CAMS what a Dilemma

[2k05gt]

With all the Hype and endless threads about CAMS like how they sound (i.e. Lopey sound)
and What Horsepower Dyno Numers people are getting. I for one want to know what 1/4 mile Numbers are people seeing, I could care less about HP and sound, Like Ricky Bobby says, "I Wanna Go Fast" Give me Actual Track Numbers...

Ok so a List of CAMS I am Looking at

COMP CAMS NSR Stage II (127200)
RPM Range: 750-6400
VALVE LIFT: IN- .450 EX- .450
ADVERTISED DURATION: IN- 261° EX- 278°
DURATION @ .050" Lift: IN- 222° EX- 235°
LOBE SEP. ANGLE: 115.5°
INTAKE CENTERLINE: 101
COMPUTER TUNING: Non required.
RECOMMEND: 3.73-4.56 gears, 2500+ stall for automatics,

FRPP HotRod Cams NSR (M-6550-3V*)
RPM Range: above 4800
VALVE LIFT: IN- .450 EX- .450
ADVERTISED DURATION: IN- 248° EX- 280°
DURATION @ .050" Lift: IN- 221° EX- 240°
LOBE SEP. ANGLE: 110°
COMPUTER TUNING: No Tune required.
RECOMMEND: lower gears, 2300+ stall for automatics,

COMP Thumper Cams NSR / Phase Limit. (127010)TH265LL
RPM Range: above 4600
VALVE LIFT: IN- .450 EX- .450
ADVERTISED DURATION: IN- 265° EX- 298°
DURATION @ .050" Lift: IN- 226° EX- 246°
LOBE SEP. ANGLE: 109°
COMPUTER TUNING: Cam Phaser Limiter Kit required.
RECOMMEND: lower gears, , and 2300+ stall for automatics,

COMP Mutha-Thumper Cams NSR / Phase Limit. (127010)MT273LL
RPM Range: 750 to 6600
VALVE LIFT: IN- .450 EX- .450
ADVERTISED DURATION: IN- 273° EX- 306°
DURATION @ .050" Lift: IN- 234° EX- 254°
LOBE SEP. ANGLE: 109°
COMPUTER TUNING: Cam Phaser Limiter Kit required.
RECOMMEND: lower gears, , and 2300+ stall for automatics,

BBR Stage I
RPM Range: 1500-6000
VALVE LIFT: IN- .480 EX- .480
ADVERTISED DURATION: IN- 270° EX- 276°
DURATION @ .050" Lift: IN- 227° EX- 233°
LOBE SEP. ANGLE: 114°
COMPUTER TUNING: Computer Programming Required.
RECOMMEND: lower gears, , and 2300+ stall for automatics, Replacing Valve Spring.

[boss281]

Went from 13.10 to 12.80 after cams. Suspension and seat time took me down to 12.40 since then.

[2k05gt]

But yours was springs correct? or did you do NSR
I have an Auto with a 3500 Stall and 4.10 Gears so I should be fine with a more mild set of CAMS

[ArtQ]

My Comp 127300 springs required gave me approx 2/10's.

I installed a set of Comp 127200 NSR's in a 2005 with CAI and offroad X prior. I also added Econo CMCV deletes at the same time and he picked up 2/10's.

Both had a very mild to un-noticeable effect on exhaust sound once tuned properly.

[chad05gt]

127300's here; et to show this Sunday. No noticeable 'lope'; and personally not a fan of 'pseudo' lope... get SPR's for lope... thumpers and hot rods I just dont get sounding like something you are not....


JMO

[ArtQ]

Ok so a List of CAMS I am Looking at

COMP CAMS NSR Stage II
FRPP HotRod Cams NSR
COMP Thumper Cams NSR / Phase Limit.

The Thumper and Hot rods are designed more for sound.

I'm guessing you want to avoid the spring change.

I would go with the Comp 127200's and keep the VCT

[boss281]

Yeah, my 127300s required springs and I put in steel retainers...

[chad05gt]

I even used Comp limiters on my 127300's

[2k05gt]

The Thumper and Hot rods are designed more for sound.

I'm guessing you want to avoid the spring change.

I would go with the Comp 127200's and keep the VCT

Yea I am doing the CAM Swap myself (With Marc's Help) Trying to save some money, We did Marc's 127200 CAMS in 4 hours

My real reason for looking into CAMS is that my car seems to loose power in the last 100 - 150ft of the 1/4 mile, I am trying to add
a little umph at the trap. I don't want to loose any low end torque though, and I guess thats why they say that if you have an automatic
you need to have at lease 3.73 gears and at minimum 3000 converter

[boss281]

Yea I am doing the CAM Swap myself (With Marc's Help) Trying to save some money, We did Marc's 127200 CAMS in 4 hours

My real reason for looking into CAMS is that my car seems to loose power in the last 100 - 150ft of the 1/4 mile, I am trying to add
a little umph at the trap. I don't want to loose any low end torque though, and I guess thats why they say that if you have an automatic
you need to have at lease 3.73 gears and at minimum 3000 converter

That is exactly the problem I have scott. I've been chased down in the last 1/8 so many times. It's like the car runs out of gas.

I've added delete plates and adjusted the a/f, so the first race this season will see if they help on the top end as advertised...

[chad05gt]

That is exactly the problem I have scott. I've been chased down in the last 1/8 so many times. It's like the car runs out of gas.

I've added delete plates and adjusted the a/f, so the first race this season will see if they help on the top end as advertised...



What is your a/f at now at the traps?

Ill be datalogging at the track this Sunday, Im just hoping my tire height worked out right (I dropped it an inch b/c 275/50/17's had me going through traps at about 62ish); hope to go through 65ish like I did w/ stock cams w/ the inch shorter tire...

Mine stays at 12.5, what are you trying different? What was it last time?

[MarcSpaz]

As you know Scott, we put the NSR Stage 2 cams in, but my suspension gave out on me, so I never really tested it right. Before my suspension went to crap, I was running 13.13 pretty regularly with a best on pump gas of 13.111.

Now, that the suspension is fixed, I will be able to get some good numbers once a track opens up.

[2k05gt]

GET OUT OF THE COLD (March 27, 2009) You Better Make it Man...
Lets make sure the Car is Dialed in...

[boss281]

What is your a/f at now at the traps?

Ill be datalogging at the track this Sunday, Im just hoping my tire height worked out right (I dropped it an inch b/c 275/50/17's had me going through traps at about 62ish); hope to go through 65ish like I did w/ stock cams w/ the inch shorter tire...

Mine stays at 12.5, what are you trying different? What was it last time?

12.5. We added the delete plates a month back and noticed that at 5000rpm or so, the damn thing kept trying to go lean, and it took a lot of adjustment. We think the cam timing profiles are doing something but aren't sure. I'll try this setup out in March and see what happens...

[John@BlowByRacing.com]

If you're staying N/A I recommend our Stage 1 3V camshafts

[boss281]

Do you have a link to your cam specs? I have the comp 127300s in now, but was thinking of a change later in the year when I put my Livernois stage ii heads in...

[MarcSpaz]

Yes, some specs would be great.

[germansheperd]

With all the Hype and endless threads about CAMS like how they sound (i.e. Lopey sound)
and What Horsepower Dyno Numers people are getting. I for one want to know what 1/4 mile Numbers are people seeing, I could care less about HP and sound, Like Ricky Bobby says, "I Wanna Go Fast" Give me Actual Track Numbers...

Ok so a List of CAMS I am Looking at

COMP CAMS NSR Stage II
FRPP HotRod Cams NSR
COMP Thumper Cams NSR / Phase Limit.Proably not much power difference between all 3 of those cams you have listed.

[chad05gt]

Do you have a link to your cam specs? I have the comp 127300s in now, but was thinking of a change later in the year when I put my Livernois stage ii heads in...

You've been down the 'shelf' cam road; when it comes time for your heads, why not get a custom grind? I think that's what Ill be doing once tb and intake are taken care of, and have a bottom end to support the revs...

[boss281]

I had to think back 25 years, but I don't think I've ever bought a custom grind! What did they cost you, compared to an off the shelf?

[chad05gt]

I had to think back 25 years, but I don't think I've ever bought a custom grind! What did they cost you, compared to an off the shelf?


I have 127300's, but when I do get cams again, Ill get some custom made. If Im not mistaken, Comp will do it for not much more than the off the shelf.

[chevykiller]

The problem with all these 'off the shelf' cams is that unless you really understand what the hell you need, the lift, duration, and LSA might as well be chinese.

If you look at all the available off the shelf cams, they are not that different from each other grind wise. They pretty much are set-up with only 2 broad strokes in mind and that is N/A or FI, and sound. That's about it really and there is SO MUCH more to cams than that, but let's be honest, that's what SELLS cams so that's all they (manufacturers) are worried about.

The truth is that the right cam for FI or NA differs GREATLY depending on a number of factors with how high you are going to spin your car, your CR, when your FI hit's and peaks, your MPH through your gears, what your flow rate, what is your volume in your intake - and these are just a FEW...lol

What surprises me is the myth that most guys think a proper cam profile is too expensive or not available and this is just not true. Chances are, there is a cam which is PERFECT for you and it has already been developed by one of the bigger shops for themselves or through testing. Once they have a custom grind made, they can re-order that grind at any time from the manufacturer (which is usually comp)

Prime example, take Livernois for instance. Many of you probably do not realize that Livernois has tested a half dozen cam profiles in their own development through the years and have easy access to them at not much more than any off the shelf cam will cost you.

So you contact someone like Mike Schropp, Andy, or Rick, and you tell them exactly what you have (motor specs very important also) and exactly what you want to do and you may find there's a lift and duration option for you that didn't see advertised as one of the usual 'stages'.

Lastly, in this long winded post, DO NOT UNDERESTIMATE YOUR VALVE TRAIN. Cams are worthless without a good train to support them. You can have the best cam on the planet and it can pull power through 8 grand - it is useless without the valve train to back it up.

IMO - the valve train is the #1 priority, the heads second, and the cams actually coming in 3rd...:cool:

[MarcSpaz]

That good to know about Livernios. I am going to be ordering a complete upper setup from them in a few days. I will have to ask them about cam profiles thay have available instead of just asking for the XFI Stage 3's.

[2k05gt]

You can see that the Cam Profiles CK was talking about here

FRPP HotRod Cams NSR (M-6550-3V*)
RPM Range: above 4800
VALVE LIFT: IN- .450 EX- .450
ADVERTISED DURATION: IN- 248° EX- 280°
DURATION @ .050" Lift: IN- 221° EX- 240°
LOBE SEP. ANGLE: 110°
COMPUTER TUNING: No Tune required.
RECOMMEND: lower gears, 2300+ stall for automatics,

COMP CAMS NSR Stage II (127200)
RPM Range: 750-6400
VALVE LIFT: IN- .450 EX- .450
ADVERTISED DURATION: IN- 261° EX- 278°
DURATION @ .050" Lift: IN- 222° EX- 235°
LOBE SEP. ANGLE: 115.5°
INTAKE CENTERLINE: 101
COMPUTER TUNING: Non required.
RECOMMEND: 3.73-4.56 gears, 2500+ stall for automatics,

COMP Thumper Cams NSR / Phase Limit. (127010)TH265LL
RPM Range: above 4600
VALVE LIFT: IN- .450 EX- .450
ADVERTISED DURATION: IN- 265° EX- 298°
DURATION @ .050" Lift: IN- 226° EX- 246°
LOBE SEP. ANGLE: 109°
COMPUTER TUNING: Cam Phaser Limiter Kit required.
RECOMMEND: lower gears, , and 2300+ stall for automatics,

COMP Mutha-Thumper Cams NSR / Phase Limit. (127010)MT273LL
RPM Range: 750 to 6600
VALVE LIFT: IN- .450 EX- .450
ADVERTISED DURATION: IN- 273° EX- 306°
DURATION @ .050" Lift: IN- 234° EX- 254°
LOBE SEP. ANGLE: 109°
COMPUTER TUNING: Cam Phaser Limiter Kit required.
RECOMMEND: lower gears, , and 2300+ stall for automatics,
-------------------------------- NON NSR -----------------------------
BBR Stage I
RPM Range: 1500-6000
VALVE LIFT: IN- .480 EX- .480
ADVERTISED DURATION: IN- 270° EX- 276°
DURATION @ .050" Lift: IN- 227° EX- 233°
LOBE SEP. ANGLE: 114°
COMPUTER TUNING: Computer Programming Required.
RECOMMEND: lower gears, , and 2300+ stall for automatics, Replacing Valve Spring.

Crower Stage 2 Camshafts (62831-2)
RPM Range: 1200 to 6200+ RPM
VALVE LIFT: IN- .492 EX- .492
Lobe ADVERTISED DURATION: IN- 258° EX- 268°
Valve ADVERTISED DURATION: IN- 274° EX- 284°
Lobe DURATION @ .050" Lift: IN- 200° EX- 216°
Valve DURATION @ .050" Lift: IN- 220° EX- 236°
LOBE SEP. ANGLE: 110°
COMPUTER TUNING: Tune required.
RECOMMEND: lower gears, 2300+ stall for automatics,
Requires Titanium Retainer Kit part# 84708.


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[2k05gt]

Understanding Camshaft Specifications

LIFT

Lift refers to maximum valve lift. This is how much the valve is "lifted" off its seat at the cam lobe’s highest point.
How is it measured?

http://www.lunatipower.com/Images/Tech/Cams/LobeLiftSmall.gif (http://www.lunatipower.com/Images/Tech/Cams/LobeLiftLarge.gif) Valve Lift is the amount (usually in inches) that the valve is lifted off of its seat. It is usually measured with a dial indicator at the tip of the valve. Lobe Lift is the amount (usually in inches) that the cam lobe increases in radius above the cam base circle.

Tip: To quickly find maximum lobe lift, measure the base circle of the cam and subtract it from the thickness across the cam lobe’s highest point (see the diagram below).

Tip: Maximum valve lift can be calculated by multiplying the maximum lobe lift times the rocker ratio. For example, a 0.310" lobe lift cam yields 0.496" of valve lift when using a 1.6 ratio rocker arm.

Formula: valve lift = lobe lift x rocker ratio
What does it do?

The intake and exhaust valves need to open to let air/fuel in and exhaust out of the cylinders. Generally, opening the valves quicker and further will increase engine output. Increasing valve lift, without increasing duration, can yield more power without much change to the nature of the power curve. However, an increase in valve lift almost always is accompanied by an increase in duration. This is because ramps are limited in their shape which is directly related to the type of lifters being used, such as flat or roller.



DURATION

Duration is the angle in crankshaft degrees that the valve stays off its seat during the lifting cycle of the cam lobe.
How is it measured?

Advertised duration is the angle in crankshaft degrees that the cam follower is lifted more than a predetermined amount (the SAE standard is 0.006") off of its seat. Duration @.050" is a measurement of the movement the cam follower, in crankshaft degrees, from the point where it’s first lifted .050" off the base circle on the opening ramp side of the camshaft lobe, to the point where it ends up being .050" from the base circle on the closing ramp side of the camshaft lobe. This is the industry standard, and is a good value to use to compare cams from different manufacturers. Both are usually measured with a dial indicator and a degree wheel.
What does it do?

Increasing duration keeps the valve open longer, and can increase high-rpm power. Doing so increases the RPM range that the engine produces power. Increasing duration without a change in lobe separation angle will result in increased valve overlap.



LOBE SEPARATION

Lobe separation is the angle in camshaft degrees between the maximum lift points of the intake and exhaust valves. It is the result of the placement of the intake and exhaust lobes on the camshaft.
How is it measured?

http://www.lunatipower.com/Images/Tech/Cams/LobeSeparationSmall.gif (http://www.lunatipower.com/Images/Tech/Cams/LobeSeparationLarge.gif) Lobe separation can be measured using a dial indicator and a degree wheel, but is usually calculated by dividing the sum of the intake centerline and the exhaust centerline by two.
What does it do?

Lobe separation affects valve overlap, which affects the nature of the power curve, idle quality, idle vacuum, etc.



OVERLAP

Overlap is the angle in crankshaft degrees that both the intake and exhaust valves are open. This occurs at the end of the exhaust stroke and the beginning of the intake stroke. Increasing lift duration and/or decreasing lobe separation increases overlap.
How is it measured?

Overlap can be calculated by adding the exhaust closing and the intake opening points. For example, a cam with an exhaust closing at 4 degrees ATDC and an intake opening of 8 degrees BTDC has 12 degrees of overlap.
But keep in mind that since these timing figures are at 0.050" of valve lift, this therefore is overlap at 0.050". A better way to think about overlap is the area that both lift curves overlap, rather than just the crankshaft angle that both valves are open. Therefore, one can see that decreasing the lobe separation only a few degrees can have a huge effect on overlap area.
What does it do?

At high engine speeds, overlap allows the rush of exhaust gasses out the exhaust valve to help pull the fresh air/fuel mixture into the cylinder through the intake valve. Increased engine speed enhances the effect. Increasing overlap increases top-end power and reduces low-speed power and idle quality.



CENTERLINES

The intake centerline is the point of highest lift on the intake lobe. It is expressed in crankshaft degrees after top dead center (ATDC). Likewise the exhaust centerline is the point of highest lift on the exhaust lobe. It is expressed in crankshaft degrees before top dead center (BTDC). The cam centerline is the point halfway between the intake and exhaust centerlines.



ADVANCE/RETARD

http://www.lunatipower.com/Images/Tech/Cams/AdvanceAndRetardSmall.gif (http://www.lunatipower.com/Images/Tech/Cams/AdvanceAndRetardLarge.gif) Advancing or retarding the camshaft moves the engine’s torque band around the RPM scale by moving the valve events further ahead or behind the movement of the piston. Typically, a racer will experiment with advancing or retarding a cam from "straight up" and see what works best for their application. Lunati camshafts are ground to provide maximum performance and are designed to be installed to the specifications listed on the cam card.
How is it measured?

A cam with a 107 degrees intake lobe centerline will actually be centered at 103 degrees ATDC when installed 4 degrees advanced.

Most Lunati camshafts have a certain amount of advance ground in. "Ground-in advance" can also be found by subtracting the intake lobe centerline from the lobe separation.
What does it do?

Advance improves low-end power and response. For a general summary of the affects of camshaft timing, refer to the following tables:

[boss281]

Scott, I wonder how we might set up a tech "repository" where we can collect and provide information like this in a centralized place?

[2k05gt]

Scott, I wonder how we might set up a tech "repository" where we can collect and provide information like this in a centralized place?

That is a Great Idea !!!
Something like a how things work or Answers Section -
I will do some research

[2k05gt]

If you're staying N/A I recommend our Stage 1 3V camshafts

What 1/4 Mile Times have your stage 1 cams done? Again I don't care about lopey sound, I want great Time slips.

[matt texass]

Dammit I'm in the same place. 2k05gt what did you decide?

[2005mach1]

I want some cams, so I'll watch here