Well, folks, the time has come for me to build a performance motor for our 1800S. Why? As produced, the P1800 came in some 400 pounds heavier than originally conceived, and that changed its character from "nimble sports car" to "pleasant grand touring car." I like my touring both pleasant and grand, but I'd really like a sports car, too -- a serious sports car.
Some 30 years ago, I had a friend whose father made a fortune as a doctor. One of the doctor's cars was a rare Lamborghini Islero -- a serious sports-touring coupe roughly the same size as a P1800. Once in a while when the doc was slumming in his Mercedes 190SL, my friend and I were allowed to take the Lambo out for its exercise. The thing had 12 cylinders, six carbs and four overhead cams (a tune-up cost as much as some new cars of the day), but what impressed me most was how unfussy it was to drive. The engine pulled hard from 2500 RPM right up to some screaming redline, and seemed just as happy at any point in between as at any other. You could cruise at 65 MPH in four of its five gears. And when you did drive it crisply, it was just excellent at turning scenery into a blur.
Since then, I've driven everything from tiny Fiats to 427 Corvettes, but nothing that felt like that Lamborghini. On the Fiat end of the spectrum, it's all revs and not much go -- you pretty much drive the things flat-out just to get around town. On the Corvette end, it's brute force and tire smoke in a car that's a handful to herd around under 70 MPH. The Lamborghini, on the other hand, commands your full attention while making few demands (if you don't count the maintenance, of course). Some upscale modern cars approach that combination of performance and ease by computerizing everything, but they got boring in the process -- I like my cars openly mechanical, not automated by electronics. Anyway, that's what I'd like: a P1800 that drives like an Italian exotic.
Fantasies may be free, but engines aren't, and I'm not a doctor, much less a wealthy one. And (as if a further reality check were needed) we're dealing with a motor that has four cylinders, one non-overhead cam and two rudimentary carburetors. There's no possible makeover that will turn Granny Clampett into Sophia Loren. The object of building the new motor, therefore, is not to turn the fantasy into reality, but to see how close we can get to it on a budget. Nothing good can result from not knowing what one wants, or from setting goals too low. The memory of that Lamborghini makes a pretty good goal to shoot for.
There's a further minor problem: when it comes to building high-performance Volvo motors, I don't know what the heck I'm doing. The last time I tried it, all I knew was to order a bunch of parts from a catalog, bolt the thing together and hope. I sort of got away with it (see How Not to Build a Motor in our Tech Archive), but I want this one to be much better. Unlike the last time, I now know a variety of people who have great experience making old Volvos go fast. When they talk performance, I pay attention. With what I've learned, I believe I could build a pretty good street motor on my own now, but I want something excellent. I'd be stupid not to cash in on some of the expertise that's now available to me (and that I'll pass on to you in this series).
The trouble with this is that everyone has their own methods, their own theories, and their own ideas about what's possible. One school has a horror of over-camming a street motor, and with good reason: I wouldn't want a motor that's unhappy under 4000 RPM, no matter how much power it made above that. Some say bigger valves are beneficial; others are sure they hurt performance. Same with whether or not to overbore. Same with what the compression ratio should be. Same with [fill in the question of your choice here].
One fact that's not open to debate is that a successful motor -- whatever characteristics it has -- runs satisfyingly because all its parts work in harmony. The balance is quite delicate; a small incorrect modification can turn a smooth machine into a cranky mess, and I already know how to build cranky messes. I might resolve this by duplicating one or another of the satisfying motors I know of, but that's not much fun. I particularly don't know one that's gone in the Lamborghini direction anyway. The only thing that's obvious is that I'll have to choose between experts -- mixing and matching advice won't do the job.
And the winner is (drum roll... may I have the envelope please...) David A. Hueppchen at OJ Rallye Automotive. There are several reasons: 1) David's a friend, and I always ask him for advice anyway (and haven't yet gone wrong following it), 2) he's done very well racing his black 1800E with a lightly-modified motor that would fit my budget, and 3) OJ Rallye is the sole U.S. source for UNITEK&ST high-performance parts from Sweden and has experience building motors based around them. Now let me interrupt the proceedings for a moment and expound on the third reason.
A few years back, I used to participate in Volvo discussion groups on the Internet. These are forums in which Volvo owners do their best to help each other resolve problems and generally support each other however they can. On one hand, there's good information to be found there. On the other hand, there's a lot of well-intended, but wrong, advice. The trick is in straining the nuggets of wisdom from the gravel of ignorance. Whenever the discussion came to increasing performance, one person (typing in slightly fractured but always clear English) got it right every time, to my way of thinking: someone who signed his messages "M. Aaro." After a few weeks of wondering "who is that masked man, anyway?" I e-mailed him directly and found out.
Mike Aaro and the UNITEK&ST company have specialized in Volvo performance for over 25 years. They are located in northern Sweden and were practically unknown in this hemisphere. A score of mails later, I put him in touch with David, who was having a tough time making parts from a different supplier work in a "real" racing motor he was building. They took it from there and a business relationship developed as well as a new friendship. I'm not involved in any way, but I've kept in touch with Mike and have remained impressed by both his knowledge and the reasoning behind it. For my project, I naturally wanted to give Mike's designs a try, and so the "who" hurdle was crossed.
The next hurdle is "what." From a large assortment of UNITEK&ST cams, headers and other components, which exact combination would give me the characteristics I wanted in the new motor, and how could they be made to fit into the overall budget? At David's request, I took this up directly with Mike. It took some work to hit a balance between "this is simple but won't give me the performance I'm after" and "this is way too expensive and simply out of the question." The list of what can't be done on my budget includes electronic engine management, stroking the motor, adding a billet crank, and using custom pistons and rods (there are many other possibilities for the better-financed). The final plan is for what Mike named the "Multi-Purpose Performance Engine" (MPPE) because that's exactly what it needs to be: a motor I can commute to work with every day with reasonable economy and undiminished reliability, race on the rare occasions I have the chance to, and have a blast driving the rest of the time.
For those purposes, the bottom end mainly needs to be strong, and economy dictates using OE Volvo parts. The main modifications will be fitting late B21 rods for strength (so-called "M rods" from a Volvo SOHC motor from '79 '84) and .040"-over B21 flat-top pistons resulting in 2175cc displacement for increased mid-range torque. We'll use steel B30 timing gears and turn down both the original flywheel and timing gear to lessen inertia. A set of Weber DCOE carbs will handle the fuel metering and breakerless ignition will permit accurate timing and a trick ignition curve. A major factor will be a high level of blueprinting -- without that, this is just another average rebuild with some good parts going to waste. So far, though, we've just mentioned standard enhancements that any experienced builder would understand.
Mike's choice of cam surprised me: 296 degrees duration and 12mm gross lift initially struck me as way too much for a street machine (the IPD Street Performance cam, thought by many to be a bit peaky for daily driving, is 268 degrees and 11.4mm gross lift). In order to get a Lamborghini-like wide powerband from a big cam like that, a lot of other areas will have to be engineered perfectly. We'll discuss resonance tuning, gas velocity and other specifics in future articles, but here's the overall concept: the engine begins at the air cleaner(s) and ends at the tip of the tailpipe(s). Everything in between affects how the engine breathes, and all of it is tunable -- get it all working together, and a great deal can be achieved. When I say tunable, I mean built tuned to produce the characteristics desired. At this point, I understand some of it but I can't yet do the math. Well, that's why I'm talking to Mike and David instead of just throwing parts together, isn't it?
I tend to be leery of horsepower figures, because they tell you a lot more about the top speed of a car than about usable power in real driving. All else being equal, the car with the highest HP will be the fastest, but not necessarily the quickest over a stretch of road. At some point, though, I casually asked Mike to guess. Well, I don't want to promise too much in public at this early stage, but I mentioned the figure to a few racing friends. "No," they said. "You're not going to get more power out of a streetable motor than we can get out of our full-on race motors. Can't be done. What do you know that everyone else doesn't? A B20 head can't be made to flow enough to get that -- the ports can only get so big..." and so on. I asked Mike again, and he quoted the same figure, and not as a guess. He says we might even get a bit more, and there's plenty enough material in the head to permit ports of sufficient size. I should please run the MPPE on a dyno at the end and see for myself.
And that's where we'll leave it for now. Only time will tell if my choices so far have been wise. I may end up with a sort of Swedish Lamborghini or another expensive lesson learned the hard way.
I know which way I'm betting my money.
