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Re: ADVANCING CAM TIMING 2-4*
[Re: Labratt]
#814533
09/29/10 11:50 AM
09/29/10 11:50 AM
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Joined: Jan 2003
Posts: 17,923
S.E. Michigan
ZIPPY
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 17,923
S.E. Michigan
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There's only one way to know on advancing the cam... The only type of motor I have ever deliberately done that on is low compression/small or stock cam beaters... You know, the stock '73-up 360 or 400 in a barge with 2.76 gears...I've had several...it works every time in that application but yours? I'm not so sure. Go with your gut. No matter what happens it'll give you some pretty valuable info.
Have you opened the lash yet to see if that has any effect? .003 or so looser than normal for a pass or two might make a difference.
If advancing the cam and/or opening the lash makes a huge change for the better, if there appears to be some "magic" in it, then (personally) I might start to wonder if it really had the right cam to begin with, but that's just the way my feeble mind works....
Mr. P has experience with collector extensions and can probably get you in the ballpark right quick. I think the usual rule of thumb is start with about 24" and go from there.
Rich H.
Esse Quam Videri
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Re: ADVANCING CAM TIMING 2-4*
[Re: Labratt]
#814535
09/29/10 04:19 PM
09/29/10 04:19 PM
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Joined: Jan 2003
Posts: 17,923
S.E. Michigan
ZIPPY
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 17,923
S.E. Michigan
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Collector extensions and/or X pipe shouldn't change peak tq rpm at all....peak should stay about the same but it will be fatter at and below the peak=it should hit harder regardless of what else is done. That was why I was asking if you ever considered that. It won't shift the peak down 500-700 rpm where it will match the converter better but it will help with everything else you already have. But will it get you into the 10s? Probably not, without other changes 
Rich H.
Esse Quam Videri
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Re: ADVANCING CAM TIMING 2-4*
[Re: Labratt]
#814536
09/29/10 04:32 PM
09/29/10 04:32 PM
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Joined: Jan 2003
Posts: 15,439
Val-haul-ass... eventually
BradH
Taking time off to work on my car
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Taking time off to work on my car
Joined: Jan 2003
Posts: 15,439
Val-haul-ass... eventually
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My 440's 266/266, 108 LSA cam is also installed on a 105 ICL. My CR is 10.8:1. My Dynamic 9.5" converter flashes to approx. 4500 from a 1800 launch off the foot. I've tested "a bunch" of different things and whittled my 60-ft. down to 1.45-1.46 on 275/60R15 DOT drag radials. Car & driver is 3750+ #s, so it's not a lightweight. IMO, raise your CR some, get the heads ported, and spend some time tuning the effer. Leave the cam ICL where it is so you know what gains resulted from the CR & porting. Oh, maybe put some 1.6 intake rockers (intakes only) on to help use the improved high-lift flow of the ported heads. Yes, you can loosen up the lash .004" from your normal setting to see if it "likes" a slightly shorter duration. Check w/ Dwayne or COMP on what the min / max lash for your cam's lobes are, since there is usually an acceptable range to run. My XX lobes are usually listed as running .020", but are OK running from .016-.024" (hot). All out of opinions on this subject... 
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Re: ADVANCING CAM TIMING 2-4*
[Re: Labratt]
#814537
09/29/10 08:39 PM
09/29/10 08:39 PM
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Joined: Jan 2003
Posts: 6,591
Canton, Ohio
Sport440
master
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master
Joined: Jan 2003
Posts: 6,591
Canton, Ohio
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Quote:
Zippity..never opened up the lash past what Comp calls for! Actually set them .004 tighter for quieter street operation! Don't get me wrong..I LOVE this cam Dwayne Porter picked out for me..just trying to find a little more bottom-end torque,coming off the line! What effect on the peak HP and TQ RPM do you think making said changes will produce??? Peak torque is at 5200,and Peak HP is 6000.   
Randy, IMO your Waay to worried about losing top end by advancing your cam by 3 or 4 more degrees.
Dont worry about it, you will be fine with that 260* cam. It will still pull way more RPM then you will need.
Do worry about posible P/V clearence though.
Advancing the cam will give you less on the intake valve as will shaving the head. Do you know your current clearences?? If so you can calculate the amount of shave and advance you can utilize.
IMO, I would do All 3 things on the shopping list to ensure a solid 10. sec. time slip.
For right now, I would try advancing it to 101* and get it To the track one more time  should cost you hardly anything.
Plus, add in some of Zippys and Brad H,s tricks. You could see a ten, maybe.
Over the winter , I would send the heads to Jeff for a CNC port and a head shave to at least a 11.1 if P/V clearences allow.
Between these 3 things, you will have your 10.?? slip, easily on even a bad day if your suspension works. mike
Last edited by Sport440; 09/29/10 11:49 PM.
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Re: ADVANCING CAM TIMING 2-4*
[Re: BradH]
#814540
09/30/10 04:06 PM
09/30/10 04:06 PM
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Joined: Jan 2003
Posts: 4,105
Shelby Twp. Mi
HardcoreB
master
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master
Joined: Jan 2003
Posts: 4,105
Shelby Twp. Mi
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Quote:
My 440's 266/266, 108 LSA cam is also installed on a 105 ICL. My CR is 10.8:1. My Dynamic 9.5" converter flashes to approx. 4500 from a 1800 launch off the foot. I've tested "a bunch" of different things and whittled my 60-ft. down to 1.45-1.46 on 275/60R15 DOT drag radials. Car & driver is 3750+ #s, so it's not a lightweight.
IMO, raise your CR some, get the heads ported, and spend some time tuning the effer. Leave the cam ICL where it is so you know what gains resulted from the CR & porting. Oh, maybe put some 1.6 intake rockers (intakes only) on to help use the improved high-lift flow of the ported heads.
Yes, you can loosen up the lash .004" from your normal setting to see if it "likes" a slightly shorter duration. Check w/ Dwayne or COMP on what the min / max lash for your cam's lobes are, since there is usually an acceptable range to run. My XX lobes are usually listed as running .020", but are OK running from .016-.024" (hot).
All out of opinions on this subject...
I agree with everything said here to a tee but, I doubt throwing a set of intake rockers at it is in the budget after the cyl. head improvements $$$. I think I kinda implied this in my first post too. (I'm just saying I'm not much of a 'post' flip-flopper.)
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Re: ADVANCING CAM TIMING 2-4*
[Re: HardcoreB]
#814541
09/30/10 05:36 PM
09/30/10 05:36 PM
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Joined: Sep 2009
Posts: 2,325
Clinton Twp... north of Deetro...
Labratt
OP
Good Ol Randy B!
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OP
Good Ol Randy B!
Joined: Sep 2009
Posts: 2,325
Clinton Twp... north of Deetro...
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Thanks Sean! Hope the wedding turned out as planned this past week-end! I will be sending you a PM later today about a bon-fire get together at our place some time in October! As far as the X goes...Brad has the right idea as far as leaving the ICL where it's it,that way I'll know how much I picked up with the head work!Also..I already am running Crane ductile 1.6 rockers,intake and exhaust! Hopefully,I have the clearance to up the CR to 11-11.5! That's gotta improve the torque some. I'm also wondering if my Edelbrock Performer RPM dual-plane would be better than the M-1 that's currently on it? With the ported heads,how much do you think the Peak HP RPM would be? Right now it's 6000rpm. Peak torque is at 5200,which I'd like to lower,without losing any torque! Converter flashes at 4500! Also,probably be a good idea to have both intakes port matched to finished CNC'd port configurations. Thanks again,Buddy!  
Last edited by Labratt; 09/30/10 05:39 PM.
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for a few more opinions! 
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