95.3 mph
Top speed------------------------ 129 mph
Passing: 30-70 mph--------------- 5.4 secs

Put some modern tires on that Grand Prix and you're looking at high-13s in the 1/4 mile.

I do believe that the GP is a Royal Bobcat prepared car. I have that road test and will look it up to be sure. Bobcats are naturally faster becuase they have been breathed upon. I will post the actual test, as well as a few others for comparsion sakes.

I actually drove a 428-390 hp GP back in the day. They are fast for their time, but, they were very rare cars. Standard SJ GP models with the 428-370 hp engine and 3.23.1 automatic versions were much, much slower...

[dog ear]

Here's what I read on that source:



Where did you find the 106-109 mph trap speeds of the Shelby Cobra?

Why don't tires or gearing affect trap speed?

As for the times being fast, don't you have to take the fastest time to get the most accurate view of the peak hp?

That 13.56 1/4 mile time was for a pre-production 3240 lbs. NHRA planned CJ with a super-tuned engine. It had no sound deadener and a few other mods meant for the strip. Actual production CJs ran mid 14s and high 90s to 100 mph with stock tires.

[dog ear]

I posted the article with the 109 MPH trap speed in this very thread.
http://www.ultimatecarpage.com/forum...3-post132.html

I am not going to play 20 questions with you again.

There were TWO 427 Cobras, which most people seemingly can't comprehend.

One was the STREET version that used the low riser 427; that was a mild engine with an advertised 10.4:1 CR that was rated at 425 Gross HP (and made far less than that in its NET "as installed" configuration.

The COMPETITION version used the medium riser 427 and ran a 12.4:1 CR and a wilder cam. That engine was not streetable and required racing fuel (110 octane plus) nor was the car itself. It was rated @ 485 Gross HP and made something on the order of 380 HP in its NET "as installed" condition.

The same engine installed in a 1966 GT40 made 480-500 hp with the utilization of what was referred to as a ''bundle of snakes'' long-tubular headers.

In 1967, the GT40 was fitted with the same 10.6.1 c.r. engine and equipped with duel 780 Holleys and made 500-520 hp.
Many people reference the COMPETITION version when discussing Cobras while remaining ignorant to what they are quoting.

Most 427 S/C Cobras ran utilized a ''true'' 10.6.1 c.r. with a medium riser (sidewinder) intake and a single 780-850 Holley. In this configuration they dyno'd around 460-485 hp.

[pimento]

Thanks for all the info dog ear, and welcome to the forum! Seems you've been a silent member for quite some time, but you're making up for it now!

[Kitdy]

Cheers dog ear, and welcome! I remember this old thread fairly well, and it was fun to skim over it again.

[dog ear]

I lived through the musclecar era in Toronto, Ontario, Canada, and I drove many of these cars talked about in this thread when they were fairly new. Some of the cars that I owned:
69 Mustang Sportsroof w 390-320 hp auto / 3.25.1 posi w (Lakewood traction bars installed)
69 Mustang Mach 1 428 SCJ 4-spd & 3.91.1 (mods: Hooker 2 1/8'' headers, Traction-Master trac bars, Ford street-strip hyd. cam, Sidewinder 427 MR intake)
70 Buick GS Stage 1 455/360 hp (headers & 2-1/2'' exhausts w / Cyclone Turbo mufflers / HEI electronic ignition)
76 Plymouth Gran Fury (Police Interceptor) 360-4V
currently own: 1998 Buick Regal GS (stock)

98 Buick Regal GS is as quick as 69 Mustang 390.

LOL! I will dig out some stuff tomorrow for you to read.

[Kitdy]

A fairly nice collection there. Where abouts where you in TO in that time period? I have lived in Metro Toronto all my life.

[dog ear]

Before I go off to sleep and dream I will leave you with a dyno session from Ronnie Kaplan Engineering on a brand new 454-450 hp engine from 1970. They wanted to know the actual gross and net hp figures for this engine since it was the highest factory-rated engine in existance.

Enjoy!

[dog ear]

For any of you interested in old 50s / 60s Ferrari road tests please go to this link posted below. Hope this works!


http://members.rennlist.com/f_car/

[dog ear]

Here is the 1968 pre-production Mustang Cobra Jet article with the 13.56 ET.

[dog ear]

Here is a 1968 NHRA Super Stock Mustang Cobra Jet article from Car Craft April 1968.

[Magnum9987]

Well of course a solid lifter set up will perform better. Hydraulics actually reduce lift because they are, as the name suggests hydraulic. Not to mention they are heavier. All the high winding engines of the 60s (Hemi, Chevy and Ford 302s, Chevy 327, 396, and 427, Ford FE 427) all had solid cams in their highest specs. Makes a better sound too, they give you the throaty roar that I love so much. Its too bad they were phased out. I would gladly drive a modern engine with a solid lifter cam. I can do the adjustments myself. It would never fly though

[dog ear]

If anyone is interested in reading various road tests and articles from Car Life, Hot Rod, Motor Trend, Road & Track, etc., browse the following link, and enjoy yourselves. Admittedly, it's a website fro Fords and Mustangs in particular, but in this library section you will find all kinds of different stuff to fascinate you.

http://www.mustangtek.com/LibraryMagazines.html