Is a Cam worth it.....the remix+Data

[JasonCzerak]

Good read there raychem.


But my point was, to see what a stock vs non-stock cam does on an other wise stock motor with 1000whp worth of twins and proper tuning. nothing more, nothing less everything else the same.

Someone send JSP a stock head!

 

[Joesixpack]

Good read there raychem.


But my point was, to see what a stock vs non-stock cam does on an other wise stock motor with 1000whp worth of twins and proper tuning. nothing more, nothing less everything else the same.

Someone send JSP a stock head!

I've got a stock head, send the wrench monkeys and they can go at it all they want.....LOL


I remember a line that Corky Bell put out in his book and has always stuck with me...

" RULE: It is hard to find a turbo cam that works better than the stock item."

This seems all the more apparent now.

Keeping in mind my tests were in the stock cam's range, this is where Cummins engineers put a pile of money into engines on test cell dyno's that cost tens of times more than mine.....think they left a whole bunch on the table?

Gains above 4000, no question. I have no doubt there are better valve timing events up there.

 

[raychem]

Good read there raychem.


But my point was, to see what a stock vs non-stock cam does on an other wise stock motor with 1000whp worth of twins and proper tuning. nothing more, nothing less everything else the same.

Someone send JSP a stock head!

What Joe said above...probably not a dam thing. Goes back to my second to last post....we can make up for the benefits of replacing the cam with tuning the software in the ECM. Joe has pretty much been proving it for us.

Gains above 4000, no question. I have no doubt there are better valve timing events up there.

Here may lie the benefit of a cam change. 4K rpm and up but then whole motor, pistons,fully ported crazy head, valves and valve train. But if I am doing this...I want 1500-1800 HP and 6-7k rpm!

 

[RonA]

Has his turbo/cylinder head info been given(turbo size and either ported, or stock head).

 

[rcarro001]

What I have seen is that when I changed the cam I lost some torque in the lower rpms. My friend said the same on his truck. nothing else changed as far as mods. this is just our opinions though as no dyno runs. But I did see 100 deg. drop in egt and the stock turbo would surge some times. the cam was my first mode. the truck was stock other than a edge EZ. I have been questioning what to put in the 6.7 still unsure but thanks for the info. And hard work.

 

[Diesel Tech]

Cam changes work really well but not what most of you are really looking for. If your expecting a big HP gain forget it, not going to happen with turbocharged engines inthe stock RPM range. What a good cam change does is move the power band around and change the size slightly of the area under the curve. So say a stock cam is designed to make peak torque at 1800 RPM you can move that to 2500 with a proper cam change but that has to be what your looking for. This is just why people get all this confusing data, they have a mismatch of parts and make a cam change and they get nothing, then the next guy has his set of mismatched parts add a cam and it looks great because the cam made his parts work better than before.

Joe's results are just what one would expected from a properly matched set of parts then changing the camshaft to something that just doesn't add in the area he is looking for. These 100 HP cam changes only show how mismatched things were before you made the change. So be careful what all you try and put together and this is no different than the same type claims from injector suppliers. You just cannot take parts from people and mix them together and expect it all to work out perfect. Once you find the proper match it's sure nice though.

 

[wildcat455]

Thanks for your post, Diesel Tech.

 

[bsmith]

Cam changes work really well but not what most of you are really looking for. If your expecting a big HP gain forget it, not going to happen with turbocharged engines inthe stock RPM range. What a good cam change does is move the power band around and change the size slightly of the area under the curve. So say a stock cam is designed to make peak torque at 1800 RPM you can move that to 2500 with a proper cam change but that has to be what your looking for. This is just why people get all this confusing data, they have a mismatch of parts and make a cam change and they get nothing, then the next guy has his set of mismatched parts add a cam and it looks great because the cam made his parts work better than before.

Joe's results are just what one would expected from a properly matched set of parts then changing the camshaft to something that just doesn't add in the area he is looking for. These 100 HP cam changes only show how mismatched things were before you made the change. So be careful what all you try and put together and this is no different than the same type claims from injector suppliers. You just cannot take parts from people and mix them together and expect it all to work out perfect. Once you find the proper match it's sure nice though.

What would be a good cam for joe then?

 

[Diesel Tech]

He may already have it for the RPM range and parts he is working with. Without knowing a bunch more about what he is trying to do and his engine, just taking a guess isn't going to do any good.

 

[joefarmer]

What Joe said above...probably not a dam thing. Goes back to my second to last post....we can make up for the benefits of replacing the cam with tuning the software in the ECM. Joe has pretty much been proving it for us.



Here may lie the benefit of a cam change. 4K rpm and up but then whole motor, pistons,fully ported crazy head, valves and valve train. But if I am doing this...I want 1500-1800 HP and 6-7k rpm!

So why does a longer duration and higher lift cam lend itself to higher RPM? Is it simply that it supports the shorter window of time to get the air 'crammed' in the cylinder? Does a later or earlier ICL mean the engine can breathe better at high RPM?

 

[JQmile]

Interesting thread.....I'll be a cam would be worth more spool-wise on a big single. That's a lot of power out of a 64/80 combo!

 

[raychem]

So why does a longer duration and higher lift cam lend itself to higher RPM? Is it simply that it supports the shorter window of time to get the air 'crammed' in the cylinder? Does a later or earlier ICL mean the engine can breathe better at high RPM?

I am by NO means a cam expert. When it comes to cams I usually go to the people who know. I tell them what I am looking for, configuration of the motor(head, port type, runner volume, intake manifold dimensions, pistons, stroke, bore...you get the idea). There main concern after I give them all the info above and about 50 other questions is rpm range. Lots of work goes into this. I rather build a motor that gives me consistent 10 sec. runs at 500hp than a motor that makes 10 sec pass and the next at 10.20 and varies the hp it makes from run to run by 20-30hp.


Why I was referencing a higher lift cam; .550 and up is to allow more air into the cylinder. I dont have my numbers in front of me but stock motor dont support anything above .380 in lift more or less, piston valve contact. Like all motors, more air in , more fuel can be burned and more power made. With higher lift cams you may or may not get more duration based on setup but you will be able to get more air in and out (theoretically). One thing to remember, a higher lift cam will slow down the velocity that the air mass enters the cylinder but it will increase the volume of air (mind you I am leaving all the turbocharger variables out).

I never said in my post that a higher lift cam would give him more rpm. What it will do is shift the power band. A stock cam lets say has an operating range from 1200 to 3400....after that the motor falls flat since any higher RPM will not have the proper exchange of air and 100 other things. A higher lift cam....say .550 and up will give me an operating range from 2500 to 5500.....this is where I want to be if I am a puller or building a drag car motor. I am building the motor for its intended use since this cam with a 2500 and up operating range makes for a horrible DD.


This is what Diesel Tech was alluding to, the right combo of parts for what you need.

Again...I am as dumb as the next guy when it comes to cams hence why I ask those who know....to me it is the heart of the engine as it will dictate what the engines will do. With the ability to control all the injection events in the diesel, we can get away with a few more things vs a gas motor. Our power is based on the fuel we can burn and not so much on fuel ratios.

 

[raychem]

Interesting thread.....I'll be a cam would be worth more spool-wise on a big single. That's a lot of power out of a 64/80 combo!

I love what my cam did for me on a silverbullet 66...that wheel on the front is a big pig and no power till you get to 15 lbs of boost. My drivability was noticeably increased...would I do it again, probably not now that EFI or a standalone is available. I can make up for the cam in the programming.

 

[joefarmer]

I am by NO means a cam expert. When it comes to cams I usually go to the people who know. I tell them what I am looking for, configuration of the motor(head, port type, runner volume, intake manifold dimensions, pistons, stroke, bore...you get the idea). There main concern after I give them all the info above and about 50 other questions is rpm range. Lots of work goes into this. I rather build a motor that gives me consistent 10 sec. runs at 500hp than a motor that makes 10 sec pass and the next at 10.20 and varies the hp it makes from run to run by 20-30hp.


Why I was referencing a higher lift cam; .550 and up is to allow more air into the cylinder. I dont have my numbers in front of me but stock motor dont support anything above .380 in lift more or less, piston valve contact. Like all motors, more air in , more fuel can be burned and more power made. With higher lift cams you may or may not get more duration based on setup but you will be able to get more air in and out (theoretically). One thing to remember, a higher lift cam will slow down the velocity that the air mass enters the cylinder but it will increase the volume of air (mind you I am leaving all the turbocharger variables out).

I never said in my post that a higher lift cam would give him more rpm. What it will do is shift the power band. A stock cam lets say has an operating range from 1200 to 3400....after that the motor falls flat since any higher RPM will not have the proper exchange of air and 100 other things. A higher lift cam....say .550 and up will give me an operating range from 2500 to 5500.....this is where I want to be if I am a puller or building a drag car motor. I am building the motor for its intended use since this cam with a 2500 and up operating range makes for a horrible DD.


This is what Diesel Tech was alluding to, the right combo of parts for what you need.

Again...I am as dumb as the next guy when it comes to cams hence why I ask those who know....to me it is the heart of the engine as it will dictate what the engines will do. With the ability to control all the injection events in the diesel, we can get away with a few more things vs a gas motor. Our power is based on the fuel we can burn and not so much on fuel ratios.

Thank you for the input. Not trying to put words in your mouth; more just thinking out loud.

 

[Joesixpack]

Thank you for the input. Not trying to put words in your mouth; more just thinking out loud.

So....what cam's going into that mill your working on?

 

[joefarmer]

So....what cam's going into that mill your working on?

I pulled my billet Helix2 out of my worn out race block last weekend and it still looks perfect. I'm as confused as ever. I wanted to run up near 6000 with the air I have planned. Likely I'll have something custom cut at LSM after consulting with DonM, Woodruff, etc.

 

[raychem]

Thank you for the input. Not trying to put words in your mouth; more just thinking out loud.

No problems there my friend. This is one of the better threads on Compd right now and I am learning just as everyone here is. I just want to make sure that I don't give a wrong impression, some things I really just don't know all that much about. That is one thing I miss about gassers....a cam cam give you 50 hp and it can take away 80hp if your not careful! I loved working on 5.0's back in the day....fun cars to mod. Diesel, as we can see from this thread are a different ball of wax to some extent.

I pulled my billet Helix2 out of my worn out race block last weekend and it still looks perfect. I'm as confused as ever. I wanted to run up near 6000 with the air I have planned. Likely I'll have something custom cut at LSM after consulting with DonM, Woodruff, etc.

Have fun with that build. I am sure I will be reading about it hear.

 

[smokindully99]

Some good info guys, being ive been in the market for a cam for the new build.

 

[dnrcustoms]

Never went straight to the dyno after a cam swap, but just the obvious plusses usually sell themselves, cleaner oil, smoother running and quicker spool. I like my 181.. And i have a few customers i put the new 188 in and they all were very pleased.

 

[Spooler]

To me, a cam is for off boost performance, expanding the powerband, and driveability. Any power gains are just a plus.