more is gooooood. smoke doesn't equal power though, but if you can burn all of that fuel that the modified p pumps put out with a balance of timing and twins, then there's your high horsepower.

oh yeah...lift pumps aren't an issue either

BR- how's combustion better...because the end of the nozzle doesn't come in at an angle and create a different swirl on one side of the combustion chamber?

Tom

 

Good points by everyone!

I own one of each; a 96' Dodge CTD 12 valve and a newer
2002 Dodge CTD 24 valve. After extensively BOMBING and
driving both of them, I still feel that the 12 valve engine
is much more reliable than the 24 valve engine due to the
design of the fuel system on the 24 valve engine! In
stock form that fuel system on the 24 valve engines is
barely adequate!! Noone has really been able to come
up with a long lasting, reliable "pusher pump" that can
be "used and abused" day in and day out without causing
problems or leaving you on the side of the road!

My 96' 12 valve now has almost 215,000 hard miles on
it and runs better now than the day I bought it!
I have NEVER had one problem with the fuel system
on this truck and as other members already pointed
out the P7100 fuel pump is one TOUGH unit!!

------
John_P

 

Total CFM flow is not the only thing to look for. Yes, the 24 valve head will flow more total CFM, but that is not the only parameter to look at. This is also under a vacuum on the flow bench. Well guess what...our engines are not under a vacuum. They are boosted with postive pressure. Flow benchs while being a good tool for balancing airflow between runners are not telling us much about flow in a cylinder head that is working under intense pressure.

A high velocity port will quickly fill a combustion chamber with air and quickly blow one down ( exhaust side ) as well.

The 12 valve head has great velocity and a fast swirl rate. The 24 valve head relies on tumble more than swirl rate.

Incorrect porting will kill the tumble and slow mixture formation in the 24 valve head. On the exhaust side the port velocity will drop. Port velocity is lowered once you port the 24 valve head.

Yes, more complete combustion can be accomplished with a 24 valve head up to a certain discharge rate and quantity of fuel.

Tempering everything above with this: The 12 valve head was designed to mix fuel parcels of greater size and under a longer duration of injection. What are we doing by using larger injectors? We are injecting more fuel for a longer duration of time.

Don~

 

Which can be made the loudest 12v or 24v?

 

[quote author=TxRedneck link=board=16;threadid=19242;start=15#msg181355 date=1062867538]
Which can be made the loudest 12v or 24v?
[/quote]
this thread was going along so well then someone asked a stupid question like that : just kiddin ya man
DM01

 

Louder..hmm...well, when i set my timing at 36 degrees...it sounded like 10 -24v trucks in Drive at 1200 rpm so freakin knocky neighbors 2 blocks away could hear it clanking!

 

And why would one set their timing to 36*?

I would hope that it was an experiment that wasn't intended to last very long.

However, DavidTD once mentioned that the now-defunct Dakota was set up above 20* so maybe 36* ain't out of the realm of possibility. Not that I would want to do that to my motor.

 

[quote author=redramnc link=board=16;threadid=19242;start=15#msg183776 date=1063334132]
And why would one set their timing to 36*?

I would hope that it was an experiment that wasn't intended to last very long.

However, DavidTD once mentioned that the now-defunct Dakota was set up above 20* so maybe 36* ain't out of the realm of possibility. Not that I would want to do that to my motor.
[/quote]

Yep it was and it is harder on the bottom end the more timing you run. People would hear the Dakota and if they knew what they were listening to always asked what it was set at.

The Dakota was built with junk parts. Pistons, rods, crank, head, everything. I was pretty proud that with a stock head, stock HX40, and 370's we got 475hp and 950tq out of the little thing. 400+hp from 2300rpm all the way to 3600rpm. Boy I sure do miss it...

 

RedramNC: we didn't realize that the plunger lift #r's are different for a 160 pump...so what should have been 17 degrees was actually like double since the smaller barrel sizes.. ...so yeah ..it was LOUD!