97 PI cams (and whatever else) swap in to non-PI heads

[Grog6]

Peopl have used the stock crank to amazing power levels, over 500hp; and the teksid blocks have been built over1500hp.

 

[rampagingsloth]

Any npi from 96-01 is virtually identical as far as longblock, the valve cover differences come from Windsor vs Romeo assembly but I don't believe any npis except for the earliest Navigators(5.4) were Windsor assembly. 94-95s have a different timing cover pattern from 96+ iron blocks, but oddly have the same pattern as Aluminum blocks(both Teksid and WAP), its just that one bolt below the water pump. A PI engine is indistinguishable from a npi engine on the outside unless you have the intake manifold off

Aha, thanks. Ok, but, except for that extra bolt on '96+ timing covers, everything else is the same in terms of accessories and mounting locations? That's good to know.

Forged crank is dead weight unless you're spinning to 8000 RPM or making 600+ horsepower, which aint happening on a npi lol

I don't doubt that, it's more my paranoia than anything along with a desire to have a "correct" engine like the V8s from the muscle car era, meaning forged crank and rods. But is there a forged crank option for any of these 2-valve 4.6s? Or is that strictly a high-priced aftermarket deal? I'm thinking in terms of there being that one year of Mark VIII with a one-piece drive shaft that fits our cars, otherwise have a shop make one, there might be a year or two of Marauder or Mustang or something that came with a forged crank.

 

[XR7-4.6]

Aha, thanks. Ok, but, except for that extra bolt on '96+ timing covers, everything else is the same in terms of accessories and mounting locations? That's good to know.



I don't doubt that, it's more my paranoia than anything along with a desire to have a "correct" engine like the V8s from the muscle car era, meaning forged crank and rods. But is there a forged crank option for any of these 2-valve 4.6s? Or is that strictly a high-priced aftermarket deal? I'm thinking in terms of there being that one year of Mark VIII with a one-piece drive shaft that fits our cars, otherwise have a shop make one, there might be a year or two of Marauder or Mustang or something that came with a forged crank.

All SVT Cobras and manual transmission Mach 1s had forged cranks, no 2Vs ever got them. Metallurgy has come a long way since the 60s, and not only is the standard 4.6 cast crank exceptionally strong, the deep skirted cross bolted 4 bolt main block is actually a lot more stable than just about anything made back then too

Keep in mind even after 25+ years of the Modular Mustangs there’s no united consensus on what exactly the horsepower and RPM limit is on the cranks, because failures really are that rare. Most people who don’t use strokers use what crank their engine came with and others shooting for big big numbers with lots of boost swap to forged for the peace of mind. I’m not sure why you’re insistent on faithfully staying 94-95 npi, but it doesn’t breathe higher than 5000rpm, the cams and intake are severe limitations. Even PI runs out of breath before 6000rpm, so you’re a long way from needing forged anything.

 

[theterminator93]

To piggyback - the weak point of the mod motor is universally considered to be their powdered rods. That said, for any NPI N/A build, there isn't likely to ever be a need to spin the engine beyond 6500-6700 RPM, which tends to be the consensus on the upper limit of the ability of the stock rods to survive.

 

[Grog6]

MMR and modular headshop , and probably summit racing will sell you a forged crank, rods, and pistons.~ 1500+1000+1000 bux, thats 3500 in parts alone. Then you need the block machined to match the pistons. Plus gaskets, etc.

 

[rampagingsloth]

All SVT Cobras and manual transmission Mach 1s had forged cranks, no 2Vs ever got them. Metallurgy has come a long way since the 60s, and not only is the standard 4.6 cast crank exceptionally strong, the deep skirted cross bolted 4 bolt main block is actually a lot more stable than just about anything made back then too

MMR and modular headshop , and probably summit racing will sell you a forged crank, rods, and pistons.~ 1500+1000+1000 bux, thats 3500 in parts alone. Then you need the block machined to match the pistons. Plus gaskets, etc.

Ok, that's sort of what info I was looking for but was too dumb to word correctly. So, possibly get a forged crank from an SVT Cobra or something but, otherwise, don't worry about it. Especially not at those prices, haahaha.

To piggyback - the weak point of the mod motor is universally considered to be their powdered rods. That said, for any NPI N/A build, there isn't likely to ever be a need to spin the engine beyond 6500-6700 RPM, which tends to be the consensus on the upper limit of the ability of the stock rods to survive.

Ah, so, if anything, the rods should be upgraded first before the crank, if I have to choose one over the other.

Keep in mind even after 25+ years of the Modular Mustangs there’s no united consensus on what exactly the horsepower and RPM limit is on the cranks, because failures really are that rare. Most people who don’t use strokers use what crank their engine came with and others shooting for big big numbers with lots of boost swap to forged for the peace of mind. I’m not sure why you’re insistent on faithfully staying 94-95 npi, but it doesn’t breathe higher than 5000rpm, the cams and intake are severe limitations. Even PI runs out of breath before 6000rpm, so you’re a long way from needing forged anything.

I just don't want to deal with any "Oh, also don't forget to change X and Y when swapping over to PI heads, otherwise blah blah blah." I want it to be dead simple for anybody to deal with when inevitable repair times arrive, no confusion about hey, this is a '95 Thunderbird but it looks like you have different [fill in blank]s.

So, am I correct in assuming that when people do head porting and cam upgrades, the cams chosen are basically always the PI cams, they're all the same specs regardless of year? There's no better cam upgrade for N/A 2-valve engines when using Ford designed heads? I mean just improved, not drag racing. I know the Trickflow head is supposed to be great and I'm sure it has its own cam to go with it but from what I remember that's a different design that's not even smog legal here so I wouldn't consider it for a fun daily driver, I will just go the 96+ heads route to solve the valve guides problem along with the cam lift improvements and also the spark plug not enough threads fix.

I don't suppose there's a preferred donor car for a 1999-2000 NPI 4.6 engine, then? I had this assumption that maybe some cars came with certain different parts vs. others (car-specific oil pans or whatnot) but it sounds like any car from those years would be fine for yanking the motor out of.

 

[Grog6]

There's a LOT of little things you'll run into; some of which bear on choice if donor vehicle. For example,you can source a pi engine from an explorer, a Gran Marquis, a mustang, a f150, a transit van.. Some are likely to be hammered on, like trucks, vans,mustangs, and the police and taxi cars. Explorers are best for a 94-5 swap, due to the front cover bolts; others are better for 96-97 cars. Panther cars and Towncars are probably best for those. Get an 02 GT maf and inlet tube/ filter box. You will need a tune, and 24lb injectors.And a bigger fuel pump. Note: a stock transmission and tc is going to go fast, so you need to upgrade that first. and the driveshaft, and the brakes...

 

[XR7-4.6]

Ok, that's sort of what info I was looking for but was too dumb to word correctly. So, possibly get a forged crank from an SVT Cobra or something but, otherwise, don't worry about it. Especially not at those prices, haahaha.



Ah, so, if anything, the rods should be upgraded first before the crank, if I have to choose one over the other.

Yeah, rods are really the main limitation, next in line would be pistons if you're going to throw boost at them, crank upgrade would be dead last. Coyote rods are actually a real good upgrade for 4.6s, they'll swap directly in place and I have even heard the weights are close enough so as to not need a rebalance if you use them with stock pistons.

I don't suppose there's a preferred donor car for a 1999-2000 NPI 4.6 engine, then? I had this assumption that maybe some cars came with certain different parts vs. others (car-specific oil pans or whatnot) but it sounds like any car from those years would be fine for yanking the motor out of.

Any 96-00 era npi longblock are equal, nothing of value changed between the 96-98s and 99-00 versions, pick whatever has the best combo of price and lowest miles.

I just don't want to deal with any "Oh, also don't forget to change X and Y when swapping over to PI heads, otherwise blah blah blah." I want it to be dead simple for anybody to deal with when inevitable repair times arrive, no confusion about hey, this is a '95 Thunderbird but it looks like you have different [fill in blank]s.

What repairs do you foresee that would cause confusion between npi and a PI swap? Other than the 96+ style intake and its components, which you should be able to easily do anything there that goes wrong yourself (IAC, EGR) the rest like the serpentine belt layout is the same, or can be made the same just swapping over the timing cover.

So, am I correct in assuming that when people do head porting and cam upgrades, the cams chosen are basically always the PI cams, they're all the same specs regardless of year? There's no better cam upgrade for N/A 2-valve engines when using Ford designed heads? I mean just improved, not drag racing. I know the Trickflow head is supposed to be great and I'm sure it has its own cam to go with it but from what I remember that's a different design that's not even smog legal here so I wouldn't consider it for a fun daily driver, I will just go the 96+ heads route to solve the valve guides problem along with the cam lift improvements and also the spark plug not enough threads fix.

Stock PI cams will work in 96+ npi heads with no changes and net you 30 horsepower paired with a PI intake, those components are more valuable to the Power Improvement than the heads themselves. PI heads have a little better exhaust flow unported but not something you'll see the benefit of it without headers and the combustion chamber is more efficient.

Aftermarket cams exist and long predated trick flow heads; Comp, Crower, MHS, Trick Flow etc, All come in various lifts, durations and LSA, it's all about the combination what works best for you, its not dependent on the heads alone unless there's a physical limitation in limiting lift. Smog would likely be a problem with aftermarket cams since you'll get more HCs with the increased overlap aftermarket cams have. With CA being strict with flash tunes getting it to run smooth would be basically impossible too

 

[Grog6]

To use aftermarket cams, you'd want to start with a 96head, and get that ported. Modular headshop does that. A 95 head needs valve guides too. But they can port and machine a 94-5 head for the right money. They can even supply a ported pi manifold. I can spend lots of money there.

I missed the part about CA; IIRC,you need the engine as it sits, with approved cats for that engine. You might get away with using a pi longblock with tbird exhaust and Airbox. The only differences are subtle.

 

[XR7-4.6]

To use aftermarket cams, you'd want to start with a 96head, and get that ported. Modular headshop does that. A 95 head needs valve guides too. But they can port and machine a 94-5 head for the right money. They can even supply a ported pi manifold. I can spend lots of money there.

I missed the part about CA; IIRC,you need the engine as it sits, with approved cats for that engine. You might get away with using a pi longblock with tbird exhaust and Airbox. The only differences are subtle.

I wonder if you'd need a ref to certify a "96" Tbird engine swap into a 95 due to the intake layout difference, or if anyone would realy notice/care if everything's all there.

Without a tune npi heads with PI cams and intake would be the better bet, less risk of pinging with the npi spark curve and output is about the same. Not to sound like a deceptive criminal liar but I'd claim it's a 96 Thunderbird engine regardless if it's npi or PI or npi with PI cams and intake. They look exactly the same and the tailpipe sniffer will say the same thing regardless.

 

[rampagingsloth]

To use aftermarket cams, you'd want to start with a 96head, and get that ported. Modular headshop does that. A 95 head needs valve guides too. But they can port and machine a 94-5 head for the right money. They can even supply a ported pi manifold. I can spend lots of money there.

I missed the part about CA; IIRC,you need the engine as it sits, with approved cats for that engine. You might get away with using a pi longblock with tbird exhaust and Airbox. The only differences are subtle.

I'm not saying I'm going the aftermarket cams route, only that I was curious if the common move when mildly upgrading these engines is to go with PI cams (and ported heads) and that's good enough and really changes things or if most people would gravitate towards a particular aftermarket cam because of X, Y and Z.

Ya, because of the California thing (which I don't mind, it's tedious but nothing terrible) I would prefer to keep the car legal (as possible, haaha). I already have the Magnaflow cat pipes, they are much better than the stock pipes were, along with dual exhaust after the 3rd cat. I will do a newer NPI engine for a complete rebuild/swap because, from everything I've been reading, it's a waste of time to pull my current '95 engine and rebuild it since the newer versions address some amount of little problems in the early engines.

I was curious what 1999-2000 cars would be the best to pull from. I only ask because I don't want to accidentally get a NPI Windsor block or a PI engine. Do sellers know if they have Romeo or Windsor blocks or must I figure that out from pictures and which car the engine came from?

 

[XR7-4.6]

I'm not saying I'm going the aftermarket cams route, only that I was curious if the common move when mildly upgrading these engines is to go with PI cams (and ported heads) and that's good enough and really changes things or if most people would gravitate towards a particular aftermarket cam because of X, Y and Z.

Ya, because of the California thing (which I don't mind, it's tedious but nothing terrible) I would prefer to keep the car legal (as possible, haaha). I already have the Magnaflow cat pipes, they are much better than the stock pipes were, along with dual exhaust after the 3rd cat. I will do a newer NPI engine for a complete rebuild/swap because, from everything I've been reading, it's a waste of time to pull my current '95 engine and rebuild it since the newer versions address some amount of little problems in the early engines.

I was curious what 1999-2000 cars would be the best to pull from. I only ask because I don't want to accidentally get a NPI Windsor block or a PI engine. Do sellers know if they have Romeo or Windsor blocks or must I figure that out from pictures and which car the engine came from?

The only Windsor npis were trucks which are pretty obvious sights, even stripped down to the long block Windsor’s have more valve cover bolts and the oil fill on bank 1 (later Romeos have that but they are all PI). Crown Vic’s, tbirds mustangs in the car line all used Romeo engines until the changeover, I think the romeo plant fire only effected the PI tooling, as the panthers were romeo in 99-00 unlike the Mustang what went Windsor in that period

With CA emissions I’d just go with ford PI cams.

 

[Grog6]

Even though the 96 npi will fit the pi cam and springs, you do need to degree it carefully, to prevent opening a valve into a piston on its way down. It's close.
I'd look for a gran marquis engine. NON-POLICE .If you can find a 2002, take the trans too. They're less likely to get hammered on. Most I've seen in the yards were from grandpa pulling out into traffic. If it has less than 200k miles, I wouldn't even take the engine apart. Use the cylinder bores as a guide, if you still see the crosshatching, I'd use it as is. you can see the bottom of the cylinders by putting it on the stand, yanking the pan, and turn it over by hand. I pour oil into the pickup tube if I'm turning it by hand. oil will come out the top of the engine, be aware.
Since you have a 95, you have the hard to source front cover from a 95, and an aluminum block explorer motor is an option. You would need to source your own intake, iirc the explorer intake won't clear the hood. But maybe that's the truck intake, I'm not sure. The aluminum block engines are a lot lighter; a teksid block weighs ~80 lbs, a 4.6 Iron block ~150, all on the front wheels.

 

[XR7-4.6]

You absolutely do not have to degree stock PI cams to use in npi heads, just dot to dot is perfectly safe.

Explorer intakes don’t have a water outlet to the heater core, otherwise it’s a standard PI intake, not a truck style

 

[GRWeldon]

Pulling one and rebuilding it is possible, but it's the same deal; once you pull it out, you can just as easily drive in the new engine on a truck
Paying a jy to deliver is probably cheaper than paying a shop. But, I'd call some shops and see what they want to do the swap for you. Junkyards deliver to shops all the time.

I've used a shop exactly 3 times in my life to do work on 3 different cars because the situation was such that I didn't have time. Since I was 18, other than those 3 times, I've done all of my own work. I'm about to be 62 now. Any work that's going to be done on my equipment will be done by me. I have a lift and a tire machine and balancer. Bought the tire machines about 5 years ago because a tire dealer pissed me off for the last time with shoddy work. And it wasn't just one dealer, it was every one I've ever used and in the last decade things have deteriorated to the point that nobody is touching my vehicles unless it's absolutely necessary.

My last search for a PI motor was not revealing prices as shown in the link above, but then again, that was closer to the COVID crazy BS. My cash supply is extremely limited and if I have the parts already, I prefer to use them. I don't give a crap about performance anymore, I just want it to run reliably. If I can do that with what I have, that's the path I'm taking, however, a valid point was mentioned about the price of boring and new pistons and rings being close to or even exceeding the price of a used PI engine. If I don't have what I need to put an engine together, I will certainly reinvestigate.

Thank YOU and everyone who has replied to my questions!

 

[rampagingsloth]

Even though the 96 npi will fit the pi cam and springs, you do need to degree it carefully, to prevent opening a valve into a piston on its way down. It's close.
I'd look for a gran marquis engine. NON-POLICE .If you can find a 2002, take the trans too. They're less likely to get hammered on. Most I've seen in the yards were from grandpa pulling out into traffic. If it has less than 200k miles, I wouldn't even take the engine apart. Use the cylinder bores as a guide, if you still see the crosshatching, I'd use it as is. you can see the bottom of the cylinders by putting it on the stand, yanking the pan, and turn it over by hand. I pour oil into the pickup tube if I'm turning it by hand. oil will come out the top of the engine, be aware.

Possibly dumb question, but are you saying only get a Grand Marquis motor, not a Crown Vic or Town Car from the same year(s)? I understand avoiding any cop cars (or taxis if they were used that way) but is there something special about those Grand Marquis cars?

 

[MadMikeyL]

Possibly dumb question, but are you saying only get a Grand Marquis motor, not a Crown Vic or Town Car from the same year(s)? I understand avoiding any cop cars (or taxis if they were used that way) but is there something special about those Grand Marquis cars?

Yeah, most Grand Marquis were owned by older people and not beat on the way a lot of Crown Vics were.

 

[XR7-4.6]

Grand Marquis tend to have lower miles too. A disproportionate amount of Crown Vic’s and Town Cars were used for taxi/ limo service racking up the miles.

 

[3_97_Sports]

Grand Marquis tend to have lower miles too. A disproportionate amount of Crown Vic’s and Town Cars were used for taxi/ limo service racking up the miles.

Also like cop cars, they spent tons of time idling, which doesn't show on the odometer.