Rick Swain 96-98 Heads vs 99 PI Heads

[VicRattlehead]

Just why the hell are you doing this with a heavy ass Thunderbird anyway, it makes no since, it is pointless, just get a Mustang if you want to make comparisons, becasue you TB is to different to even compare numbers and times with us, but like I said 13's is no feat buddy, there are LIGHT bolt-on 99+ GT with stock heads going 12's, and KenB who has ported 99+ heads is about to crack 11's NA, N2098GT ran 12.03 @111 while breaking in 4rth gear, with what heads, OH YEA PI HEADS, and you are trying to run mid 13's, get real.

to answer your question, why the hell are you doing this with a heavy ass Thunderbird anyway because mustangs are a dime a dozen, i dont like being like the 19 other people on the block that have one, i like being different, i dont fit in a mustang, the insurance is way to expensive, i like the IRS suspension, i like the handling that i have, (i can keep up with most stock c4 vetts in the corners with no trouble at all) i like the style of the tbird much better than the mustang, i like the fact that the chassis in my car isnt from 1979, i like the fact that i can put 5 people in my car with no trouble, i like the fact that i can put the same amount of stuff in the trunk of my car that fits in the back of a chevy blazer. I had a 97 mustang, and i just fit better in the tbird.

I must say that going from my first run of a 16.60's to the current 14.30's isnt half bad.

 

[97MattGT]

wow. this debate has gone on for the better part of the last year-year and a half since the ported PI head trend seemed to hit full swing.


the PI head group has gathered up info, flow numbers, dyno numbers, and track times to support it's side.


the non-PI head group pretty much has nothing but claims and theorys.



how many non-pi headed cars have gone 12's? (excluding SVO heads)

how many non-pi headed cars have broken 300 rwhp?


the answer to those questions should be all you need to realize PI heads are better.


And i'm not trying to bash at all, cuz if Rick comes through with some serious hard data that shows non-pi heads being good.....i'll be the first to send him my '97 heads that are sitting in my garage since i put on my DTA ported PI heads.....which haven't performed up to par. Otherwise, i'm buying another set of PI heads and sending them to Foxlake, which is what i shoulda done last year.

 

[mrvax]

And i'm not trying to bash at all, cuz if Rick comes through with some serious hard data that shows non-pi heads being good.....i'll be the first to send him my '97 heads that are sitting in my garage since i put on my DTA ported PI heads.....which haven't performed up to par. Otherwise, i'm buying another set of PI heads and sending them to Foxlake, which is what i shoulda done last year.

:OT:
Matt: What do you mean they haven't performed up to par? What mods do you have now and where do you think you should be? I'll get a dyno run in next month.

 

[onlyme]

cobra killer

You have ported p.i heads that flow 248 cfm? The most I have seen by others places was 224, thats pretty awesome. What do you think a ford racing 96-98 head would do fully ported?

 

[KenB]

Give the guy a chance to prove his point with ET's run against people at the SAME place at the SAME time.

The Mod shootout is this weekend. Take a look at the 2VNA class. My guess is that EVERY car will have either PI heads or SVO heads. At least the fast ones will.

 

[STANGateURlilSS]

pi heads & cams

i'm all for this porting of non pi heads trying to make them flow as well as ported pi heads, but until there are flow bench numbers of the heads side by side and then dyno runs to prove it then i have to agree with cobra killer also.. ford would not have redesigned the heads if they coudl of done changes to the non pi to make is perform the way it should have.. hence they redesigned the head hence the pi head.. i have seen porting claims from many different places.. promising this promising that.. yes a ported non pi head will flow and produce more power then it did stock but ported pi heads will preform better..

 

[Beau]

way to bring back an old thread.

 

[Sick96Stang]

Just did a search for PI headswap and came up with this link. Read through the whole thing and found it to be very intresting. Anybody know any results of Rick's testing?

 

[BanginStang97GT]

For me the only option was to get non-pi heads for my car. I cannot financially afford to make the PI heads work in my situation. I am running an s-trim so using the PI heads would cause a major meltdown with out tearing the motor apart to drop the new increased compression. I have seen ported non pi heads flow a pretty high amount but not as frequently as I have seen PI heads make the charts shake. I believe PI heads will be the best on an NA car but I also think that with a good pandp on non pi heads its not a big difference between the two. Im just thinking out loud, all my information is from several different sources. I do not have hardcore facts here so all of my information is my opinion and there for should be taken with a grain of salt.

 

[JohnnyLangton]

Just did a search for PI headswap and came up with this link. Read through the whole thing and found it to be very intresting. Anybody know any results of Rick's testing?

Even better..go do a search at modulardepot....
There's 2-3 threads there that will open your eyes a bit.
JL

 

[Moonlight97GT]

Now here is a question for the non believers, what mods is it taking for a PI headswapped 5-speed to hit the 300 rwhp mark?

My thought is that with the following a non-PI car could do it:

P&P'd non-PI heads with PI exhaust valves
P&P'd SVO Intake (Just like the bullitt)
10.5:1 Compression just like the headswap cars
PI cams or SHM 2730 cams (similar grinds)
Longtubes with matching shorty off-road x
and typical bolt-ons it should be able to be done.

My car is putting down 240 rwhp & 275 rwtq right now with the mods in my sig. That is with untouched non-PI heads on a 132K mile motor. I am in no way trying to fuel and arguement I am just asking a honest question and offering my thoughts on the situation.

 

[Moonlight97GT]

Anyone???

 

[97slowpoke]

NON-PI

from what i read cnc ported non-pi vs. cnc ported pi heads the non pi heads only lost 25hp! wow throw cams on a non-pi and make that up but i have a 1997 GT non-pi 4.6 4.10's,msd dis-4,hooker LTs,accel coil packs,short throw

.678
1.95 60'
8.921/8'@78mph
14.021/4'@96mph

this ain't no stinkin pushrod

 

[JohnnyLangton]

Reading back through this one..it's amazing how much has changed in the last year or so...and how many guys have opened their eyes,and learned a few things about the capabilities of the Non-PI heads.
JL

 

[CanadaStang]

The way I see it, is the PI heads and non PI heads are the same except for the ports. If you take a non PI head, and enlarge the ports so they flow well,and shave it down, to get the same compression, you basically just made a PI head out of a non PI head. By doing even more porting to it, you are surpassing the PI head, which by doing the same thing to the PI head, they will both be the same. I guess what I'm saying, is sure you can make a non PI head outflow a PI head, but in the end, with enough porting, they would be the same.

 

[JohnnyLangton]

The way I see it, is the PI heads and non PI heads are the same except for the ports. If you take a non PI head, and enlarge the ports so they flow well,and shave it down, to get the same compression, you basically just made a PI head out of a non PI head. By doing even more porting to it, you are surpassing the PI head, which by doing the same thing to the PI head, they will both be the same. I guess what I'm saying, is sure you can make a non PI head outflow a PI head, but in the end, with enough porting, they would be the same.

Close,but that's not exactly how it is.
The combustion chambers still have approx a 10cc size difference,and no machinist will mill the heads down enough to make up for that-so Compression will always be a difference between the 2 heads with the same shortblock.And it's not just the portsize that's the difference-there's alot more to it that I won't discuss.
JL

 

[Marc99GT]

I had a contriversial post lined up but decided it wasn't necessary. I know that I went 10s on the stock PI heads so they flowed enough. I also know that no 96-98 GT with non-PI heads or ported PI heads has ever come close to that time on a stock longblock in the 5 years I was working on, building and racing my own.

Put away the flow benches and theories and show me setups, timeslips and dyno numbers from GTs with non-PI heads because the rest is meaningless.

JohnnyLangton, I think it is very misleading to attribute your better ET and trapspeed to the heads alone. You changed the converter which makes a significant difference to an automatic car. Not only did you change the stall, but you changed the efficiency as well of the power getting to the ground. The stock converter has the worse STR(stall torque ratio) you will ever see. I would say that part of the trapspeed and 3-5 tenths of the ET relates to the converter upgrade.

 

[mrvax]

Hey Marc, good to see you stopped by here at SN. How's Joey?

Likewise, I haven't seen any non-PI heads out-perform equally modified PI heads to date.

The original poster complained about having to swap a lot of other things including the intake. Many here have swaped to the PI intake and picked up power! The original non-PI intake is also well known for cracking. Doing the swap, if you have the $ is well worth it.

 

[JohnnyLangton]

I had a contriversial post lined up but decided it wasn't necessary. I know that I went 10s on the stock PI heads so they flowed enough. I also know that no 96-98 GT with non-PI heads or ported PI heads has ever come close to that time on a stock longblock in the 5 years I was working on, building and racing my own.

Put away the flow benches and theories and show me setups, timeslips and dyno numbers from GTs with non-PI heads because the rest is meaningless.

JohnnyLangton, I think it is very misleading to attribute your better ET and trapspeed to the heads alone. You changed the converter which makes a significant difference to an automatic car. Not only did you change the stall, but you changed the efficiency as well of the power getting to the ground. The stock converter has the worse STR(stall torque ratio) you will ever see. I would say that part of the trapspeed and 3-5 tenths of the ET relates to the converter upgrade.

No way in hell 3-5 tenths of the improvement was from that converter-it was a failry inefficient A4LD/4R70W hybird converter,and we're talking about a car that is heavier than a Mustang by approx 600 lbs

BTW...after I swapped out to an intake that was halfway worth a ****-It dropped down to a 12.98@103..
And again...to this date NOBODY with a Tbird has ran a 12 second pass N/A with a 4.6L and PI heads-even headswapped cars,yet there are 3 of us running 12's with Non-PI heads.
JL

 

[Marc99GT]

Hey Marc, good to see you stopped by here at SN. How's Joey?

Likewise, I haven't seen any non-PI heads out-perform equally modified PI heads to date.

The original poster complained about having to swap a lot of other things including the intake. Many here have swaped to the PI intake and picked up power! The original non-PI intake is also well known for cracking. Doing the swap, if you have the $ is well worth it.

Hey,

How is everything? I hope you had a great holiday. I still love Mustangs so I pop in from time to time. I actually haven't spoken to Joey in over a year. I have been busy with the house, baby and working on my GN. I don't want to run into any of you guys and not be prepared. I'm dong everything in my power not to go Price a 05 GT. It just has so many upgrades that I'm a big fan of. I sat in one last weekend and I refused to go for a ride or I was rushing to the dealer afterwards.

As far as the comments about the NON PI heads, show me a SOHC 4.6 with non PI heads making approx. 450+ rwhp with a poweradder on pump gas. I'm sure I can find a few with PI heads making that around here if I look. Hell, I was one of them in the past.

JohnnyLangton,

Are you sure the other T-birds with PI heads are running 3.73 gears, exhaust, converter & tuning like you are? There are so many variables that it's hard to compare vehicles. We will see how well your heads perform when/if you ever decide to get over 400 rwhp. Your non PI heads may work well for a car running high 12s with a decent trap speed, but that could mean they flow well enough in the first 1/8th and die in the 2nd.

Many of us have gone alot faster than 12s and I can't think of one person that was running a very good ET and trap speed using non-PI heads. The problem is your sample size is dwarfed by the number of modified mustangs out there and one car compared to a few others which may or may not have the same modifications will yield inaccurate results.