Another Camshaft Opinon

[RCE1962]

The 409 is currently being rebuilt.


The engine has retained its 11:1 Ross pistons and will have the 690's installed with new stainless valves, and remaining components. The intake and carbs will be stock 1962 (2X4) however will be rebuilt..lines, fittings, and linkage etc.

Currently the car has a manual 4-speed trans and will most likely consist of a 4:10 to 4:56 posi rear.

I'm still stuck on the Z11 cam issue. Should I go Isky Z11 or install another grind that may be similar but, as a previous post indicated, would assist on the weak exhaust side for the Isky Z11 cam.

Although I tend to keep everything...(pack-rat)...I may look at this rebuild and the car, as a potential offering for sale in a few years. Not sure yet. But if I sell...will the 409 crowd prefer the 110 LSA - "Z-11" cam in this engine or a cam that is a "custom" grind?

This is not a numbers car but will hopefuly be an above average, factory looking re-creation, from engine bay to interior, as well as, exterior.

Yes...I know the 1962 -409 had quite different cam specs, and I have the 409-425hp Isky cam in the engine now. Nice low-end response, but in my opinon, the engine/cam should sound a bit more lumpy/performance. I guess it may be a 1960's thing.....

What does the forum say???

Ron






Ron

[models916]

Modern grinds can idle smooth and produce superior power. If you like the old sound, expect to lose some power. Most mfgs. offer Muscle Car Grinds from the past to sound like the factory cams, but they are down on power. I would call Crane or Comp for a cam. No extra charge for custom grinds. Less than a week on delivery.

[chevytaylor]

Ron,

I found the Isky Z-33 grind to be an excellent cam. Not a race grind by any means but just a good all rounder. It all depends on what you want to do with the car.

Fellow member Aubrey has a good selection of grinds available.

Here's a couple of cam cards for everyone to comment on.

chevytaylor :D

[Bungy]

Ron, you don't consider 250 degress duration @ .050" lift a race grind? Yikes! What do you consider a race grind?

[RCE1962]

Ron, you don't consider 250 degress duration @ .050" lift a race grind? Yikes! What do you consider a race grind?

Hi Bungy

Yes I would consider that a race grind but I wasn't referring to that...just inquiring if there were other favourites here, that are close to this one.

Ron

[Bungy]

Sorry Ron, I meant to address that question to chevytaylor.

[CDNpontiac409guy]

The factory stock 1964/65 high perf cam has 250 deg @ .050":dunno

Anyhow... my favourite street performance mechanical:

M-242595D
Lift: .595"/.608" ( net lift at valve, using 1.7 rockers, after lash... appox. .557"/.570" )
Adv duration: 272/276
Duration @ .050": 242/246
Grind on 110 or 108 centre line

A number of members here are running this cam. Perhaps someone will chime in with their thoughts on it ?:coffee:

[Skip FIx]

Just remember too guys in comparing a solid to a hydraulic because of the solid's ramps you need to ADD 10 or so degrees at 0.050.

[jim_ss409]

Just remember too guys in comparing a solid to a hydraulic because of the solid's ramps you need to ADD 10 or so degrees at 0.050.

Good point!
I find with my limited knowledge that comparing hydraulic and solid cams can get tricky. I think that the advertised duration of most hydraulic cams is based on .006 lift and most solid cams use the recommended valve lash, .016 for example, when figuring the advertised duration. Apparently a hydraulic lifter compresses about .006, but I think Crane Cams uses .004 :scratch But I think you can pretty much use the advertised duration number as a direct comparison from a solid to a hydraulic cam.
But we often use the duration at .050 instead of the advertised duration because it gives us a better idea of how large or small the cam is. So while the hydraulic cam would loose about .006 at the valve because of compression the solid lifter looses .016 because of valve lash.
So I tend to deduct about 8 or 10deg. from the duration at .050 figure from a solid cam when I'm comparing it to a hydraulic.
Therefore I think a solid cam with 250 deg. duration @ .050 is comparable to a hydraulic cam with 240 deg. duration @ .050
Of course, most solid cams have more aggressive lobes so it's fairly hard to really compare the two.
I might be wrong about this but that's the method I use to compare duration @ .050

By the way, I think the specs. on the cam Aubrey listed are great for a street performance cam.

[fatride]

It seems to be the duration under the curve that makes a hydraulic and a solid hard to compare! With a faster ramp the solid is opened to more air fuel charge even if the duration numbers are simular.