408 xe274

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ir3333

ir3333

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larger displacement usually handle a little more cam
anybody running an XE274 Xtreme energy cam in a 408
..quiet valvetrain? smooth idle? performance?
 
i thought about this cam, went with a xr286hr in my 408 instead because i could get a pre magnum roller cam block. This one is pulling strong to 6500 rpm (my personal rpm limit). Since then the racing bug bit me, if i had to choose again i´d go even bigger with the cam, the crank and the heads......:D

I´d imagine it´s pretty mild in a stroker, idling nice around 750 rpm. I think the most usable power will be below 5500 rpm. What lift can your heads handle? Take a look at the XE275HL or sth. from Lunati. With enough initial timing there will be no problem with these cams.

Michael
 
.. just doing some research on a mild,streetable 408 with stock 72 cc heads
..no interest in a nasty idle,noisy valvetrain powerhouse.
 
I agree. That should work really well in a street cruising 408. I'd still use the 2200 stall as a min. As recommended by Comp.
 
I run the XE274S. I drive my car a lot. Putt around town, run errands, and such.

I don't like rumbling idle. It's about my limit. It's smokes the tires on the street at will. I'd trade HP/TQ on the low end for high end. But that because I like to go on road course track days here and there.

If I had it to do over I'd have it ground on a 112 LSA for smother idle. MRL does that when he runs a XE275 in a stroker. And maybe run the higher lift on the "HL" to keep power at the higher RPM's? I'd ask Comp about that though.

It's really tough to communicate idle loudness and roughness.

Here's a video of my car idling:

[ame="https://www.youtube.com/watch?v=-8QSTlvdqSs"]416 Idling sound walk around - YouTube[/ame]

Motor specs:
  • 416 stroker
  • SCAT rotating assy from IMM Motor (OU812)
  • X274S cam
  • edelbrock heads ported
  • M1-Single plane
  • BG Silver Claw DP "750" carb
  • open element air cleaner
  • hood pad
  • TTI step headers
  • X-pipe, full exhaust
  • TTI supplied turbo mufflers
  • 3.23 Sure grip with very short 24.6" diameter tires (3500 RPM @75mph)
 
ir3333 said:
larger displacement usually handle a little more cam
anybody running an XE274 Xtreme energy cam in a 408
..quiet valvetrain? smooth idle? performance?
Click to expand...

That cam is nothing a 4" arm can't handle.

It's really what your eventual combo will want? If your head flow is mild, and the compression ratio can handle it, you can even go milder? Could sound like a stock engine and still run easy 13's in a regulation weight A body with low 3 or even high 2 gearing in my opinion.

It's really going to depend on the components used, heads, compression, bolt on's, etc, and how much performance you're actually looking for?
 
I have a similar sized roller cam (227/231 .530 liift) in a 340 and it's fine for the street. 900 rpm idle with only a little bit of shake. In a 408 it should be pretty smooth.
 
no....the dart is finished but still needs license ,insurance etc.
i've been too lazy lately.
 
Thats going to seem mild in a 408. I run a XE285HL 20-228-4 cam. It idles smooth and comes off mild to me in my 408. 3800 stall.
 
71swing said:
Thats going to seem mild in a 408. I run a XE285HL 20-228-4 cam. It idles smooth and comes off mild to me in my 408. 3800 stall.
Click to expand...

I'd think the 3800 stall would help the idling in gear. What RPM does it like to idle at?

And here's someone's 410 stroker with a smaller XR280HR cam (64 degrees of overlap) that thinks the idle is too choppy: http://board.moparts.org/ubbthreads/showflat.php?Cat=0&Number=8249623&page=2&fpart=2&vc=1

XE285HL 20-228-4 has 71 degrees of overlap

XS274S has 54 degrees of overlap (my video above)

XR274HR-10 has 60 degrees of overlap
 
autoxcuda said:
I'd think the 3800 stall would help the idling in gear. What RPM does it like to idle at?
Click to expand...

Im sure it does help, mine doesn't seem too choppy. It idles somewhere around 800rpms. Im still getting things back together from unrelated upgrades. I hope to fire it up Monday. I will try and get a video to post.
 
here is my car at idle with the 285. idling at 900rpms because I had to reset my tune. Once the tune settled out I moved it to 750-800rpms.
71dart dwinger 408 stroker FAST ez efi: [ame]http://youtu.be/k5w13vVNnmE[/ame]
 
Mine is a 416 with XE274H and I really don't like it, it is tempermental and idles like crap. I have messed with the tune quite a bit and it is still a little "rough around the edges" if you will.
 
dukes69 said:
Mine is a 416 with XE274H and I really don't like it, it is tempermental and idles like crap. I have messed with the tune quite a bit and it is still a little "rough around the edges" if you will.
Click to expand...

Single plane or dual plane intake?

I think if I changed to dual plane mine would smooth some.

Mine seems temperamental to the idle throttle blade adjustment.

And it seems not to like Champion plugs. Switched to Autolite and last longer.
 
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