Cost for camshaft prototype or very short run

[acannell]

Wondering what the $$$ is to have a single camshaft run for our 8V 2.2/2.5.

And perhaps a small run, say 5 or 10.

The idea being if we end up having some ideas we want to try out, how much would it cost to pull the trigger on a prototype or small group buy.

[bakes]

best to keep them all new billets not regrinds lookng some where in the 250-350 mark

I know my goals a .520 lift with the most aggressive ramp rates that test are followers limits with power band ending/dropping around 8000rpm

[acannell]

best to keep them all new billets not regrinds lookng some where in the 250-350 mark

I know my goals a .520 lift with the most aggressive ramp rates that test are followers limits with power band ending/dropping around 8000rpm

??? It costs the same to buy a new off-the-shelf camshaft as it does to have one custom ground to some made up specification? Who does this??

(rubs hands together gleefully)..I see myself doing some "experiments" as well, especially in the area you describe as far as steep ramp rates.

[Chris W]

Finding the cam blanks will be the most challenging and costly part of your project. And the profiles you come out with will all be experimental so you could wind up with several camshafts investments without a return.

Chris

[acannell]

Finding the cam blanks will be the most challenging and costly part of your project. And the profiles you come out with will all be experimental so you could wind up with several camshafts investments without a return.

Chris

Story of my life lol. I would like a way to try out ideas though. Someones gotta be machining blanks out of barstock on a CNC lathe. Actually I'm sure I read an article awhile back, I think it was about Comp Cams, and how they had purchased the first Mori Seiki CNC lathe in the USA, and were getting a couple new ones, specifically for cams. Im not sure what their prototype situation looks like though. Could be $$$

[shackwrrr]

Is there a reason cams need to be cast? I'm sure a steel cylinder is cheaper than casting blanks.

[83scamp]

Here is an article where some of the top manufactures tell what materials they use to make cams:

http://performancebiz.com/features/whats-camshaft

[shackwrrr]

HMM, don't have any access to steel suppliers, I could only imagine what a stick of 5160 round bar would cost, let alone 8650. I know how hard allen keys and drill bits are and Im sure they wouldn't be fun to machine.

[acannell]

HMM, don't have any access to steel suppliers, I could only imagine what a stick of 5160 round bar would cost, let alone 8650. I know how hard allen keys and drill bits are and Im sure they wouldn't be fun to machine.

Machine the blank in the unhardened state to close to size, then harden, then grind. It doesnt have to be machined in the hardened state necessarily.

Casting them accomplishing making the blank to size without any machining, so when making a lot of them, it makes sense. No wasted material, no machining. Just harden and grind.

[Shadow]

Making a "new grind" Exactly to the specs you want could cost tens of thousands of $'s, as (if no master exists for your spec) you would need to pay to have those masters made Before any cams could be ground.

That would be a Huge investment at a potentially high risk for something that you would be "speculating" to work.

So IF you could machine it from a billet blank that Would be a more cost effective way of doing a small run (1-10) of cams for sure.

[Ondonti]

Its not even made clear if you are just looking for a custom profile or just billet blank supply to do tests with.

For tests, some companies offer quite cheap welded lobes if you cant get blanks. Considering welded lobes do work, regrinds too, the paranoid crowd that prefers running stock or talking about billet without buying it shouldn't be worried about a TEST camshaft wearing out, especially when you are on rollers. The point of a test is to prove an idea, not to last 10,000,000,000 miles.
Finding someone who will actually do what you want, not sure about that. I would love to see a cam order card that gave you the option to do more than determine lift and open/close times. That said, a good cam guy will do better than your math every time. Assuming you can pull one out of thin air is presumptuous. If you really wanted a nasty camshaft, your guy can probably do it, but they don't like hearing complaints about things you should have expected. No matter what people say, a non adjustable cam profile has a range of peak efficiency and there is no magic to get around that. Set it and forget it. There is a guy on TD who made a self retarding 8 valve cam pulley. That is something you could combine with a special camshaft that is designed knowing cam timing will change as rpms increase.

No matter what you do, your big turbo/cam/manifold/head motor with low compression will be a turd out of boost, 16 valves or 8. I definitely would have been trying to be best bud's with that guy who made the self retarding 8 valve cam gear if I wanted some cool camshaft potential. You could make a street cam breath up top or a nasty race cam idle/cruise better. The potential fun there blows my mind and would make camshaft experimentation possibly have some value.

[knownenemy]

Just my opinion, but maybe thinking somewhat "out of the box" here would be most cost effective.

Would it be possible, and more feasible to grind the lobes off of a stock cam;
CNC replacement lobes from steel using the CNC;
And attach them for testing?

I'm simply trying to come up with a somewhat cost-effective DIY means to test different cam profiles.

I am by no means a machinist, or am I knowledgeable ENOUGH in the design, and manufacture of cams.
Like most, I am one who buys the best "off the shelf" cam I can get based on several other measurable factors.

But, swapping out lobes is an idea that should have been common by now. lol
Don't like the cam you've got, buy new lobes, and install! :thumb:

[acannell]

Its not even made clear if you are just looking for a custom profile or just billet blank supply to do tests with.

For tests, some companies offer quite cheap welded lobes if you cant get blanks. Considering welded lobes do work, regrinds too, the paranoid crowd that prefers running stock or talking about billet without buying it shouldn't be worried about a TEST camshaft wearing out, especially when you are on rollers. The point of a test is to prove an idea, not to last 10,000,000,000 miles.
Finding someone who will actually do what you want, not sure about that. I would love to see a cam order card that gave you the option to do more than determine lift and open/close times. That said, a good cam guy will do better than your math every time.

Good point. So lets see how close we can get:

"Experimental / Idea testing prototype cam, cheap as possible."

Step 1:

Machine all cam geometry on manual or CNC lathe. Lobes get machined as big circles slightly bigger than the lobes will end up being. Nothing special here. The CNC lathe would just make it automated. But this sort of thing is right up even an ancient manual lathes alley.

Step 2:

Place machined "blank" into CNC mill with 4th axis. Machine lobes to final size.

Step 3:

Hand finish lobes to as good a surface finish as you can using various hand finishing techniques like emery paper, etc.

Step 4:

Harden the camshaft using various heat treat methods. Perhaps send it to a cam manufacturer to have them harden. Or perhaps have it treated in an oven. Lots of processes. Not sure which is appropriate.

OR, make the camshaft to begin with out of a material that is hard enough to survive testing, but also be machinable.

Im not sure what materials would meet the bill (if any) for reasonable durability of a camshaft and also machinability that makes this all work, i.e. eliminating CNC/jig grinding.

The welded lobes idea is very interesting. Once you make a nice camshaft "core", making lobes could be done on a mill and they could be hand lapped or polished to the right finish. You could heat treat them in a small oven I bet.

Camshafts and lathes go wayyyyyyyyyyyyyyyyyyyyy back. I would not be surprised if there are many devices and methods that fit on manual lathes to allow camshaft machining and tool post grinding of the lobes. That would be a whole other possibility.

If you look at a manual camshaft grinder, its just a lathe with a grinding wheel on a pivot that has a guide cam that moves the grinding wheel to make the lobe. You can make something like that that bolts to a lathe and does the same thing. Im sure someones done it.

In other words, if I look at my Atlas lathe made in 1950 or whatever. It already has everything needed to hold and support barstock for precision machining of bearing surfaces. All you need to make lobes is a way to dress and move a grinding wheel according to the lobe profile.

[86Shelby]

FWIW, when I had my TIII cams reground it was $350 for the pair. That included a bit of profit for the guy handling the transaction & such. Perhaps that might be an option that's more agreable with the pocketbook?

[acannell]

Just my opinion, but maybe thinking somewhat "out of the box" here would be most cost effective.

Would it be possible, and more feasible to grind the lobes off of a stock cam;
CNC replacement lobes from steel using the CNC;
And attach them for testing?

I'm simply trying to come up with a somewhat cost-effective DIY means to test different cam profiles.

I am by no means a machinist, or am I knowledgeable ENOUGH in the design, and manufacture of cams.
Like most, I am one who buys the best "off the shelf" cam I can get based on several other measurable factors.

But, swapping out lobes is an idea that should have been common by now. lol
Don't like the cam you've got, buy new lobes, and install! :thumb:

I have had exactly the same idea!

I even tried turning a scrap camshaft to see how it turned. I think it might be possible. I would probably machine the lobes down using something aggressive then precisely get them to size on the lathe.

http://i242.photobucket.com/albums/ff197/acannell/20141109_165233_zpshe6m4uga.jpg

[Reaper1]

I might be remembering something a little off here, but I swear I've read something about pressed on cam lobes here recently for production vehicles. Maybe it was even the Viper. I know they were using a 2-peice cam with a cam phaser to get VVT out of the V10.

How about machining the bar stock so you key on the lobes then maybe hold them on with split c-rings and a sleeve (similar to how the gears are held on the intermediate shaft in the transmissions).

[acannell]

I might be remembering something a little off here, but I swear I've read something about pressed on cam lobes here recently for production vehicles. Maybe it was even the Viper. I know they were using a 2-peice cam with a cam phaser to get VVT out of the V10.

How about machining the bar stock so you key on the lobes then maybe hold them on with split c-rings and a sleeve (similar to how the gears are held on the intermediate shaft in the transmissions).

Theres how someone who does it for a living would do it, and then theres how I might be able to pull it off to a professional quality with what I got.

Im pretty sure I can turn a circular bearing surface concentric with several others over the length of the cam. Its not trivial actually, but I can probably pull it off.

Grinding them to a specific finish and very tight tolerance diameter is also something I might be able to do with a tool post grinder.

The gears in the tranny have splines dont they? Thats how they are being locked into place. Plus they only have to transmit torque in one direction and there isnt a requirement for them to have a precision relationship to the shaft besides being concentric. The problem with cam lobes is that they need to be concentric, and locked in place relative to the shaft. And both precision.

Okay..eyeballing our cam it looks like the base circle of the lobes is slightly larger than the bearing surfaces. Not large enough to where we could make lobes and slip them over the bearing surfaces to their final resting spot. Especially with the flanges on the ends of the cam.

So..maybe what we do is make a cam with much smaller bearing surfaces that you COULD slip pre-made lobes over. And then use sleeves on those small bearing surfaces to bring them back up to stock size? Along with as solution for the flanged ends.

What that does is mean we can machine a lobe on the mill right out of the stock of our choosing, without having to worry about splitting it in half and making sure it goes back together smoothly.

We could secure it to the camshaft with a couple set screws the go into divits in the surface the lobe mounts to. Make the lobes wider than need be so there is room for the set screw to be installed without being on the surface that the follower rolls on.

The lobes could be machined close to final, then heat treated in a small oven, and final machined using beefy tooling and going really slow, followed by hand polishing to get the right surface finish.

Sounds like a fun project! Job #1 would be to measure the camshaft and confirm this idea is possible as far as things slipping over things. Then model the cam in SW and draw up all the parts.

[thedon809]

Chrysler 2.7l uses hallow steel cam with pressed on cam lobes.

[c2xejk]

For tests, some companies offer quite cheap welded lobes if you cant get blanks. Considering welded lobes do work, regrinds too, the paranoid crowd that prefers running stock or talking about billet without buying it shouldn't be worried about a TEST camshaft wearing out, especially when you are on rollers. The point of a test is to prove an idea, not to last 10,000,000,000 miles.

Delta cams has been recommended before for welding cam lobes. Just a guess, but I think they will charge in the $250-300 range to weld and regrind a cam.

[Ondonti]

Delta cams has been recommended before for welding cam lobes. Just a guess, but I think they will charge in the $250-300 range to weld and regrind a cam.

Yeah, they are famous for welding lobes cheap. My cam guy doesn't want to so he charges $100 per lobe even though he only charged 100 per regrind at the time.

I am okay with regrinds for any reason but if people are trying to optimize geometry in their tests then they might want to retain OEM base circle or even try something different. I wonder if its possible to do something like a cracked cap connecting rod with machined lobes? Get them super cold and break them in half?

[Reaper1]

I like the idea of splines. You can build the entire cam as a "stack"...bearing, lobe, spacer, lobe, bearing...etc. You could choose to make it so the splines are asymmetric so that you can't spline the lobes "off timing".

Or, cut down the bearing surfaces and find a needle bearing that will work. Expense is my worry here, but it saves from having to make the bearing surfaces.

In order to pull off the set screw idea I think the shaft would have to be through-drilled so the screw can engage both sides of the lobe, so the other side of the screw would actually go into the other side of the lobe and act like a drive pin. Of course the hole would have to be countersunk and beveled.

Ooohh...how about could you "dovetail" or "christmas tree" the base of a prototype lobe and have it slide into a receiving slot on the cam that has been machined? This is how jet engine blades are held into their hubs. There are a multitude of ways that the blades are captured so they don't fall out.

[acannell]

I like the idea of splines. You can build the entire cam as a "stack"...bearing, lobe, spacer, lobe, bearing...etc. You could choose to make it so the splines are asymmetric so that you can't spline the lobes "off timing".

Or, cut down the bearing surfaces and find a needle bearing that will work. Expense is my worry here, but it saves from having to make the bearing surfaces.

In order to pull off the set screw idea I think the shaft would have to be through-drilled so the screw can engage both sides of the lobe, so the other side of the screw would actually go into the other side of the lobe and act like a drive pin. Of course the hole would have to be countersunk and beveled.

Ooohh...how about could you "dovetail" or "christmas tree" the base of a prototype lobe and have it slide into a receiving slot on the cam that has been machined? This is how jet engine blades are held into their hubs. There are a multitude of ways that the blades are captured so they don't fall out.

Anything besides a circle is much more difficult to make precision. Needle bearings still need a precision bearing surface to ride on, no free lunch there.