This may seem like a really dumb question but here goes. My 70 W30 4 spd (confirmed with broadcast cards) had it's original cam replaced with a standard 70 442 cam. I'm having her completely restored. So she will be getting the correct cam. Here's my question. She ran VERY strong with the wrong cam. What, if anything, will change with the correct cam? I was told once that the W30 cam only really worked with steep gears. I have 433s. Thoughts....

 

I had the opposite problem. I put a 4 speed W30 cam in my 1970 W30 automatic and my car ran over a full second slower in the quarter mile. My elapsed time went from 13.28 ET @ 106.28 MPH with the automatic cam compared to 14.40ET @ barely 100MPH with the W30 4 Speed cam.
This was in the strictly stock class, street tires, and factory exhaust.
My conclusion is that my 1970 W30 automatic wouldn't run with the W30 4 Speed cam which was too radical for the 1970 W30 automatic.
FYI: The 1970 W30 automatic cam is identical to the 1970 455/365 442 cam.
I hope this helped.

 

The 328 degree cam really likes headers and fairly open exhaust.

 

I believe the cam you referenced at the end there is what I had in mine. I'd have to find it to confirm that. But I'm pretty certain that's what it was. As a 4 spd car with steep gears, she ran hard, very hard with this cam.

 

How does it feel about W/Z manifolds and turbo mufflers? lol

 

Back in 1973 I ran a 431 with the 328 degree cam and -877 Turbo Mufflers The car was about 1/2 second quicker in the quarter with cheap headers vs. the manifolds, iirc.

 

It will run fine with the 4.33s. Give it plenty of initial timing. The 328 cam is too much cam for exhaust manifolds, Olds was planning for racers to swap to headers. One of the Pure Stock drags guys switched from a 308 cam in a 455 back to the original 442 cam (285/287 or whatever it is) and the car gained more midrange power, but hasn't been noticeably faster in either configuration. The downside of the 328 is not only the increased duration, Olds narrowed the lobe separation, which increases the overlap. Overlap and exhaust manifolds don't really mix well for performance.

 

Thanks for sharing your experiences, guys; stumbling on threads like this is a cool way to learn.

 

Do you have the stock torque converter ? Whats the stall ?

 

Stock '70 W30 automatic with factory transmission .only change was the 4 speed cam which killed my cars performance.

I swapped back the automatic cam and ran low 13's @ 105-106MPH all day. Yes, only change was the cam.

 

The 328 cam won't work well with your stock torque converter.

 

Makes perfect sense. They both have the same lift. We Cam Doctored an original W-30 stick cam about 15 yrs. ago and the numbers were right on. The graph showed with the extra duration they were able to make the opening and closing ramps gentler. This would probably reduce the chance of valve float at higher rpm. Since these were warrantied engines I suspect this was deliberately done to reduce failures. Todays cams and springs can give you much better power. Good luck with your restoration.

 

I suggest a custom Comp cam like the XE274H but on 112 degree lobe centers for manifolds and max performance.

 

I appreciate the information. But I am restoring it to original factory condition. All this insight is very interesting though. Thanks

 

I used the 308 duration version in my 1970 442 automatic.

2200 stall and 3.91 gears - the cam worked well.

Decent isle, good vacuum, and power up to 6000 RPM.