Muscle car motors HP & TQ

[Dwight]

Watched American Muscle Car on the Speed channel this morning. The show took 5 original stock muscle area motor and dyno'ed them. They want to see how close factory HP ratings were to the real thing. I had a pen and paper, so here is some of my notes

409 Chev 409 HP test 406.5 hp @ 6,000 & 430 tq

427 FE 425 HP test 637 hp @ 6,500 & 554 tq

421 Pontiac 405 HP test 488 hp & 470 tq

426 Hemi test 820 hp & 689 tq

427 Rat L88 425 HP test 527 hp @ 6,000 & 501 tq @ 5,000

I hope my notes are correct. Very interesting show and it looked like they tried to show just the true HP of each engine. They closed the show by saying there were a lot more muscle motors and they would do another show to include more motors.
If some of you guys saw this show and have more numbers to add, please do.

Dwight

[KevinM]

I really wonder about the correction factor on that dyno.

The numbers on the FE and Hemi are WAY high, even the L-88 sounds high. Almost 700 ft/lbs of torque from a 426 cu in motor? Not without a blower.

The 427FEs only made 480 to 500 HP in full race trim.

They said those were stock production engines?

Kevin

[fsstnotch]

So the FE put down more than 200hp more than advertised?

[Bob In Ct]

It's hard to believe that a hemi would put out twice the HP of a 409! I would have to think they were not telling us the whole truth.

Bob

[Ron61]

Those readings sound more like what you would have gotten from racing engines back then. The 409 is pretty close, but the rest are way off from any stock ones that I have ever seen any magazine reports on. And several of the car magazines did dyno tests back in the 60s and early 70s on many of the High Performance motors, both big and small block, and most of them came out either a little less than the factory rating or a small amount above it. I have a sheet here that I saved and it shows the 427 Ford with dual 4s that was rated at 425 horse actually putting out 437 horse. That was pretty much the same for most of the engines with on exception and that was the 428 CJ & SCJ. They were way underrated because of insurance reasons if you believe Ford. Mine was rated at 335 horse and actually put out 440 on the dyno. And I am sure the readings would vary froom dyno to dyno, but I don't think by that large of a margine.

Ron

[Power Surge]

Rule of thumb... if it's aired on American Muscle Car, it most likely isn't true. That show has more errors than a one armed baseball player.

[emberglo66]

Noticed two Pro System carbs on the hemi Don't think that was stock

[marcocsx3121]

My experience with period-correct muscle car engines is that they were pretty much all overrated. I've watched many 442 W30s, Ram Air 455 Pontiacs, 427 and 454 Chevies and a couple of 427 FE-powered Cobra replicas struggle to produce over 300 HP at the wheels. My old Cobra ran 118 in the quarter at a total race weight of a little over 2700 pounds, which doesn't compute to anything like 500+ flywheel HP.

[Silverback51]

Something stinks in TV land.

I had a 66 Chevelle with an L88 in it, and I could spank stock HEMI Challangers and Cuda's.

No way were they putting out close to 300HP more than I was.

[Excaliber]

Big horse power don't mean much if you can't hook it up. Traction has always been a serious problem for Cobras. Same goes for the Challengers and Cuda's. Short wheel base cars need a LOT of suspension work and great tires to run quick, most of the street cars had neither good suspension or tires.

[FFR428]

The FE was a tunnelport. Those were over the counter parts and not production. Carbs were mounted sideways not inline. Depending on what cam, internals etc... it could be a fairly close number.

[mpanten]

The guys who built the hemi admitted that it was juiced. You could also tell when the ran it that they reved it up to about 8k. The poster who made the comment about american muscle car being wrong all the time is exactly right. Cool show idea badly produced and documented.

[Stentor]

There was some discussion about this show earlier in the summer when the program aired on SPEED.

Dyno Shootout on Speed Channel

Suffice it to say that this was not an "apples" to "apples" comparison with the engines.

[69boss429]

I should have used their dyno!
I ran my 10 over Boss 429 last Friday on an engine dyno and came up with:
-run from 3900 rpm to 6000 rpm
-max hp at 6000 was 536
-max torque at 5500 was 486
-hyd roller cam
-11.5 comp
-dual 715 Holleys
Doesn't have the monster numbers I see for other BBF builds,but it gets the Boss down the road just fine
P.S. cam redline is around 7200,didn't want to abuse it,and the pull was made at normal engine temp. 180 degrees

[Tim Brewer]

Those numbers are ridiculous....

[69boss429]

Originally Posted by Tim Brewer

Those numbers are ridiculous....

Which ones?

[Excaliber]

Actually I think there fairly accurate for a MODIFIED well built engine. It is NOT unreasonable to expect 600 plus horse power from a side oiler using 'over the counter' parts that WERE available in the 60's. Like Tunnel Port heads, High Riser heads, Tunnel Wedge Heads, etc. 12 to 1 or better compression was 'standard' on a side oiler. Wild cams were available as well, in the 60's! Theres a reason NASCAR banned BOTH the Hemi and the High Riser side oilers in 1965 or so, TO much horse power!

As for the Hemi running 800 plus, yeah I could see that. But I'm not SURE it could have been done using 'over the counter parts' available in the 60's. Not an expert on Hemi's, all I could say is 'maybe'. I wouldn't be surprised if it was possible even in the 60's, using the 'good stuff'.

Chevy? I have no clue...

[marcocsx3121]

For the twenty third time, side oilers do not make any more power than good, old center oilers. The mod was done for high rpm longevity.

[Tim Brewer]

Well OK, in STOCK trim, the 427 FE and the 426 Hemi for sure are quite a bit overrated, I think you could almost cut those numbers in half. I"ll also bet nothing else probably could break the 400 mark. Very few people stick their muscle cars on dynos, probably because they don't want to be dissapointed. I don't have anything against muscle cars, in fact I love them. They just don't have as much HP as most people would like them to have.

[Excaliber]

Well Marcos, your '23rd point' is at best controversial when all things are considered. Center oilers tend to crack the block at the main bearing area when pushed much beyond 6500 rpm under full power. This is a major limiting factor in how much horse power they could ultimatly make. Side Oiler design can spin up to 9000, at least for brief periods, a center oiler would disentegrate at that rpm.