Another cam selection thread.

[kjalltrac]

Welcome to join the club

 

[Bee1971]

Found this, very interesting.
Pretty close to my combo
https://www.hotrod.com/articles/mopp-0312-solid-vs-hydraulic-lifters/

Great article , and dead nuts with my XE 275HL at 5200-5400 RPMs

Thanx Scott

 

[kjalltrac]

Are you looking at solid cams as well?

 

[Bee1971]

Are you looking at solid cams as well?

I have all Winter to figure that out I guess

 

[justcruisin]

I haven't run my car at the track for some time but I ran the xe275hl cam in a 440, I shifted at 5500, any later and it would slow down, it typically ran 12.8's at 110. It is a dedicated street car with a true street tire and 3.23's so the trap RPM was well under the shift point. I have a solid to throw in at some stage, will be interesting to see the difference.

 

[kjalltrac]

So.. Narrowed it down to these two cams.
Trying to calc the dynamic compression but the ivc for the lunati is speced at 0.02 lift and the Hughes at 0.05 lift.

Lunati 30230742:
[email protected]: 251/259
Lift. 566/.586
Lsa/icl: 110/106
Ivc @.020: 52 deg

Hughes stl4650bs:
[email protected]: 246/250
Lift:. 576/588
Lsa/icl: 108/104
Ivc @.050: 47 deg

Im at 10.3 static comp
I've calculated the Hughes cam to be at 8.3 dynamic comp.
Can anyone help me calculate the Lunati please.
Thanks

 

[Hemirunner]

So.. Narrowed it down to these two cams.
Trying to calc the dynamic compression but the ivc for the lunati is speced at 0.02 lift and the Hughes at 0.05 lift.

Lunati 30230742:
[email protected]: 251/259
Lift. 566/.586
Lsa/icl: 110/106
Ivc @.020: 52 deg

Hughes stl4650bs:
[email protected]: 246/250
Lift:. 576/588
Lsa/icl: 108/104
Ivc @.050: 47 deg

Im at 10.3 static comp
I've calculated the Hughes cam to be at 8.3 dynamic comp.
Can anyone help me calculate the Lunati please.
Thanks

Wallace racing calculator says 8.9 dynamic using 52 degrees IVC.

 

[kjalltrac]

Wallace racing calculator says 8.9 dynamic using 52 degrees IVC.

That must be wrong, rhe wallace calculator requires seat to seat specs.
I only have 0.05 and 0.02 specs

 

[Hemirunner]

That must be wrong, rhe wallace calculator requires seat to seat specs.
I only have 0.05 and 0.02 specs

It does require seat to seat. I used the .020 figure. Using Lunatis advertised duration of 280/288 it gives an IVC of 66 degrees. Putting that in Wallace gives an 8.09 DCR.

 

[biomedtechguy]

Since a couple of you have said your engine is nosing over at higher RPMs, my experience with my 440+6bbl was problems with the hydraulic lifters and springs that were in the engine when I bought the car. I missed a shift and one collapsed, but pumped back up after a minute or so. The next time I missed a shift (I had to replace my shifter and the hardware, it was all wrong) a lifter collapsed and stayed that way. Also, the engine would nose over, or fall on its face right about the time it was really coming into serious power, at the beginning of that peak, around 5k. I suspected weak springs, and I was right-after having the spring pressure measured they were way down on force both open and closed.
I replaced the hydraulic lifters with CompCams hydraulic lifters and CompCams springs, locks and retainers.
Ever since then, my engine pulls HARD to 6k and seems to always want to go to 6,200 hard. The only explanation I can give is the cam (purple stripe suspected to be 292°/.509) headers, and 6bbl intake.
When I get it on a chassis dyno I'll know the truth, but I'm not pushing it to 6k, it WANTS to go there!

 

[PRHeads]

The Hughes cam is ground by Howard’s.

Howard’s shows that [email protected] lobe to have an adv duration of 274....... but they don’t specify at what lift figure that’s at.
It’s probably .020, but I can’t say for sure.

 

[kjalltrac]

Due to the covid situation, there has not been any racing.
However, I finally ordered a camshaft, I think will perform pretty good.
Howards cams, if the valve to piston clearance allows, I will use 1.6 rockers for a lift of 0.6

Year:
 1959 - 1980
Make:
 Chrysler

Engine:
 383-440

Camshaft Type:
 Mechanical Flat Tappet
Basic RPM Range:
 2500 to 5800
Valve Lift Intake:
 .576
Valve Lift Exhaust:
 .576
Duration Intake:
 274
Duration Exhaust:
 274
Duration at 050 Intake:
 246
Duration at 050 Exhaust:
 246
Lobe Separation:
 108
Intake Centerline:
 104
Firing Order:
 1-8-4-3-6-5-7-2

 

[LemonWedge]

I’ve had decent success with a cam in the range you’re looking at in my 451. I run an Engle solid flat tappet on a 109* LSA; 252* @ .050 & .573 lift with 1.5r. Square pattern. I don’t think Engle is around anymore, but this was a custom grind using their KV3 lobe. I now run 1.6 rockers which moves lift to about .611. I lash it at .018e & .016i. Combo is 400/451 @ 10.6:1 with CNC’d Stealths, an RPM intake with a 1000 annular 4150, 1-7/8” headers, a 9-1/2” converter and 4.10s with a 28” tire. It’s porky at 3875 with me in the seat. It drives pretty nicely on the street although nobody sitting next to me at a light is going to mistake it for stock. It typically runs 11.2x’s at 118.

I like the look of both Howard’s and Hughes specs, but I don’t know much about cams. It was notable with my combo that went I went to the 1.6 rockers, it picked up nearly a full tenth. This tells me that the rest of the combo could make use of more cam (??). I’m currently in the process of changing some of this though. We’ll see if my changes yield good results or not.

good luck with your build. I like the cam you picked, and wouldn’t hesitate to be a little more aggressive if anything.

 

[kjalltrac]

Update,
Well, pretty much impossible to get a cam these days.
I found a swedish company that had a cam on the shelf, so I pulled the trigger

 

[66Satellite47]

I'm sure you will be happy with that choice.