Vortec 454 cams

[durbo.jones]

I need some thoughts from some of the more knowledgeable engine builders. I am looking to swap the cam on my 97 for something that would be more supercharger friendly. The setup right now is a 0411 PCM swap, Whipple 2300, Hooker headers (midlength), and a custom 3.5" single exhaust. I am only seeing about 6 PSI of boost and would like to swap the pulley out to bring the boost to 8 or 9 PSI. I don't really know a lot about cam selection on a BBC and need some experienced advise on this. The truck is my tow rig. I am also swapping out the 4L80 out for a NV4500 in the early spring.

[COONDOG 96]

Come on nobody???????????

[1998454]

I'm no cam expert, but i do know sc engines like alot of exhaust duration. I would think that would be especially true with our engines not having the greatest exhaust flow.

[tg8804]

What I would like to know is what cams are other people running in there 454. what kind of power and milage. Im in the market for a new cam and would like some real world input.

Travis

[N0DIH]

Personally, if you tow or have it in a heavy vehicle, I would highly recommend the VooDoo 60620. It is reasonable duration that we need for our insane torque needs....

[durbo.jones]

http://www.lunatipower.com/Product.aspx?id=2169&gid=260

I decided on this cam. I may get some heat on this because it is a small cam, but when you look at what I am trying to accomplish this works out. I want a cam that will be very efficient NA with either zero overlap or - overlap. This cam will be better than stock by probably 20 or 30 HP at the wheels and will work out really well with the supercharger. It should also net me a little better fuel mileage and keep the peak torque low in the RPMs. My guess is NA this cam will give me peak torque somewhere between 29-3200 RPMs while out performing the stock cam.

[1998454]

Wonder why they list the specs at the bottom of the page for a ford?

Personally, if you tow or have it in a heavy vehicle, I would highly recommend the VooDoo 60620. It is reasonable duration that we need for our insane torque needs....

[tg8804]

yeah I was wondering that too. But I do like the voodoo 60620. NODIH have you run or know someone that runs that cam?

[2500ak]

[QUOTE=durbo.jones;5504556]http://www.lunatipower.com/Product.aspx?id=2169&gid=260

If you're going to go to the trouble of swapping out the cam I'd run something bigger than that. That cam would be small in a naturally aspirated sbc.

More durations, and wider lobe sep to keep the overlap in check imo.

[N0DIH]

Not that one in my truck (mine's still stock), but camwise that is more where we want to be rpm wise for torque peak. I had a 228 @ 0.050 cam in my 455 (4 deg adv) and it was very good in a street car (4000 lbs) with an intake, duals (small though) and h-pipe and 750 cfm carb and intake. But the cam it replaced was 200/213 duration @ 0.050, much much smaller, ran more or less the same. You have to be careful cranking duration up, it moves the powerband up higher and higher. The lift has more control over the hp/torque peak itself. Duration is WHERE in the rpm range the peak occurs.

The HO 454 cam or some of the other cams do move the powerband up pretty high for a peak and our heads don't flow that well up there, so we overall are weak on power compared to an smaller cam with shorter duration. Worst thing to do is overcam an engine. Not usually a problem have too much lift (aside from bending valves), but too much duration is a bigger problem. You can advance the cam to a point, but 6 degrees is about absolutely as much as you can advance it without problems. I know, I had mine advanced too far once, it ran good down low, but higher rpm it bucked and backfired.

The LT1 with a 192 degree intake duration (iron head) torque peaks around 2400 rpm, but is over 300 lb/ft by 1600 rpm. As duration is increased the powerband moves up and low end power drops off. As the engine displacement increases, the duration must increase accordingly. There are always exceptions, there are tweaks that can help boltser lower end power so you can run a larger cam and not lose the bottom end and make a broader powerband (like the flaps that Audi uses to flatten and widen the torque band on the 4.2L V8). Then you can run a larger cam, moving power up, but yet still keep good low end power.

With a big truck we don't really want peaky, we want broad and powerful.

yeah I was wondering that too. But I do like the voodoo 60620. NODIH have you run or know someone that runs that cam?

[N0DIH]

Here is a good article discussing cams and effects of displacement and duration.

[2500ak]

Not that one in my truck (mine's still stock), but camwise that is more where we want to be rpm wise for torque peak. I had a 228 @ 0.050 cam in my 455 (4 deg adv) and it was very good in a street car (4000 lbs) with an intake, duals (small though) and h-pipe and 750 cfm carb and intake. But the cam it replaced was 200/213 duration @ 0.050, much much smaller, ran more or less the same. You have to be careful cranking duration up, it moves the powerband up higher and higher. The lift has more control over the hp/torque peak itself. Duration is WHERE in the rpm range the peak occurs.

The HO 454 cam or some of the other cams do move the powerband up pretty high for a peak and our heads don't flow that well up there, so we overall are weak on power compared to an smaller cam with shorter duration. Worst thing to do is overcam an engine. Not usually a problem have too much lift (aside from bending valves), but too much duration is a bigger problem. You can advance the cam to a point, but 6 degrees is about absolutely as much as you can advance it without problems. I know, I had mine advanced too far once, it ran good down low, but higher rpm it bucked and backfired.

The LT1 with a 192 degree intake duration (iron head) torque peaks around 2400 rpm, but is over 300 lb/ft by 1600 rpm. As duration is increased the powerband moves up and low end power drops off. As the engine displacement increases, the duration must increase accordingly. There are always exceptions, there are tweaks that can help boltser lower end power so you can run a larger cam and not lose the bottom end and make a broader powerband (like the flaps that Audi uses to flatten and widen the torque band on the 4.2L V8). Then you can run a larger cam, moving power up, but yet still keep good low end power.

With a big truck we don't really want peaky, we want broad and powerful.

In the case you list I'd be inclined to agree, but he's running forced induction and fuel injection which has completely different needs than a carbed N/A motor.

What he needs is a cam with a wide lobe separation angle, long intake durations, and an exhaust duration few degrees more.

With a N/A motor a tighter lsa primarily give a little extra dynamic compression (up to a certain point), some added scavenging, and better response (mainly with carb and tbi)

Carbed and TBI engines like the valve events to be closer because a little extra overlap is beneficial in distributing the fuel to the ports quickly. He has multiport injection which sees no benefit from that.

Also widening the lsa will lower the dynamic compression, which is a big deal on a N/A motor, but not at all (up to a point) on something with a supercharger.

A carbed engine doesn't care about unsteady vacuum, but 112 is about as low as you can go with fuel injection before the tuning gets hectic. Even with the smaller durations that small cam is still going to have about 49 degrees of total overlap. I just don't see the benefit.

Longer intake durations will give the blower more time to pack the cylinders, and he'll need more exhaust duration to account for the increase in air being pushed in.

For his engine I'd say he's better off running a 114-118 LSA, and 220 range durations. The motor should have a broader powerband and a significant increase in power across the board whenever it's under boost. Lower dynamic compression should mean better mileage out of boost.

That's my understanding at least.

[durbo.jones]

Here is my concern with going with a cam with duration in the 220 range is that the power will move up. It seems that the peak torque is moved up closer to 4000 RPMs with a cam in the 220 range. I have no desire for that. The Supercharger is making peak boost by 1800 RPMs on this setup. When I am towing the engine never goes past 3500 RPMs and is cruising between 1800-2400 RPMs, depending on where we are going. I see little need to wind it up any higher than that. My purpose for this is to have a strong running efficient towing setup. This cam is a bit small but it will keep the power where I want it. I am not looking to make crazy numbers with this. I want an easy on valvetrain, efficient, smooth idling cam that will provide a bit more power than stock. This cam has a -4.5 overlap which will help out with the idle and with the supercharger.

[2500ak]

I still say it's too much of a N/A cam. I looked around at the off the shelf cam choices and didn't see much though.

I'd say that your particular setup is uncommon compared to the vast majority of 454 engines out there. Most of the cams seemed to be geared towards N/A, carbed motors with high static compression. I can't imagine there's a huge market for cams for supercharged, fuel injected, low compression truck versions of the 454.

If it were me I'd call Comp, Luanti, whoever else makes camshafts for that engine and have them work out a design that puts the power where you want it while getting the largest gain you can. Pretty sure comp claims that they don't even charge anything extra over the off the shelf grinds.

I am not inclined to trust cam sheets that it says a given cam will make power at from x-rpm to y-rpm, because that's assuming a certain compression ratio, heads, fuel system, etc... that may not be consistent with what you're using.

[durbo.jones]

I was able to get in touch with Comp and Lunati and both actually recommended either this or a cam close to this. The specs that Comp gave me were 206/212 on a 115 LSA. I decided to go with Lunati because I have had a few issues with Comp grinds in the past. It may have not been a widespread issue but it was enough to not want to take a chance with having a cam go flat prematurely. I had a Comp grind in my 04 GTO and every lobe started showing signs of premature wear and damaged all of my lifters. I had seen the issue in a few other LS motors and didn't want to take the chance on my DD truck.

I still say it's too much of a N/A cam. I looked around at the off the shelf cam choices and didn't see much though.

I'd say that your particular setup is uncommon compared to the vast majority of 454 engines out there. Most of the cams seemed to be geared towards N/A, carbed motors with high static compression. I can't imagine there's a huge market for cams for supercharged, fuel injected, low compression truck versions of the 454.

If it were me I'd call Comp, Luanti, whoever else makes camshafts for that engine and have them work out a design that puts the power where you want it while getting the largest gain you can. Pretty sure comp claims that they don't even charge anything extra over the off the shelf grinds.

I am not inclined to trust cam sheets that it says a given cam will make power at from x-rpm to y-rpm, because that's assuming a certain compression ratio, heads, fuel system, etc... that may not be consistent with what you're using.

[PonyKiller87]

Did you end up going with that cam? How did it turn out?

Did you have to upgrade the valve springs? If so did the spring pockets need to be cut for the larger springs to fit?

I'm looking at the Lunati 60620 or the next one up the 60621. Trying to figure out what I all need to have done to the heads when they are in the machine shop.

[durbo.jones]

I never went with anything on the truck. I ended up selling it and bought a 03 Duramax. My dad is getting the Whipple for his 98.