I recently bought an '06 Impala 3900 & 4T65E tranny. My reason for the purchase was to find what would be needed to swap it into older cars and RWD vehicles. What I have found so far is kind of interesting. I have only removed the UIM, exhaust manifolds, TC cover, coolant return system, PS pump & valve cover.
Excluding electronics, the engine with Impala brackets will bolt into a W-body.... no mods required except you would need to use the Impala AC comp, alternator and a very long upper radiator hose. The U cooling system and VVT require that you use the front covers for the 3900.
The length of the engine and heads are the same as the 3X00 engines. Spacing between exhaust ports is very close to the 3X00 but the bolt pattern is completely different (Holes are diagonal). Exhaust ports are larger also.
LIM does not have coolant passages. The U cooling system pushes the water into the front of the block on each side, it circulates through the engine and exits from the end of the heads above the TC cover (exits through the freeze plug openings in the heads). The coolant return system bolts to both heads and holds the PS pump and alternator. The alternator mounts different than 3X00s that I have seen and is a 125 amp Bosch. The thermostat is located on the inlet side of the water pump.
The heads have 4 mounting holes in each end and the pattern is different than earlier models.
LIM, UIM, TC cover, coolant return and water pump use metal gaskets with molded rubber inserts. They look like they will be expensive to replace, who knows.
The 3900 uses a 70mm electronic TB and the UIM will accept a 76mm without porting. I am going to make an adapter to mount a 75mm TB from a 5.3.
The camshaft has a hub that extends about 3/4" from the face of the block. It is used for the VVT feature and will not allow the old style TC gear & cover to fit. I have not removed the cam yet to see if an old style cam can be used. Also, a chain tensioner is used instead of a guide.
All of the TC cover bolts are M8 instead of having (5) M8, (2) M10 and (3) M12 bolts on previous models. One of the three bolt holes on the front of the block that were used to mount the engine was eliminated. The 3900 only has one hole on each side of crank.
I need to get some pictures to post, perhaps I can do that this weekend. Let me know if there is something special you would like to see.
I'm really curious about the operation of the VVT. It only uses two wires to control it. If anyone has any info on it's electrical operation, I would appreciate the input.
Excluding electronics, the engine with Impala brackets will bolt into a W-body.... no mods required except you would need to use the Impala AC comp, alternator and a very long upper radiator hose. The U cooling system and VVT require that you use the front covers for the 3900.
The length of the engine and heads are the same as the 3X00 engines. Spacing between exhaust ports is very close to the 3X00 but the bolt pattern is completely different (Holes are diagonal). Exhaust ports are larger also.
LIM does not have coolant passages. The U cooling system pushes the water into the front of the block on each side, it circulates through the engine and exits from the end of the heads above the TC cover (exits through the freeze plug openings in the heads). The coolant return system bolts to both heads and holds the PS pump and alternator. The alternator mounts different than 3X00s that I have seen and is a 125 amp Bosch. The thermostat is located on the inlet side of the water pump.
The heads have 4 mounting holes in each end and the pattern is different than earlier models.
LIM, UIM, TC cover, coolant return and water pump use metal gaskets with molded rubber inserts. They look like they will be expensive to replace, who knows.
The 3900 uses a 70mm electronic TB and the UIM will accept a 76mm without porting. I am going to make an adapter to mount a 75mm TB from a 5.3.
The camshaft has a hub that extends about 3/4" from the face of the block. It is used for the VVT feature and will not allow the old style TC gear & cover to fit. I have not removed the cam yet to see if an old style cam can be used. Also, a chain tensioner is used instead of a guide.
All of the TC cover bolts are M8 instead of having (5) M8, (2) M10 and (3) M12 bolts on previous models. One of the three bolt holes on the front of the block that were used to mount the engine was eliminated. The 3900 only has one hole on each side of crank.
I need to get some pictures to post, perhaps I can do that this weekend. Let me know if there is something special you would like to see.
I'm really curious about the operation of the VVT. It only uses two wires to control it. If anyone has any info on it's electrical operation, I would appreciate the input.
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