I'm looking in an old "Motor" auto repair manual that my wife's grandpap gave me and saw something I was wondering about:

It lists three other 455 engines for 1970 Oldsmobile that were more than 370 HP:

375 HP/510 TQ
390 HP/500 TQ
400 HP/500 TQ

Just was wondering what models these went to. I haven't seen anyone talk about them here.

 

375 HP= W30 in A-body (yeah right)
390 HP= W33 in 88 (I think it was available in Ninety Eight but not 100% sure)
400 HP= W34 in Toronado


You'll notice these follow the GM power to weight formula of 1 horsepower per 10 pounds of car weight...

 

It just seems crazy even making these different. I have heard that that there is a huge difference between the advertised numbers on a true W30 and what the real HP is. But on these other engines you mentioned, were those numbers actually the real numbers?

 

"give me a dyno run on this 455 showing at most 375 HP"

"Ok"

By varying the state of tune, temperature, air temp, exhaust, ancillary loads, fuel supplied, camshaft profile, etc. a good dyno operator can produce such results.

Then the marketing guys can work their magic that sells cars w/o violating the 10 lb/hp limit.

The engines are not all that different, it's the way they are presented.

 

Another question...it also shows in that same "Motors" manual that the engine prefix for the car I have should be "UN-O". Any idea where I find that at?

 

It would have been a paper label on the oil filler tube which is usually MIA in a year or two. Once in a great while you may find it stamped on the tube, but I've seen only a very few. It was there mainly to assure the assembly line dropped the right engine in the right chassis.


I've always held the opinion that ALL 4-bbl hi-compression Olds 455s made north of 400 horsepower, it's just the way the factory rated them for marketing and to keep insurance companies and Feds off their asses. So, yes, I'd say the W33/34 are probably close to as advertised. The W30 is the fluke due to GM's power to weight finagling.

 

Not quite, Glenn.

W-30 was rated at 370 HP (coincidentally in a 3700 lb car...)

375 HP motor was the standard Toro motor
390 HP motor was the W-33, optional in the D88 line (and also available with the police package in those cars)
400 HP motor was the W-34, optional in the Toro line.

As noted, the factory HP ratings are pure fabrications. Does it really make sense that Olds would go through all the trouble of developing unique W-30 heads and intake and carb, etc, etc, when they could have simply bolted in the W-34 motor and gotten more power? Of course not. And, as I've noted previously, the 1970 W-30 AT motor used the same cam as all other AT 442 motors, yet allegedly made the same 370 HP as the manual trans W-30 motor with the 328/328 cam. These numbers are pure fabrication, which is why automakers were forced to go to the net HP ratings starting with the 1971 model year.

FYI, here's the 1970 power teams manual with more details.

 

I like that power teams manual. If they would have posted a similar one in this "Motors" repair guide, it would be a little less confusing. One probably has to be very careful with a repair guide like this, as they cover so many models that it makes it subject to a few errors. I do like the "Grille Identification" section they have though. Interesting to see the pics.

 

Personally, I would throw away any Motors/Chilton/Haynes manuals and just get a Chassis Service Manual.

 

Yeah, while they are indeed interesting, they are a little "information overload" for me right now. Is this the one you are talking about? If so, is the price good at around $70?

 

Don't get a reprint or a CD. Get a paper original. Reprints and electronic copies all came from scans of an original, and details tend to get lost in the translation. There are a number of originals on ebay right now. Least expensive one is $22.

Edit: that one for $22 is about ten minutes from my house. I may need to grab a spare!

 

Hey slow down there! Only if you are sending your original to me.

I also need to get an Assembly Manual that isn't blurry and sometimes has two copies on each page. I'll check to see if there are any originals of those around because the one I have is driving me nuts. My eyes aren't the best as is...

 

Check the larger swap meets. I found some in Portland last year in various conditions ranging between $25 and $45.

 

These HP ratings discussions remind me of years back one of the Daves on ROP commented about the W-31 being rated 325 hp. He said that yes, on the dyno it made 325hp at 5,400 RPM as specified by GM, but the HP kept climbing as the RPM increased to a bit over 6,000 RPM.

 

These are all "Rockets"!

 

Not only did the '70 W30 AT engine use the same cam as the non-W30 AT 442s, it also used the same cam as the 390 HP W33 and 400 HP W34 engines! Obviously it's that low-rise intake manifold of the Toronado that makes the 30 extra horsepower .....

 

Well, I top my good friend's new Stingray on torque (465), but I still doubt it on the HP at 460. Would be nice to brag about both though...haha!

 

Power was rated in a different manner back then, so don't get too excited.

 

Way to burst my bubble. Boooooooo.

 

Brian, that's not quite as far-fetched as it sounds. Chrysler experimented with a lot of different manifold configurations and some of the tests showed that a low-rise (OK, negative rise) manifold could increase ram effect in certain RPM ranges. That was the reasoning behind the cross-rams, though they also found that changing runner length would dramatically increase horsepower in certain RPM ranges.


Though I doubt Olds got into all that- they were trying to make the engine fit under the Toro's low hoodline!

 

Considering that the same 455 engine with the same 285/287 cam, the same big valve "E" heads and essentially the same carb and distributor was rated at 365 HP in the A-body, 390 HP in the B-body, and 400 HP in the Toro, apparently the W/Z exhaust manifolds HURT HP as compared to the crappy rear-steer B-body manifolds or the over-the-trans Toro manifolds...

Or, alternately, perhaps the factory HP horsepower ratings are unrelated to reality...

 

Did a search and found that Brian documented some real world testing of these engines: https://classicoldsmobile.com/forums...tml#post173087

 

Brian's opinion that most race engines launch at 3500 rpm is not real world. If you don't include foot brake racers no two step the i guess opinion would be a fair statement. I race pro foot brake quite a few are foot brake. Then again one of the motors he ref was not stock. Good read and thanks for posting the link.

 

I have seen a write-up on the Toro development wherein it stated that, being the company flagship, less performance would not be tolerated, in fact, more is required.


I had that one experience where I changed more than one thing but it went like this:


Race car
14.5 in the quarter
'69 455 Toro engine, HC at oh 10.25:1
Holley hi rise intake, Holley carb, special HEI? Ign.
C heads


I let him borrow an engine directly out of the '66 Toro parts car.
Almost untouched
squirrel fodder all over the intake
I did change WP and pulleys to that from his engine.
425 CID, UHC- 10.5:1 ?
112k miles old
I think I used his dist'r / ign also
same headers that were in the car.
Stock Lo-Rise Toro intman. Stock QJet.
13.5 quarter first run
12.9 after timing and carb adjustments.


I found that to be a most impressive showing.
To be fair, whoever built the 455 last had used ONE LC piston. Sheeeesh.
Still, the bone stock 112k mile old TORONAO LO-RISE 425 handed the "built 455" a severe spanking.