Uh oh, here's a first - AutoSpeed's first Volvo feature car!
Don't think that we'll soon be heading off to the funny farm though, 'cos this isn't the sort of Volv you spend half an hour trying to pass on the outside lane. That's the last thing you'll see Rick Nosnal doing in his 1987 740 turbo. His road habits are more in the direction of chasing down WRXs and chopping them off at the knees. And, no doubt, Rex owners would find that a tough one to swallow!
This big turbocharged luxury Swede was bought by Rick back in about '91 and the intent was just to enjoy the car for its refinement and practicality. But despite having 154hp worth of factory turbocharger-induced power, it didn't have the performance that Rick felt he needed. So the first step was to fit up a boost switch that allowed up to 12 psi to hit the engine. This was fitted together with a 3 inch exhaust system using dual straight-through mufflers to make sure the engine wasn't being strangled in the process. Nothing out of the ordinary here.
Yep, the Volvo could pull a fair bit harder now - but all that was sunny suddenly turned dark and gloomy - the cylinder head decided to spit the dummy. But rather than replace it with another stockie head, Rick went for a whole new engine package comprising another new BF230 bottom end and, most importantly, a 16 valve head and intake manifold from a later model atmo Volvo. The only mod to fit the high flowing head was to make some minor timing belt pulley mods. To ensure the bottom-end's durability, a set of Argo rods and Ross (8.3-8.4:1 CR) pistons are currently included as well. After the build, the engine was also equipped with a custom fabricated exhaust manifold and big turbo - which you'll read more about later.
The next step was to head from Rick's home of Canberra to visit Adelaide's Allan Engineering for a programmable ECU - an Autronic SMC. Here's what Adam Allan had to say about the hybrid Volvo engine:
"We had the car come to get its engine dyno'd, have an Autronic ECU wired in and then have it all fitted into the vehicle. But once on the road, as soon as the day temperature went up it was too close to the line of detonation. And the thing was as rattly as buggery with piston slap, too.
So we decided we'd pull the head off to decompress the engine via a thicker head gasket or different pistons. But when we checked the facings of the head, they were bent. We sent it off for an inspection and the report said that the head was soft and bent, and one exhaust port had cracked". Ouch.
Adam added that he knew the engine had had some abuse too, and had already gone through a couple of head gaskets by this stage. And the only thing he could do was to have the head fixed ready for re-use - they couldn't do anything about its inherent softness.
Rick also asked the guys to check out the bottom end while it was apart. Much to the Allan's surprise, what they found was 5mm of rod end-float, which they initially thought must be a mistake. After consultation with the aftermarket rod manufacturer though, the Allans were assured they were exact copies of the originals - so it was then off to a local wrecker to check out the story. And sure enough, after pulling off the sump of another engine, there was a measured 5mm of float. Bugger me.
Anyhow, Rick's engine was then fully reassembled with a copper head gasket - which actually let coolant into the engine about 2 kilometres down the road... So it was back to the standard gasket (which was 20 thou thicker than the copper one). Problem fixed.
The turbo fitted is "a dog of a thing" says Adam Allan. It's a high-flow T3/T4 with a T4 S-trim comp wheel, a RX-7 bored cover, a T31 turbine wheel and a T3 exhaust housing that may have been be machined out. It's mounted on a handmade tubular exhaust manifold, with short, approximately 1½ inch diameter runners.
"When we had it on the dyno we originally thought it was bored and stroked to 2.5 litres, and so we worked it harder than we otherwise would have. But in the end it made 280hp at 7-10 psi and 350hp at 14.7 psi. Torque-wise, it made 290ft/lb at 3-4000 rpm. The standard intercooler was good and gave around double ambient temperatures on the road. I think it could do 400hp with a different turbo, intake and exhaust manifold.
"Structurally, it's not the ideal engine. It's got thin walls, a fragile bottom end, poor combustion chambers and a fairly long stroke. We also found a 15% air distribution problem at opposite ends of the engine." The individual cylinder trimming function of the programmable ECU catered for the latter.
Rick agrees that with a new turbo, intake and exhaust manifold there's a lot more power to be dug up. In fact, his aim is to achieve around 450hp with these mods, plus a bigger air-to-air intercooler! But even as it is, it's "a very surprising car". Not only for other road users, but it's deceptively quick inside - you barely know about that pesky Rex snapping at the Volvo's heels...
Under normal driving conditions Rick says it's really beautiful car. He gets over 600 kilometres from a tank of PULP and it's just so easy and flexible to drive. Granted, it's a little slow off the mark, but it's got long touring legs.
And to say it's a stealthy-looking car is a true mutha of an understatement. Despite wearing soft compound Falken tyres and stylish Volvo alloy wheels it looks 100% stock-as-a-rock. The same goes inside too - the only exception being an Autometer boost gauge on top of the dash.
But pop the clutch and you'll quickly realise this ain't a take-it-to-the-bowls-on-Sunday loafer! Oh Helga, can you give me a massage please - I think I've strained my neck muscles in that damn car...
Contact:
Allan Engineering
+61 8 8527 2266
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