Welcome Visitor! Please take a few seconds and Natedog
New Member
- Joined
- Aug 7, 2007
- Messages
- 917
- Reaction score
- 5
- Points
- 0
- Location
- CA
- Vehicle Year
- 87
- Make / Model
- Ranger
- Transmission
- Manual
3.8 & 4.2 Information
Resource - www.mercurycapri.com
* Carbureted and FI heads are different. Carb heads have larger intake ports. FI ports are shaped similarly, but smaller. FI heads have the injectors stuck right into the head, not the intake. There is a bulge in the top of the intake port for the stream from the injector.
* The roller cam from the later 3.8s ones is a billet, not a casting. Several late 3.8s have a provision for the balance shaft, but not all of them had them. As far as I know, the late model Sable/Taurus/Continental FWD 3.8s apparently had them.
* There are RWD and FWD blocks. They're marked with big letters "RWD" and "FWD" on the front. The RWD blocks have the Windsor bolt pattern, but the bellhousing bolt holes are metric. They're close enough to cross-thread a 3/8" bolt into if you're not careful.
The FWD 3.8 bellhousing is the same as the 3.0 Vulcan V6(FWD & RWD), 3.0 SHO V6, FWD 2.3, FWD 2.5HSC. You can put a FWD 3.8 V6 into a RWD application by using a RWD bellhousing from a 3.0 equipped Ranger/Explorer and a T5.
* Early 3.8s had plastic valve covers. Later ones have cast aluminum valve covers.
* The front cover, oil pump, and distributor drive still look remarkably similar to the Buick V6. Remove the front cover, and the cam chain tensioner and front of the cam look remarkably similar to the Buick too.
* Rod and main bearings are Cleveland size - 2.311 and 2.75. Rods are 5.95", same as a 351... or a Buick 3.8...
* The water pump has a true scroll housing, matched by the front cover. It has a real impeller. It looks much nicer than the 5.0's "paddle in a box" water pump.
* The oil pump looks to have about twice the capacity of the Buick V6. The Buick is a known 'bleeder', with lots of internal oil leaks and restrictions. Nevetheless, the ugly Buick oiling system suffices, even for the Grand National turbomotors. The Cleveland-style oiling of the Ford V6 is much cleaner. Given that, and the big pump, oiling ought not to be a problem for the Ford.
* Two heads from the same motor - one has .502" OD valve guides, one has .498" OD valve guides. .498" is a bastard size; You should ream the holes out to use standard .502" guides.
* Valve lengths are standard small block Ford, i.e., same as the old Ford flathead. Stem diameter is standard flathead 11/32".
* The cylinder head bolts are metric, close enough to 7/16". Same size as the 5.0 Ford, the 454 Chevy, or the 455 Olds. The gasket-blowing problem may be because the bolt pattern is so *wide* - the bolts are out near the water jackets instead of in near the cylinders, like on most 4-bolt cylinders. There's a lot more unsupported head on the 3.8 than on a 5.0.
* The block looks adequately strong on the bottom end. You might want to weld or plug up some of the unused core holes on the deck surface, though. Same with the heads.
* It's a metric engine, but it wasn't *designed* metric. The calipers tell you it was designed in inches, then they just used metric fasteners.
* The new 4.2 V6 found in the newest F150s will physically interchange with the 3.8 V6.
* The crank in the 4.2 is a direct replacement for the 3.8 V6. The mains and balance are the same as the 3.8 V6. I am not sure on the deck height of the 4.2. I believe it is the same as the 3.8 as well. Just swap in the entire motor, or swap in the crank, rods and pistons and you have yourself a nice little stroker.
Resource - www.mercurycapri.com
* Carbureted and FI heads are different. Carb heads have larger intake ports. FI ports are shaped similarly, but smaller. FI heads have the injectors stuck right into the head, not the intake. There is a bulge in the top of the intake port for the stream from the injector.
* The roller cam from the later 3.8s ones is a billet, not a casting. Several late 3.8s have a provision for the balance shaft, but not all of them had them. As far as I know, the late model Sable/Taurus/Continental FWD 3.8s apparently had them.
* There are RWD and FWD blocks. They're marked with big letters "RWD" and "FWD" on the front. The RWD blocks have the Windsor bolt pattern, but the bellhousing bolt holes are metric. They're close enough to cross-thread a 3/8" bolt into if you're not careful.
The FWD 3.8 bellhousing is the same as the 3.0 Vulcan V6(FWD & RWD), 3.0 SHO V6, FWD 2.3, FWD 2.5HSC. You can put a FWD 3.8 V6 into a RWD application by using a RWD bellhousing from a 3.0 equipped Ranger/Explorer and a T5.
* Early 3.8s had plastic valve covers. Later ones have cast aluminum valve covers.
* The front cover, oil pump, and distributor drive still look remarkably similar to the Buick V6. Remove the front cover, and the cam chain tensioner and front of the cam look remarkably similar to the Buick too.
* Rod and main bearings are Cleveland size - 2.311 and 2.75. Rods are 5.95", same as a 351... or a Buick 3.8...
* The water pump has a true scroll housing, matched by the front cover. It has a real impeller. It looks much nicer than the 5.0's "paddle in a box" water pump.
* The oil pump looks to have about twice the capacity of the Buick V6. The Buick is a known 'bleeder', with lots of internal oil leaks and restrictions. Nevetheless, the ugly Buick oiling system suffices, even for the Grand National turbomotors. The Cleveland-style oiling of the Ford V6 is much cleaner. Given that, and the big pump, oiling ought not to be a problem for the Ford.
* Two heads from the same motor - one has .502" OD valve guides, one has .498" OD valve guides. .498" is a bastard size; You should ream the holes out to use standard .502" guides.
* Valve lengths are standard small block Ford, i.e., same as the old Ford flathead. Stem diameter is standard flathead 11/32".
* The cylinder head bolts are metric, close enough to 7/16". Same size as the 5.0 Ford, the 454 Chevy, or the 455 Olds. The gasket-blowing problem may be because the bolt pattern is so *wide* - the bolts are out near the water jackets instead of in near the cylinders, like on most 4-bolt cylinders. There's a lot more unsupported head on the 3.8 than on a 5.0.
* The block looks adequately strong on the bottom end. You might want to weld or plug up some of the unused core holes on the deck surface, though. Same with the heads.
* It's a metric engine, but it wasn't *designed* metric. The calipers tell you it was designed in inches, then they just used metric fasteners.
* The new 4.2 V6 found in the newest F150s will physically interchange with the 3.8 V6.
* The crank in the 4.2 is a direct replacement for the 3.8 V6. The mains and balance are the same as the 3.8 V6. I am not sure on the deck height of the 4.2. I believe it is the same as the 3.8 as well. Just swap in the entire motor, or swap in the crank, rods and pistons and you have yourself a nice little stroker.
