There has been much debate as to which transmission to use for the swap. Transmissions play a very big part in the selection of a block to work with. As you may have read in the 4G6x section, there are two types of bellhousings available: wide and narrow. These two bellhousing when measured from the lower two bolts are 13.25" (Wideblock) and 12.25" (Narrowblock). These are not the only differnces. The upper bolts are also both different as are the starter bolt positions. These differences can open and close windows very quickly for your swap. Choose wisely and read this site to determine which transmission to use.
There are many differnet ways to mate a transmission to the 4G6x Engine. Details on the following can be found below:
- Stock Starion Transmission using a wideblock
- D50 Transmission using a narrowblock
- Mazda B2600 / RX7 transmission using a wideblock
- Aftermarket Adapters
The Mitsubishi KM-132
To understand the relationship between the D50 and Starion transmissions, we need to do a quick lesson on the KM132 transmission.
The KM-132 was used in several RWD and 4WD Mitsubishi Vehicles. The Starions, 2WD and 4WD pickups, and even the montero used this transmission. The transmissions are far from the same though. The tailhousings can be of different lengths, including ones with a tranfercase hanging off the back. The major difference that we need to pay attention to is the bellhousing pattern. This transmission is offered with both patterns so switching is very simple. More details area available below.
|KM132-M-CNL Gear Ratios||Car||1st||2nd||3rd||4th||5th|
|D50 Truck (KM132)||3.369:1||2.035:1||1.360:1||1:1||.856:1|
The Starion transmission is a great choice for a Starion swapper on a budget who plans to rebuild the motor. This is a great alternative to tossing in a tired old 4G63 straight from the donor and dealing with the consequences. The savings from using this transmission will offset the costs of sourcing a wideblock and rebuilding it. You avoid the costs (both time and money) of replacing the clutch, flywheel, driveshaft, shifter, crossmember, etc. This transmission can only be used with wideblock 4G63s and 4G64s which are available in various vehicles. Most people find the transmission will handle about 400hp and this should be fine for most swaps. If you do out grow this transmission there are several great options to upgrade to below.
- Transmission: KM132 - Conquest / Starion
- Flywheel: Starion
- Pressure Plate: Starion
- Clutch Disk: Starion
- Starter: Starion
Because the DSMs come with a narrow block 4G63, many of the swappers coming here will be looking to use this transmission. It is truely the budget choice at first glance. The small trucks also known as the "Dodge Ram D50, Mitsubishi Mighty Max and Plymouth Arrow" came equipt with several engines: the 2.0L 4G63 (G63B), the 2.4L 4G64 (G64B), and 2.6L G54B. Depending on year and type of transmission, the 2.0L trucks may have a narrowblock. The narrowblock bellhousing transmission is basically the same KM-132 that is found in the Starion, only with a narrow bellhousing! This allows you to bolt the transmission up to the 4G63 and use the stock Starion transmission crossmember and driveshaft... or so you'd think. The shifter location on the truck transmission is 2" forward of that of the Starion. This is easily remedied by swapping the tail housings between the two transmissions.
The D50 transmission is also a pull-cable type setup. Because of this you will need to make your own hydrauilic setup or adapt the cable mechanism. On my first swap I chose to make a hydraulic setup. Wilwood (the brake company) makes a small hydraulic clutch slave cylinder that works well. Prices for this are around $60. You will also have to make brackets and modify the swing arm being careful that no binding will occur.
The Clutch for this setup is fairly easy to obtain. You need to use the FWD version of the flywheel. AWD flywheels have a smaller ring gear and thus, the starter will not align properly. You can use the pressure plate from whichever flywheel you are using, but you will need to specify the spline pattern to use. The DSM spline pattern is 7/8" 20 count. Most clutch companies can easily (and for no extra charge) rivit a 225mm clutch disk to a 1" 23 count spline center. If you are really on a tight budget, the 215 (or smaller) flywheel/disk combo can be used from the pickup trucks.
Moving the shifter back 2" is going to be required with the D50 transmission. This is easily accomplished by swapping the tail housings between the Starion and the D50 transmissions. Be sure to test out the shifter before you say you're finished. It will usually take several attempts. Just get a good mental image of what is going on inside and you will be able to feel your way around literally with your eyes closed.
Less imporant is the bottom cover. The Starion uses a "waffled" cast aluminum cover which seals with a reusable o-ring. This can help the rigidity of the case as well as oil cooling compared to the stamped steel piece of the D50 transmission with replacable cork gasket. Since you'll be using the Starion box to donate the tail housing, you might as well steal this as well.
- Transmission: KM132 - D50 / Mighty Max
- Flywheel: FWD Eclipse
- Pressure Plate: FWD Eclipse
- Clutch Disk: 225mm disk with 23 1" spline
- Starter: Eclipse
D50 / Starion Hybrids
Some intelligent (and brave) souls have actually swapped the Starion internals into the D50 case. Well known names such as Eric Phlebani and Alex from www.dentsport.com come to mind. I, however, tried to swap these internals and it was a total failure. The integrated bellhousing/cases were actually slightly different. Shimming of the bearings is required. The shafts also varied. Certain bearings would need to be kept with the case and others with the shafts. The real challenge is finding the correct combination. Eric P. apparently has figured this out. I would love for him to contribute to the pool of knowlege, but he has yet to show an interest in sharing this info. Sadly, the Dentsport transmission died within one season of racing. There are many contributing factors to its death, but the ultimate failure was in the bearings. This failure resulted in Alex tossing the 4G63 to use the popular Nissan SR20DET.
Mazda RX7 / B2600 Transmission
How the hell will an RX7 transmission work? This came as quite a suprise to me as well. Here is the background. Mazda built the Mazda B2600 for several years. During two of those years ('87-'88), the carburated engine blocks were the 2.6L G54B! The other "2.6" engine produced during this time was called the G6. This is also known as the MPV block.
The RX7 transmission WILL NOT bolt to any 4G6x engine. You will need a B2600 bellhousing to adapt it to the Mitsubishi wideblock. It is also possible to bolt the B2600 transmission up, but it may have a longer input shaft which will not work with the Starion flywheel.
Here is an image comparing the bellhousings:
- Transmission: Mazda Model R - B2600 / RX7 Turbo
- Flywheel: Starion
- Pressure Plate: Starion / RX7
- Clutch Disk: Starion / RX7
- Starter: Starion
Click here for a detailed page with information on the RX7 transmission.
These options are very flexible. They can adapt literally any block to any transmission... if you can find one. For our particular swap, there is very little market share and therefore, very few bellhousings. Most are developed by intrepid fabricators in small numbers. Usually once this person runs out of inventory, there are no more.
Bill Hincher's Adapters
A member of our site, Bill Hincher, has designed and built several custom cast aluminum bellhousings for 4G6x swaps. He is currently offering narrowblock adapter bellhousings for the Toyota W55/W58 and R154 and the GM T56. He plans to soon add a few wideblock options starting with the GM T56. More information on Bill Hincher's bellhousings can be found here.
Buschur Racing's Powerglide Adapter
One custom RWD alternative was developed by Bushur Racing in the late '90s. It uses an adapter plate to bolt an automatic Powerglide transmission to a narrowblock. Lots of money went into research to develop this kit. If you are building a HIGH power drag car, this is the best option available. You can purchase many of the parts from Buschur's Website. I have seen this install in person and it looks very nice.
"Myself, Plebani, Brent Rau, Mike Simon, Albert Lioe-a-tjam, all of us and many more use our adapter. Silly to design and make something when what is out there is perfect." ~David Buschur
Rod Shop's Toyota Adapter
A shop in Australia has actually put together a partial kit for adapting the Supra transmission to the Mitsubishi wideblock (for the 2.6L Starions). It can be found here. The part number is "AP 20". It uses an aussie Borg Warner 507 bellhousing which according to one source are "cheap as chips" down there.
Chad's T56 Adapter
Chad Samuel made an adapter kit for the wideblock G54B which will also work on a wideblock 4G6x. It uses a 6 speed T56 transmission from the Camero LT-1 Camaro / Firebird (93-97). This was originally sold by Chad and also Midwest turbo. I am currently unaware of who sells parts for this. If you cannot find it, post a question on StarQuestClub or on our forum and someone should be able to find out. Here are some pictures of some adapter flywheels. These adapt the Mitsubishi 6 bolt to the 11" GM clutch:
Make Your Own Adapter
If you'd like to make your own adapter Jason aka "PiercedJD" in Port Charlotte, FL. has explained his method below:
The very very simple version of how to do this... use a DSM starter plate. Make a new starter plate and bolt it to the engine and locate the center of the crank shaft on the plate with it bolted to the engine and drill a pilot hole.
Locate the center of the plate on the transmission input shaft and clamp the plate to the bellhousing. Relocate the old bellhousing bolt locations to match the new locations which you are taking from the starter plate. Make sure the hole diameters are the same, as the two lower bolt holes also house the guide dowels. Do the same for the starter opening/bll and bolt locations. You can leave the old starter bell where it is, or cut it off and add a piece of aluminum). Your bellhousing is now complete.
Modify your flywheel (DSM FLYWHEEL)to accept a pilot bearing of the correct size. Whatever car your transmission came from, buy the pilot bearing. Take the flywheel and pilot bearing to a machine shop and hand the proprioter both pieces. tell him make this (pilot bearing) fit into this ( flywheel).... come back in about an hour. Your flywheel is now complete.
Purchase a 225mm clutch disc that will fit your transmission input shaft.
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