[grivera]

I am looking at a used Comp Cams HR cam listed as a 242/248 with no additional specs.

The stamp on the back of the cam has the following numbers: "001743-16, 3018B, 3039B HR 113".

Is anyone able to identify specs from that stamp? Lift, LSA, Recommended ICL, any advance ground in? Are duration and lift numbers with a 1.5 rocker arm?

[i82much]

3018B, 3039B are lobe numbers, check comp master lobe catalog. 113 is lobe sep.

[JLMounce]

3018 and 3039 are XFI hydraulic roller lobes. They match the durations you have listed.

So it's a hyd roller 242/248 on 113 LSA.

3018 - .365 gross lobe lift, 242 @.050, 165 @.200
3039 - .362 gross lobe lift, 248 @.050, 169@.200

I have a smaller comp that uses XFI lobes. They are among the most aggressive hyd roller lobes you can get. Yes my valvetrain is noisy, but I don't know if the lobe profiles contribute to that, or it's mostly the lunati lifters I run.

[grivera]

Thanks, Jason - that helps. Will

[Steve C.]

The lobes are listed on pages 23 & 24 here:

https://issuu.com/cpg-development/docs/lc2017_hi_res

Also note they have a "B" suffix code after the lobe number. With the code they can, but not always, alter the rated duration. Typically with 1-2 degree less duration.
The duration at .050" and .200" remain the same. Also sometimes a "B' suffix code can, but not always, add an additional 0.001" to the lobe lift.

Without the actual cam card you cannot tell if there is advance ground into the cam.



.

[Cliff R]

I ran an XFI profile on the old 455 that powered the Ventura. I did it as part of the cam swaps and dyno testing performed about 15 years ago. The specs were 284/296, 230/242 @ .050" and .361" lobes on a 112LSA.

It only made 3hp/4ft lbs more power than the Crower 60919 cam it replaced, but the numbers didn't really show all the improvements from swapping to a roller profile. The best ever runs with the Crower cam were 11.64 @ 115mph.

The 230/242 @ .050 XFI HR was good for 11.52 @ 118mph so in actual use the engine revved quicker and made more additional power than the dyno showed.

I would add here that it was dead quiet even with the aggressive lobe profiles, but would NOT rev past 5800rpm's with the valve train parts I was using. I even upped the spring pressure on the dyno and it still quit right at 5800rpms so the quick valve action just wasn't having those heavy HR lifters and other items on top of them.

When I built my next 455 I switched over to running Crower HIPPO lifters tight lashed at .005" on an SD Performance Old Faithful cam. It would rev to and right past 6000rpm's so quick you could barely move the shift quick enough to keep it from spinning well past 6500rpm's.

Lesson learned for me with HR's in these engines and I continued to use Crower HIPPO lifters on HR cams until I quit building engines here about 5 years ago..........FWIW.......

[grivera]

Thanks - it was purchased at KRE in 2017 so I sent them the info to learn whatever I can.

[grivera]

This is the response from KRE:

"Cam is :

292 adv 242 @ .050 .365 lobe lift
300 adv 248 @ .050 .362 lobe lift
113 Lobe sep no advance

So I would install this cam around 109-110. Lift with 1.5 rocker would be .547/543"

[JLMounce]

Originally Posted by grivera

This is the response from KRE:

"Cam is :

292 adv 242 @ .050 .365 lobe lift
300 adv 248 @ .050 .362 lobe lift
113 Lobe sep no advance

So I would install this cam around 109-110. Lift with 1.5 rocker would be .547/543"

Would probably run pretty nicely in either of your listed engines. I run a 232/238 112+4 spec'd from Kauffman in my 462. It makes good power, but is very tame. Incredibly smooth idle and makes power to 5600 rpm. I really think an aftermarket headed (even as cast) 460+ engine can use that additional duration.

I'd run 1.6 ratio rockers on it if your springs have the installed height to do so.

[Formulajones]

Originally Posted by grivera

This is the response from KRE:

"Cam is :

292 adv 242 @ .050 .365 lobe lift
300 adv 248 @ .050 .362 lobe lift
113 Lobe sep no advance

So I would install this cam around 109-110. Lift with 1.5 rocker would be .547/543"

I run the same duration hydraulic roller cam but with slightly different lobe lift. It's a 242/248 but lobes are .360 intake and .375 exhaust and it's ground on a 110 LSA which makes the idle a little more aggressive. Been running this cam for 25 years and it's a pretty good performer in a 450-470ci engine with decent street manors.
With a 113 LSA on yours I would expect it to idle quite a bit smoother and make more vacuum. Probably pushes the peak HP up a bit more as well.

[grivera]

This is the rest of the package: https://forums.maxperformanceinc.com...d.php?t=867753

[grivera]

No luck getting a cam card via KRE. Is this enough info to degree the cam?

Recommended install ICL: 109-110
Lobe Separation: 113

Lift: Intake .365 / Exhaust .362
Duration at .050 Intake 242 / Exhaust 248
Valve Lift with 1.50 Rocker .547 .543
Valve Lift with 1.65 Rocker .602 .597

[i82much]

how is it that xfi lobes are considered more "aggressive" than magnum lobes, yet those lobes have more .050 duration and less lobe lift than the 3122 magnum lobe (236 and .3800) on the original old faithful cam?

[grivera]

Cam card created - hopefully it's accurate