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Goto 540 or Tweek out the 489

Old 05-05-2022, 12:43 PM
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Originally Posted by jeffswav
Anyone have experience with this cam?
https://www.cpperformance.com/p-1675...-camshaft.aspx
Specifically says "Will not work with silent choice or switchable systems".....

Why is that? Curious....

Thanks. Brad.
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Old 05-05-2022, 03:24 PM
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Originally Posted by jeffswav
Anyone have experience with this cam?
https://www.cpperformance.com/p-1675...-camshaft.aspx
244/248... you better have great flowing exhaust runners. That split is to close in my opinion.
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Old 05-05-2022, 06:17 PM
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Originally Posted by Rookie
244/248... you better have great flowing exhaust runners. That split is to close in my opinion.

worked well in mine with 2” cmi. Non ported. JME
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Old 05-05-2022, 07:48 PM
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Originally Posted by getrdunn
worked well in mine with 2” cmi. Non ported. JME
Not saying it wouldn't work, I just don't believe it would be the best choice if buying a new cam. If it was sitting on the shelf I would definitely throw it in.
Switched out a straight split cam with one that has a 6° split and it was much healthier and better performing. These heads were optimized and have great exhaust ports. JMO
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Old 05-06-2022, 08:16 AM
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Originally Posted by Brad Christy
Specifically says "Will not work with silent choice or switchable systems".....

Why is that? Curious....

Thanks. Brad.
(937)545-8991
Reversion. You have to have long risers or dry exhaust.
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Old 05-06-2022, 08:25 AM
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Originally Posted by getrdunn
No but I like it. Very similar to mine with a little less lift but not much… like .013 less + -
This would be a little easier on VT

623 hp at 6k on my 496’s - same duration!
Here are the heads I have, great flow numbers with the big valves. 10.3 compression, EMI exhaust with long wet risers.
https://www.flotekheads.com/store/Bi...2cc-p130160438

Last edited by jeffswav; 05-06-2022 at 08:30 AM.
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Old 05-06-2022, 08:51 AM
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Originally Posted by SB
More round table talk….

Another note: if you are truly at 10.3:1, the cam you have is too short in duration. The cam you have was trying to achieve more cylinder pressure , which you don’t need nor want now.

Note#2: You where reving 5500rpm. My guess is that was just passed max power. 224 is a tow truck cam for near 500cid.

Somewhere 236-240 at .050” intake duration is where your motor will want to eat. Prob 240
You have an exhaust to handle it?
Any downside to using this cam again for the season? I ran it last year with no problems. Probably going to switch out as a winter project.
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Old 05-06-2022, 09:26 AM
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Originally Posted by jeffswav
Reversion. You have to have long risers or dry exhaust.
Jeff,

I always thought the key to mitigating reversion was lob-sep of 112 or more. No?

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Old 05-06-2022, 09:47 AM
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Originally Posted by Brad Christy
Jeff,

I always thought the key to mitigating reversion was lob-sep of 112 or more. No?

Thanks. Brad.
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-As you add duration you also add overlap.
-Tightening lobe centers (lsa) does also.
-Amt of Exhaust open degrees past TDC on intake stroke is what really means the most when it comes to reversion possibilities since the exhaust valve still open (but closing) when piston going down drawing in air from both valves (intake valve starts opening before tdc intake stroke) at lower rpms.

Look for some of my cam charts comparing the mag 454/502MPI/ HP500/Crane 731/500EFI/525EFI/Crane 741 and you’ll see seat overlap, .050” overlap (including btdc and atdc), etc, etc. Really good info that if studied, paints great pictures. :thumbs

Last edited by SB; 05-06-2022 at 09:50 AM.
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Old 05-06-2022, 10:32 AM
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Originally Posted by jeffswav
I talked to RMbuilder a few days ago. He seemed to think I could get 620HP out of my engine. I would need AFR heads, new cam and bump up comp.
It`s killing me.


EDIT: didn`t realize this is an old thread .

Last edited by ICDEDPPL; 05-06-2022 at 10:45 AM.
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