Volvo Turbo Conversion Insights - Installing a B23/230 ET/FT engine into a 240 chassis
by Anthony Hyde and friends - Last update May 2010
At bottom of page is a few words on SUPERCHARGING

Background: In the early 1980's Volvo's most powerful production model was the 240 Turbo being 2.1 litre, 4 cylinder and 2 valves per cylinder, being sold in left-hand drive countries in Europe and USA. The 240T was produced from 1981 to 1985 and featured a strong 2.1 litre B21 ET/FT turbo engine with a Garrett TB03 turbocharger, Bosch K-Jet mechanical fuel injection and a transistor coil ignition system. The ET was the higher performance version tuned for high octane leaded fuel, and hence a more agressive advance curve, the FT for lower octane unleaded fuel in markets such as the USA.

Further development of the engine was made for the new 700 series, resulting in a larger capacity 2.3 litre version, the B23 ET/FT. This engine was fitted to the 760 released in late 1983/84 and featured Motronic computer fuel and ignition management. More development in successive years saw changes resulting in a low friction B230 ET/FT version, and from 1989 a stronger 3rd generation 'K' series B230 ET/FT motor was released. Development continued in the 90's and the later engines are very robust units with oil squirters (link) to cool the pistons. The B230 FT version was manufactured through to 1998, the last being in the 940T model. A new all alloy, 5 cylinder, 20 valve engine for the 850 ended the era.

Retrofit: Sourcing a late model B230 FT turbo engine and fitting it into a 240 becomes a desirable thought, as from a mechanical fitment point of view the engine bolts in near perfectly. However, theres a lot of smaller issues such as wiring it all up that make a conversion task more of a challenge. This web page will enlighten you to most of the hurdles.
Heaven is another parts car nearby to transfer from.

The following articles give the reader an insight into these other issues - Thanks to the many contibutors.

Donor engine: The best general advice is to seek the youngest and healthiest engine available, OR obtain a cheap worn one and trade-in with the Volvo Exchange Engine program. The money spent on a decent engine is worth it in the long run. In Australia, chances are the Volvo exchange will be brand new. Although the low friction engines are not as tough as later (or earlier B21/B23 ET/FT) units, if it has been well looked after and doesn't tick within reason from worn components, eg piston slap, valve buckets, then still worthy of consideration.

Wiring Loom nicely labelled (photo Tim Curry)

Dashboard & wiring: - if using mechanical K-Jet injection or an aftermarket engine management computer system you won't have to change the dash, but will need to delete or reassign wiring elsewhere.

If you decide to use the original Volvo Turbo EFI 'LH computer' and separate 'EZK Ignition system that comes with the B230 ET/FT, and if your car is made before 1981, it is best to fit the newer style 1981-on 240 dash. Reason is the later 240 dash has the same/similar style electrical plug connector design as a 740. See additional detailed information below.

Ignition distributor: Changes are required. The B230 T comes standard with a rear mounted distributor, running off the end of the camshaft. With the 240 there is no room at the rear for the distributor ( unless you modify the firewall and remove the heater) as engine is positioned very close to the firewall, and so a left front mounted Bosch Hall effect ignition distributor is required. source - B230F to 1988 Bosch # 0 237 520 004 with no advance or retard mechanism ** Ask for the cable as well so you get the connector. Check to see if your engine has an intermediate shaft with a gear cut into it to drive the front mount distributor. If not, no big problem as you can source them readily from most 240 B21/23/230 engines.
When changing from rear mount distributor to front-left mount, you will need to seal the rear hole with a Volvo seal metal/rubber plug. For secondary security to ensure the seal never blows out, a light alloy cover plate should be fitted using two screw holes available. The plate is also available from IPD 'rear cam oil seal plate' #MJ2301. The front distributor O-ring seal to block is 35mm outside dia x 2.5mm thick.

The plug to cover the rear distributor on the B230 head is part 133673. No big deal on this part, just a welch plug with rubber coating and all late 240's with B230 motors use it. Remember to make a bracket to stop the seal popping out under adverse conditions.

A good exhaust shop can do this!

Exhaust: On RH Drive models the turbo side is far more crowded with components than LH Drive models. The 'right side' includes a brake booster, brake & clutch master cylinders and steering shaft.
Add to this turbo water & oil cooling lines, wastegate, exhaust pipe, air entry + aircleaner - its crowded. Exhaust Pipe: Great attention should be paid to the exit flange area, so the exhaust gases exit into a large diameter downpipe pipe straight away. On right hand drive conversions exit angle is a big issue. attaches straight to the flange, and comes directly out at the appropriate angle. Route ultra close to exh manifold near 4th cyl, spend time planning to get this right with your custom exhaust bloke, it can be done.

You will need a new exhaust system, 2.5" to 3", include this in your budget.

Exhaust Manifold: Check for cracks, clean up all flange surfaces, ensure flanges are filed flat before final fitting, do a trial fitment. Be sure to refit the manifold support brace under the manifold.
Head studs - Replace any damaged studs before fitment and buy eight new interference nuts from your Volvo dealer.
Specifically for RH Drive 240's - (to give more steering rod clearance) To give more room to fit the turbo exhaust pipe it should be possible to reduce the mounting flange thickness (on milling machine), so the turbo sits closer to the engine - thus giving more clearance room for the exhaust past the steering shaft. Allow at least 10 mm for steering clearance - One way to achieve this and to keep a big pipe diameter is to heat up the exhaust header in the chosen place & angle and press a pipe against the section, which should result in a nice neat curve and additional shaft clearance.

Steering Rod: - (RH drive) if your running out of room, source the thin rod type from an older 240.
Gearbox: If available the M46 with P type overdrive, otherwise the M46 with J type overdrive is good also.
Tailshaft - ensure universal joints, centre bearing, and balance of tailshaft are in top order. Fuel pump - the turbo model main pump has a higher flow rate.

OTHER: The 740 engine bay is both wider and deeper than a 240.
Intercooler and mounting brackets are the same for 240/740. (940 IC has a different shape). Some custom pipework and hoses required between turbo and intercooler.
In cabin boost pressure gauge. Air fuel ratio meter.

MAINTENANCE: Perform as much preventitive maintenance as possible on the engine & gearbox before fitting, eg new clutch/pressure plate, replace or clean out oil trap, new oxygen sensor perhaps, waterpump, engine mounts, seals, gaskets, oil cooler hoses, universal joints, eliminate oil leaks.
CONVERSIONS - A LIST of TASKS by Natham in Australia
Conversions cost a lot of money - more than you'll ever initially budget for...Think: Motor / ECU / Wiring of ECU / Big fuel injectors / EFI return line (if changing from Carby) / Radiator / Oil-cooler / Intercooler / Intercooler piping / Exhaust system / Engine mounts / ECU mapping / Gearbox / Gearbox conversion kit fabrication / Tailshaft mods / Speedo cable mods / Speedo re-calibration / Clutch / Flywheel / Clutch hydraulics / Auto to Manual Pedal box + firewall panel that it mounts on so you get the clutch master cyl hole etc / Sump mods (non Volvo engines) / Air cleaner Pod / Power steering hoses / Air con mods + regassing / Oils and filters / Engineer's report / Registration approval .....
Wiring Information EZK, LH

Rear seal cover & tips before installing

Click to enlarge - Dashboard removed


Date: Thu, 4 Sep 1997 19:21:58 -0400
From: "FAP"
740T Turbo swap to 240

I have done this swap, here is some of what you run into: The injection systems are different -1990 240 has LH 2.4, 1987 turbo has LH 2.2.

Distributor is in the wrong place. Have to install the intermediate shaft from the 200 into the 700 turbo block to drive the distributor. Need a distributor from an early 1984 760 and an EZK 115 ignition computer. Fuel pump has to be upgraded to the turbo type, have to install the ballast resistors for the injectors, fuel shut off switch (overboost) switch in the injection harness. Mass air flow sensors are different, the turbo has a 007 MAF the 240 has a 016 MAF. They won't interchange. I used the exhaust from the turbo car till the end of the converter. From there rearward it is your own engineered system.

These are just the high points. The detail work comes into play in rewiring and manufacturing the wiring harnesses. I used and modified one from a 1992 240 because the basic wiring was in the correct places and it utilized both ECU'S in the right side passenger kick panel area. I just changed the plugs and refit the wiring to the appropriate terminal. The distributor pickup wiring is a little tricky, just make sure you use some kind of shielded wire in the appropriate place.

You can't use the crank angle sensor ignition system unless you can use one from a turbo vehicle. (E-mail me directly for a more lengthy explanation.) Use the accessory (ps pump, alt), positions for the 240 on the 740T ie make the turbo motor look like a 240 with a turbo hanging on it. There is some interference with the oil cooler lines from the 700 in the area of the right side engine mount. The intercooler piping is very easy to mount an only requires very little modification. I have yet to engineer a good looking air filter box, I would like to modify the 700 unit somehow to work with the 200.

This description is pretty much basic, you have to make sure that all of the sensors, switches, idle motor, throttle body and TP switch are all installed from the turbo car. If you think a part looks the same on the 240, check it out for compatibility before you install it. This is not for the faint of heart or for anyone that is easily discouraged. Fred

B21FT into a B230F car - From: Tim Curry <>

You can use the turbo motor in the '86. Label all connections first, take pictures and then start pulling apart the donor car, first. I used 5 gal. buckets to put parts from one side or system in for storage. Use zip-locks to contain fasteners and tape the bag to the part.
The wiring harness should include computer plugs. DO NOT CUT ANY WIRES! The harness comes out intact.
Once the donor is stripped, go over the motor for soft parts (seals, tubing, hoses, belts) and do as much as possible with things already apart. It is easier to do with the motor out of the car. Assembly is reverse of removal.

P.S. My b230f to b230ft took 140 hrs total (researching the wire harness is lots of fun) and cost about $1500 including the donor car and a new exhaust system. Contact me off list if you have further specific questions.
I found a wrecked 1987 760 sedan with b230ft engine and decided to do a complete conversion with this car as the donor. It just seemed like the logical thing to do. Your path to greater performance may be different, but getting there is half the fun.

DONOR CAR - The 760 and 240 are very similar when it comes to engines and transmissions. They use the same blocks, fuel supply systems and many other items that make a swap relatively simple. My '87 245 had the AW 70 and the donor car had the AW 71, both use the same castings so fit and location of mounts are the same. I started with the donor car first: use labels on each wire connector (masking tape / magic marker), take lots of pictures before starting and have plenty of boxes or plastic 5 gallon buckets to store parts for the various systems as they are removed. Zip lok baggies are ideal for storing fasteners for each part. A magic marker helps label things. As you take things apart, take pictures. Its hard to remember where everything goes unless you have another similar car to look at as you go.

The wire harness needs special care. Label all connectors. Do not cut any wires. Spend the time necessary to completely remove everything from the fuel and ignition computers forward to the front bumpers. This will assure your having the right connectors when it is time for installation. Don't throw anything away until the new motor is running. Remove the grommets that go through the fire wall so the computer plugs can stay intact on the harness. You can cut new holes in the fire wall on the 240 for these.

Once the donor car is stripped, start on your car. By this time you will have a pretty good idea of what parts you need to keep and which parts will need to be replaced with new ones. Don't try to do this in one week. Its too much work. Take your time and do the donor car completely. Work on the motor and install any new parts before you tear into your daily driver.

Fuel Pump: The 700 pump is needed for adequate fuel flow to the turbo motor. It will install in the 240 like a new pump.
Distributor: The 700 distributor is located on the back of the cylinder head and is driven by the cam. It will not fit in the 240 due to clearance at the firewall. If you have the distributor from a Volvo Chrysler ignition system (1987 in a 240) it can be used in the turbo motor. Plug the back of the head (see mods page) after removing the 700 distributor.

The intermediate shaft on the 700 does not have a gear to drive the block mounted distributor, so the shaft from your 240 will have to be installed in the turbo motor. To remove the shaft, first move it forward a bit, the drive gear for the oil pump must be lifted slightly before the shaft will clear the pinion. I used nylon mason's line with a loop on the end to lift the gear enough to clear the shaft.

Once this shaft is removed, the bore for the distributor must be cleaned. Use a screw driver to hit one side of the plug in the distributor hole and then pull it out with pliers. You will see lots of varnish in this hole along the sides. I stuffed a rag, soaked with oil, into the front of the motor where the intermediate shaft was and held it in place under the distributor bore hole. A bronze carriage bolt works well to scrape the bore with an up and down motion, the rag will catch the crud that drops onto the hole. Bronze will not scratch the block. After getting the major stuff, a small stiff wire brush works well to remove the rest of the crud and polish the bore. Once this is done, the distributor will slide into place easily (use a new "O" ring that is lubed). Remember to mark the location of the rotor on the 240 with the timing marks at "TDC" when it is pulled and place it in the same position on the turbo motor when it is replaced.

The Distributor from the 240 will be hard to pull out if the motor has lots of miles on it. I used hardwood wedges and liberal amounts of penetrating oil (WD40) to lift it out gradually. It takes some time but will come out with tapping on the wedges and oil. The connector from the 700 Bosch distributor has the same end on it for both the 700 and 240.

Wiring polarity is the same in both systems, so once the distributor is in place the connector plug snaps into position and you are ready for ignition. Make sure you have a distributor with the Bosch connector and no ignition advance or the computer will get mad at the distributor.

Fuel and Ignition Computers: I found it easier to use both fuel and ignition computers with their wiring harnesses intact from the 700 than try to build a new harness. You will need to have the schematic for both the 240 and the 700 cars in order to trace these systems (see main page for link). I located the LH computer from the 700 in the normal location for the 240 and installed the EZK above it in the same area at the fire wall. This keeps all wiring in one place and provides access where there is the most room beneath the dash. The boost over-pressure switch also goes into this area.

Intercooler: I used mounts from the 700 to locate the intercooler. The top brackets need to be bent slightly and the bottom mounts need a 1/2" spacer beneath them to hold things in place securely.

Transmission Fluid Cooler: There is room for it between the A/C condenser and the intercooler. The sheet metal shroud must be trimmed to make enough room for the lines to clear the radiator and intercooler. I used an electrical box knockout tool (see mods page). The lines can then be bent to make good connections. Make sure they are properly aligned with no binding at the threads before tightening. Spend some time to get this right.
Engine Oil Cooler: It will fit in the same location as the 700. I made a simple bracket out of 1/8" x 1" x 6" aluminum strap for the top mount (see mods page).
Cruise Control: I kept the 240 system and it works well enough until boost kicks in. Once the vacuum returns it will settle down again. You could use the vacuum pump from the 700 if necessary, but I think it works well enough as is.
Labor: It took 140 hours to do the complete swap. This includes a lot of time in research, tracing wires, reading and working on both cars. I'm not a mechanic, so it took me a while.

Performance: Before, 0-60 mph was a dismal 14.5 seconds at 70 f and 2600' elevation. Top speed after mods was straining at 108 mph. Now 0-60 is 7.5 seconds (with factory boost) and top speed has yet to be reached. I can tell you that it climbs to 100 mph very fast and is still pulling strong. Don't have any 1/4 mile times and speeds yet.

SUPERCHARGING - Supercharger into B230E - thoughts & considerations:

Steve McGrane writes 'The Supercharger vs. TurboCharger debate is one of religion. You'll find zealots on both sides' :

Click B21 image to enlarge
Owmer Peter Brown, Australia

* supercharger has no lag.
* supercharger is always engaged (fuel economy suffers)
* where the supercharger loses power through the pulley, a turbo loses power by being a restriction in the exhaust system.
* turbo fitments usually require more expensive exhaust piping.
* superchargers require bracketing to be made-up.
* there are two basic types of supercharger power-delivery; most traditional types deliver power quite linearly with revs, but the newer "centrifugal" types (basically the back half of a turbo with a pulley on the front) pump air exponentially with revs; they're for power higher in the rev-range.

I looked into supercharging, and didn't see any cost savings. Sure you can buy a used supercharger, but you can buy a used turbo as well. You can buy used exhaust manifolds from a factory turbo car to fit a turbocharger, but with a supercharger I needed to pay someone to measure-up and make brackets and possibly fit an extra pulley.

I'm specically thinking about the bit about Toyota SC14 screw-type superchargers from 2.0 6cyl 1G-GZE engines, and how you can't overdrive them much or boost them past about 12psi at a maximum because the teflon delaminates from the screws if you do ... and whether the stock ECU will handle the extra airflow etc

In other words, examine all the costs before assuming superchargers are cheaper; a lot of people are finding they're not, in conversion situations like this.

Hope you found this webpage informative. Good luck with your conversion.

Back to Quick Technical Index OR Back to Volvo Turbo World