ibd2328

iTrader: (2)

More good stuff
Crankshafts
DOHC & SOHC Cranks will interchange. Some blocks may require minor block modifications for counter weight clearance when installing a forged crank in a block that previously contained a cast crank. The
most common cranks for 4.6L engines are the nodular cast iron units. They come in both 6 & 8 bolt flywheel configurations. Note that just because a crank has 8 bolts does not mean that it is forged. The
2-valve Windsor engines use both a 6 & 8 bolt flywheel, the Romeo engines use 6. The only factory forged cranks available for the 4.6L DOHC engines are installed in the Cobra. These cranks are manufactured by Gertach in Germany for Ford. Ford Racing Performance Parts (FRPP) offers these cranks for sale under part # M-6303-D46 for 425.00. The correct 8-bolt flywheel for this crank is sold under part # M-6375-G46
for 250.00. This is a billet steel flywheel.
The cranks in the 5.4L DOHC and SOHC engines are also available in cast or forged. Most of the cranks are forged, but not all. The only way to know for certain is to look at the parting line. Thick line for forged, thin line for cast.
All 6.8L V10 engines have forged crankshafts.




Connecting Rods
With the exception of the 2000 Cobra R (Carillo) and the 2003-2004 Cobra's (Manley H-beam), all modular engines have come with sinter forged powdered metal connecting rods. There has been a lot written about these much maligned rods. The truth is, they are fine for use in mild performance applications. If a blower, nitrous or turbo is in your future, you would be doing yourself a favor by upgrading your rods to forged steel like Manley's H-beam rods.
There are several versions of the factory rods. The Windsor engines use full floating pins where the Romeo based engines use pressed pins. The 4.6L SOHC passenger car engines have the weakest rods, the Windsor (or Triton) engines use a larger connecting rod that is stronger than the passenger car engines. The 4.6L DOHC engines use the same rods as are used in the Windsor's. The strongest factory style rods to date are the rods used in the supercharged 5.4L lightning. These rods have a larger big end than the standard modular rods.
4.6L Rod length = 5.93"
5.4L Rod length = 6.65"




Pistons
The pistons used in modular engines are all of the hypereutectic style, with a few exceptions. These exceptions are the supercharged Lightning and Cobra

BossRacing71

You forgot to add that only the Romeo NPI rods are press fit, Romeo PIs (2001-up) are floating pins like the Ws (at least in the Mustangs).

Question.....are the rods in my 97 4.6, the thicker Tritons?

BTW, both of the swaps on my Stangs included the "upgrade" to Coyote rods. Still a "powder" rod, but still has a much better rep and rating than the older ones.


IBD, I've read enough on this forum to know you are a knowledgeable man when it comes to our trucks. Of course I know that Stangs and trucks are 2 different beasts. What is your opinion of doing the swap on my truck? Worth it or not?

ibd2328

iTrader: (2)

Quote:

Originally Posted by BossRacing71

You forgot to add that only the Romeo NPI rods are press fit, Romeo PIs (2001-up) are floating pins like the Ws (at least in the Mustangs).

Question.....are the rods in my 97 4.6, the thicker Tritons?

BTW, both of the swaps on my Stangs included the "upgrade" to Coyote rods. Still a "powder" rod, but still has a much better rep and rating than the older ones.


IBD, I've read enough on this forum to know you are a knowledgeable man when it comes to our trucks. Of course I know that Stangs and trucks are 2 different beasts. What is your opinion of doing the swap on my truck? Worth it or not?

You seem very knowledgeable yourself. From my understanding and research all Windsor engines (our generation) use full floating pins where the Romeo based engines use pressed pins.

I know the windsor's used the larger rod's, so if your block is from the romeo plant, you more than likely don't. However, I don't think that will be an issue. THe stroke of the 4.6 doesn't create near as much stress as the 5.4 on the beams. I think you would be find doing the swap,

ibd2328

iTrader: (2)

I know one magazine did a big write up dyno testing with the swap and made great numbers. They even included numbers at the crank with and without cam swaps.

If you reuse the factory cams and don't turn over 6k rpm, I wouldn't think twice about it.

BossRacing71

Well, I've built more than my share of 302s and 351s in my time, back when I was dirt tracking. Mine and my wife's Mustangs were the first mod motors I ever messed with. But I believe in lots of research, so I did the lion's share before tearing into my first PI swap. Like I said in my OP, the first one was just a straight PI head/cam/intake swap, but the difference on her 96 GT was night and day. After adding 3.55 gears, 75mm TB/plenum, CAI, 24# injectors, and LTs. Her GT will run right along with the 05+ sn197s all day long. She's even made a few older Cobras tuck tail....lol. My 98 GT is a whole different beast.
But anyway, like I said before, being that we're talking trucks, not muscle cars, I was just curious to see if anyone's done the swap in a F150 4X4, and were the results worth the effort. My initial thoughts are that as long as the new-found power can be tailored to the useable range that a truck needs (I wouldn't think that would be too hard), you can never go wrong with MORE POWER. If I do decide to do it, maybe I'll do a write up for others to read as I go along.

BossRacing71

I would really be interested in reading that article. Any idea what mag, or where you saw it?

One other thing I'm wondering about; might you have any references concerning different Ford factory cam specs for the trucks? Specifically, NPI cams vs. PI cams. I have all the factory cam specs for Mustangs from 96-04. There's not as many changes from year to year as one might think, except between 98 & 99, when the Windsor PIs came out. Just interested to see how the truck cams compare.

jprevat

iTrader: (1)

It would make sense that with the factory setup would keep the added power in the usable range wouldnt it?

BossRacing71

Mostly, you're right. But just adding parts without a plan or goal is about the same as waiting till the night before your senior prom to find a date. You're likely to be REAL unhappy with the results. In my experience, PI swaps see the best results when everything from the heads up is upgraded, but what if the donor vehicle for the PI heads is a Mustang, and not a truck? Now cam options come up. Do you stay with NPI truck cams(probably not), go with the Mustang PIs, or hunt down some PI truck cams elsewhere? Then there's intake choices. Obviously I'm not gonna slap on a Edelbrock single plane like I would on a Mustang, but I'm sure there's better options than just re-using my stock one. Seems that I remember reading somewhere about certain Navigator intakes being an upgrade. Then there's TB/plenum combos, CAI options, injectors....... I COULD go on and on.
My point being that just the head swap alone is not the only thing to factor in. My goal is to plan out and assemble the best package I can for a one-time project. My other toys(oh yeah, AND the missus) keep me plenty busy, so I need to do my truck right the first time.

BossRacing71

Well IBD, I found some new info on 4.6 Romeos vs. Windsors that I didn't know. I was not aware that the Windsor NPI piston had the same dish (-10.5cc) as the Romeo NPI piston, but had the floating pins.
Something else you stated got me wondering too. You said the Triton engines were built at the Windsor plant, yet my truck badges and engine cover say "4.6 Triton", but has a W in the VIN meaning Romeo engine. A Ford marketing ploy? Anyway, it just so happens I have a set of 98 cobra rods just waiting to be used. Those should do the trick.

jferg92

Interested to see your build! Welcome