looking for twin advice

Forrest Nearing said:
here ya go big brain...

regulate your air compressor down to 60psi... put a 3/8" orifice at the end of the hose and record how long it takes to fill up a 5gal trash bag full of air.

now... put a 1/8" orifice at the end of the hose and record how long it takes to fill up the same trash bag.

by your... uh... logic? they should take the same amount of time because there's 60psi on the back side of your orifice, right? :umno:

you realize that on a naturally aspirated engine, there's 14.7psi of pressure at sea level slamming its way into your cylinders right?

there's a SLIGHT difference between density and CFM... you can move the same amount of oxygen at higher density with less CFM, but if you maintain the same density (boost), if you open up the port to flow more CFM, you WILL move more oxygen at that same density. :eek:wned:
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Here you go big brain ITS ABOUT VELOCITY, sorry for the yelling but go ahead and port your intake while you have 100psi waiting to come in :hehe: and enjoy the UMM 5HP increase if that, its weird how wicked had that badazz ZZ fabrication head on it then swapped on a stock head and made more power with just a stock head swap. Ive tested fully ported heads on my truck and with no power increase and even a loss in psi once the head was ported, Ill stick with my slightly modified :hehe: stocker.

Yea now take your orifice and start increasing the size, Forrest there comes a point where too much porting is well.... too much, other than hurting the longevity and strength of your head you will finally come to a point were the more porting you do you will not see a increase in power, our shop has built and tested more heads then you have ruined :hehe: but no use explaining it to you ALMIGHTY CUMMINS MASTER :hehe: Hey your not Greg Hogues son are you? LOL
 
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Forrest Nearing said:
well... intake side porting does help (more oxygen in = bigger bang in the cylinder = more exhaust energy at the turbine)

not sure what you mean by "huge" intake porting, but I certainly don't subscribe to the backwoods/redneck "hog it out" school of portwork

you got anything else to try to make me look stupid because I made fun of your favorite grill manufacturer? :confused:
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you should put smaller valves in your head... just IMAGINE the velocity you'll have then!!!! :hehe:
 
TMONEYDIESEL said:
Here you go big brain ITS ABOUT VELOCITY, sorry for the yelling ... and even a loss in psi once the head was ported

there comes a point where too much porting is well.... too much, other than hurting the longevity and strength of your head you will finally come to a point were the more porting you do you will not see a increase in power,
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OK, started off good then lost it somewhere. velocity is GOOD, but pressure is not velocity! Porting the Cummins 5.9 head is more about smooth even flow to all cylinders than total power. also PSI is a measure of RESTRICTION, thats why ported heads often see a psi drop but a hp increase and egt reduction.*bdh*
 
TMONEYDIESEL said:
Here you go big brain ITS ABOUT VELOCITY, sorry for the yelling but go ahead and port your intake while you have 100psi waiting to come in :hehe: and enjoy the UMM 5HP increase if that, its weird how wicked had that badazz ZZ fabrication head on it then swapped on a stock head and made more power with just a stock head swap. Ive tested fully ported heads on my truck and with no power increase and even a loss in psi once the head was ported, Ill stick with my slightly modified :hehe: stocker.

Yea now take your orifice and start increasing the size, Forrest there comes a point where too much porting is well.... too much, other than hurting the longevity and strength of your head you will finally come to a point were the more porting you do you will not see a increase in power, our shop has built and tested more heads then you have ruined :hehe: but no use explaining it to you ALMIGHTY CUMMINS MASTER :hehe: Hey your not Greg Hogues son are you? LOL
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Hey Pot.......It's kettle calling. :hehe::hehe:
 
Yea I was talking to someone this weekend about the manifold and head porting thing as I just built another head for the 01' project and didn't spend nearly as much time with the porting.

His statement basically said it all "What does Dan Scheid run"

Jim
 
rumors on TDR back in the day was a stock, unported head, or maybe they were talking about Haisley... anyhow, someone piped in and said "no, we do not run unported heads, they are ported"
 
This head is ported it's just not on the ragged edge, I was even looking at it tonight and the intake side just sucks compared to the exhaust side.

Jim
 
and as I stated above... I'm not an n'th degree guy... I'm not talking chop off the intake, hog everything out, bigger valves, etc.

But to suggest that portwork doesn't help because there's a turbocharger on the engine is plain ignorant.
 
I'll agree with you there but there is a line were cost just doesn't make sence.

Randy (my head porter) basically with all out on the 98's head without having a wall thickness tester, he even had trouble reaching #1 and #6 so he drilled holes in the intake on the ends to reach them then tapped and plugged them. The head flowed 214 intake 198 exhaust@.550

I have a rough figure in my head for this cost but won't post it......it's not high. Now take a look at what the guys spend that cut the manifolds off, buy or build a manifold ect and what do those heads flow......250@550 lift....maybe, and they spend $1500 more than me.

I'll snap some pics of the new head, is say 2/3rds of the other head.

Jim
 
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