Horsepower of original 427

[Dominik]

Based on an extensive coast down test with my car (with hardtop though) Dick Smith's car had in the region of 550 DIN hp to achieve 198 mph - which is around 650 SEA hp.

Which was more or less a NASCAR power rating in 1968, wasn't it?

[Cobra #3170]

Originally Posted by Dominik

Based on an extensive coast down test with my car (with hardtop though) Dick Smith's car had in the region of 550 DIN hp to achieve 198 mph - which is around 650 SEA hp.

Which was more or less a NASCAR power rating in 1968, wasn't it?

NASCAR Ford engines were in the 500's then SAE short track 530 and Daytona in the 560-580 range according to Mose Knowland who was a key engine guy with Ford then. He showed me some of the dyno runs from that era and the highest power levels were dual four barrel engines.

[Lightingrod]

I think the "BOSS" motors were the real wild ones! The Boss 302 was built for the 5.0L limit Pony car (Trans Am?) road race wars. The intake, ports, cam and valves were HUGE for a 302 engine! No low-end torque but would make some BIG hp when you spin the heck out of them! The 302 was not much of a street engine but they had to sell like 500 of them to qualify for the race series. I feel the Boss 429 was Ford's drag strip warrior of the time, they made some pretty big hp. Ford also had a 460 CID version in Can-Am cars. This all how I remember my impressions from 40+ years ago and not necessarily facts!

[marcocsx3121]

Based on actual, period test results of 427 Cobras (including my own CSX 3121): at 2700 pounds including driver, fuel, etc, a typical trap speed of 118 mph calculates to 355 hp.

[cycleguy55]

Originally Posted by marcocsx3121

Based on actual, period test results of 427 Cobras (including my own CSX 3121): at 2700 pounds including driver, fuel, etc, a typical trap speed of 118 mph calculates to 355 hp.

355 flywheel HP or rear wheel HP?

[marcocsx3121]

Based on the calculator I used.I have to guess flywheel. But it's only a guess.

[pcww]

Thanks for feedback

[DanEC]

Originally Posted by marcocsx3121

Based on actual, period test results of 427 Cobras (including my own CSX 3121): at 2700 pounds including driver, fuel, etc, a typical trap speed of 118 mph calculates to 355 hp.

Assuming the Ford Engineering dyno results of 425 SAE gross flywheel HP was accurate for the early LR, dual quad intake 427s (no reason to think otherwise), by the time alternator, air cleaners, log-type exhaust manifolds, and mufflers were added - 355 net hp at the flywheel seems pretty reasonable to me.

[wkooiman]

I would expect that we've all seen the explanations about A-curve, B-curve, wheel HP, net/gross, etc.

If you consider that the 425 HP quoted for the 427 was A-curve (no accessories, no full exhaust), I bet it was pretty accurate. At the wheels? 350 would be about right.

The same thing is true for the 427 SOHC with 616HP for 1x4 and 657HP for 2x4. These were the numbers they made during testing on the Ford dyno.

[hawk 325]

I thought all cobras had 500 horsepower?

[wkooiman]

Only the big block cars. ;-)

[mikeinatlanta]

This thread is like one of those web sites where they post all the untouched photos of the hot women of our fantasies, and not a positive thing can come of it.

Myself, I say let's keep the photoshop pictures and all cobras make at least 500hp.

[frdfver]

I’m sure that the parts and assembly at ford had quite a lot to do with the variances in horsepower. I know from my own experience working at a ford dealership in the late sixties that we could have identical equipped 428 cobra jet mustangs and more often than not one of them was faster than the other. I had a 1971 Mustang 351 cleveland stone stock that was significantly faster than any of the others , all the right parts and balance must have come together in that engine. Big difference between hand assembled engines from an engine builder and one that is built on an assembly line.

Paul

[blykins]

Amen.

That's the biggest thing about "assembly line" engines. They just bolt them together.

I had a buddy that bought a new SS Camaro around 2000-2001. It was supposed to have been 320-330 hp if I remember correctly, but he routinely got his butt dusted by other SS and Z28 Camaros.

You take a bunch of engine parts, throw them together randomly, and sometimes you will get lucky....sometimes you won't. When you take time to degree the cam, make sure it's where it needs to be, make sure all the bearing clearances are right, make sure the quench is right, etc., etc., that's where the success comes from.

[DanEC]

Very true - in 1969 I had a buddy who got a brand new 390/315 hp Mach 1 that ran like a scalded cat but was supposed to be a total dog. He was a typical kid and was boiling tires and winding it past redline the same day it rolled off the dealer lot. He mounted a nice SW tach in it (why - I don't know as it had a factory one) and I sat in the back seat one day on the interstate outside of KC and watched over his shoulder as it register 130 mph on the factory speedo and watched him make shifts at 6,000 rpm to get there. You just weren't supposed to be able to do that with a stock 390. And although it later started floating valves at a little over 5000 rpm, he never blew it up.

I ran him in my 383 Plymouth but after about 25 mph he would just start slowly pulling away from me and keep going. I had another buddy with his parents 390 Cougar GT that I also ran and I walked away from him so bad in first gear that I thought he had killed the engine. Found out otherwisie when he made me promise never to tell anyone we ever raced and I beat him. I couldn't get over how embarassed he was.

A common remark at the time was break it in the way you plan to drive it. Guess it worked for that Mach 1.

[Maricopa]

I thought all cobras had 500 horsepower?

They do man, they do.

[cwrandolph]

Speaking of assembly line engines - in '65 two of my older brothers ordered new GT Mustang with the 225HP 4 barrel engines. One coupe and one convertible. The coupe was always just a little faster (probably a bit lighter too). Over the years, the coupe got sold and the convertible went up on blocks until a complete restoration about 10 years ago. When they tore the engine down, it had 7 "eyebrow" pistons and 1 flat piston from the lower compression 195HP 289. That explained a lot!