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P&P NPI BUILD

  • Thread starter Thread starter 98COBRA281
  • Start date Start date Jun 10, 2008
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98COBRA281

10 Year Member
Nov 24, 2007
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Port St. Lucie, Florida
Jun 10, 2008
#1
  • Jun 10, 2008
  • #1
so i just picked up a set of NPI heads, im planning on doing a full P&P job on them my self, im trying to make the most hp with the hpi heads and basic bolt ons as possible, on a low budget, i also plan to get a set of FRPP shorties, because you can pick up a cheap set off ebay. when its all done i hope to make 240-250RWHP with tune, so i have to pick up atleast 15rwhp, think its possible?, and i will post pics as i go along.

here are some pics, cleaned them up a little, and took all the valves out


 

CobraRed_96_GT

Active Member
May 20, 2006
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Jun 11, 2008
#2
  • Jun 11, 2008
  • #2
power from a cylinder head isn't all about flow capacity, it's also about consistency of flow. If each cylinder sucks/flows at a different rate you're not going to get nearly the same amount of usable cfm as a C&C ported head. Not sure if it's intake turbulence or what - but i know it makes the difference. I wouldn't even bring my heads to someone who doesn't specialize in mustang heads - so i hope it goes well for you.
 

Winters98GT

Whoop...whoop-whoop-whoop-whoop...GANGNAM STYLE!!!
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#3
  • Jun 11, 2008
  • #3
dont put a single penny to frpp shorties, not even 50 bucks.
 

98COBRA281

10 Year Member
Nov 24, 2007
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Port St. Lucie, Florida
Jun 11, 2008
#4
  • Jun 11, 2008
  • #4
Winters98GT said:
dont put a single penny to frpp shorties, not even 50 bucks.
Click to expand...

rely, maybe thats why they are cheap
 

tank_567

Active Member
Mar 19, 2007
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Raleigh, Nc
Jun 11, 2008
#5
  • Jun 11, 2008
  • #5
you're better off buying cheap L/T than buying shorties for the mod engine. After you port the heads you should have bigger valves installed w/ a 5 angle job done to them. Then you'll see some power made.
 

98COBRA281

10 Year Member
Nov 24, 2007
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Jun 11, 2008
#6
  • Jun 11, 2008
  • #6
tank_567 said:
you're better off buying cheap L/T than buying shorties for the mod engine. After you port the heads you should have bigger valves installed w/ a 5 angle job done to them. Then you'll see some power made.
Click to expand...

i wanted to do bigger valves too, but there isnt that much room
 

CobraRed_96_GT

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#7
  • Jun 11, 2008
  • #7
98COBRA281 said:
i wanted to do bigger valves too, but there isnt that much room
Click to expand...
over sized valves are only like + 1mm, and they help a lot
 

98COBRA281

10 Year Member
Nov 24, 2007
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Jun 11, 2008
#8
  • Jun 11, 2008
  • #8
i went to a hardware store to buy a coulpe bits, i only found one, it was $15.99, i took it to the register, when he rang it up he said your total is $5.31, i paid, and ran out of the store so fast. it works rely good, ill post pics later.
 

98COBRA281

10 Year Member
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Jun 11, 2008
#9
  • Jun 11, 2008
  • #9
i just did a quick clean up on the intake side
 

98COBRA281

10 Year Member
Nov 24, 2007
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Port St. Lucie, Florida
Jun 16, 2008
#10
  • Jun 16, 2008
  • #10
stock intake port

View attachment 313971

after porting

View attachment 313972

I think they came out pretty good, i just need to polish them up a bit
 

deftsound

Please ask me how much my supercharger cost
Apr 6, 2004
945
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Texas City TX
Jun 16, 2008
#11
  • Jun 16, 2008
  • #11
98COBRA281 said:
rely, maybe thats why they are cheap
Click to expand...

its because shorties are a complete waste of money on our cars, you'd be better off with the stock manifolds...you may gain 1-2hp max with shorties...

if you do headers get longtubes and don't think twice
 

96GT281

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Apr 12, 2008
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Jun 16, 2008
#12
  • Jun 16, 2008
  • #12
im going to have a lot of porting to do
 

98COBRA281

10 Year Member
Nov 24, 2007
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Port St. Lucie, Florida
Jun 16, 2008
#13
  • Jun 16, 2008
  • #13
i dont think to many people care.... but here is a pic with pi gaskets on, they almost look like pi heads

View attachment 313935
 

CobraRed_96_GT

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May 20, 2006
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Jun 16, 2008
#14
  • Jun 16, 2008
  • #14
98COBRA281 said:
i dont think to many people care.... but here is a pic with pi gaskets on, they almost look like pi heads
Click to expand...
yeah the deck face does, but how are you going to port the inner cavity around the guides? Are you going to do any chamber porting around the valves as well?
 

98COBRA281

10 Year Member
Nov 24, 2007
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Jun 16, 2008
#15
  • Jun 16, 2008
  • #15
CobraRed_96_GT said:
yeah the deck face does, but how are you going to port the inner cavity around the guides? Are you going to do any chamber porting around the valves as well?
Click to expand...

i have a 6" bit extender i used to port in the cavity, and i have tiny bits that i cleaned up around the guides, i am doing to do a little chamber porting, but i dont want to lower the comp to much, i talked to a local machine shop, he said he decks 4.6 heads all the time to raise comp for N/A motors, but i have heard from people on here it causes problems, the guys knows what he's doing, he has americas fastest street car, you can find it on you tude, so i trust his work
 

CobraRed_96_GT

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#16
  • Jun 16, 2008
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Sounds good, just focus on making each chamber even/consistent. With the valve closed you could measure how much liquid it holds perhaps. Won't tell you the flow capability, but will tell you volume at least.
 

98COBRA281

10 Year Member
Nov 24, 2007
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Jun 16, 2008
#17
  • Jun 16, 2008
  • #17
yeah i probaly have about 2 hours of work just going back and forth trying to make everthing as consistant as possible, i wanna see how many cc's the intake/exhaust ports will hold, do you know how many cc's stock npi's hold?
 

tank_567

Active Member
Mar 19, 2007
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Jun 18, 2008
#18
  • Jun 18, 2008
  • #18
are you going to get the valve job done?
 

98COBRA281

10 Year Member
Nov 24, 2007
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Jun 18, 2008
#19
  • Jun 18, 2008
  • #19
tank_567 said:
are you going to get the valve job done?
Click to expand...

i want to, i can do them at my school for cheap, but i want to do bigger valves so i might have to have the local machien shop do them
 

98COBRA281

10 Year Member
Nov 24, 2007
1,348
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Port St. Lucie, Florida
Jun 25, 2008
#20
  • Jun 25, 2008
  • #20
getting closer, im going with flowtech longtubes instead of frpp shorties, and getting stainless steel swirl polished valves, and a valve job,

 
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