When is a Cam Needed?

Texashighways said:
Injectors are a part of rate of injection. It appears that there were additional pump modifications and modification to programming to make more power. As stated before I will give you $1600 to have you put the stock cam in and dyno with no other changes
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Might take you up on that, we're set up with a remote rad and a cam gear cutout to make for quick swaps and timing adjustment. Just never quite got there before the block gave up.
 
In the last three years, we have tested about every stick that is readily available and a few custom grinds. In tow trucks and race trucks. Anything under 1100hp gets a stock cr cam here.
 
Texashighways said:
Injectors are a part of rate of injection. It appears that there were additional pump modifications and modification to programming to make more power. As stated before I will give you $1600 to have you put the stock cam in and dyno with no other changes
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Hell, if you need a guinea pig, pick me!!! :cheer: :cheer:

I have a decent build, 750-800hp. The only thing I don't have is a cam. Providing eveything is clicking, it runs 11.1s pretty consistantly, with an occasional dip in the 11.0s. I have enough smoke to warrant more air, but my converter is likely too tight to spool bigger charger(s). And, I don't want a higher stall converter.

I'm on the verge of buying a cam to help it spool and for more top end. But due to clearance issues, and the possibility that it might not help that much, I'm on the fence.

My proposal is....

Zach, send me a 188/220 cam and lifters. I'll run next week with my standard tune, record times. Then I'll stick the cam in, and run again the next week without changing anything else. Then compare times. If and where the cam helps should be pretty obvious by the time slips. I don't have a data logger, so I can't really do pretty graphs. But I do shoot video of my gauges during a run, and my gauges record peak measurements. So I'd have useful data.

You'd have a direct comparison between cams for your cost on the cam and lifters, instead of $1600.

Seems like a no brainer to me. LOL
 
^^^ Now that is a test that I would love to see happen and certainly more affordable than a $1600 payout.
 
Drothgeb said:
Hell, if you need a guinea pig, pick me!!! :cheer: :cheer:

I have a decent build, 750-800hp. The only thing I don't have is a cam. Providing eveything is clicking, it runs 11.1s pretty consistantly, with an occasional dip in the 11.0s. I have enough smoke to warrant more air, but my converter is likely too tight to spool bigger charger(s). And, I don't want a higher stall converter.

I'm on the verge of buying a cam to help it spool and for more top end. But due to clearance issues, and the possibility that it might not help that much, I'm on the fence.

My proposal is....

Zach, send me a 188/220 cam and lifters. I'll run next week with my standard tune, record times. Then I'll stick the cam in, and run again the next week without changing anything else. Then compare times. If and where the cam helps should be pretty obvious by the time slips. I don't have a data logger, so I can't really do pretty graphs. But I do shoot video of my gauges during a run, and my gauges record peak measurements. So I'd have useful data.

You'd have a direct comparison between cams for your cost on the cam and lifters, instead of $1600.

Seems like a no brainer to me. LOL
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Joesixpack has a little bit better data collection system. No offense.
 
RonA said:
Joesixpack has a little bit better data collection system. No offense.
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Certainly no offense taken. But he'd just be producing numbers on a piece of paper. It would mean something to some of you guys that can understand and dwell on those results. But to someone simple like me, a bump or blip on the dyno graph doesn't mean anything if it doesn't equate to real world results. I've watched dyno queens boasting big numbers in my rearview mirror more than once.

Now, knocking .005s off my 60 from better spooling, or, picking up a single mph on the big end, that means something to me.
 
RonA said:
Joesixpack has a little bit better data collection system. No offense.
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Drothgeb said:
Certainly no offense taken. But he'd just be producing numbers on a piece of paper. It would mean something to some of you guys that can understand and dwell on those results. But to someone simple like me, a bump or blip on the dyno graph doesn't mean anything if it doesn't equate to real world results. I've watched dyno queens boasting big numbers in my rearview mirror more than once.

Now, knocking .005s off my 60 from better spooling, or, picking up a single mph on the big end, that means something to me.
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There is usefullness in both of these testing scenarios quite honestly. The dyno will not show dummies like myself a video of how well the truck spooled up at the line with the same converter, how it e.t'd, etc. I would like to see both results but in all honestly I'm more interested in a comparison like the one Drothgeb is offering. A simple few minutes of research could allow for him to arrive at what Density Altitude he was at when he ran his truck on previous 11.1-11.0 passes and what DA he would be at with the addition of only the cam.
 
NickTF said:
There is usefullness in both of these testing scenarios quite honestly. The dyno will not show dummies like myself a video of how well the truck spooled up at the line with the same converter, how it e.t'd, etc. I would like to see both results but in all honestly I'm more interested in a comparison like the one Drothgeb is offering. A simple few minutes of research could allow for him to arrive at what Density Altitude he was at when he ran his truck on previous 11.1-11.0 passes and what DA he would be at with the addition of only the cam.
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Yep, like he said. And I've got a rather high end weather station at my house a couple of miles from the track. It records temperature, humidty, barometric pressure and etc. So, I could match results with conditions as well as a dyno could.
 
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Few years ago we trashed a motor on a Monday, had a points pull the fallowing Saturday. No time to assemble anything. Ran across a decent complete engine already had a good head on it but only had a stock cr cam in it(12v engine). Bought it just to make last hook and go on from there. Was running a cast 475 and 5x18 injectors. Had ran that setup all year with 33s 4.88 gears in 4lo. New engine would not run that gear at all. Had to drop down to make a pass. We tore the engine down that winter and did nothing but cut pistons and instal our old cam. Ran like a different truck. No changes to fuel injectors or nothing else at all. After a few hooks went to a 35 and 5.13s for the rest of that year. I would never build a "performance" engine without installing a cam.$.02
 
Maybe p-pumped trucks benefit from a cam more than common rails.
 
How about vp trucks? Is there a perfect cam to utilize the short rpm range?
 
RonA said:
Maybe p-pumped trucks benefit from a cam more than common rails.
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Wasn't that one of his points from his given information? Since the cr has so much more tunability than the ppump he could virtually recreate having an aftermarket cam in the engine. Seems logical to me. I think my ppump spools a 66 quite nicely with only a blip of smoke right around 10psi and all I have to my advantage is a 188/220 Hamilton.
 
Drothgeb said:
Yep, like he said. And I've got a rather high end weather station at my house a couple of miles from the track. It records temperature, humidty, barometric pressure and etc. So, I could match results with conditions as well as a dyno could.
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If I buy the cam back from Joe, I will send it to you. That being said, I base my entire living on the fact that cams work. If they did not, I would be in a different line of work. I stand by my claim that cams only change the potential for gain, they cannot change tuning or combinations. There are many other factors involved. If they let the valve open longer to trap more air, there must be more air ready to come in and there must be fuel enough(injected at the right time) to take advantage of the air.

On a side note, I have done plenty of Dyno testing and real world testing proving gains. The issue is that people have been lied to long enough that nobody believes dyno numbers any more. Any truthful statement or proven data can easily get lost in a sea of misinformation and half-truths.
 
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Blacksdieselhp said:
In the last three years, we have tested about every stick that is readily available and a few custom grinds. In tow trucks and race trucks. Anything under 1100hp gets a stock cr cam here.
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Well I'm glad that someone else is seeing what I did. So what cam does it get after 1100HP....:poke:



Zach has made a very generous offer, and we'll try to work it in, Likely with the triples.
 
When folks become more than part swapers...and learn about engine combinations, airflow and timing events, and effieciency camshafts become very valuable!

our duramax cams have shown to produce over 200+hp over stock, in the correct application. Dyno and track proven.

Zach has a very good handle on the cummins camshafts, he would be one of my first choices if i had a current cummins build....But one must realize that the cambuilder cant know everything about the engine. The engine builder should.

It's not the camshafts fault.
 
[ame="http://s240.photobucket.com/user/zacheryhamilton/media/TIMEvsCam_zps23a3d098.png.html"]TIMEvsCam_zps23a3d098.png Photo by zacheryhamilton | Photobucket[/ame]

Although this graph will be called false, these are the dyno graphs from a 26 hour time period.

The 181-210 netted 7hp and 3 ft-lbs, peak to peak over the stock cam and the spool time was cut by almost 2.25 seconds. In this way a graph with Hp as a function of rpm does not fully show how the cam will help driveability like hp as a function of time. The 188-220 shortened spool by almost 4 seconds plus added 43hp and 111 ft-lbs peak to peak. The 200-220 also shortened spool by 4 seconds over the stock cam but ony made 22hp and 26ft-lbs over the stock cam.

There was additional fuel to be burned so that any increase in air showed up in hp. If that fuel was not available, there would have been almost no gain. In that way, these gains may or may not be representative of the gain you will see. That is why we try to spend a lot of time with peoples combinations. Sometimes, poor tuning is a bigger roadblock to HP production than the cam. In many cases the benefit of a cam is that more fuel can be added by additional tuning, resulting in more power.
 
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oldblue116 said:
How about vp trucks? Is there a perfect cam to utilize the short rpm range?
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Since they are similar to VE pumps, BC847 showed that the 188/210 moved peak power into lower RPMs and held it longer than the 181/208 i believe. No additional power was really made but the graph showed the power band got broader
 
Texashighways said:
TIMEvsCam_zps23a3d098.png Photo by zacheryhamilton | Photobucket

Although this graph will be called false, these are the dyno graphs from a 26 hour time period.

The 181-210 netted 7hp and 3 ft-lbs, peak to peak over the stock cam and the spool time was cut by almost 2.25 seconds. In this way a graph with Hp as a function of rpm does not fully show how the cam will help driveability like hp as a function of time. The 188-220 shortened spool by almost 4 seconds plus added 43hp and 111 ft-lbs peak to peak. The 200-220 also shortened spool by 4 seconds over the stock cam but ony made 22hp and 26ft-lbs over the stock cam.

There was additional fuel to be burned so that any increase in air showed up in hp. If that fuel was not available, there would have been almost no gain. In that way, these gains may or may not be representative of the gain you will see. That is why we try to spend a lot of time with peoples combinations. Sometimes, poor tuning is a bigger roadblock to HP production than the cam. In many cases the benefit of a cam is that more fuel can be added by additional tuning, resulting in more power.
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What are the specs on the engine?
 
stock 12v head
marine pistons
.150" valve reliefs
370 injectors honed 30%
913 pump
191 d-valves
box stock 66/74/.91 t-4
banks twin ram
21 degrees timing
beehive 175# springs
Pretty mild setup on the whole
 
Pretty good hp numbers for that build with and without the cam.
 
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