4cyl Engine Persionality

Focusing on 4 cylinders, what gives an engine its personality? What allows it to rev smoothly to redline? What make it quiet while doing so?

Is a smooth revving motor a product of a short stroke (or balance shafts for a large 4cyl)? Or a long duration cam? Or good flowing intake and exhaust ports?

Is a quiet motor a result of good NVH reduction such as using a timing belt vs. chain? Or cam followers vs. cam-on-bucket? Or aluminum vs. iron block?

From past experience for comparison:

-1.6L B6 Miata: smooth and free revving, not very quiet, but not harsh either. Belt driven, cam-on-bucket, iron block, short stroke.

-2.2L F22A Accord: very smooth to redline, very quiet. Cam followers, timing belt. Long stroke, no balance shafts.

-2.4L KA24E Nissan (pickup): quiet but harsh at high revs. Cam followers, timing chain, long stroke.

-2.2L M111 Mercedes: rough and very noisy at higher revs. Cam-on-bucket, chain drive, shortish stroke.

What I've heard/read from others:

-Nissan SR20: very smooth revving, don't know about noise. Timing chain.

-Mitsubishi 4G63: smooth revving also, don't know about noise levels

-Toyota 2AZ: some say somewhat noisy and harsh. Timing chain, balance shaft, cam-on-bucket.

So what makes a motor have a good personalty and easy to live with? What four cylinders do you like best for a daily driver?

I will just add this, as an engineer I cringe at the words "free revving". The only way to tell if an engine is "free revving" is to rev it to redline in neutral. This isn't particularly useful, obviously. Car weight, gearing, balancer weight, tire diameter all have a part in this characteristic as installed on the car, but one shouldn't confuse the car with the engine.

In my opinion there are too many variables to say that ONE thing is responsible.

I loved the way my 2.2L Ecotec made power, the only negative was the flywheel that had the mass of a small planet. I drove an Ecotec Cavalier with a Fidanza flywheel and that car "revved" easily through the gears but you could almost feel every combustion pulse as it ran. The flywheel made the engine feel smoother but smothered the performance.

The four cylinder engine I most like for a daily driver so far is the V4 on my VFR VTEC. Very low vibration, good power all around the dial, and it sounds great.

I hate 4 cylinders. No torque, rough running, must be rev'd like hell to do anything. Sadly, these tiny motors are a nesessary evil with todays high gas prices.

I think revving them is half the fun of getting the performance out of them. At least that was the case on my mk1 MR2; it still puts a smile on my face when I think about the supercharger kicking in...that was 9 years ago.

Yes, too many variables to say as a "rule".

Having said that, the old rule of thumb used to be that as you approached 2 liters of disp. it got harder to make a smooth engine.

A good car manufacturer can get around most limitations, nowadays, so my opinion is rulled by how smoothly it revs (REALLY squishy engine mounts are/were often used by the "big 3" to fake this sensation in cars like the Vega, Pinto, Cavalier), and how smoothly it "steps off" once the clutch is engaged.

BTW, I once owned a J2000 (Sunbird?) with the 2 liter OHV engine and a manual trans. The engine revved okay, but the SOUND.......YUCK. It sounded like a small wheat thresher. The clutch also, if I remember correctly, had a somewhat disconnected feel to it. One car I didn't regret getting rid of.

tuna55 wrote: I will just add this, as an engineer I cringe at the words "free revving". The only way to tell if an engine is "free revving" is to rev it to redline in neutral.

That's what I always thought free revving meant...a "free revving" engine can make shifting a little quicker, and of course is more fun at stop lights

Gearheadotaku wrote: I hate 4 cylinders. No torque, rough running, must be rev'd like hell to do anything. Sadly, these tiny motors are a nessassary evil with toadys high gas prices.

I actually prefer 4's. I love to rev the snot out of them and I find them a great compromise between fun and frugality. Using the gear box to get the most from a small engine is all part of the fun of owning a sports car

My 2.5L 4 Cyl has two balance shafts in it. It helps, but only a little.

the dead motor mounts are probably why the vibrations come though the streeing wheel.

mad_machine wrote: I actually prefer 4's. I love to rev the snot out of them and I find them a great compromise between fun and frugality. Using the gear box to get the most from a small engine is all part of the fun of owning a sports car

+1

I do miss the torque of bigger engines, but I rev the E36 M3 out of my Miata and get 30-32 mpg consistently.

Gearheadotaku wrote: I hate 4 cylinders. No torque, rough running, must be rev'd like hell to do anything. Sadly, these tiny motors are a nessassary evil with toadys high gas prices.

I dare you to go test drive a car with the direct injected Ecotec turbo (Sky Redline, Solstice GXP, Cobalt SS, HHR SS) and then re-evaluate. That engine (especially with the GMPP tune) defies everything you just said.

Bryce

mad_machine wrote:

Gearheadotaku wrote: I hate 4 cylinders. No torque, rough running, must be rev'd like hell to do anything. Sadly, these tiny motors are a nessassary evil with toadys high gas prices.

I actually prefer 4's. I love to rev the snot out of them and I find them a great compromise between fun and frugality. Using the gear box to get the most from a small engine is all part of the fun of owning a sports car

voted up for excessive win content

Depends on the application. In a FWD little runabout, or small cars in general, i like 4-bangers. They're fun to beat the hell out of, and in most cases, if you blow them up, you can lift them out with your hands.

My escort has a VERY smooth motor, and LOVES to be beaten within an inch of it's life.

As for no torque, rough running, and needs to be revved, sounds like someone needs to meet my MX6.

4cylndrfury wrote:

mad_machine wrote:

Gearheadotaku wrote: I hate 4 cylinders. No torque, rough running, must be rev'd like hell to do anything. Sadly, these tiny motors are a nessassary evil with toadys high gas prices.

I actually prefer 4's. I love to rev the snot out of them and I find them a great compromise between fun and frugality. Using the gear box to get the most from a small engine is all part of the fun of owning a sports car

voted up for excessive win content

This.

Where's that + eleventybillion smiley?

Nashco wrote:

Gearheadotaku wrote: I hate 4 cylinders. No torque, rough running, must be rev'd like hell to do anything. Sadly, these tiny motors are a nessassary evil with toadys high gas prices.

I dare you to go test drive a car with the direct injected Ecotec turbo (Sky Redline, Solstice GXP, Cobalt SS, HHR SS) and then re-evaluate. That engine (especially with the GMPP tune) defies everything you just said. Bryce

Yes, the Ecotech turbos are impressive. Anything that expensive should be.

mad_machine wrote:

Gearheadotaku wrote: I hate 4 cylinders. No torque, rough running, must be rev'd like hell to do anything. Sadly, these tiny motors are a nessassary evil with toadys high gas prices.

I actually prefer 4's. I love to rev the snot out of them and I find them a great compromise between fun and frugality. Using the gear box to get the most from a small engine is all part of the fun of owning a sports car

High revs and working the gearbox is fun, don't get me wrong. It's something I enjoy too, however, given the choice (and funds) I'd rather grab gears with a thundering V8 than singing 4. Also, I like an engine that cruises the hi-way at 2,000 rpm or so, not wailing at nearly 4 grand. Whats a Miata turning at 80mph? For a 10 hour road trip? I know some people do it, and thats fine. Just not my choice. Not dissin' the 4 cly crowd, it's just not my thing. Yes I do own one for a DD.

I have polar opposites in the my two favorite 4cyls at home (I won't count the pos Alpha in the wife's accent, it is merely a tool). The Elantra's 2.0L has a nice fat midrange, decent torque on step off and a decent smoothness to it that is great for the price range it competed in. Sadly, it's 140ft/lbs of tq are saddled to 2900lbs of car minus occupants. It's perfectly happy in the 2000-5000rpm range, runs out of breath around 6200 and the rev limiter steps in at 6300. It gets a little thrashy/noisy/unhappy above 6k and it really does no good to rev up there anyway. It's forte is in it's cruising rpms.

The Swift, well it;'s another beast entirely. Smash the go pedal below 4k rpms and it stares at you with a "whiskey tango foxtrot do you expect me do do down here?" attitude. It's not happy unless it's in that magic 6-8500 range. And it sings.... really really sings at 8k and has plenty of power for the sub-2k lbs of car and driver. Torque? What's that? Luckily the 4.10 final drive and short gearing make use of the revs to keep it moving.

THe wife's car... gutless, thrashy, noisey and weak. Saddled to a 2300lb car with 92hp, hates anything above 5000rpms (redline at 6200, HA!) and it will let you know by 5500 that "there's nothing up here, why are we here?". But for a 40mpg car that cost us less than $2k 16 months ago and is running great, I can't complain. I don't drive it everyday.

By free-revving, I meant willingness to rev (think opposite of a diesel).

I have the Mercedes M111 (C220) motor in my car now, and it will get to redline and make power while doing so, but it fells like I'm being excessively hard on it taking it there, with a ton of valvetrain noise, and roughness. I'm guessing that Mercedes engineers focused all their efforts on making a very efficient motor and forgot to do any NVH reduction at all.

I grew up driving a 1990 Honda accord with the base H22A motor, and that motor loved to rev, yet could be lugged around at 1500 rpm. It was also whisper quiet, and very smooth. The willingness to rev made the car fun to drive, even if it rarely saw past 3500 rpm in normal driving.

I know Honda is famous for making great motors, but how do both 2.2L motors mentioned above have such different characteristics? The Honda even has a longer stroke.

I have done 6 hours in the Ti... aside from the super stiff suspension, I came away fine. Still managed to walk away with 35mpg too (i was slow at 65mph)

Honestly, I kind of disliked the engine in my ti when I first got it. Yes, it was torquey, but it was very mechanical sounding and feeling. Once I got good plugs, wires, an intake, and then finally an exhaust on her.. she sings almost all the way to redline.. and if I hold it just that little bit before upshifting, it almost sounds like she would want to backfire between shifts, but is being held back by the cat and the programming of the computer.

My Fiat.. the 132 series engine is a little gem and LOVES to rev, even with the strangled carb the US cars got.

The saab does not like to rev at all.. but get her on boost and you have torque galore

Remember that having to rev an engine to get power doesn't make an engine more fun, or better, it means the engine has little torque, and the engineers have traded that for high rpm power by shifting camshaft parameters around. Basically, a lopey 400 hp small block chevy has tons of torque, but the same engine with better heads and a huge camshaft would make 700 hp if you tailored it at 8000 RPM. The same characteristic, "willingness to rev", or whatever you call it, would be present, but the engine would be less tractable, and less happy unless in a narrow RPM range. If you have a bazillion gears and 0 second shifting time, and never drive from a stop (or have a crazy high stall converter) you'll be happy, but for the 90% of us that drive on the street most of the time, the 400 hp engine will be way faster.

I understand the thrill behind wringing an engines neck at 7000 and flinging it about, but if another four banger can do it, at the same power, at 4000, it's going to last longer and be just as fast.

What did Datsun put in the little fastback (210?) That car sounded like a mini-Ferrari when built with a big cam and high compression.

4eyes wrote: What did Datsun put in the little fastback (210?) That car sounded like a mini-Ferrari when built with a big cam and high compression.

A-series I think. 1.2 A12, maybe?

The only experience I have with 4cylinders is the toyota pickup with the 22re and 5speed. It is a great engine. Not a revver but it has plenty of down low power. If I pop the clutch and hit the gas that thing goes and will surprise folks as the pickup is rather ratty looking. It doesn't have much power in the top end though.

Then there is my dad's focus with the z-tec or whatever engine in it. That thing loves to rev up and makes good decent power, but is more "buzzy" than the 22re. The focus will pull 85mph pretty quickly, it would probably beat the benz up to 85-90mph where it runs out of gas and I6 power takes over.

Gearheadotaku wrote:

mad_machine wrote:

Gearheadotaku wrote: I hate 4 cylinders. No torque, rough running, must be rev'd like hell to do anything. Sadly, these tiny motors are a nessassary evil with toadys high gas prices.

I actually prefer 4's. I love to rev the snot out of them and I find them a great compromise between fun and frugality. Using the gear box to get the most from a small engine is all part of the fun of owning a sports car

High revs and working the gearbox is fun, don't get me wrong. It's something I enjoy too, however, given the choice (and funds) I'd rather grab gears with a thundering V8 than singing 4. Also, I like an engine that cruises the hi-way at 2,000 rpm or so, not wailing at nearly 4 grand. Whats a Miata turning at 80mph? For a 10 hour road trip? I know some people do it, and thats fine. Just not my choice. Not dissin' the 4 cly crowd, it's just not my thing. Yes I do own one for a DD.

Boost fixes everything!

later, matt