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View Full Version : 502...what a joke! GM should be shot!



Scott Pearson
04-06-2001, 07:38 PM
FYI....Hot Rod TV did a test on some motors. The 502 being one of them. And the Dyno say's....are you holding your breath?........................................... .....Still holding?

Get this 335 hp. You believe that. Hope nobody bought one.


I was up at my friends shop that does all the street rods and they have a dyno there. I was talking with them and they said yup....GM is way over rating there motors.

Hot Rod tv did Ford and Cry. also and they came up looking worse then GM.

Happy shopping pilgrims....


(NJ)Scott

Looped
04-06-2001, 09:38 PM
Makes you wonder what the sb's dyno in at? http://www.donzi.net/ubb/eek.gif http://www.donzi.net/ubb/eek.gif

http://www.donzi.net/ubb/eek.gif http://www.donzi.net/ubb/eek.gif http://www.donzi.net/ubb/mad.gif http://www.donzi.net/ubb/mad.gif

Frank Civitano
04-07-2001, 07:30 AM
There had to be something wrong with that motor. Another Question was it Marine or Street, Marine Has no Polution control devices, And its also just a block when GM sold them to Mercruiser! All the 502s I have seen on the Dyno at Typhoons ran between 405hp and 420hp.

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Frank Civitano

BigGrizzly
04-07-2001, 07:31 AM
It doesn't make any difference GM doesn't make any more. It is now a 496. As or overating. That has been going on since I was a kid.

Randy

Tom on Lanier
04-07-2001, 01:10 PM
Frank - good points.I think Mercury Marine puts some pretty high performance components into, and on, the blocks of GM motors before they go into boats. Especially the "Magnums" and such. However, over rating for marketing purposes is pretty common.

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Tom
"Tomahawk"

Scott Elgas
04-07-2001, 02:57 PM
Sounds like they had a truck motor on the dyno, not a marine motor. The Chevrolet 3/4 ton HD or 1 ton Silverado with an 8100(8.1 liter) motor is rated at 340 hp @4200 rpm and 455 lbs of torque @3200 rpm. So at 335 hp it sounds like that motor was right on target!

rayjay
04-08-2001, 08:42 AM
Which 502 was tested? GM has quite a few from a hi torque "towing" motor to the "H.O."? This sounds like the peanut port towing motor. What, and where (rpm), was the torque? The peanut port has its torgue peak at just over 3K, and doesn't rev at all. Remember HP is just a formula derived rating and revs = high hp.
rayjay

Scott Pearson
04-08-2001, 09:23 AM
Guy's

It wasnt a marine motor thats for sure. It was a 502 street version. Not a truck. Just a 502 creat motor. Still listed as a 502 hp creat motor. I would think it would be more then 335 hp. Oh well.

(NJ)Scott

olredalert
04-08-2001, 09:57 AM
Hi Guys,
By your description that 502 sure sounds like the rated 338hp motor that GM gave me for testing 3 years ago.It went in my 93 Suburban and I did a magazine article on the differences between the stock 454 drivetrain and new 502.I can tell you that the original 454 with 50,000 miles could only muster 309ft-lbs of torque and 186hp.Once I got the chip reprogrammed and the throttle body reworked to GMs specs,the 502 showed us 375ft-lbs of torque and horsepower was at 233.These figures are at the rear wheels of a 93 suburban converted to a dually,that has a tremendous amount of parasitic drag loss.As well,the testing was done on an earlier chip than I have now(new one much better)and only 300 miles on it.The 502 has given me some 70,000 miles of great service now,and I can tell you that the 502 is tremendously strong.It makes any stock drivetrain GM truck look silly.I have been known to take on stock 5-litre mustangs,and they dont embarass me a bit.As well,I can tow my 26ft.enclosed trailer with race car,all tools,a spare motor,etc.,(about 12,000lbs.)as if its not behind me!The gas mileage is actually better than the 454 as well,with no gearing changes.Flywheel horsepower and rear wheel,real world horsepower are vastly different numbers.The rear wheel horsepower on the same motor will also vary from car to car depending on the drag of the drivetrain.Horsepower figures always need to be carefully analyzed,before jumping to conclusions!..........just........ol red!