PI Heads vs Ford Racing Cylinder Heads

[sneaky98gt]

I've lately been looking around at heads for my 98 gt (although I don't plan on getting any just yet...). I found a couple of different options, but there is one setup that I have yet to find any information on: the Ford Racing Cylinder Heads for the 96-98 NPI mustangs.

I found them at the Steeda website, and I have seen them in magazines before. They claim to be a 35 hp increase by themselves and a 70 hp increase w/ the Ford Racing Intake Manifold, and that they are "great for high lift cams, larger springs, and custom porting and polishing jobs."

I was wondering, are they any different from the regular PI heads? If so, how? It says that they are a direct replacement for the NPI heads; therefore, will they increase the compression? What's the HP gain of these heads compared to that of the PI heads? And also, is this Ford Racing Intake Manifold the same as a PI Intake manifold? Any help would be great. Thanks.

 

[mogs01gt]

same heads.

 

[mrvax]

Mogs, before the PI swap became popular, Ford made different heads for the non-PI. FRPP heads? I forget exactly what they were but remember it was expensive & did not raise the C/R.

 

[sneaky98gt]

I'm not sure if it's a FRPP head. It just says Ford Racing Cylinder Head. Here's the link: Ford Racing 4.6L GT Cylinder Heads for Ford Mustang

I don't really think it's the same as the PI. Steeda has both this head and the PI head, and these are about $100 more per head than the PI heads. As for the difference:

 

[CobraRed_96_GT]

Mogs, before the PI swap became popular, Ford made different heads for the non-PI. FRPP heads? I forget exactly what they were but remember it was expensive & did not raise the C/R.

SVO/FRPP heads

 

[mogs01gt]

Mogs, before the PI swap became popular, Ford made different heads for the non-PI. FRPP heads? I forget exactly what they were but remember it was expensive & did not raise the C/R.

I thought he was talking about these standard PI heads.
Ford Racing M-6049-P46 - Ford Racing 4.6L Performance Improvement Cylinder Heads - summitracing.com

 

[CobraRed_96_GT]

I thought he was talking about these standard PI heads.
Ford Racing M-6049-P46 - Ford Racing 4.6L Performance Improvement Cylinder Heads - summitracing.com

The OP was, vax is talking about the discontinued performance heads.

 

[sneaky98gt]

I'm looking for the difference between these 'performance' heads: Ford Racing 4.6L GT Cylinder Heads for Ford Mustang

and these PI heads: Ford Racing SOHC PI Cylinder Heads for Ford Mustang

and how they compare to the stock NPI ones.

 

[Dragstr05]

I'm looking for the difference between these 'performance' heads: Ford Racing 4.6L GT Cylinder Heads for Ford Mustang

and these PI heads: Ford Racing SOHC PI Cylinder Heads for Ford Mustang

and how they compare to the stock NPI ones.

They are the same heads. And they are the same heads that the 99-04 2v's were equipped with.

The are a performance cylinder head in comparrison to the 96-98 NPI heads. PI heads flow better than the NPI heads, and slightly bump the compression due to the redesigned combustion chamber.

The only FRPP *performance* heads were the SVO heads, which as far as I know are discontinued; and also IIRC the SVO heads must be matched with an NPI intake or the FRPP intake for the SVO heads.

 

[sneaky98gt]

They are the same heads. And they are the same heads that the 99-04 2v's were equipped with.

So why do they cost $100 a piece more? And do they still raise the compression?

 

[billfisher]

if they are PI heads they will increse compression with 96-98 pistons

 

[TGJ]

Last time I checked, about a month ago, the SVO/FRPP head is NOT discontinued. Ford has lowered the price significantly on these.

From the current 2009 FRPP Catalog. Still available...

Ford Racing Performance Parts [M-6049-D46]

 

[TGJ]

The SVO head was the King of 2V heads until Trick Flow released their 2V head. They won't raise the compression ratio on a NPI engine, they will lower it on a PI engine. They will work fine with a PI intake, same deal for the SVO head as it is for the NPI head to do a PI Intake swap on.

 

[sneaky98gt]

So is this FRPP head the equivalent of the old SVO head? It's what it sounds like, and therefore I need to start doing a little research on them. From reading around a bit it appears that the price has dropped drastically on these heads, from about $1400 per side to $560 per side. (plus the valves, cams, intake.)

If that is right, and what they are claiming is true, then 75+ horsepower for a ballpark $1600-$1700 for these heads/cams/accessories (I already have a PI Intake) brand new doesn't sound all that bad. And most importantly for me, because I one day want to go supercharged, it keeps the compression the same.

But at the same time, I don't have the money to do all of this yet. I'll probably just put the PI cams in for now, tune it, and be happy until I can afford some heads.

 

[CobraRed_96_GT]

Last time I checked, about a month ago, the SVO/FRPP head is NOT discontinued. Ford has lowered the price significantly on these.

From the current 2009 FRPP Catalog. Still available...

Ford Racing Performance Parts [M-6049-D46]

Thanks TGJ, i've actually seen that same ad recently and have no idea why i didn't think of it

 

[TGJ]

So is this FRPP head the equivalent of the old SVO head? It's what it sounds like, and therefore I need to start doing a little research on them. From reading around a bit it appears that the price has dropped drastically on these heads, from about $1400 per side to $560 per side. (plus the valves, cams, intake.)

If that is right, and what they are claiming is true, then 75+ horsepower for a ballpark $1600-$1700 for these heads/cams/accessories (I already have a PI Intake) brand new doesn't sound all that bad. And most importantly for me, because I one day want to go supercharged, it keeps the compression the same.

But at the same time, I don't have the money to do all of this yet. I'll probably just put the PI cams in for now, tune it, and be happy until I can afford some heads.

The head I listed is the old SVO head, just rebadged as an FRPP head. They have been FRPP for quite a few years.

Just a note on these heads with a SuperCharger( SC ) or TurboCharger( TC ). These are not good heads for a streetable engine with either a SC or TC. If you are going to a SC down the road, PI heads would be a better choice...

 

[sneaky98gt]

The head I listed is the old SVO head, just rebadged as an FRPP head. They have been FRPP for quite a few years.

Just a note on these heads with a SuperCharger( SC ) or TurboCharger( TC ). These are not good heads for a streetable engine with either a SC or TC. If you are going to a SC down the road, PI heads would be a better choice...

Why are they not as good for supercharging? I've read somewhere that they flow better than the PI heads. And that the compression bump in the PI heads is not a good thing for supercharging either. Thanks for your help.

 

[Gearbanger 101]

They are the same heads. And they are the same heads that the 99-04 2v's were equipped with.

The are a performance cylinder head in comparrison to the 96-98 NPI heads. PI heads flow better than the NPI heads, and slightly bump the compression due to the redesigned combustion chamber.

The only FRPP *performance* heads were the SVO heads, which as far as I know are discontinued; and also IIRC the SVO heads must be matched with an NPI intake or the FRPP intake for the SVO heads.

They are not the same head. The first link is to the Ford Racing performance heads (these are the ones previously known as the SVO heads before the SVO performance division was disbanded). They're the same heads, only now known under the Ford Racing moniker. They utilize large tear drop style intake ports (similar to non-PI castings) and larger diameter exhaust ports.....both with straighter, larger volume runners. Their combustion chambers are also noticeably larger (51cc FR vs. 42.5-45cc PI) and house larger Intake (46.83mm FR vs. 44.5mm PI) and Exhaust (35.88mm vs. 34.0mm PI) valves that have been moved closer to the center of the chamber to reduce shrouding. I believe they've also had the emmisions mask reduced, or removed in order to decrease turbulance and increase flow. They're also machined to accept cams upwards of .600 lift.

You are correct though, they're designed to match the tear drop style ports of the the Ford Racing intake manifold, but like any Modular head, they'll conform to the PI intake with the use of a little silicone or some custom adapter plates.

The second link is the Romeo based PI head castings used on the '01-'04 GT



Further information on the two heads can be found here.....

View attachment 274011

 

[Midnight2V]

Gentleman, I have these heads. I have had them on my car in unported condition, then in NA ported levels. Now in a supercharged, ported conditions. I will tell you, these heads are not bigger NPI's, they are not PI heads. They are the same heads with the same part number whether you call them SVO or FRPP 2v High Performance Cylinder heads.

DO NOT confuse them with FRPP Performance Improved Heads, which are simply PI castings sold out of Ford Racing.

These heads compared at unported levels outflow either PI or NPI castings at ALL lift levels.

The ports, valves, and chambers are unlike any of the other castings. Even when ported, these heads maintain excellent flow velocity, which is actually just as important (if not more important) as overall flow numbers.
They can be port matched to a PI or Bullit intake. They can accept high lift cams and springs.

Unported max flow is 205 at .500 intake, and 160ish on the exhaust. When ported they will flow 240/205 at .550. That is better even than any unported four valve head except the Cobra R / GT castings.

Yes, you can port a PI (or NPI) casting to match net flow, but SVO castings will ALWAYS have a higher velocity.
These heads get a bad rap compared to pi castings for one reason - combustion port size is 53cc. PI is 43cc and NPI is 51cc. Because of this, putting them on a 99 up 2v will drop compression to 8.8. on a 96-98 it will be 9.1. People have touted PI swaps as better in NA because of the compression bump.

On a properly built platform there is no better 2V head....except the Trick Flows. When ported, SVO, will flow as much as the Trick Flows. I don't know about velocity though.
Here were my numbers at the wheels on a chassis dynojet corrected for atmospheric conditions using a free-flowing exhaust.

NA unported, with FRPP intake, and PI cams - 258 HP 314 TQ @ 5400rpm

NA Ported , FRPP intake, Comp 270 AH and Built short block at 10.0:1 compression
332HP 359tq @ 5800rpm

add an intercooled Paxton Novi 2000 @ 14 psi 546hp 498tq 6900rpm at 160 degrees inlet temp and 16 total ignition timing.

i paid 895.00 PER head back in 2002. If they are $850 per pair now, get a set and get them ported, you will save a bit against the trick flow castings, and a bunch for a 4V conversion. If you have any questions, please email me at [email protected]. I welcome any questions you may have as I have been using these heads for more than six years and I have learned quite a bit about them. I just found out about the price drop and I consider it to be a fantastic deal.

 

[navarro98gt]

Good info. Midnight2V 6 years back when I did my PI swap I wanted to go with the SVO heads and intake but I couldn’t justify spending that kind of money on them. If they were as cheap as they are now I would have definitely pick up a pair.

Do they still sell the matching intake?