NE frmhnd

Now has an aluminum head for the 12 valve. I saw it in Diesel Power last night. I just flip through it at the store, I don't like reading stories about guys that drop 50K into a truck they just paid 50K for, anymore. Same reason I don't read the MOPAR magazines much anymore. Anyhow, I'm wondering if it would make much more power, it supposed to flow something like almost double what the stock head does, if I recall the figures right.

Rick 12v CTD

Well if it flows nearly double, then it's flowing pretty good.

IIRC the stock head flows 118CFM. A decent ported head will flow 190CFM (+/- 2-5CFM). If that head flows nearly double then it should flow 220+CFM. At least, one would think... who knows on the quality of the build though.

92smokin blacky

That is neat. I read the article a while back. Its like a 1/2" or 1" taller or something to flow more and flows something like 300 cfm. I think for 8 grand though you could buy lots of other stuff to get more power than that would give ya. It would be cool though

Rick 12v CTD

$8000!!!

Mark Nixon

IIRC, with the properties of aluminum, don't you have to raise compression, or run more boost to get an equal amount of heat for proper combustion?
I believe this applies to both gassers and diesels.

Indy Cylinder Heads hasn't been noted for their ease on the wallet, that's for sure.

Mark.

BC847

Zach Hamilton is in the final stages of developing a 12v Cummins head that supposedly flows a LOT more than stock right out of the box. It isn't aluminum, and it isn't $8K.

Rick 12v CTD

I've been waiting for some time for that head to come out but is it the same thing that's been mentioned by them that's built around a ppump running higher RPM? so it won't be as useful to us running the lower RPMs because it doesn't flow as much at lower RPM. (that doesn't seem to make sense to me but I dunno... it's just what I've read.)

Mark Nixon

For "Torque" it's not really about "flow" in the typical sense, but rather "velocity"

Velocity is a big factor in making torque at lower RPMS.
A bigger hole reduces velocity, similar to a bigger cam reducing low end torque.

Some of the best (gasser) truck engines have a tiny cam and a small intake port.

A diesel, in general, is a low RPM engine, small ports, high (static) compression, small cam, all aimed at producing the most power below 2500 RPMs.

Never understood the "Rev it to the moon" mentality, especially on a Turbocharged Diesel.

Mark.

Rick 12v CTD

That's apparently over my head due to ignorance then.

I would have thought that air (volume) + fuel = higher tq regardless of revs. I would have thought that the more air you can get in there at lower RPM would mean more torque.

DevilzTower

you are not off track - that's correct. Fill the cylinder with more air, you get more boom - yields more torque.

Rick 12v CTD

and I guess a smaller orifice allows the air to get there sooner due to its higher velocity... even if there is less of it. it allows the torque to come on lower.

Mark Nixon

That's why there are turbos on these engines, to increase air into the engine, while not affecting velocity.
Not enough air down there?
Put on a tighter exhaust housing.

Maybe it's me, but I don't like to RPM the daylights out of an engine to get maybe 10% more efficiency from it, while increasing the possibility of damage and shorten it's life span.

Improving low end torque is where having dynamic timing shines through, as well.

Airflow increases in the head (porting, etc.) are generally targeted at generating more RPM, which seems counterintuitive to how a 4 stroke turbodiesel was originally designed.

Mark.

The_Head

HP = TQ x RPM / 5252

So if you can keep it breathing (and for us VE guys, fueled) at higher rpms you'll make more power. Usually have to make a trade off in the low rpm power though, which wouldn't make sense on a working truck.

I am more interested in mods that give you more "area under the curve" aka as a wider powerband.

Mark Nixon

That's the holy grail, a wide and predictable powerband and it would seem that the compound turbo set-ups have at least PART of the issue covered with a smoother, more consistent airflow.

A P-7100 version of injection pump with dynamic timing could prove to be the cat's meow for both worlds.

There is someone making a P-7100 timing gear with manually adjustable timing, I understand?

Mark.

dieselJon

Schied makes one Mark.