99 2V Dyno'd
Postmaster
Joined: Oct 2006
Posts: 4,171
Likes: 12
From: SE Texas
The piston dish on NPI shortblocks is smaller than the PI shortblocks(10cc vs 17cc if memory serves me right).
The difference is 9:1 CR vs ~10.3:1.
JL
The difference is 9:1 CR vs ~10.3:1.
JL
FTE Leadership Emeritus
Joined: Jul 2002
Posts: 42,561
Likes: 423
From: Long Island USA
I was always under the impression that the V10 pistons were the same from 1997 through 2004 or even up through the 3-valver.
For instance, from a Ford parts online web site:
"Piston, f250 pick-up - 6.8l - 1999-07 super duty - 6.8L - 1999-07 SUPER DUTY"
The V8's are definitely different between PI and non-PI.
For instance, from a Ford parts online web site:
"Piston, f250 pick-up - 6.8l - 1999-07 super duty - 6.8L - 1999-07 SUPER DUTY"
The V8's are definitely different between PI and non-PI.
FTE Leadership Emeritus
Joined: Jul 2002
Posts: 42,561
Likes: 423
From: Long Island USA
And from Sealed Power, for their piston # H885CP
FORD E SUPER DUTY (1997 - 2002)
FORD E-350 ECONOLINE (1997 - 2005)
FORD E-350 ECONOLINE HD CLUB WAGON (1997 - 1998)
FORD E-350 ECONOLINE SUPER (1997 - 1998)
FORD E-350 ECONOLINE SUPER WAGON (1997 - 1998)
FORD E-450 ECONOLINE (2003 - 2005)
FORD E-550 SUPER DUTY CUSTOM 2003
FORD EXCURSION (2000 - 2005)
FORD F-250 SUPER DUTY (1999 - 2004)
FORD F-350 SUPER DUTY (1999 - 2004)
FORD F-450 SUPER DUTY (1999 - 2004)
FORD F-550 SUPER DUTY (1999 - 2004)
FORD E SUPER DUTY (1997 - 2002)
FORD E-350 ECONOLINE (1997 - 2005)
FORD E-350 ECONOLINE HD CLUB WAGON (1997 - 1998)
FORD E-350 ECONOLINE SUPER (1997 - 1998)
FORD E-350 ECONOLINE SUPER WAGON (1997 - 1998)
FORD E-450 ECONOLINE (2003 - 2005)
FORD E-550 SUPER DUTY CUSTOM 2003
FORD EXCURSION (2000 - 2005)
FORD F-250 SUPER DUTY (1999 - 2004)
FORD F-350 SUPER DUTY (1999 - 2004)
FORD F-450 SUPER DUTY (1999 - 2004)
FORD F-550 SUPER DUTY (1999 - 2004)
Postmaster
Joined: Oct 2006
Posts: 4,171
Likes: 12
From: SE Texas
I was always under the impression that the V10 pistons were the same from 1997 through 2004 or even up through the 3-valver.
For instance, from a Ford parts online web site:
"Piston, f250 pick-up - 6.8l - 1999-07 super duty - 6.8L - 1999-07 SUPER DUTY"
The V8's are definitely different between PI and non-PI.
For instance, from a Ford parts online web site:
"Piston, f250 pick-up - 6.8l - 1999-07 super duty - 6.8L - 1999-07 SUPER DUTY"
The V8's are definitely different between PI and non-PI.
There IS a compression difference,with PI heads on a NPI shortblock being higher. The pistons ARE different as well. Seeing the Sealer Power numbers shows me that it isn't the first time I've seen the aftermarket get something about a modular screwed up,and it won't be the last.
JL
Thread Starter
|
Former Vendor
Joined: Sep 2000
Posts: 2,627
Likes: 76
From: South Carolina
Just to clarify, the engine in 99 truck is a complete PI engine... We did a complete engine swap from a non PI to PI... same exhaust system, S&B intake and calibration.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Postmaster
Joined: Oct 2006
Posts: 4,171
Likes: 12
From: SE Texas
Using a different engine can result in that engine being in better condition than the original.
JL
FTE Leadership Emeritus
Joined: Jul 2002
Posts: 42,561
Likes: 423
From: Long Island USA
The cylinder heads also have different size combustion chambers. The PI being approx 42cc and the NPI being 50cc.
There IS a compression difference,with PI heads on a NPI shortblock being higher. The pistons ARE different as well. Seeing the Sealer Power numbers shows me that it isn't the first time I've seen the aftermarket get something about a modular screwed up,and it won't be the last.
JL
There IS a compression difference,with PI heads on a NPI shortblock being higher. The pistons ARE different as well. Seeing the Sealer Power numbers shows me that it isn't the first time I've seen the aftermarket get something about a modular screwed up,and it won't be the last.
JL
Are you sure this is true for the V10 and not just the 4.6/5.4 PI vs. non-PI?
Postmaster
Joined: Oct 2006
Posts: 4,171
Likes: 12
From: SE Texas
If they used the same pistons for ALL 6.8L's,then the non-PI engines would have less than 8.5:1 CR,and the PI engines would be right around 9:1.
They 6.8L's all use the same con rods as the 5.4L, and the crankshaft stroke is the same between all of them, so with the same head gasket, same piston and different head combustion chamber cc's,then you have a vastly different compression ratio. Over the years I've found countless errors in Ford's printed and online reference material,and their part number/cross reference interface is hideous.
JL
Thread Starter
|
Former Vendor
Joined: Sep 2000
Posts: 2,627
Likes: 76
From: South Carolina
You can look at it that way... I guess
FTE Leadership Emeritus
Joined: Jul 2002
Posts: 42,561
Likes: 423
From: Long Island USA
Ford service manual I downloaded from motorcraft.com back when it was still available without a subscription, also says 51.5 cc's for 2001. Not to say, of course, that there aren't errors in Ford's literature
I dunno, I know at least one person here has put PI heads onto a '99 long block and I doubt he's running over 10:1 compression on 87 octane without issues. The knock sensor logic will only pull back the timing so far - 4 degrees?
Picture of a '99 head, typical NPI.
V10 PI head:
Typical 4.6 NPI vs. PI:
Looks like you might be right - the PI V10 head does look like a smaller combustion chamber.
Oh well, there's something about "assuming"
Postmaster
Joined: Oct 2006
Posts: 4,171
Likes: 12
From: SE Texas
My service manual CD for 2001 says combustion chamber size is 52.6-51.6 cc. For a PI head V10.
Ford service manual I downloaded from motorcraft.com back when it was still available without a subscription, also says 51.5 cc's for 2001. Not to say, of course, that there aren't errors in Ford's literature
I dunno, I know at least one person here has put PI heads onto a '99 long block and I doubt he's running over 10:1 compression on 87 octane without issues. The knock sensor logic will only pull back the timing so far - 4 degrees?
Looks like you might be right - the PI V10 head does look like a smaller combustion chamber.
Oh well, there's something about "assuming"
Ford service manual I downloaded from motorcraft.com back when it was still available without a subscription, also says 51.5 cc's for 2001. Not to say, of course, that there aren't errors in Ford's literature
I dunno, I know at least one person here has put PI heads onto a '99 long block and I doubt he's running over 10:1 compression on 87 octane without issues. The knock sensor logic will only pull back the timing so far - 4 degrees?
Looks like you might be right - the PI V10 head does look like a smaller combustion chamber.
Oh well, there's something about "assuming"
JL
Postmaster
Joined: Jun 2008
Posts: 2,564
Likes: 11
From: Wayyy NoCal, USA
Regarding pistons, the piston crown looked different on my '06 3V block as compared to the '99 2v block. The "ridge" around the edge was wider, so the dished part was smaller diameter.
But some rough measurements and math indicated the "volume" between the piston top and plane of the cylinder head was really close.
So while the pistons appear to have changed over the years, the changes may be so small that they are effectively interchangeable. So Ford (and others) may be offering only 1 to fit all to minimize inventory.
But some rough measurements and math indicated the "volume" between the piston top and plane of the cylinder head was really close.
So while the pistons appear to have changed over the years, the changes may be so small that they are effectively interchangeable. So Ford (and others) may be offering only 1 to fit all to minimize inventory.