Stocker Cam Lobe Profile ?

[Aubrey N Bruneau]

On the gear change, of course it doesn't drop to 4500. Transmission has only a 2.83 first gear, so in terms of modern drag racing stick shift... it's almost a close ratio.
I know... not enough first gear for a 3640 pound car.
Also, these engines have a nortoriously long torque curve... never a lot, but very flat. A wider spread in gears would be better. Peak torque is at 4600-4800... still within 5 ft pounds at 5400 RPM. More gear spread would allow the engine to fall back into the real "thick" of the torque.
Simple math, if I lower the RPM range of the engine, I have to go taller gear ratio in order to retain trap speed.

Alan, I don't know WHAT you are using for a spring, but I've studied the hell out of this, and I can't find a single spring that will get near those figures. Also, in these engines, there's no room for a 7/16" pushrod ( the "pinch" in the intake port, adjacent to the pushrod hole, is already paper thin ). Can't be done. I have 3/8" Manton.
Also, header tube length under about 42", with a merge collector... ? Impossible, period. Chassis will not allow it. My headers are about 33"-34" long.16" total collector length.

maybe it's just destined to remain a slug ? ! ! !

[Pvt Parts]

"Currently, the engine never sees below 4500 RPM on a run"


You'd better be making peak torque no higher than 4300 rpm.

200 rpm above peak torque is the basement. If you drop below that it won't recover.

[Alan Roehrich]

You might get by with a 3/8" x 0.125" wall. Consider a dual taper, Trend has a dual taper 3/8" - 7/16" pushrod, it's 3/8" on the ends, and 7/16" in the middle. Trend will measure for you to see if they can make something work.

You do not have to run a single spring any more. They opened the spring rule up.

Not sure what you mean about the headers. If your headers are 33-34" long, with a 16" long collector, that's about what I was suggesting, length wise. A merge collector will fit where a plain collector will.

[Aubrey N Bruneau]

Originally Posted by Alan Roehrich

You might get by with a 3/8" x 0.125" wall. Consider a dual taper, Trend has a dual taper 3/8" - 7/16" pushrod, it's 3/8" on the ends, and 7/16" in the middle. Trend will measure for you to see if they can make something work.

You do not have to run a single spring any more. They opened the spring rule up.

Not sure what you mean about the headers. If your headers are 33-34" long, with a 16" long collector, that's about what I was suggesting, length wise. A merge collector will fit where a plain collector will.

HEE HEE !!... I could use a pushrod that has the bottom 3 inches 7/16" in diameter, but I'd have to put the pushords in place, then install the heads over them ! !
My pushrods ARE those ridiculous, almost solid wall things.

No more "stock spring arrangement" ?
HHMMM. they really are loosening those rules, aren't they ?

The header tubes can finally merge together, under the frame, at about a 30 degree angle back from straight out the sides, approximately 12" from the outside of the car.
A merge collector piece such as this one that I just used on headers that I built for a customer car.... would actually exit out from under the front fender, extending about 6" outside the car !
Can't be done.

[CFMCNC]

Aubrey ,You can get Manley to make valves on there Gen2 custom stainless blanks.Also look at how much coil bind clearance you have ,too much may cause spring bounce or surge.We agree with Billy Nees and others ,the headers are probably to big.We see engines that get The National Dragster Tune Up ,Big headers,Big carb,bag of ice on the manifold and take 2 quarts of oil out.Bill C.

[Aubrey N Bruneau]

I know, Bill... the 'ol "bigger is better" thinking.
I suupose I could try and justify it by saying that it alreadhy has the "bigger" carburetion... and that I was just trying to follow suit ?

Anyhow
I just had a lengthy conversation with the Stocker guy at Comp Cams.
One thing I know for sure now... you guys with the BBC's, spinning big RPM, are NOT using a lobe that resembles this intake lobe that is on my cam. He confirmed that it is NOT an RPM stable lobe... especially with inherently heavy valves / high ratio rockers.

So, I have taken heed to everybody's recommendations and advice.
And it looks like I WILL build a new set of headers.

If I can retain even half of what I learn around here, maybe I won't blow up again... and maybe even go faster ? !

thanks guys

[Alan Roehrich]

Originally Posted by Aubrey N Bruneau

Anyhow
I just had a lengthy conversation with the Stocker guy at Comp Cams.
One thing I know for sure now... you guys with the BBC's, spinning big RPM, are NOT using a lobe that resembles this intake lobe that is on my cam. He confirmed that it is NOT an RPM stable lobe... especially with inherently heavy valves / high ratio rockers.

So, I have taken heed to everybody's recommendations and advice.
And it looks like I WILL build a new set of headers.

If I can retain even half of what I learn around here, maybe I won't blow up again... and maybe even go faster ? !

thanks guys

THE stocker guy at Comp Cams = Tim Cole, or Chris Padgitt.

You're in good hands now if that's who you're talking to.

You're going to love what a good stable camshaft and valvetrain does for your engine program. You will now be able to use the cylinder head flow and the carburetors you have.

Let me know if you want to see about getting some REAL good stainless valves for that thing.

When you get the engine right, you should be able to use about a 3.05 first gear and a 5.14 rear gear. Just be ready to get it in second gear real quick.