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

 

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)

 

Thank you very much for the info......sno

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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)

 

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

 

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 listening to my thoughts....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.

..... Drop the bi-turbo Inline 6 engine in...... that would be sweet 268hp
stock ;-). (I think this would involve a LOT of work tho..)

 

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)

 

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)

 

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

 

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.

 

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)

 

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...

 

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 http://www.bgsoflex.com/megasquirt.html. Max power is
actually not produced right at stoich, it's a compromise on either side
between performance, economy and emissions. Lots of good info out there.

 

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.

--
Mike F.
Thornhill (near Toronto), Ont.

NOTE: new address!!
Replace tt with t (twice!) and remove parentheses to email me directly.
(But I check the newsgroup more often than this email address.)

 

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.
http://www.powerchipgroup.com/

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)