Hi, Below is the spec sheet I received from the builder of my 455 (69) engine. Since I don't understand CAMs I don't know if this is a good CAM, BAD CAM or wrong CAM. The engine was rebuilt by a Speed Shop a friend recommended. Brian Darcy, who is now a professional Drag Racer was in on the build. My car ran fairly well for a few years. I add an MSD distributor and Quick Fuel Carb. I also had the 12 in rear changed to 391 gears. I just feel I am not getting the

power out of the engine I should. The heads are C heads, but were not rebuilt. I have had this car for some time now and it has done very well at car shows.

One other item. The car has run very rough when I first start it. As it warms up it runs smother. It has always run a little rough and was sold that it was the CAM the makes run a little rough/rocky.

If the heads have to be redone, I am looking at the Mondello heads.

 

That cam card is for a very mild cam. It should never run rough, even starting--that's probably a carb problem.

With a 3.91 axle it should burn those rear tires from a start until you get to I-84.

The cam should give you a lot of torque off idle, so it's a mismatch to the 3.91 axle.

A 455 with that cam would have punch with a 2.78 axle ratio.

 

Can't say if it's a "good" or "bad" cam as that depends upon compression ratio. What's good for a high compression ratio may be bad for a low compression ratio and vice versa.

It's odd that the valve lift is shown for a 1.8 rocker ratio, and Olds is typically 1.6, which would put it at .469" valve lift.

The 214/221 duration seems like a moderate cam for a 455.

The rough running at startup if more likely your carburetor choke than it is the cam.

 

Yes, very mild for a 455. Agreed on the cold start problem as well.

 

That cam card says it is for a first-gen Olds motor, not a 455. Are you sure that's even the right card for your cam?

 

Wow, I totally I missed that, but I saw the 1.8 rocker ratio. Is that what the first-gen engines used?

 

You've now exceed my knowledge of the first gen motors.

 

I was gonna say...that's the first thing I saw was '49-'55 Olds...

 

I thought the same, but never took the time to research. I will see if I can contact the builder and Engle Came. See what they say. I believe one cylinder is not firing when it's cold. I thought it was the carb initially. I had an Edlebrock 750 so I had it rebuilt. Still had the same problem. I then installed a Quick Fuel carb. Nice 730 carb. Still the same problem. I just have the feeling it's one cylinder. I know I need to do more research. I have been wrestling with Parkinson's and have a good deal of difficulty doing things, but still slowly do some things. I may have to farm this one out. I have always appreciated all of your help over the years.

I'll add more after I find out more.

 

I hope those are Bernard Mondello's heads you are talking about. The other Mondello Performance heads are no doubt out of box Procomp heads with their name on them and jack up the price.

 

Think about this for a second and you will realize that a problem with ONE cylinder can't be caused by the carb. The same barrels on the carb feed all the cylinders. How can it selectively cause a problem with only one?

 

Thanks Joe, I​​​​​​I do not think it is a carb problem either. I am leaning towards a flat lobe or a valve problem.

 

Sorry to read about your illness but it's good you are pushing on with your Oldsmobile hobby. I'm thinking you have a leaking valve (probably a couple). I'd do a compression/leak down test for starters. Good luck and keep us informed.

 

OK, I finally got a hold of Chris at Engle Cams. He stated that the cam on the card could not be the cam in my 455. It simply would not fit, as the journals on the cam, outlined on the card, are smaller then the ones on a 455 cam. The card outlines a very mild cam. Not sure how the cam card got attached to my invoice, but it is not for my car. So, that settles that. Off to run compression tests and we will see where we go from there.