Overhaulin 70 GTO Lance Armstrong

I only caught part of this show- I saw they dynoed the engine he had in it before it was replaced with a new crate motor- the engine he had in his 70 GTO Only dispalced 200 hp, and they said they where surprised to get that....

I did not hear if he had a 400 YS coded engine or other similiar stock GTO engine that only rated that HP- did anyone catch the first part of the show that indicated the exact engine he had in his car?- I also own a 70 GTO mine has the YS code engine and fairly certain that it pushes a lot more than 200 hp, however seeing that made me wonder as I've never had mine on a dyno...

now that I think about it thats another good question- anyone ever Dyno a 70 GTO with the stock 400 YS code engine in it- if so how did it rate? Mine is an automatic TH400 with 3.55 posi gears.- Thanks!

I seen the whole show. They didn't say if it was the original or what size the engine was. I was kinda surprised too from the horsepower results they got. I have a 67 YS but it's never been "dyno'd"

Joe

I know, I seen it too all the way through and lemme tell you somethin: that was a 400 YS engine - the hot chick said it - and clearly its age had caught up to it but that's not uncommon for a 35 year old engine. I ain't dyno'd my '68 GTO because I just got it and its only got 58,453 original miles on her but I'd like to - its a 400 too.

I do have some experience on these old engines losin power over the years cause I dyno'd my '67 Eldorado with 429 at Colvin who done Lance's car here in Austin where I live. That 429 was only spinning 235 horses on the dyno before they rebuilt it and after that it span a more respectful 310 but short of the original 340 rating.

Thats all I got, hope it helps.

The advertised horsepower figures from cars back in the 1960s and early 70s were kind of inflated. In the early 1970s automakers started using the SAE net horsepower ratings that better depicted the actual output of the engines.
That's why a 1972 455 HO GTO was rated at "only" 300 horsepower. It was the horsepower measured after the engine was installed in the car with all of the accessories loading down the engine (alternator, steering pump, etc).
The zero- to- sixty and quarter mile performance figures is the best method of determining how much power those old cars had. And those cars ran great considering the tire technology that was available back then.

OK...so if a car is built....say a 400 69 Judge RA III to have 360 HP.....that doesn't mean you will get that much at the wheels, does it????? Seems to me that HP at the wheels may be much different than rated HP.

It has been a while....can anyone clarify that for me?

I AGREE THAT REAR WHEEL HORSE POWER IS TURNING THE DYNO WITH THE REAR WHEELS. ENGINE HORSE POWER IS TURNING THE DYNO WITH THE CRANK.REAR WHEEL HP IS GOING TO BE LOWER THAN WHAT PONTIAC HAD FOR A HP RATE
MARV

im pretty sure they rated the cars in engine horse power. I saw a restored to original 70 hemi cuda put on the dyno and at the rear wheels it was only 317 horsepower, well short of the advertised 425 hp.