Mystery Erson BB Cam

[65PlymSatellite]

I bought this cam because I was told it’s an NOS piece. Cam doesn’t appear to be used, but no info such as cam card was given.

 

[65PlymSatellite]

This measurement is the lobe width

 

[65PlymSatellite]

This is lobe HEIGHT

 

[1 Wild R/T]

So right @ .510 lift...

 

[Jerry Hall]

Is it even a Mopar cam. All the info I can find says Chevy small block.

 

[65PlymSatellite]

So right @ .510 lift...

Thanks! I was hoping a guru would chime in.

 

[65PlymSatellite]

Is it even a Mopar cam. All the info I can find says Chevy small block.

I was skeptical too, but I bought another cam that I’m going to use so I’d know the specs. The right cam is the one for sale, and the left is what’s going in my 440.

 

[Jerry Hall]

I was skeptical too, but I bought another cam that I’m going to use so I’d know the specs. The right cam is the one for sale, and the left is what’s going in my 440.

View attachment 1458464

Exact measurements between the two, I can't say, but the ramps look a little quicker on the cam you are using.

 

[BeepBeepRR]

Is it even a Mopar cam. All the info I can find says Chevy small block.

1962-1965 Mopars - Stories Read this article.

 

[1 Wild R/T]

Thanks! I was hoping a guru would chime in.

Keep hoping... No guru here... Just understand the math...

 

[65PlymSatellite]

Well it was moved over to this thread because I need to find out “what I have”.

Still for sale…

 

[65PlymSatellite]

Well it was moved over to this thread because I need to find out “what I have”.

Still for sale…

Sold

 

[Geoff 2]

999XX: 320 adv duration; 277* @ 050; 0.575" lift; 0.028/0.030" lash. Triple treated billet core.
Same grind number is used for 440 & Hemi. You would need to check the lobe positions to see which one you have.

 

[1 Wild R/T]

999XX: 320 adv duration; 277* @ 050; 0.575" lift; 0.028/0.030" lash. Triple treated billet core.
Same grind number is used for 440 & Hemi. You would need to check the lobe positions to see which one you have.

.575 lift? Don't think so... He posted pictures of the base circle dimension and the lobe dimension...

Lobe = 1.5555
Base = 1.2145 Subtract the base from the lobe and you get
Lobe Lift = .341 multiply by the rocker ratio, standard is 1.5 and that gives you
Valve Lift = .5115

 

[4mulas]

I think the 999xx is maybe just referring to custom grind only. Maybe the info is in the 1 94 numbers? Who knows?

kinda like mopar fender tag code for custom paint?

 

[Geoff 2]

1wild, where you are making your error is in ignoring the adv duration. With 320* adv of duration, measuring across the flanks to get the base circle diam will include some of the lash ramp.
The info I gave in post #13 is correct.
The 999XX designation is the grind #, not the part #. It is used in a number of popular engines.

 

[1 Wild R/T]

Advertised duration of 320.... On a cam because it runs at half crankshaft speed you have 720 degrees in a full circle. 360 = half a circle, calipers touching opposing sides & looking for the lowest reading should give you the base circle... If you miss a little your only going up one ramp... To add .064 to the lift means you missed the base circle by a bunch....

.064 divided by 1.5 (rocker ratio) gives you .042
Advertised duration 320 and an @.050 duration of 277 so 43 degrees of crankshaft rotation to pick up .044

You have half of 40 degrees from 320 to 360 and half of 43 degrees in the ramp to hit .050

So lets be safe and say it would take about 35 degrees of cam rotation

Not meaning to be a dick but the math doesn't add up...

 

[Geoff 2]

The maths does add up......if you do it correctly. This is a sol lifter cam, so 320* is at tappet lash.
Closest example I could find with actual numbers is an Isky 550. 330 * adv duration, 279 @ 050, 0.538" valve lift.
Yes, 720* of rotation. So half [ where you are measuring for base circle is 360* ]. This Isky cam @ 361* has 0.012" lobe lift, 321* @ 0.020" lobe lift. And this is just one side, you have to multiply by two.

As I said in the earlier post, with big cams you CANNOT measure across the lobe for the BC with long duration cams as a means of verifying lift.

 

[Geoff 2]

Here it is. It is also possible that the #s are misprints.

 

[1 Wild R/T]

Here it is. It is also possible that the #s are misprints.

View attachment 1462281

Vintage catalog is hard to argue with, I would love to throw that cam on a set of V blocks & map it to see what it really is... Maybe the guy who bought it can post, most guys can't throw an unknown cam in an engine without figuring out what they are working with...