Thoughts on engines of some of the cars I've owned
Engines are such a large part of a cars personality I thought it might be fun to discuss impressions the engines of cars that weíve owned. The following is a list of engines and impressions on some of my past cars.
Honda b17a1 Ė 1.7L naturally aspirated inline 4 - Integra GSR Ė Highest naturally aspirated specific output per liter in itís time. This engine, more than any other, is just fun to thrash and there is absolute certainty that the engine loves it. The torque level was very low in general, even when winding the car out, the torque is never very impressive. Itís the high speed power that motivates the car. But especially at low engine speeds there was minimal grunt. Itís not hard to get the car moving from 1200 RPM, but itís not going to jump off the line that way. I could get some torque steer from a standing start when launching from 4000RPM or above. As is well known with the vtec engines, this carís forte is revving. The engine lives between 5500 and the 8000 RPM redline. Up there, the urgency and noise is fantastic. There is not a lot of rotating inertia, so it is easy to get up to the high rev levels as well. The switch over to the high lift cam was noticeable, but not disturbing. The urgency, torque, and noise all increase in that one step. 200,000 miles of thrashing and the engine just kept running and returning consistent 30+MPG. Great, willing personality. This engine was a genuine engineering marvel.
Mazda 12a Ė 1.1L Naturally Aspirated Rotary - FB Rx-7 Ė I had two of these. These cars had a 4 barrel carburetor with secondaries that opened at higher speed. Rotaries, similar to the small Honda vtecs have little low end torque but are happy to rev to very high levels. This engine was less free revving than the b17, but more than most contemporary engines. 7000 RPM in the late 70s was pretty rare. Similar to an engine with a second intake track or cam profile, there was a noticeable increase in engine breathing when the secondary carburetor throats opened up. The noise of a rotary is very unique, loud humming and brapping is the best way to describe it. The low levels of power meant that the engine spends a lot of time at the upper end of the rev range, which is fine, the power delivery was very consistent and very linear. There are only three moving parts and they are all rotating, so the engine is very smooth. The sense of engine speed comes more from sound than vibration. Bury the gas pedal and enjoy as the revs and power rise to redline. These lower powered engines really allow the driver to experience the power plantís character. It helps the driver to become more connected to the car.
Mazda 13b Ė 1.3L Naturally Aspirated Rotary - street ported in the FB Rx-7 Ė this engine is not stock, making about double the power of the 12a. The increase in torque over the 12a from idle all the way up is profound. While the 12a is faster to rev, this one still loves to rise through itís rotating speed, all the way up to 8000 RPM. At 5500 RPM, when the short runners in the intake track are activated, the ride to redline is loud and powerful in this car.
Mitsubishi 4G63 Ė 2.0L turbo inline 4 - Eclipse GSX Ė I actually had two of these also. This engine is one of those highly regarded mills that lives seemingly forever in a companyís product line. Itís an iron block/aluminum head turbo that has powered cars from the 80s up to the 2010s. A run ending with the Lancer Evo 9. In the second gen Eclipse, it was mated to a small T-25 Garrett turbo. It spools up very quickly, so much so that this engine has good torque from as low as 2000 RPM. On the other side, it runs out of steam at about 5500 RPM, 1000RPM short of the carís redline. So around town, itís a real sweetheart, low end grunt, lots of thrust in reaction to large throttle input, really not much turbo lag. This engine used dual counter rotating balance shafts to reduce vibration. It was a relatively smooth engine, but not really noticeably moreso than other inline 4s that Iíve experienced. However, with all of the rotating mass and the turbo, the engine was someone slow to respond to throttle position and revs compared to others. Unfortunately, these engines had design issues, leaking oil seals, thrust bearing failure, and head warpage plagued the engine through its use during the Eclipse era, of which I experienced the first and last issues. I generally liked this engine, but with the lack of top end urgency, it didnít feel particularly eager to be used as a sports car powerplant, more fitting to a relaxed GT.
Porsche M96 Ė 3.2L horizontally opposed 6 cylinder Ė Porsche Boxster Ė This engine is an absolute sweatheart. Decent torque off idle, loves to smoothly rev all the way up to itís 7200 RPM redline and makes more and more power all the way up. Very effective valve and ignition timing system. It had entertaining thrust above 3500 RPM and the sound that it made while doing it all is pure symphony. The intake and exhaust both make convincing noises. If I had a complaint, I suppose that even though there is decent low end torque, itís not exceptional. The engine is happier at reve above 4500RPM. Really, only at the track did I feel that the car could have used more power but on the street, 250hp was plenty to get the car moving spiritedly. Porsche knows how to make engines with endearing personality. Despite its reliability concern with the IMS, this engine is a gem.
Toyota 2ZZ Ė 1.8L Inline 4 Ė Lotus Elise Ė A 2000 pound car can make pretty much any engine feel powerful, so itís hard to say what this engine would be like in anything with normal car weight (Iíve never driven the other Toyotas in which this engine was used). But in the Elise, this engine has no problem getting the car going. 0-60 is in the mid 4ís in the Elise. I bought my car with the stock Lotus tune and later installed a modified tune that added midrange torque, lowered the cam change over point and gained about 10hp to an even 200hp. In stock tune, the engine never feels weak, it will pull but not especially impressively under 4000RPM. Over 4k, the car really moves forward and at 6200 RPM, when the engine switches to the more aggressive cam, it absolutely explodes with acceleration. So much so that the sudden change in torque can upset the chassis. With the tune, the change over point is much harder to discern. The midrange toque improves with the tune, bringing the car from peppy to extremely peppy in the 3000-4000 range. Throttle response is excellent at any engine speed. Itís very lively and happy to respond to your inputs. On the higher lift cam, these behaviors are just magnified. Up there, the engine response is so fast that it seems to rev up before you even put your foot into it. The exhaust, stock, is loud and somewhat thrashy. Not annoying by any means, but you are always aware that this is a 4 cylinder car and you are driving a minimalist sports car. Compared to the b17a1, itís more powerful and more torquey but has a very similar character. The engineís total rev range is very accessible, which makes it a fun engine to ring out when driving agressively. Itís easy and enjoyable to use full throttle. On the down side, this is not a smooth engine. It makes lots of vibration and much of that makes its way into the chassis. Having said that, itís a really nice fit to the carís personality.
Jaguar/Aston Martin AJ-V8 Ė 4.3L V8 Ė Aston Martin V8Vantage Ė Oh, that glorious sound. As great as the sound is in the Porsche H6, it pales in comparison to the incredible growl/howl/scream that comes out of the exhaust pipes of a V8Vantage. This engine was criticized as not being powerful enough when it was released in the Vantage in 2006, but mine (with the 400HP power package) is fantastic as far as Iím concerned. Being a smaller v8, it doesnít have the low end punch of the later 4.7, the V12 cars, or something like a Corvette, but itís not a slouch either. I think the problem is that certain engine characteristics are expected from a front engine car that is to at least partially perform as a high end GT. What is does though, is a pretty good impression of a smaller, lighter engine in that it loves to rev and makes almost scary power up there. The power and torque generation is linear with RPM. Higher engine speed gets you increasingly more thrust. At 5000 RPM, full throttle is rarely possible on public roads because itís pushing the car so strongly. I find that I very rarely get up to the 7200RPM redline because the car is moving so violently forward. I long for empty onramps. It could use a lighter flywheel, and the transmissionís heft donít help it to be more entertaining to rev hard, but still, itís a fantastic power plant. Itís all done in such a slick, refined way that just oozes class. Luckily, that amazing noise is there at any engine speed.
Nissan VQ37VHR Ė 3.7L V6 Ė Infiniti G37 Ė I really like this engine in a big sporty sedan, itís more of a brute than a screamer. It feels torquey through a wide rev range. Itís not particularly rev happy, but will wind the tach. It does seem to prefer to just provide toque at whatever engine speed itís currently at. It has a nice, rich torque curve that allows it to drive the car forward from anywhere in the rev range. The engine moves the car with plenty of authority. It makes this a fast car. It makes nice noises too at all throttle positions. Again, very much in line with the brutish personality. There is some roughness to the way it runs, and itís mostly evident at larger throttle openings and higher speed, but in the Infiniti, itís quelled better than in the Z.
Subaru EJ20T Ė 2.0L turbo H4 Ė Impreza WRX Ė The quirkiness that pervades any Subaru vehicle starts with the engine. Subaruís well known engine noise generated by the unequal length manifold/headers points to the kind of engine this is. Itís deeply raspy and rough from a stock exhaust system. The 2.0 drivetrain tends to rubber band and can be hard to launch smoothly. Then once underway, at low throttle positions, it can still be a jerky. Itís not a powertrain that will impress the passenger in itís smoothness. The TD04 turbo in this car doesnít really provide any boost until about 3500RPM. Below that, thereís basically not much to speak of. You can get the car moving without any problem, but itís not impressive. Once the turbo is on boil however, the car has great torque and the acceleration is fun. The throttle response at low rpm is very laggy and turbo-ish. On boost, itís a much more responsive device. Ultimately, this turbo engine is more of an on/off switch than the GSXís smaller turbo engine. Itís fun, and powerful, but still a high pressure, low displacement turbo engine that tends to have a less enjoyable, playful character than the normally aspirated engines. Aside from seemingly constant head gasket leaks, the engine is relatively robust. Iíve got over 120,000 miles on it and it still runs strong.
3vz-fe Ė 3.0L naturally aspirated V6 Ė swapped MR2 Ė This engine had a few popular modifications such as fuel leaning and timing that brought output up to about 200hp at the crank, it was 185 stock. This is another great V6 that Iíve had the pleasure of owning. The tune was stock from a Camry but with a custom exhaust to work in the MR2. This car sounded awesome. Very low, mean growl. It was as much fun to open the windows, hit the gas, and listen to the revs rise as the Aston Martin. Toyota clearly designed this car to provide a flat torque curve because everywhere from 1500RPM to 7000RPM the engine could push the car forward with authority. The car never felt as fast as the Boxster and the engine revs were always a bit more lazy than the Porsche, but still, the consistent torque and that great sound made for a thoroughly entertaining experience. It most closely compares with the Nissan VQ engine in power and torque characteristic but the 2/3 level of power is evident. Still it made itís power much more smoothly than the VQ.