Floor It

As we keep going up in HP ,things are going to start to break that we never even thought would.Don is right on the money about harmonics,what we really need is a fluid dampener made for are trucks.

Jetpilot

As always everyone would love to buy the toughest and most durable product available. But, everyone must decide for themselves what they think will be the weak points they encounter..... So far Input shafts on the auto's are a good example, they have been prone to breakage and so stronger parts are now available. Price and common sense needs to be applied to choosing the right parts.<br><br>Currently I have over 750 HP to the wheels with no camshaft failure. In fact I can find nobody that even knows of anyone with a camshaft failure on our trucks. Don M. indicated that Piers cam is reground, this is true but what he left out is DD's cam is reground as well. Granted DD's is a new cam and Piers regrinds an OEM camshaft but both are reground.<br><br>Personally I feel that there are a LOT of other parts within our engines and drivetrain that will break well before a camshaft. Also Don spoke on gassers using chain drives for their camshafts..... Well virtually all high HP gasser application use gear drives similiar to ours!

KatDiesel

[quote author=Jetpilot link=board=7;threadid=5607;start=15#52107 date=1034466612]
Currently I have over 750 HP to the wheels with no camshaft failure. In fact I can find nobody that even knows of anyone with a camshaft failure on our trucks. [/quote]

I've seen one......broke in three places. Stock camshaft. I am sure both cams are good, each has its pros and cons. One of the &quot;neat&quot; things about the DD version is it has the gear to drive a mechanical lift pump should one convert to the P7100.

PourinDiesel

Breaking Cams is not common (unless there is a rod shooting through it!), but you can back the cam gear off of one at extreme rpm with a sudden overload, (like going into 2nd gear at about 90mph.<br><br>--Justin

Sled Puller

After reading Jetpilots post, I went back and reread the whole thread.<br><br>The things Don is concerned about have already been taken care of, by more than one Hi-Po Cummins shop. Shops that produce(for several years) 4000+ rpm custom cams, and massive TQ &amp; HP.<br><br>You are late, but please continue on your quest to solve these problems(?) and concerns you have Don, it may turn into discovering several, &quot;been there, done thats&quot; but you also may discover something that the pros have not.<br><br>

Don M

Virtually all modern day gasser engine builders will choose to by-pass a gear drive these days. Jenkins was one of the first to figure out that a gear drive will transmit the crankshaft vibrations through these gears much easier than a chain or as Jesel designed, a belt drive. You will not ever find a gear drive on a serious pro class engine anywhere. Sportman class, maybe a few. Pro-stock, Top Fuel, and all the Alcohol cars would never do such a thing. Its old hat and destructive.
Gear drives became popular to help make timing more accurate, it turns out it can make it worse from harmonics.

Cummmins figured out as engine power was increased that these vibrations were a problem as well. I gave the history and the Cummins &quot;upfit&quot; (their terminology) to the camshafts as the power went up over the years. The marine cam was built stronger yet. The 370HP Diamond &quot;B&quot; was/is Cummins best camshaft design so far.

Yep, the gears on the non bolted camshaft come off. Also the cams break behind the number two bearing journal nearly every time first. Funny how the shot-peening is stopped just behind the number two bearing journal on the older &quot;B&quot; engines huh? Coincidence? I personally dont think so. I see the weak point as the area that does not receive the shot peening as the first place a stress risers will occur.

DD re-grinds the marine cam. I believe I said that earlier when I explained how the marine cam was a better candidate for a regrind because you dont run the risk of getting into a softer area of the lobes. The lobes on the marine cam are much larger than the standard cam lobes to begin with. You just have to grind away less material with the big marine cam compared to the standard cam.

Cummins felt the harmonics were a serious consideration when they upfitted the engines with stronger camshafts as the power went up. The Diamond B is not even a 100% duty cycle engine like many other B's are and it has the strongest cam yet. If I had 750HP,over double the output of the Diamond B, I would at least run a marine cam.

Has anyone priced a marine cam alone yet? I have. The cam, new larger gear, bolt, key, and new lifters are more money to buy from Cummins than any other re-grind sells for out the door. The price for a higher quality and stronger design is nearly always more money.

Last point, as the power increased on the &quot;B&quot;...guess what else was changed (upfitted) to help deal with the harmonics?

The harmonic balancer, as eluded to earlier by Floor-It. Yep, we now need a better one yet.

Don~

Don M

[quote author=Sled Puller link=board=7;threadid=5607;start=15#52162 date=1034476987]
After reading Jetpilots post, I went back and reread the whole thread.

The things Don is concerned about have already been taken care of, by more than one Hi-Po Cummins shop. Shops that produce(for several years) 4000+ rpm custom cams, and massive TQ &amp; HP.

You are late, but please continue on your quest to solve these problems(?) and concerns you have Don, it may turn into discovering several, &quot;been there, done thats&quot; but you also may discover something that the pros have not.


[/quote]

Funny you asked earlier how many cams the pullers have broken. I actually received some of my info from Charles. If you dont know him, ask Dave. He knows him. Charles is well versed in Cummins camshafts. Like I said earlier, your cam is not going to break.


Don~

Sled Puller

No, what I asked is below, and you neglected to answer it.<br>I hope this does not fall under the same category as, &quot;I heard a certain White Dodge dynoed 407hp.&quot; in other words, complete bunk.<br>Just the facts Don, just the facts. We are on the verge of learning something here, I don't want any hearsay.[quote author=Sled Puller link=board=7;threadid=5607;start=0#51735 date=1034377085]<br>[quote author=Don M link=board=7;threadid=5607;start=0#49396 date=1033996322]<br> <br>I have heard of breakage problems from truck pullers. <br><br>Don~<br><br><br> <br>[/quote]<br><br><br>Really?<br>What truck pullers are those? Dodge Cummins? ???<br><br>I like to know details on carnage, in hopes I can avoid the same.<br>[/quote]<br><br>

Don M

Gene,<br><br>I never said anything like the white dodge dynoed 407. I think that was someone else. The white dodge would have difficulty dynoing on that mustang dyno anyway because of traction problems. Too much power. <br><br>I know that Cummins camshafts break. Charles told me of several he had that were busted from the pulling track in 4 wheel drive Cummins powered Dodges. Dave will know who Charles is...ask him, shoot ask Dave....he knows how many have.<br><br>Why fault anyone or any builder be it Cummins or whomever for making a better product and asking more money for it?<br>Price that marine cam and tell me what you find out. It aint a cheap date. It is a stout shaft with a higher nickle content and shot peened from end to end. <br><br>I dont think that Piers cam is a pile of bolts. I think it is a great shaft for guys that want to have a lower cost alternative to the other cams available and dont mind using re-ground lifters. I would not use this cam in high HP ( 500HP plus)trucks for the reasons I spoke about earlier unless the re-grind was based on a marine cam. For the majority of Piers customers the cam he offers is great. I like him and his products, especially my gov springs ;D I just feel the re-grind based on a stock shaft is not the strongest choice on the market.<br><br><br>Doug,<br><br>What components do you feel are going to fail before the cam would ???<br><br>Don~<br><br>

Jetpilot

Don,<br><br>I feel that most of the driveline components are the weakest link right now. (ie) Transmission input/output shafts, t-case, clutches, and rear ends. I am not saying someone is waisting their money on a DD camshaft, heck the guys who run them are very happy. What does bother me is why you would come on a post detailing Piers camshaft and parade around with your pom poms for another manufactorer. <br><br>You mention high rpm's causing problems..... Well 24v guys are pretty much stuck around 3400 right now due to ecm constraints. I know you wouldn't run Piers cam in a 500 HP truck, but tell ya what when mine busts I will let you know. As you know I am well past the 500 HP mark you are playing with now and personally I am not worried about my camshaft failing. I may be wrong but this is my opinion.<br><br>Doug

Don M

Doug,<br><br>Someone else started/asked the question about DD's cam. I just gave him some info on it. ??? I realize it is a Piers cam thread, but discussions sometimes take different directions. <br><br>As stated earlier, the Piers cam is based on a stock or very small lobe camshaft. The way the lift and duration is increased is by grinding away material on the base circle of the lobe. If you begin the process with a larger lobe i.e. the marine cam, the amount of material that needs to be removed is lessened. This is good for two things: it does not get into the surface hardening of the lobe as far, be it nitriding, induction hardening, etc. so the lobe retains a consistant hardness across the lobe. Secondly, and the most important part is: the valvetrain geometry does not change as much with less material ground away from the base circle. Remember, the base circle or the lowest part of the lobe is where the valve adjustment/lash is made. If you lower this point by re-grinding too much, the geometry is off by quite a bit from factory specs. This bad geometry creates steeper ramp and lobe angles and adds stress to the valvetrain. A valvetrain that is already under stress. <br>I see you are at 500HP on diesel, less than my truck at this time, with a stock cam I might add. Nitrous/Propane users are or should be in class all by themselves. The Olympics dont allow drugs, the NHRA pro classes dont allow drugs, the NBA does not allow drugs, and neither does NASCAR. It is difficult to learn about the engine and how to get more power from it if you add the variable of Nitrous/Propane. I guess there is a reason NOS uses the name &quot;cheater&quot; in some of their systems. ;D<br><br>Regardless of the HP level of anyones truck, this does not qualify or disqualify them to speak about what could or could not be a problem. No pom poms, megaphones, or spirit sticks are being used, just facts Man.<br><br><br>Don~<br>

Jetpilot

Actually Don the fact is nobody ask about DD's cam. One guy did mention that the price was $1500 installed and you did correct that info. <br><br>Now as for drugs..... When one elects to utilize other sources of fuels for our engines this is not cheating. You may have more HP on #2 than I, but as I recall you did not dyno at DFW because of issues with your truck. Nor have I seen any #'s from the strip so what your HP level is I do not know. I do know that my truck produces lots of HP. Levels that you have not played with yet. Racers use lots of different fuels.... Are we going to call top fuel racers cheaters for using nitromethane? As you say it is difficult to learn about the engine when you add additional variables, well they can just compound the issue not keep one from learning.<br><br>I do feel that at some point on the racing circuit we may have to look at classes for types of fuels. Maybe even trannies, chargers, etc. But right now we are discussing cams. And as you say just the facts. So the fact is I have over 750 HP using a Piers camshaft and love it!<br><br>Doug

Don M

Doug,<br><br>Im aware you have &quot;lots of HP&quot;. You have said it time and time again. Four times in this thread alone. I know you have the power with drugs, so do olympic contestants until they get caught :P<br><br>Regardless, your correct the thread was started as a Piers Cam thread. I can see how you might be a bit upset that I posted about the DD cam. For that I apologize and for the record I like Piers and his products. I was not slamming on Piers prodcuts at all, just stating an honest opinion of the weaknesses that can occur from re-grinding a stock cam. I use his turbo at this time and it has helped me to 531HP. On a baby non nascar dynojet that consistantly measures low because of its lower inertia that cripples turbodiesels.<br><br>Of course we dont call nitro users cheaters, they run a single fuel and air enhancement i.e. blower. If one of them decided to begin using nitrous I would consider that cheating. You use a two fuels (diesel, propane) and two air enhancements ( turbo, nitrous) No you are not cheating at all, its all wide open for now, no rules anyway. <br><br>Your right though about input shafts being a weak link....I twisted mine while rolling into the throttle just before the dyno event after some serious tuning that was making more HP than I have ever made. Too bad I could not show everyone at the dyno event. it was very strong. Im still waiting on a better and stronger input shaft and then I will be able to show you proof. <br><br>Don~

Jetpilot

Don,

Here ya go.... Gloves off. I really enjoy bantering with you because You have a lot of good points. Point being both DD and Piers make a lot of good products we all benefit by. Enough said on the pro's and con's. I really think it is time for a good oil or tranny thread

Doug

Don M

We agree on the best tranny at least.

Don~

not sure about oil, I have Gene for that anyway.