By popular demand: MV Agusta's 'two-stroke beater' boxer motor, rediscovered

OK, maybe it wasn't popular demand, but I got a message, posted as a comment on bikewriter.com a few weeks ago, asking for more information on MV Agusta's ill-fated mid-'70s efforts to build a four-stroke boxer motor for the 500GP class. The request came from someone who got a search-engine hit on one of my roadracerx.com Backmarker columns, but when he tried to follow the link he found that the whole site's not just no longer being updated, it's been pulled down. Even though it was only posted less than a year ago, all those old bits have been reassigned elsewhere on the Internet, I guess.

So, here it is again, from March of 2010...

Rob Iannucci, a successful real estate developer in New York, is the owner of Team Obsolete. His collection includes several historically significant MV Agustas, including the last 350 and 500cc motorcycles to win Grands Prix.

Honda was the first Japanese manufacturer to show real promise in Grands Prix, but in many ways Honda had more in common with European makes than it did with its Japanese compatriots. Count Boselli, who owned the Italian firm Mondial, gave Soichiro Honda one of his 125 GP racers after the 1957 season, when the major Italian manufacturers all agreed to withdraw from World Championship competition because it was too expensive. That Mondial inspired Honda's early GP efforts. It had a four-stroke motor, of course.

But by the mid-'60s (thanks in part to Suzuki's subterfuge, in stealing East Germany's secret expansion-chamber technology) the other Japanese makes were fielding two-strokes that – when they weren't seizing and throwing their riders down the road – were lighter and more powerful than any four stroke.

The two-strokes started small, winning in the 125cc and 50cc classes before they pushed the four-strokes out of the 250, 350, and finally out of the 500cc classes. Soichiro Honda was determined not to succumb to the two-stroke onslaught. Honda's response was to build four-stroke motors with more and more cylinders, that would rev to higher and higher redlines; a 50cc twin, 125cc five, and a 250cc six.

MV Agusta was the one Italian company that reneged and maintained a factory effort at the World Championship level. It will forever be linked with Giacomo Agostini; Ago gave MV the lion's share of its wins, and most of Ago's victories came on MV Agusta race bikes which – most years – were head-and-shoulders above his rivals' machines.

But in 1974 and '75, Ago eschewed MV four-strokes and raced Yamaha two-strokes in the 350 and 500 classes. In 1976 he raced a Suzuki 500 for most of the season, though he rode an MV 350-four to the last four-stroke victory in that class at Assen, and an MV 500 to the last four stroke victory of the pre-MotoGP period at the Nurburgring.

Side view of the rough castings, bolted into the dyno-mule chassis. I did a double-take when I noticed this bike, a motorcycle that I had no idea had ever existed. Team Obsolete found it in pieces when it acquired much of the MV Agusta race shop inventory back in the 1980s.

The story goes that each spring in those last years – in 1974, '75, and '76 – MV invited Ago to the race shop where they showed him “the four-stroke that could beat the two-strokes” and that each year he looked at their latest creation, but chose to race a stinkwheel. That smelled of myth, to me, until a few months ago when I was in Team Obsolete's shop in Brooklyn, interviewing Dave Roper.

I got Roper to come over to a spot in the basement workshop where a window provided a little pool of light, so I could shoot his portrait. Then I took a second look at the bike he was standing beside, and wondered why I'd never seen anything quite like it.

It was far from complete. The frame was a steel-tube spaceframe, from which hung an empty set of engine cases – still rough castings. Not only had I never seen the motor, I'd never seen a motor that even had this fundamental architecture. It was a water-cooled 180-degree opposed boxer four, laid out horizontally (as you'd expect) but aligned fore-and-aft, facilitating a chain drive. The gearbox was beneath it.

Naturally, I asked Dave about it. He told me that at some point in the 1980's, long after MV had withdrawn from racing, some bean-counter in the helicopter business had looked into a room full of motorcycle parts and wondered what they were doing storing such useless stuff. To make a long story short, Team Obsolete ended up acquiring much of the MV race shop's new-old stock, and amongst thousands of uncataloged parts for more familiar MV race bikes – air-cooled in-line triples and fours – they found the rough castings for two such boxer fours, and the chassis that I was looking at.

“I think that this frame was built just so they could run the motor on a chassis dyno,” Roper told me, “because it really doesn't seem raceworthy.”

Team Obsolete does the vast majority of its restoration work in-house, relying on a handful of craftsmen. They work as much for love (and so they can be around Rob's amazing bikes) as they do for money. Frank's one of that inner circle. Assembling this motor was part egg hunt, digging through mounds of uncataloged pieces to find the ones that would fit, and part three-dimensional jigsaw puzzle.

Roper walked me through to another basement room, where Ferruccio Giannini was toying with the second boxer motor. That one had been found with finished castings, and they could tell that it had been run before it had been disassembled and put away. That made them wonder if there were enough parts – in the literally tons of stuff TO had brought from Italy – to assemble a working motor.

Ferruccio (most people call him either 'Frank' or 'Ooch') told me about putting it together.

Rob said to me, “Build it.” I spent about three weeks searching out parts, and then I said, Maybe.

I worked on it and worked on it. And he said, “When's it going to be done?” and I told him, I think maybe by Thanksgiving.

What they had done is, they started trying different firing orders. The last run they did, they tried it 'full boxer' and the crankshaft cracked. They took it apart and cut the crankshaft in half. They took all the pieces out and they weren't that careful, they put a little here, a little there; they weren't planning on putting it back together. So it was like an egg hunt. It took me months to decide what piece belonged where.

According to Rob, the engineer who developed this also designed Ferrari motors; he was also a car engineer, and there are a lot of aspects of this that are more like a car motor. But the detail on it is extraordinary; every little thing is beautiful. There are ten gears that run this; one of them is also set up to run an injection pump. They were going to have fuel injection, which was far out. This was the first time they put on a real CI-style magneto, with a trigger and a power generator, it was in effect an early CI. There is a pilot gear here which runs this gear, then there's another gear, which runs another gear, and then another gear and then two more gears. So it's ten gears to run the two gears [running the overhead cams—MG].

A lot of the parts are marked '76'. Agusta had this policy; who ever made a part almost had to sign it and put a year on it, and a date. I don't know if it ran after '76, but I assume that's when it come to a grinding halt. It's got some strange anomalies to it; the transmission is gorgeous. Every single gear that rotates on a shaft has needle bearings, and they're loose needles – it's crazy hard to put together. You're wondering, how many do I put?..

Everything from this—if you would go to, say, a late MV four—the part looks similar but it's heavier. If you would look at a shifter, if it's a shifting drum, a connecting rods... We have only a few connecting rods left, and they're not even machined, but they're heavier. It's a pentium head—an amazingly beautiful pentium head—there's very little rise on the piston, with pockets for the valves. It's buckets over the valves, with tiny little lash caps inside. And at that time most four strokes were still air-cooled. If you look at this water pump, you can see it's some kind of automobile part.

The crank's a built-up crank. And I have all the configurations in unfinished cranks, whether it runs like this, or one here and there and there [illustrating different firing orders—MG] they tried a few different ones because you can see from the way the cranks are cut. The one that failed was the one that was going like this [illustrates classic 4-cyl boxer arrangement, ie two 360-degree parallel twins running in opposition—MG] and I think it just way overstressed the crank that way. This one runs one, four, three, two.

It actually has a CI on it. This is magnetic. I know they tried different firing orders because I can see where they had the magnets. They tried fully opposed, as if it was two Nortons; this configuration was obviously designed to fire, boom-boom-boom-boom. Look at the detail on that clutch [actuator]. That's all machined, there's no welding there.

There are no gaskets in the motor. That's very early for a four-stroke to be built that way. The heads go on, they have little cones; round buttons with oil seals to make sure that the oil seals didn't collapse. The reason I know it was that way is, if you put it together with no gaskets, the gears fit. If you start adding gaskets, the gears are wobbly. What happened was, we had all the gears, and there's a big one in here [indicates final gear on OHC]. And we had a gear for this side, but not this side. We had an extra one for this side, but it didn't quite fit on the other side. It would go 'rrr, rrr...'

I thought, we're #ucked, but I asked Yukio to order me a set of diamond files, and I started blueing and filing the gear, and little by little I found, OK, that area's starting to sound quiet. There's no way you could move the head away, or move the barrel up. It was the right number of teeth and right design but it didn't quite fit.

I'll show you the injection... you won't believe this. There's your injector, the timing pump. I found the nozzles; they were really playing with a mechanical fuel injection. They must have run it, because I could see that some of the injectors had had fuel running through them.

Even the cams turn on needle bearings. They were continually promising Ago that, We had the two-stroke beater. We got the machine that's going to kill the two-strokes... And he would come and watch them run it on the dyno. And you know the story, eventually the factory stopped racing.

I came in the Tuesday before Thanksgiving, and I closed up the cases.

Rob said, “When's it going to be done?” and I said, Add gas.

But before we do that we're going to set up a system where we can spin it. I know the oil pump works, I know that... We didn't even have the couplings for the bases of the crank. There was no way to get oil from the body of the engine to the crank, they'd thrown them away. So I looked at how it was and I finally made little holders for oil rings, to feed the crank blocks. I've pushed oil through lines, and I do know that the oil's going where it has to go.

I think it's a good idea to spin it and see where the oil goes; we can take some covers off, see how it looks; are we getting oil? If it's not growling... Because once it's running you can't hear $#!+. I'd like to hear if it's starting to click or squeak, because it's the only one.

Although this version is fitted with four carbs, MV also tested a mechanical fuel-injection system.

What a fascinating footnote to the history of the 500 class!

I guess Agostini didn't believe that this motor would beat the two-strokes. But even if he had, MV might not have continued to develop it. By 1976, Count Domenico Agusta had been dead a few years, and the company was looking for an excuse to get out of the game, anyway.

Maybe, with a strong 1000cc motor in hand, the company will return to Grand Prix racing when, come 2012, production-based motors will return to the premier class... After all, even if the new F4 was above all the Japanese bikes at Masterbike, MV Agusta has some unfinished business in the World Championship.

Team Obsolete's motor is proof of that.