Where to degree my cam?

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vntned

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About to slide the cam in my LA 360 and am curious as to if I should advance or retard the cam, or just run it straight up.

The build is as follows:

'70 360 .060" overbore
SpeedPro H116CP pistons
Measured SCR of 9.3:1
Stock crank and rods
Cleaned up 587 heads with 1.88/1.60 valves
LD340 intake
340HP exhaust manifolds
833 4spd w/ 2.66 low gear
3.55FD
Sub 3000lb car

The cam I've selected is the CompCams 268AH-10 cam. I've attached a pic of the cam card.

Curious to as what you guys would do.

image.jpg
 
Install at 106....That is a small cam but a good split pattern for use with stock HP manifolds.....Help with scavenging effect
 
I'm aware of the benefits of degreeing the cam. I'm not asking why should I, I'm asking where should I degree it at...
 
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What's the vehicle purpose? Do you want added power up high or down low? With the low 1st gear in a standard transmission with a sub 3000 vehicle, I'd go straight up or < 4 deg retarded to delay the power band to a more usable area. Although you might be lacking enough exhaust flow with log manifolds, then again, it is a relatively small cam. From the look at the cam card, it sounds like they designed it for a 340, and the valve events may be based up on that. A 360, having a slightly larger stroke, will have a tendency to "soak up" some cam duration attitude. Meaning it will act a little smaller, if at all noticeable. Make absolutely sure you have proper piston/valve clearance, especially when changing cam time events.
 
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have same cam in my 360 in 73 Duster...I put it in at 106......
 
Power is great....Has a little lope to it....360 with 9 to 1 compression ....stock 1.88 J heads...eddy performer rpm intake...holley 750dp....mp race electronic distributor with 30 degree on initial timing...full 34 degree total...
 
Steve, it would be installed @ 102 to achieve 4 deg advance. 102 meaning the degree after after true tdc that the intake valve is on its peak opening. Its "centerline" of the lobe. So If they want it at 106, 102 would be advanced and 110 is retarded. Changing the icl also changes the intake and exhaust valve open/close in the same way.
 
So for EX valves 4* adv would now be closes 20* atdc and opening 76* btdc?
Thanks T56!
Steve, it would be installed @ 102 to achieve 4 deg advance. 102 meaning the degree after after true tdc that the intake valve is on its peak opening. Its "centerline" of the lobe. So If they want it at 106, 102 would be advanced and 110 is retarded. Changing the icl also changes the intake and exhaust valve open/close in the same way.
 
I'm aware of the benefits of degreeing the cam. I'm not asking why should I, I'm asking where should I degree it at...
You must not of been following the "Where's the wow?" thread, freezerman just advanced His same cam to crutch the fact His 360 is close to only 8.1:1CR, You shouldn't with
over 9.....................................
 
So the spec card says 106* ICL and you guys say 106* so would the cam be installed straight up?
Sorry trying to learn. 4* advance would make ICl 110?
Thanks
Steve

The cam in question is ground on a 110 lobe separation and is to be installed at 106. If installed at the 106 number, it's 4* advanced.

Advance/retard has too do with the ground LSA and the installed centerline (ICL). Installed number smaller than the LSA = advanced.

I would NEVER retard the timing of a camshaft in a mopar, except in extreme situations that most on this board will never come across.
 
If drag racing, I would install straight up. Retarding would be a matter of seeing if it helped ET's.

If mostly for the street, or for road race or rally, I'd advance it 4 degrees to move the torque band a bit lower in the RPM range.
 
Steve, it would be installed @ 102 to achieve 4 deg advance. 102 meaning the degree after after true tdc that the intake valve is on its peak opening. Its "centerline" of the lobe. So If they want it at 106, 102 would be advanced and 110 is retarded. Changing the icl also changes the intake and exhaust valve open/close in the same way.

This is why it is really important to discuss with the person you are advising what you mean by advanced. Because if you have a 110 LSA, to me a 110 ICL would be straight up. 106 ICL is 4 degrees advance 102 ICL is 8 degrees advanced and 112 ICL is 2 degrees retarded.

On a 110 LSA, if everything is perfect, i.e. crankshaft keyway, cam and crank gears, camshaft pin, and you install the timing set dot-to-dot and the ICL comes out to 106, you have a camshaft that is ground 4 degrees advanced.

The 20-309-4 is a cam that is supposed to be ground with 4 degrees of advance in it. It should come out that way (106 ICL) when installed dot-to-dot. But to know for certain that everything is correct, the camshaft should be timed.

The above description doesn't mean that anyone who see's camshaft advance/retard differently is wrong. It only means, this is how I describe it. So if you are talking to a camshaft company or another person, get your definition straight before hand, so you understand each other.
 
If drag racing, I would install straight up. Retarding would be a matter of seeing if it helped ET's.

If mostly for the street, or for road race or rally, I'd advance it 4 degrees to move the torque band a bit lower in the RPM range.
Just so we are clear here..................

So to you, a camshaft with a 110 LSA would have what ICL when installed "straight up"?
 
Good point IQ52. When I say straight up, I would put in the cam with the ground-in advance of this cam, which would be and ICL of 106. That would be dot-to-dot IF everything is machined spot on, OR the machining errors canceled each other out...

The OP's reported CR is why I would tend to stick with the ground-in advance or add more for pure street driveability and responsiveness.
 
If drag racing, I would install straight up. Retarding would be a matter of seeing if it helped ET's.

If mostly for the street, or for road race or rally, I'd advance it 4 degrees to move the torque band a bit lower in the RPM range.
Via your description of straight up, If I'm understanding you correctly, you would suggest he might install this cam at 102 ICL. Yes?
 
Correct, in this case, the cam in question already has a built in 4 deg advance. Even more reason to not mechanically advance it even further.
 
Via your description of straight up, If I'm understanding you correctly, you would suggest he might install this cam at 102 ICL. Yes?
Yes if it is street engine only, as said.

The following is all to explain my viewpoint.....

1. I can't see where the ground-in advance has ANYTHING to do with where one decides to put the ICL. The manufacturers just do it IMHO to make the cam peppier in a stock setup so the customers won't be AS likely to call it a crappy cam when they just shove it in dot-to-dot with a worn chain and low CR pistons LOL

2. The ICL decision is all in the application as well stated earlier. That is why I distinguished between drag race and other uses. One thing to keep in mind that not only does the torque RPM range tend to go lower with cam advance but the min to max RPM RATIO for good torque improves. As an easy to see example:
- If the torque range is 3000-6000; the min/max RPM ratio is 2:1.
- Move it down to 2000-5000, and the min/max RPM ratio is 2.5:1. Same total range, but a better min/max RPM ratio.
That means in racing venues like road race and rally, you are not as likely to 'fall off' the torque curve as you manage the gears in various turns. I rally, and I want as close to a 3:1 usable torque RPM ratio as I can get. A 2:1 RPM ratio really SUCKS for rallying; I tried it when I was younger and was just doing the standard big cam stuff that everyone else was doing!

3. IF this case is for the street only, why not? The SCR is here not gawdawfully high and the DCR will be around 7.8/7.9 with the ICL at 102. The cam lift is not very high, and nothing will crash in the valves with these pistons. It'll definitely help low end torque to improve response and driveability on the street.

IMHO 102 is not a radical ICL in this setup. I went 106 on a 112 LSA with a true 10:1 SCR for street (vs the 107 ICL ground in timing) of the Crane cam we used to get the DCR to the 8.2 range, and thought about more (but chickened out on the DCR LOL). The OP won't have that high a DCR at 102. If there is a factor, like another cam timing event, to consider that I am missing, then that would be good to understand.

BTW, 102 is easy to get with this cam, with the +4 advance crank sprocket position commonly found on multi-keyway sprockets. So that is a coincidental reason to use that number.

4. I think everyone here does not do cam advance like this for a drag race engines. More peak HP at a higher peak RPM for better ET's makes sense, bu that will reduce the usable RPM range: higher TC stalls, and slipping the clutch more get around that problem.
 
I tell you what my experience was,
With the 292/292/108 cam,it didn't matter one bit to my butt-dyno. I tried it in at 104,108,100, and on the street it barely changed the idle with 11.3 scr. With a 4 speed and 3.55s,the bottom was soft no matter what I did.That took a whole lotta gear to change.
>Next I installed a 270/280/110. This little guy pulled so hard and so long and so far, it could care less where it went in at. The first year it went in at 106. I had so much tire frying torque and it pulled and pulled and pulled.I could tell it was nosing over about 600 rpm sooner than the 292, but it was still charging hard at 7000. Well the second year I put it in at 110 hoping to trade away some low to get some high. Waste of time. I doubt the peak changed more than 100 rpm. And was still a tire fryer, pulling hard to 7000.
So the third and 4th years it went back in at 106.
>Going into the 5th year, that cam dropped 2 lobes right after an oilchange. That was the year they took the Zddp out of the oil.So I got greedy and ordered me a 276/286/110cam and dropped in per the card at 106. This cam is exactly like the 270, except more of everything.More low rpm torque, more midrange, and still pulls to 7000 and beyond. By far is it better than that 292; by far.It's been in there since about 2006,I'm guessing.
>So as a streeter, I gotta say, 4* one way or another in my combo was an immeasurable performance change. I'd be surprised to see a power peak change of 100 rpm with 4* change, and just as surprised to see the torque peak move 50 rpm. If the tires are spinning you can't tell chit. And a top-speed run is out of the question. With 3.55s, third gear starts at 3500=57mph and ends at 7000=114mph, so I cannot legally test third on the street,either. To me, on the street, with at least a 360; dot-to-dot is as good a place as any.
>In any case these two smaller cams make way more low-speed torque than the tires can handle, and way more top speed power than my chassis can handle, and the midrange is so fat, it's like driving a 60s BB. Stomp her down at 30,40, or even 50 and poof, the tires are screaming.
>My opinion is the cam manufacturer probably knows best.

In your combo that 268 will be a terror in second gear, from 40/45 mph to about 60/65, no matter where you put it in at. If you need the power in a different spot, change the gearing. If you need more power in the same spot,get a bigger engine. Or a bigger cam, and increased gearing,both together.
Parting shot
If you manage to move the torque peak up 100 rpm,from say 3800 to 3900 and get 2 more ftlbs there, that might be a gain of 8 hp, if this carried on to the power peak at say 5100 moving to 5200 with 4 ftlbs gained,this might be 7 hp gained. This 7 or 8 hp gain,might represent a 2% improvement in hp,from peak to peak. Moving to the next bigger number gear, from 3.55 to 3.73 will get you 5% improvement everywhere in the RPM band, even at 1500 rpm past the power-peak,lol.
 
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Well this is going in my daily driver, so I wanted a very usuable power band an torque curve. I'm not going for peak hp, just a good all around performer.
 
Well this is going in my daily driver, so I wanted a very usuable power band an torque curve. I'm not going for peak hp, just a good all around performer.
Well then just slam in in there, and start smoking tires
That 222@050 cam is a monster torque maker, and the 268* gives it just a tiny bit of lope. At least it was/did in my Eddie-headed 367.I absolutely loved it. I would still be running it if somebody wouldda told they were gonna take the ZDDP outta the oil.
I'll tell you a little secret.
If you gear this combo with a super tall final drive,to get 60mph@1500rpm, and then put a metering rod carb on it, you will be able to tune it lean enough to get fuel economy well into the 20mpgUSs. It will take a ton of timing. Just keep giving it to her. It might take 45 or more degrees; just give her what she wants, don't make her beg.
I had a bit more compression than you and a lot more weight than you and when I tell people what mine did, they say that's impossible, so I'm not gonna tell you.
Speaking of carbs, mine liked about 750 DP on the AG, with long-tube headers. It also liked any rear gear I threw at it, from 2.76s to 4.88s. It was not happy with either the 600VAc secondary nor the next bigger one. It did like the smaller TQ. That was awesome on an Excelerator manifold. It also liked the 3.09 low box, and with 3.23s. I put a GVOD behind an A833od on it for double OD and gear splitting. That was 7 useable gear ratios, from 3.09 to .55 in Double od. Yeah those were the days.That's also the combo that used to spin out on me almost every corner I took. It took 295s to cure that, jus saying.
>I took 200 pounds out of her one day and scaled 3467 at the track, with me in it. We went 93 in the 1/8th, best of 4 runs, the other 3 of which were no good.
I ran those Eddies at 10.9 SCr/8.9Dcr@185psi, and she liked 87E10 with full timing.
With sub 3000 pounds you are looking at an awesome little mover.
 
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