P&P NPI BUILD

[98COBRA281]

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]

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]

dont put a single penny to frpp shorties, not even 50 bucks.

 

[98COBRA281]

dont put a single penny to frpp shorties, not even 50 bucks.

rely, maybe thats why they are cheap

 

[tank_567]

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]

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.

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

 

[CobraRed_96_GT]

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

over sized valves are only like + 1mm, and they help a lot

 

[98COBRA281]

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]

i just did a quick clean up on the intake side

 

[98COBRA281]

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]

rely, maybe thats why they are cheap

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]

im going to have a lot of porting to do

 

[98COBRA281]

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]

i dont think to many people care.... but here is a pic with pi gaskets on, they almost look like pi heads

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]

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?

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]

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]

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]

are you going to get the valve job done?

 

[98COBRA281]

are you going to get the valve job done?

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]

getting closer, im going with flowtech longtubes instead of frpp shorties, and getting stainless steel swirl polished valves, and a valve job,