|
i decided to bring this over from the grand prix forum, to answer all the questions about top swaps
But First Some General Engine Information about Our 3800's, the Engine Years are GP specific, cause I don't know which was in which of the other W-bodys
The Grand Prix has come with 4 different engines since 97:
Engine Basics/ Availability
There are two NA(naturally aspirated engines):
The Series II motor is the L36 97 - 03
The Series III motor is the L26 and went 04*ish to 08
The ishs are because some of the motors in 04 are series III with Series II conecting rods(
*There is an aluminum oil pan in some series III engines 05+ and all Series III engines 06+
There are two Supercharged motors
The Series II motor is the L67 and uses the Gen III M90(supercharger) 97-03ish
The Series III motor is the L32 and uses the Gen V M90(supercharger) 04*ish-07
The ishs are the same as above, except all 04 and up have the Gen V M90, just the rest of the engine may be a Series II/III Hybrid
*There is an aluminum oil pan in some series III engines 05+ and all Series III engines 06+
While the motors are very similar, there are several differences:
Engine Info/Differences
The L67 and L32 have a 8.5 to 1 compression ratio
The L36 and L26 have a 9.4 to 1 compression ratio
The L67 and L32 have the fuel injector bosses in the heads
The L36 and L26 have the fuel injector bosses in the LIM(lower intake manifold)
The L32 and L26 have an Electronically Controlled Throttle
The L67 and L36 have a Cable Controlled Throttle
The L26 and L36 have one Belt
The L67 and L32 have two Belts
The L32 and L26 have a 4 bolt square throttle body bolt pattern
The L67 and L36 have a 3 bolt triangle throttle body bolt pattern
The L32 and L67 cars have a 3/4" Radiator
The L36 and L26(Maybe) have a 5/8" radiator
The L67 has a Gen III M90
The L32 has a Gen V M90(the gen V is considered much more efficient)
****The Stock Pulley for both Gen III and Gen V is 3.8 inches in Diameter
The L36 has a Plastic Upper intake
The L26 has an Aluminum Upper intake
The NA motors have the cam timing off one degree from the factory
The SC pistons have more space between the piston top and top compression ring than the NA pistons
The L32 and L26 engines have Powder Forged connecting rods and Moly Coated Piston skirts
The L32 and L26 engines' heads flow slightly better than the Series II heads
(thanks to slightly bigger valves and slightly better port design)
Fuel System:
The L36 and L26 have 26 LB an Hour injectors
The L32 and L67 have 36 Lb an Hour injectors
**** the GTP's 97-03 have a two speed fuel pump system as well
The L32 and L26 engines have a Return-Less fuel system while the L67 and L36 have a continuous flow system(not sure of the correct name)
Transmission Info:
The L32* and L67 cars have a 4T65E-Hd transmission
The L36 and L26 cars have a 4T65E transmission
* The Comp G has a specific trans that has 3.29 Final drive, and other enhancements
The L32* and L67 Cars have a Final drive of 2.93 to 1
The L36 and L26 Cars have a Final drive of 3.29 to 1
* The Comp G has a specific trans that has 3.29 Final drive, and other enhancements
Other Info:
The crank, Block, and Cam are the same between the NA and SC motors of the same year range (L67 and L36 share their parts, and the L32 and L26 share their parts)
The connecting rods should be the same length, but the wrist pin ends are different, so it may measure different since they measure connecting rods center to center
Now on to the Top Swap Stuff:
Many Ask what is the Reason to top swap, Well there are a few:
A top swap motor has higher compresion giving it about 5% more power at the same mod level as its originaly SC cousin
The SC cannot be bolted on to the L36/L26 heads because of the engine differences stated above.
It can be less costly than a motor swap, and you get to change many engine gaskets, possibly ones that need to be replaced
What is required for a Top Swap?
I will have a parts list later on, but pretty much everything block up other than the main belt tensioner and alternator need to be swapped
Lots of Patience
Lots of searching, There is tons more info on this forum that you can find in any one post of thread, read all that you can before attempting a topswap
Some time, it can take from 6hours and up to complete the Swap
PARTS LIST
Heads from SC motor (Either Series will do, all the blocks are the came so all the heads can be interchanged)
Head Bolts, can be OEM replacements or Studs, up to you(Stock are Torque to Yield(one time use)
Thread Sealer (the head bolts go into the coolant jacket, and if they aren't sealed, they will weap coolant out)
Head Gaskets
Rocker boltsSame reason as the head bolts
Valve Cover Gaskets
Harmonic Balancer From the SC motor
Tensioner for SC belt
Idlers for Sc beltThese require bolts that aren't on the L26/L36
Coil Pack BracketThe tensioner and one of the idlers bolt to the SC Coil bracket (some 97 and 98 cars may not need a different bracket)
Lower Intake Manifold from the SC motor(The bolts are the same, so you can use your old LIM bolts if needed)
Lower intake Manifold Gaskets(the Aluminum ones are the Best)
Fuel Rail(you need the one that matches your fuel system, 97-03 gets the standard rail, while 04+ needs the return-less)
Fuel InjectorsAre not a requirement, but you should run the SC injectors or better flowing units
**Injector connectors may be required on some years
Supercharger
Supercharger Gasket(If you use a Gen III M90 you need O-rings as well)
Supercharger Belt
Throttle Body from SC motor(This isn't required but recommended)
Throttle Body Gasket
Colder Thermostat I Recommend 180*, but that is all personal preference
1 Step Cooler Spark PlugsUsually recommended for the Top Swap
Fluids Oil(a change needs to be done after Swap and before engine is started) Coolant(you will loose a good amount doing the Swap
Oil FilterFor above change
Tunned PCM Stock Gt settings are way too aggressive for a SC application, I suggest a tuner, but if you don't have time, a Canned tune can work
Exhaust Manifold Gaskets (optional)
Some Common Questions(FAQ)
Which blower should I Use:
Well that depends, the Gen V is more efficient, but also more expensive, if you run a Gen V you need a Gen V LIM as well (you can modify the older LIM, but that is up to you) A Gen V will also require custom Vacuum and EVAP routing( if you have a L36, the L26 has similar vacuum routing to the L32)
Will this Series II part bolt to this Series III part?
99% the parts will bolt together, the Alternators were different for different years, so those may need to be swapped, the only parts that don't have the same bolt pattern Series II to Series III are the Throttle Bodys
How much Boost Does it get?
I get 5 - 7lbs depending on temp( with a stock Pulley), but boost numbers are very mod specific and will vary from person to person
How much Power do I gain?
General Consencus is that you will have 5% more power than a L67 with identical mods, so stock vs stock, you should have about 252HP at the crank (Stock 240hp * 1.05(5%)).... A stock GTP is somewhere between 185 - 195WHP, so expect similar like 185-200whp if you Dyno your car.....
How Much Faster Does the Car Get?
The usual Gain is 1 full second from where you are now, I gained .89 seconds on my custom tune(which isn't very good) So a full second to 1.2 seconds seems right (this Depends on mods though)
Does It Affect Fuel Mileage?
That Depends if you can stay out of boost, If your going WOT every time your car moves, then of course you fuel mileage is gonna drop, I noticed a gain in Gas Mileage in my car, driving the same as I did before the Swap.
How Long Does The Swap Take To do?
It took me about 11 hours of work from start to finish, but this all depends on how good you are with a wrench and how much patience you have
Will it Kill my Trans
If your trans is already weak/abused then this may very well kill it, anytime you up engine power you increase the stress on the trans. Now, a well maintained trans will last well(If you don't beat on it and drive like a madman) with a Swap, but in our cars the Trans is the weak link, so sadly there is no guarantee( many Na motors have destroyed their Transmisions) that the added 40 - 60 Hp won't kill the Trans
|
