Voodoo Voodoo what would you do?

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Ironmike

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Cam came today and I jumped right on getting it degreed. I'm degreeing with heads off, intake centerline method.

So, intalled straight up on my Cloyes timing set it comes up 105. Move to the next keyway and it's 102.5. As you can see Lunati wants it at 104. That's 6 degrees advance ground in.

Now I'm indecisive about where to leave it...it's either 1 degree retarded from what they recommend or 1 and a half advanced for a total of 7 and a half advance.

Hope you guys can help me decide.

It's a typical 414 stroker build. 10.7 to 1, ported heads and Super Victor. Car is 3090lbs, 4 speed, 4:10 gear. I'm running 1.6 rockers so my lift will be .640/.640. Don't wanna give up bottom end but don't want to choke it either. Will probably shift at 66-6700RPM.

My first thought is install straight up at 105 degrees and call it done....

What would you do?
 

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I am running the same cam in a very similar 416 it works great, I
Put mine in a degree or two retarded I think it was the way to soften bottom end a little, its been a year or two so double check me. But it still has tons of bottom and made power to 6800. Good luck
 
The 1* diff. isn't going to be a noticeable issue. The cam companies say this themselves.
My main concern would be in the valve to piston clearance.

I'm about to use the cam 1 step down with 1.6 rockers as well. A little more torque is what I'm after. Looking foward to your results.
 
I would put it in at 108.5, +/-2 .This will put your intake closing angle at 85 degrees. If this pumps your Dcr up to the octane limit of the chosen fuel, then you can retard the centerline some. Going to 112.5 will change the ICA to 91. This will also reduce your cranking compression a few psi, making blowing the tires off a wee tad harder.And it will give you an extra 4* of power extraction.
Advancing the cam from this, any amount even to 104, will just pump up the Dcr and the low speed torque.Do you need the torque?
So why did I choose 108.5? Cuz it puts the cam at almost exactly at split overlap.What's the big deal about that?No big deal, but I don't need any tools to establish that point other than a short straightedge across the two lifters involved with the cylinder I'm checking, at TDC-exhaust. Very fast/no mistakes.
And why did I choose the 112.5 point? Cuz that splits in half,the degrees where no valves are open; so compression degrees equals extraction degrees.Whenever you move the ICA you are shuffling degrees between those two. What's the big deal about that you may ask.No big deal. But in your case, with your combo, you only have 183* that have to be shared between those two;compression and power extraction. And depending on your Dcr,and intended usage, you can favor one over the other.
If you are racing, I know nothing,
but with 4.10s and your P/W, Ima thinking you are targeting close to 10.5/128ish mph, so a retarded cam might get you the power to get there, at the expense of the 60fts.Whereas an advanced cam might boost the 60 fts at the expense of mph. Since you may have some history with this car, you might be/probably are, in the best position to make this decision.
On the street, with a 292/[email protected],in my 367cuber, I noticed very little difference, between 4* adv all the way to 4* ret. Yes, I actually degreed that stinker 3 times; twice in chassis. I wouldn't call it a total waste of time, but..........on the street, it's kindof a drop it in and go deal.
 
I'm still leaning towards letting it be at 105. I mean that's still 5 degrees advanced. Last year I ran a Comp 109 LSA, installed at 107 and it was soft on the bottom.

AJ, you make my brain hurt, but I think I get what ya mean. But isn't your thought towards a real high RPM peak? Like I said, I do not plan on spinning this old block much past 6700.
 
1° from recommended won't affect it to much. Put it there.
 
rumblefish360 said:
The 1* diff. isn't going to be a noticeable issue. The cam companies say this themselves.
My main concern would be in the valve to piston clearance.

I'm about to use the cam 1 step down with 1.6 rockers as well. A little more torque is what I'm after. Looking foward to your results.
Click to expand...

With Rumble ,on this..get it in within 1-1.5 degree,let it rock.
Rumble, please post ,on that combination.. (Much appreciated, if you did....)
 
Abodybomber said:
With Rumble ,on this..get it in within 1-1.5 degree,let it rock.
Rumble, please post ,on that combination.. (Much appreciated, if you did....)
Click to expand...

fuget-a-bout it . install it. 1 degree aint going to do squat, unless ur too close on valve clearance already .
 
I think 105-106 is perfect, my 260*/260* @ .050" is in at 107* and with an ld340 dual plane and 360 cubes it is stong from 1000-7000. last year did U run the super victor=soft bottom end
 
I should probably stay out of these kinds of discussions, cuz of my extremely limited experience of racing set ups.But I feel I should maybe expand at least on my thinking. So here it is, kick me to the curb if you like.
With my experience with the 292 I came to the conclusion that moving the centerline over 8 degrees, only moved the point of peak power some 200 or so rpm. How did I figure that out? Windshield mounted accelerometer.And on the bottom, cuz of almost no traction, I couldn't tell the difference. Now as I recall, that cam was a 108LDA and it peaked around 5700, and the peak was clearly evident.Well with my 4spd and it's 72% split, this required a shift rpm of 6700 to come in at; 6700 x .72 = 4824,(powerband requirement of 1876rpm) with the peak sorta centered, on the graph.

I, in my head extrapolated that your cam being 313/110, would have a slightly broader,flatter curve, and in a stroker, might peak about 200 or a little higher,than mine. A guess to be sure. But with the slow nose-over, you can wring it out a bit through the traps. With your stated 6700, I jumped to the conclusion that you would want to trap at 6300 or so, given that the power peak was at 5900/6000 ish.So that made the 108.5,straight up, a natural choice.Moving the installed centerline either way might move the powerpeak 100 to 150 rpm, to fine tune your trapping rpm, and off-the-line torque delivery some too. Being a stick-man, I have adjustable "stall" so I go for the mph at the top end. With an automatic, IDK. That led to the question "Do you need the torque?"If you do, then where it is now, will be just fine.
Now this is all pure speculation on my part, cuz of my very limited experience.
There are quite a few guys on here that do have real-world experience, And I hope I don't hurt my head when the curb comes.
 
Ironmike said:
I'm still leaning towards letting it be at 105. I mean that's still 5 degrees advanced. Last year I ran a Comp 109 LSA, installed at 107 and it was soft on the bottom.
Click to expand...
IIRC, your last cam was of a longer duration and lift, and so that fact, with only 2 degrees cam advance, was the likely cause of the soft lower end RPM's. Going larger LSA, and with 5 degrees advance, I would expect a noticeable difference with the 105 setting.

But, looking at this cam's description in the Lunati catalog (per the old PN), it is at the top end of the RPM range in that group of cams. Being that, I would not expect the best from the bottom end RPM's anyway; the recommended rear gearing is 4.56+ so that says a high RPM cam. So I would favor going more advanced on the setting.
 
I vote for the 102.5. Your chain is going to wear/stretch some and retard the cam timing.
 
AJ/forms : you have some Nice info! but how do you know the intake port isnt limiting your cams top end power?
overcammed engines does usually dont react well at timing changes.

its really scary to adjust and compare engines thats not exactrly the same, too many variables.
there are 2 ways to set Power rpm peak
1: intake port size
2: duration

most Power made is when both is calculated to each other!
and someone also use a not optimal combination to get the exact engine powerband they want.didn mean to step on someones toes
 
Borrowed an old 20 inch degree wheel today and went through it again. I came up with 4.5 3 times. Yippee.

Also with my old h gaskets and heads installed I have .110 intake and .160 exhaust as far as valve to piston clearance. Did all 4 corners with zero lash. Oh yeah. .032 quench.

Boy from what I can see, the machining on this block is friggin dead on.

Leaving it where it is and as usual THANKS for the suggestions!:prayer:
 
Norway-dart said:
AJ/forms : you have some Nice info! but how do you know the intake port isnt limiting your cams top end power?
overcammed engines does usually dont react well at timing changes.

its really scary to adjust and compare engines thats not exactrly the same, too many variables.
there are 2 ways to set Power rpm peak
1: intake port size
2: duration

most Power made is when both is calculated to each other!
and someone also use a not optimal combination to get the exact engine powerband they want.didn mean to step on someones toes
Click to expand...
other parts that can be limiting top end
3: intake manifold size 4: carb. size 5: exhaust size 6: valve springs
 
sure! intake port has to be seen as a package from intake valve to carb.
if you have a intake that is tuned to 6500rpm but Your cam peak lobe rpm is 5000, I Guess you get the peak far over 5000, but the engine will be a dog, and does never reach its potential.


I dont think exhaust size is a big deal unless you are running a Stock manifold ofcourse.
many top end porters pay little attention to exhaust flow compared to intake. its alot easyer to emty the sylinder than to fill it.
 
Will definitely post results. Should be on the dyno last week of the month. Sure hope this all works out better than last year's disaster... Just not up for another summer of frustration.

Thinking about contacting Thumperdart about tweaking my carb. Heard some good stuff there. That could push my dyno time up a bit.
 
mine made 583 hp at 6800 with step headers on 93 , and ran 6.69 at 104 in full weight 74 duster, 416 , same cam 1.6 rockers, now has big headers, stage 3 eddies, 10.3 comp, victor 340 intake, good luck on your strokers guys, that cam is awesome, completely streetable, and pulls great
 
Locker down at 105 and let er rip.

Good God this ain't rocket science.
 
345man2 thank you for the dyno and track results.



Ironmike said:
Will definitely post results. Should be on the dyno last week of the month. Sure hope this all works out better than last year's disaster... Just not up for another summer of frustration.

Thinking about contacting Thumperdart about tweaking my carb. Heard some good stuff there. That could push my dyno time up a bit.
Click to expand...

Cant wait to hear how you go IronMike
 
No prob l4 hope it will help with your build and good luck
 
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