Volvo 740 engine to 940...

I was wondering if anyone knew, if a 16 valve 1990

740 engine, would fit into a 1995 940....without major problems...???

thank you for your help......sno

Reply to
sno
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The short answer is yes, it will fit. But it won't be just changing the engine, you'll also need to change some fuel injection components to suit the 16 valve engine, such as ECU. And if your car is auto, it is also strongly advised that you change the gearbox too. 16 valve engine got AW72 gearbox, it has slightly modified gear ratio compared to AW70 / 71 fitted to all other models to improve driveability as 16 valve has less torque at lower revs. _________________ Will '90 Volvo 744 GLT B230F converted to B230FB (531 Head & VX3 Cam)

Reply to
William Liao

On the other hand, I personally don't think the 16 Valve engine is worth converting to. For starters, the 16 Valve engine is an interference design, which means if the timing belt breaks, the cylinders will smash into the valves and bend them and you'll need to replace the valves... or replace the whole cylinder head (which usually turns out to be cheaper if you factor in the labour cost, unless you're doing it yourself). The 16 Valve's cylinder block is also different to the 8 Valve's, it's not as robust. It also has an external mounted oil pump, with very long (and weak) bolts. And when that breaks, your timing belt comes loose and you're looking at replacing the valves again. It is a more advanced design, with balance shafts and hydraulic self-adjusting tappets. But remember, the more complicated the design is, the more potential there is for something to go wrong. After all, this engine is 13 years old.

I presume the original engine for your 940 is 8 Valve, non-turbo. If it's more power you're interested in, you can either tune the current engine (if it's still running) or drop in a Turbo engine. A well tuned B230F engine with a different cylinder head, hotter cam, better ignition system (better plugs, leads, coils) plus modifications to the intake & exhaust to free up the restrictions (eg. sports exhaust, polished head, better air filter... etc) can deliver as much power as the 16 Valve, if not more. And you don't need to worry about changing the gearbox. Alternatively, a stock 740 / 940 Turbo engine offers you more power than a 16 Valve engine and shares the same reliable cylinder block / head design as the non-turbo models. If you're changing to a Turbo engine, you'll also need to change some of the fuel injection components, and if your gearbox is AW70 it's a good idea to upgrade to AW71, same gear ratios but a stronger, more durable version designed to handle the extra power.

Anyway that's just my personal opinion. Good luck with whatever you decide to go with. _________________ Will '90 Volvo 744 GLT B230F converted to B230FB (531 Head & VX3 Cam)

Reply to
William Liao

B230F SOHC motor with the same HP as a DOHC ? How exactly do you pick up that extra 52 HP ?

Reply to
A Very Old Kid

I agree with what you say....about the 16 valve....had a oil pump bolt break 20 K miles ago and had it rebuilt... Is the reason would like to keep it (the engine)....feel it is good for another 200 K.....at least....

Have ran across a 940 that has a great body....much better looking and shape then mine....but has blown engine.. since it is much easier for me to trade engines am thinking that is what I will do....if there are no major problems....which appears to be the case....

thank you for listen>

Reply to
sno

Why not the turbo 8 valve?

My dad had a 16 Valve 740 when I was growing up, and he said it was an annoying engine to have... More power then our 8V, but you had to rev high to really get it. He loved how much smoother the thing ran tho.

Reply to
Rob Guenther

For starters, you're only picking up an extra 35 HP, not 52 HP. B230F SOHC produces 115 HP, while B234F DOHC produces 150 HP.

With a B230F, the first place you'd start is probably the cylinder head and camshaft. From 1991 the B230F engine received an update, with a 531 cylinder head and VX3 camshaft. This updated engine was re-named B230FB and it produces 130 HP, but for some reason not released in North American market. Having said that, you can still build your own B230FB simply by mounting a 531 head and VX cam on an origianl B230F engine. 531 cylinder head has a better designed intake and exhaust ports for extra flow, slightly larger combustion chamber and more centrally located spark position, and VX cam has a lot more lift on the intake lobe than the M cam found in B230F engines.

After this conversion, you're looking at only 20 extra HP to close the gap between SOHC and DOHC engines, which isn't a lot. A ported & polished head with a free flow exhaust is probably the next thing I'll be looking at, and anything else to reduce the intake & exhaust restrictions, such as K&N high performance air filter. I'll also use the fuel injectors from the Turbo models which has a higher flow rate. Depends what you do here, you can easily gain 5 to 7 extra HP, if not more. Lastly, a ECU / Chip upgrade will give you at least 15 extra HP. Volvo (and few other car manufacturers I persume) has an ECU which de-tune the engine so it can handle more abuse and negligence on maintenance, which you can re-gain by ECU or chip upgrade. And if you fit a set of good high performance spark plugs, such as NGK iridiums, and a good set of ignition lead and coil, it might even give your SOHC engine an edge over a stock DOHC!

If you're serious, it's not hard to modify a B230F to give as much output as a B234F. Afterall, the old B20 block used in 144's can be modified to produce 160 HP, still naturally aspirated, and that's only 2.0 litres with overhead valve technology! _________________ Will '90 Volvo 744 GLT B230F converted to B230FB (531 Head & VX3 Cam)

Reply to
William Liao

In that case I can understand. Just remember, you're not only fitting the engine, you're also fitting all the associated electronic fuel injection components as well. You may also need to convert the engine cooling fan. '95 Volvo 940 has an electric fan, but your '90 Volvo 740 has an mechanical engine driven fan. Since the '90 model's ECU isn't programmed to run the electric fan, you may have to convert the electric fan setup in the '95 back to the mechanical engine driven setup, and add the auxilary electric fan in the front for the aircon... although I can't be certain. Either case, I would strongly recommend a good set of engine wiring diagrams for fuel injection and ignition system for both cars, preferably from Volvo, and study them carefully before you proceed with the conversion.

Oh, and check if the 940 has Bosch fuel injection system, or the Bendix / Regina. If it's the Bendix Regina system then you'll need to swap a whole lot of engine wiring harness, as the 16 Valve only had Bosch system. If the

940 also has Bosch system then you're in luck and most, if not all of the fuel injection components should be just plug and play.

Other than that, it's highly recommended to swap the transmission too as I mentioned in an earlier reply. I believe the rear diff. ratio for both cars are the same at 4.10:1 (presuming the 940 is non-turbo) so you should be fine with that.

Good luck with the conversion, hope it all work out as planned. _________________ Will '90 Volvo 744 GLT B230F converted to B230FB (531 Head & VX3 Cam)

Reply to
William Liao

Thanks again for the info....I had planned on really checking the wiring close....as had assumed would be some changes....

Have had experience with rewiring....and did a couple of 240's with no problem....making my own harnesses....

sno

William Liao wrote:

Reply to
sno

You can't just swap the injectors, the injection computer is hard coded with the amount of fuel that will flow for a given duty cycle to the injectors. Put the wrong ones in there and it'll just run rich, if it runs at all.

Reply to
James Sweet

You're right... my bad. Just checked the data on the N/A injectors and Turbo injectors for Volvo online, the flow rate is quite different and it's likely to flood the engine.

So maybe a more subtle way to increase fuel flow would be using a different fuel pressure regulator with a slightly higher pressure rating? Coz if you've modified your cylinder head, camshaft, exhaust and intake system to increase the airflow, you'll probably want to increase the amount of fuel going to the engine slightly to take advantage of the extra air and thus produce more power... As long as you still maintain the stoichiometry ratio of 14.7 : 1 _________________ Will '90 Volvo 744 GLT B230F converted to B230FB (531 Head & VX3 Cam)

Reply to
William Liao

How much do you figure this upgrade would cost ? Sounds as expensive as a turbo upgrade. Do you have a link for ecu / chip upgrades ? I thought the dohc put out 156hp, not 150. Do you have any dyno'd proof of the hp ratings of this upgrade ? I am looking for some low costs upgrades until I can finish my 347 stroker motor for my 240. By the way, the K&N filter, upgraded coil, plugs and wires might net you 1 hp if you're lucky...

Reply to
A Very Old Kid

Some research is in order, you need to calculate out the maximum flow rate of the stock injectors and see if they're capable of the HP you intend to produce. Without forced injection you need to focus on air flow, get the air flow up and more fuel will automatically be injected until you run out of headroom with the stock injectors. If you need more flow, you can install turbo injectors but you'll need to change the ECU, I would recommend something like this

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Max power isactually not produced right at stoich, it's a compromise on either sidebetween performance, economy and emissions. Lots of good info out there.

Reply to
James Sweet

Not only are the flow rates completely different, the turbo injectors are used with a voltage dropping resistor pack, and will quickly burn out if used at the full 12 volts that the non turbo injectors are used at.

You shouldn't have to increase fuel flow, that's all mapped out in the ECU. The air mass meter measures air mass, the ECU gets RPM info from the ignition computer, so it knows when and how long to open the injectors. The only problem would be if you get beyond what is mapped. Generally extra fuel is injected at high power settings on highly tuned engines to make sure that there is no chance that the mixture will go into a lean condition.

The other problem you'd need to deal with is the spark advance curve - the camshaft will have an effect on the optimum advance curve.

Reply to
Mike F

Volvo did produce a tune-up kit for B230F engine. The kit includes a 531 cylinder head, VX cam and 60mm exhaust (same size as Turbo / 16V I assume). In the Volvo accessories brochure, it claims that you can achieve 136hp (100kW). The brochure also includes power and torque graph before and after the tune-up kit. I haven't checked the cost or availability of this kit at a Volvo dealer, but I've head that it cost around USD$2000 and they stopped marketing them about a year ago.

So far what I've done to my 740 is almost the same as the kit, except I got my 531 cylinder head and VX3 cam (VX3 is VX retarded 3 degrees to improve low end and driveability) used at a wrecking yard and had it reconditioned before I installed it. All up including labour and the gaskets I've spent a bit over AU$1200 (USD$900). I haven't done my exhaust yet and I'm estimating my engine output to be 130hp (96kW), which is the output Volvo publishes for the B230FB engine, as my upgrade effectively converts my engine from a B230F to B230FB.

You're right about the K&N filter, coil, plugs, wires and distributor cap giving you a very small power gain, if at all. But if they are a bit old and haven't been changed for a while, you might actually have lost 1 or 2hp there, so changing them allows you to regain the power you've lost and freshen up your engine. That's what I was trying to suggest.

Different market have different emission equipments and thus different power output rating. Take the B230F engine for example, the American brochure says 114hp, the Japanese brochure says 115hp, the UK brochure (and my owner's manual) says 116hp. Also there's the difference of SAE vs. DIN, SAE (American standard) measures power at the flywheel and allows ancillaries (alternator, power steering pump etc.) to be disconnected, while DIN (German standard) measures power at the rear wheels and all engine ancillaries has to be connected. The B30E engine in my 164E for example is rated at 175hp SAE and 160hp DIN, exact same engine. For fairness, I got all my performance data out of a '91 Japanese catalogue, which has specs on B230F, B230FB, B234F and other engines such as B230FT and B280F. All the power rating in that catalogue is in DIN, except the 16 Valve B234F's power is given as 150hp (SAE), so really the true DIN rating of the B234F is LESS than 150hp.

Here's a link to a website that produces ECU / chip upgrades.

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I don't have any dyno'd proof as I've only done the cylinder head and cam. I can however scan you the torque and power graph from the accessories brochure, which includes the upgraded 60mm exhaust as well (only 3 pieces - the bend over the rear axle, rear muffler and tailpipe). But given that you can easily gain 20hp with the tune-up kit and reach 136hp, I think it won't be hard to gain another 14hp to reach 150hp if you do a more comprehensive upgrade of the exhaust (doing the header and cat section as well), port and polish your intake manifold, ECU upgrade or even a hotter cam. The VX cam which I've been referring to so far is NOT a performance cam, it is a mild cam designed to boost mainly the mid range and slight gain on top end without too much compromise at the low end, and still allow you to pass emissions. If you're more interested in high end performance and increasing your HP rating, try A cam or V cam. I decided to stick with VX because my car's automatic and I don't want to loose my low end too much otherwise driveability will be affected. _________________ Will '90 Volvo 744 GLT B230F converted to B230FB (531 Head & VX3 Cam)

Reply to
William Liao

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