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5K views 43 replies 19 participants last post by  cowboy_dan 
#1 ·
So I am wondering what the benefit of a Cam on a powerstroke is? Does anyone have any factual data to back up any claim? What kind of gain would you see with one?

Do they do anything - really?

Sam
 
#3 ·
I was hoping for feedback from someone not trying to sell a Cam...

Sam
 
#6 ·
I am sorry - I didn't mean to imply that you were trying to sell something. I meant Matt is trying to sell something in his thread. I was trying to see if people in the real world had knowledge/experience they would share. Similar to powerstrokenstang's post. I appreciate the post, I read the entire thread and then all of the linked threads in it. Had some really good information.

Sam
 
#5 ·
i ran one in my blown motor and when i had my motor built i felt it was worth it to get another one.
 
#7 ·
There are several that have ran them, most seem to like them. From what I have read, I don't however have any personal experience running a cam. I would like to try one though to see if it is something I would like for a daily driven application.
Wasn't trying to come across as pi$$ed off or anything! :ford:
 
#9 ·
This could be a really good discussion if it was filled with facts about how a cam works and not opinions. I will be the first to admit that I have very little knowledge when it comes to this subject. It seems as there must be some black magic to it or something. I would love for some of the old farts around here that have the knowledge to share it.
 
#10 ·
The problem is that everything that usually applies to cams doesn't work on the 7.3 because of it's unique construction. On diesels in general you can move the powerband up just like a gasser but you must pay special attention to things because you have compression ignition. The more duration you add, the more you have to deal with overlap (bad) and/or loss of cylinder pressure (also bad) in the lower rpms. The goal is get the right amount of airflow in the range you want to make peak power and nothing more. But I can tell you this, for the size of the engine we have the stock cam isn't enough to let the engine breathe properly even with ported heads. It's always a compromise though, you are basically taking away bottom end to gain top end. The trick is moving the VE of the engine enough to make a difference while not moving it enough to hurt drivability in the desired rpm range. Even in the gasser world, everyone has to install a higher stall converter if they want to make peak power at 6000 rpms. I don't think it is worth it though for someone to have a 3000 stall converter on a street diesel LOL. I just want to see a 7.3 start carrying some torque out to 3000+ RPMs instead of doing the grand canyon we are used to seeing.
 
#11 ·
Volumetric efficiency.....


Like you said, that is the reason for the torque/horsepower nose-dive because we see it on the dyno all the time, get the air in the cylinder and it will go away.

I'm not sure what exactly you are doing with the lobes on the cam but posting some cam doctor data would help as I would like to see what the .006", .050", and .200" numbers are to get a better idea of your ramp intensity. That is where the gains will be made - get the valves opened as fast as possible and keep the overlap out like you had said. This obviously creates problems controlling the valve train with the valve acceleration being so fast but the hypermax springs give enough pressure to get it done without allowing valve float especially with the low rpms.

On the right path :D
 
#12 ·
I can't give out those numbers because that is part of the reason they will work as good as they do, but let's just say that they are quite a bit more aggressive than stock as far as the ramp rates go. Let's just say that the duration at .050 grew more than the seat timing on the stage 1 over stock. That's also why I am mandating 125-150 lbs of seat pressure on the springs. The opening rate is very fast and the closing ramps are more gentle. I bounced my numbers off the grinder and they even made some some adjustments to the ramps, but we settled on something that will work for its intended purpose. The stage 2 actually has a slower lobe ramp rate since its intended rpm range is higher than the stage 1.
 
#17 ·
I don't think anyone is in business to lose money, so that's in invalid argument. Regardless, Matt wanting to keep specifics to himself does not mean his input is not appreciated nor helpful. He has dedicated a lot of time and effort towards something that most were telling him was a waste of his time. Are site sponsors disqualified from giving general advice/information to the general public?
 
#20 ·
I'll say this, until people start understanding that it's a combination of parts not just one part by itself that makes a difference, cam threads will be just like injector and turbo threads.
I had a guy tell me my cam didn't make a bit difference in his truck:doh:
 
#24 ·
i must say it didn do a thing in my truck either...... but once i put it in the motor i could tell the diffLOL
 
#22 ·
On my build, I'm using David's cam, along with his pushrods, 910 springs, ported exhuast ports, and the 38r. I hope the 910 springs will hold up the cam.
 
#25 ·
Matt has spent a ton of time working on this and from what I have seen of it speaking with him its all based on very solid work. The great thing ,as Matt has even said, is with this cam it is either gonna work ( better than average chance IMO) or its not. It should be obvious.
 
#26 ·
The Race Cam that Zane (***) came up with a few years back seems to work pretty damn good in my new motor. Thing makes pretty good power throughout the entire rpm range, even Jody was impressed while we were dyno tuning. It requires piston work though, it's pretty aggressive.
 
#35 ·
not to derail, but if the cover allowed it what would we do to hold up the lifters?
 
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