Camshaft choice for 408 Magnum w/ boost plans

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thomasfouraker

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I have two camshafts on hand and am hoping one will be suitable for my plans.
Being that I dont know anything about the numbers on camshafts, I hope the community can take the information I do know and can provide me the best option.

2000 Dodge Ram 4x4, trying to keep power low...... idle-5000
Keeping EFI
Hughes Airgap
408 9.0:1 compression
RT 2.02 Heads
KB356 pistons
Eagle Forged Crank
Eagle Forged I beam rods
55mm F&B Throttle body

Cams on hand are:
Hughes HER1828ALN
Comp 20-746-9 XR265R-14

Springs are Hughes 1110 good to .550"

I have the option to use 1.6 or 1.7 Roller rockers to adjust lift accordingly.

Below I will attach each card.

Here is the catch, within the next year I plan on adding a Kenne Bell Supercharger that should provide 6-7 lbs boost. Ideally I would use a Cam that would not need to be swapped out at that time. I am gapping my rings for the boost now with future plans in mind.
 
Cam cards attached.

0FCB005F-23B6-4B62-B542-0B0DE6FA1F74.png


15973103-267B-40C2-BE49-CE2E67AE1ACB.jpeg
 
The two cams are close enough that you probably won’t notice a difference. Ask for the valve timing at .006 from Hughes and see what they say.
 
There basically the same cam. Are the heads ported? Stick one in and run it.
 
I would run the Hughes with 1.6s for the lift factor alone.
 
How many CC’s are those heads?

Those pistons have a 23.5cc dish and will be at 9:1CR with a 72cc head chamber
 
rumblefish360 said:
There basically the same cam. Are the heads ported? Stick one in and run it.
Click to expand...

The heads are ported with a nice bowl blend for the larger valves.
I should have clarified that the Comp Cam is .506 with 1.6 rockers and the Hughes is .544 with 1.6 rockers. I can up the Comp to .537 by running the 1.7 RR I have.

MOPAROFFICIAL said:
I would have a cam ground for the supercharger. There is what "Works" and whats 'ideal'
Click to expand...

It seems even amongst popular engine builders there is a varying opinion of what "ideal" is. I wish I had a greater understanding of the science behind cam specs and valve timing and how that dynamic changes when boost is introduced. I have sent duplicate messages to the same people months apart and gotten different answers before. Wish someone could put it simply and say choose A because of X,Y and Z.

MiradaMegaCab said:
How many CC’s are those heads?

Those pistons have a 23.5cc dish and will be at 9:1CR with a 72cc head chamber
Click to expand...

The piston quench dome has been milled down. The heads are 63cc. From my preliminary calculations I should be hovering around 9.0:1 CR but will know for sure once I can CC the cylinder and dial it in with my head gasket or combustion chamber porting.
 
As Richard Holdern would say, any cam is a blower cam, what ever it does NA it will do under boost. (Cam vs cam, NA vs Blower cam, run both NA & under pressure.)
 
If you can get the seat timing from the Hughes cam it will tell you if it has a faster lobe than the comp which may be of some small benefit. But reality is they are both about the same. Especially if you use the 1.7s with the comp and get the lift similar.
 
MiradaMegaCab said:
Hmm, those KB 356 pistons are Hypereutectic, milling the domes, coupled with boost is a gamble.

Try these out, forged 2618, designed for boost with a 34cc dish. You’ll still be around your 9:1cr.
Icon Pistons IC982-030 Fits SB Chrysler Dish 34cc Bore 4.030
Click to expand...

No.
I've lrun them more than any other type of piston and i will tell you..they are made to be milled to your desired quench distance.

My 410 with a 60cc chamber and a .046 gasket i had 9.8 compression. I squared the block, all pistons were zero at the quench ledge with the actual pads above the deck .046 or zero with the gasket. I had to grind about .020 worth put of the shallow side of a set of J heads to end up with the target .030 quench distance.
The piston just need plenty of top ring gap and not too much total timing. When all is 'right' ...30 degrees or less is where they live long.
 
6PSI of boost and a 150 shot of spray coupled with excessive RPM’s (7,000+) don’t do well with hyper skirts.
I’ve never burned a piston or popped the crown from a butted ring land.
I’ll have to try out these KB 356 pistons.
How much did you mill off the pistons?
Looks like I’ll need to mill off 7cc worth of volume across a 4.030 diameter.
And, yes, I stayed at or below 30* total timing with non projected tip spark plugs.

What’s your preference on main bearings, half groove or full groove for full time oiling to the rod bearings?
How much boost were you running??

TIA Cheers!
1A0A97BF-5589-4E98-AC21-81A00C97A94B.jpeg
 
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