I was just reading the Olds factory H/O spec sheet that came that came with my GM of Canada documents for my 69 442.

I never knew Oldsmobile made a dual pattern cam for the 69 H/O

Advertised duration

285 int 287 exh


They also used some healthy valve springs

125 lb closed
308 lb open


Came could have used a little more lift only .472




The sheet did not list valve spring spes for the W 30
Does anyone no what valve spring the W cars ran?

 

Thats looks like the same grind as the mid change on the stick shift 310 hp L74 350's not much of a split grind though 2 degrees ish guessing its about 210 @ 050 ? Seems small for H/O 455

 

That's P/N 400165, used from 1968-1971. It was used in the following:

Police Package 455s
455 marine engines with 4bbl
1968-70 W-34 Toros
1968 H/O with A/C (non-A/C cars got the 308/308 cam that year)
1969 H/O both with and without A/C
1970 Cutlass Supreme with 455
1970 442s with A/T (INCLUDING W-30s)
1971 442s with A/T (except non-A/C W-30s)
1971 W-30s with A/C

 

Thanks for the reply's
Joe your knowledge always amazes me.
I had know idea that it was such a common cam, it did say on the paper work same as L32 engine except for then it listed all the parts and a cam was not on the list.

Joe do you know what valve spring they used in the 68/69 W30/31?



Yes it is not much of a dual pattern cam just never new Olds made one

 

Not so rare. For example, five of the eight cams used in 1970 were dual-pattern. Ironically, the W-30 with MT, W-31, and mid-year 4-bbl 350 with MT -- in other words, the performance engines -- were the cams with equal intake and exhaust duration.

 

Dual Pattern? Really?


So now a cam with 2 deg more exhaust duration is considered a "dual pattern' grind.


Hmm.... learn something new every day.

 

the lift couldnt be more in order to meet the stock nhra

 

So the 390 and 400 hp rated H/O and Toro have this 285/287 cam? But the real HP of a 308 or 328 degree W30 455 is what ?

 

370hp or so with a 328 these hp ratings come from olds and all of them are probably underestimated

 

For shure man, that is silly the "mild" 455 HP versus a huge cam 455 rated less ...didn't recall seeing any old magazine dyno tests to show the real HP of the W30 stick motors with headers. Like when they took a Ls6 450 hp 70 Chebbie 454 and with manifolds it only made 380 hp but made 451 hp with headers. This explains the street stock performance not out classing the the "inferior" BOP cars..LOL

 

Whatever, just passing the ratings from olds

 

Not bashing just find it all funny.

 

Not in the modern world of cam design where lobe ramps can very from int to exhaust, and lift and duration numbers have much larger variations.

 

Well, they certainly aren't the SAME pattern...

I'll also point out that total lift and advertised duration are NOT the only metrics of a cam pattern. It's certainly possible to have two lobes with exactly the same lift and duration that have different ramps and thus different patterns.

This has been discussed many, many times. An even bigger mystery is how the 1970 W-30 with AT and the 285/287 cam made the same 370 HP as the manual trans version with the 328/328 cam.

Obviously, this had more to do with limiting advertised HP to 10 lb/HP (370 HP in a 3700 lb car) than with the real numbers. As I've posted often in the past, in a period article, noted automotive journalist Roger Huntington tested several musclecar engines on a dyno and reportedly got 440 HP out of a 1970 W-30 motor with the 328 cam.

You should also ask yourself why Olds went through the trouble to develop F head castings when the Toro motor allegedly made more HP with the E castings. The answer is, in reality it didn't.

 

You should also ask yourself why Olds went through the trouble to develop F head castings when the Toro motor allegedly made more HP with the E castings. The answer is, in reality it didn't.



This is a good point Joe.
It might not mater if you are porting heads what you start with but in stock form some are better than others.
Only sure way of knowing is through testing on a running engine not just a flow bench.

 

That 440 hp sounds about right for a 10:1 455 with a big ole hyd cam , I would like to see that article. I will take a look for it. For what its worth, I know the Poncho equivelant engine ratings were done with the stick version of the engines that were normally one up larger on the cam. In some cases it is a pretty drastic difference.