24V cam in a 3rd gen?

[AWeaver]

A friend of mine bought a 3rd gen motor and is having it rebuilt and was told that a 24v cam would give it better performance and a little boost in hp. Is this true and has anyone tried this? I know the engines are essentially the same and I dont see why this wouldnt work... . I was just wondering if anyone else had done this and had noticed any marked improvements.

 

[WCounts]

You are going to get a lot of opinions on this but I'm going to start with mine. I believe the stock cam in the 3rd gen is not as bad as some folks make it out to be. If I were going to install a new cam other than stock I would go with one of the proven aftermarket cams.

Billy

 

[AWeaver]

Suggestions ?

Have you had any good/bad experiences w/ any of the aftermarket cams available out there? Any you would recommend over others?

 

[WCounts]

From what I've seen you only get marginal "barely noticable" gains with aftermarket cams in a 3rd gen. Some will claim worth while and others will claim not worth while differances. With most aftermarket cams the pistons need to be cut for clearance. Something I would do for reliability but some of the 04. 5 and up have rattling problems. The reduced compression, differant cam timing and overlap hasn't been worked out yet with the 3rd gen electronics. For a daily driven truck I'll stick with stock for now but some where down the road I believe the rattle problem will get worked out with electronics.

Billy

 

[GDMRTN]

I've installed several 3rd gen cams. Everyone noticed better bottom end power and 2 - 3 mpg fuel mileage. I'd recommend haisely street puller cam. It seems to have been my best experience so far.

 

[CKelley1]

i have this from a cummins engineer, in the 04. 5 up they used a in cylinder egr to meet the epa goal some time in late 03 they changed the cam for the new design so now if you order a cam for a 01 or a 06 you are going to get one of these those of us that tow like the pdr cam the younger generation like the helix it is a little more high rpm and horse power oriented where the pdr is better on low end torque. if the truck is a 04. 5 up and it is milage you want get a smarty jr to restore the retarded timing the pdr cam to correct the exhaust valve timing and ddp 50 hp nozzles th shift more in the first and second injection pulse and less use of the third each one of these will get you 1. 5 mpg or about 4. 5 mpg total. this also increases the low end torque by about 250 ft lbs with the jr on economy some of our trucks can handle tow setting with out the clutch slipping some can not if his has the g56 get a south bend kit this does away with the dmf and has a real pilot bearing in it with this he could go to power if he wanted but on power he will have to watch his egt on steep grades towing

 

[AWeaver]

Thanks for the input guys... all great advice

 

[Matt400]

ddp 50 hp nozzles th shift more in the first and second injection pulse and less use of the third

I don't see how the nozzles would do that??

 

[RHestand]

Doesn't a 3rd gen engine already use a 24 valve cam?

Am I missing something here?

 

[Vaughn MacKenzie]

Doesn't a 3rd gen engine already use a 24 valve cam?
Am I missing something here?

There are differences with duration & lobe "timing" between 24V & 3rd Gen cams like CKelley was mentioning, especially with the 04. 5+ trucks. Someone posted all the duration/lift specs for 12V, 24V & 3G cams, they were all different, will have to see if I can find it.

 

[CKelley1]

400 the reason is the ecm controls the third pulse to a high degree with throttle setting with the larger injectors it thinks you are not pulling as much power and the ecm does not deliver as much fuel if any in the third pulse. thinking has to be changed when the ecm controls the variables and not mechanical

 

[CKelley1]

a more understandable way to say it. the ecm controls the timing, and duration of each pulse individually

 

[AWeaver]

I thought the 3rd gen cams were more "environmentally friendly" thus taking away some performance to resolve exhaust restrictions for the new engines...

 

[Matt400]

the ecm controls the third pulse to a high degree with throttle setting with the larger injectors it thinks you are not pulling as much power and the ecm does not deliver as much fuel if any in the third pulse.

Didn't know that about the 3rd event / apps correlation. Seems to reason then pressure & duration boxes could have an effect also in cutting back that event.

Do you know at what throttle settings - 1/4, 1/2, 3/4 that the ecm runs the 3rd event? Have to remember then also that if a 3rd event is run it will run with a larger injector.

 

[WCounts]

I thought the 3rd gen cams were more "environmentally friendly" thus taking away some performance to resolve exhaust restrictions for the new engines...

They most likely do but make good hp too.

Billy

 

[CKelley1]

they are more environmentally friendly but at a cost of performance

 

[p-Bar]

I like the way the Europeans think Economy 1st then worry about the emissions