Comparison of the best ~2 liter N/A engines ever produced

[wbradley]

my thoughts are that if the rotary engine was so great why didn't other manufacturers license it is well. to me it's more of a novelty item something Mazda needed to differentiate itself as a relatively small fish in a big sea.

In 89/90 I sold Mazda. The RX7 wasnt selling so well and at the time it ocurred to me that the 240SX had a better engine and was a better overall value.

[fatoni]

Originally Posted by wbradley

my thoughts are that if the rotary engine was so great why didn't other manufacturers license it is well. to me it's more of a novelty item something Mazda needed to differentiate itself as a relatively small fish in a big sea.

In 89/90 I sold Mazda. The RX7 wasnt selling so well and at the time it ocurred to me that the 240SX had a better engine and was a better overall value.

the boxer isnt exactly ubiquitous either. the rotary is simply millions of hours behind piston engines in technology and it suffers from that.

[brn12345]

Anyone who has worked with the K20A motor knows that there is something next to godly in the way that motor was built. It is literally a race motor tamed for the street via the VTEC mechanism which the FA20 unfortunately lacks. Case in point, if the FA20 had cams as big as the K20A it would not be able to idle.

Also in response to Honda not building ultra high power NA motors anymore, that is directly related to the move in the motorsport world to a unified 1.6L turbo engine.

[regal]

Originally Posted by brn12345

Anyone who has worked with the K20A motor knows that there is something next to godly in the way that motor was built. It is literally a race motor tamed for the street via the VTEC mechanism which the FA20 unfortunately lacks. Case in point, if the FA20 had cams as big as the K20A it would not be able to idle.

.

The KA20A has a forged crank vs the cast cranked FA20. I thought that the K20 also had piston oil squirters? FA20 just wasn't built for variable lift or high revs like a K series or the F20C. Time will tell if the FA20's open deck can really handle boost without head gasket issues.

My vote goes to the F20C for NA and the SR20DET for FI. Bullet proof reliable engines that have stood the test of time.

[ThisIsChrisKim]

Originally Posted by brn12345

Anyone who has worked with the K20A motor knows that there is something next to godly in the way that motor was built. It is literally a race motor tamed for the street via the VTEC mechanism which the FA20 unfortunately lacks. Case in point, if the FA20 had cams as big as the K20A it would not be able to idle.

Also in response to Honda not building ultra high power NA motors anymore, that is directly related to the move in the motorsport world to a unified 1.6L turbo engine.

I've personally never been a fan of cars with variable lift. That jekyll and hyde low-RPM/high-RPM behavior was always a turn off for me.

Making the same amount of power over a linear curve of powerband is preferable to the erratic behavior of an engine with variable lift. 2ZZ-GE is also similar in that regard. I feel as if the high-RPM power is too big a trade off for the horrendous low-end power. Luckily, the other famous DOHC VTEC engine (NSX's C32B) doesn't exhibit that on/off behavior of the B and K series engines.

[regal]

Originally Posted by ThisIsChrisKim

I've personally never been a fan of cars with variable lift. That jekyll and hyde low-RPM/high-RPM behavior was always a turn off for me.

Making the same amount of power over a linear curve of powerband is preferable to the erratic behavior of an engine with variable lift. 2ZZ-GE is also similar in that regard. I feel as if the high-RPM power is too big a trade off for the horrendous low-end power. Luckily, the other famous DOHC VTEC engine (NSX's C32B) doesn't exhibit that on/off behavior of the B and K series engines.

You like 6 cylinders. Very rare for a 2L 4 cylinder to have a linear powerband, maybe the old BMW S14.

[ThisIsChrisKim]

Originally Posted by regal

You like 6 cylinders. Very rare for a 2L 4 cylinder to have a linear powerband, maybe the old BMW S14.

The 3S-GE BEAMS and SR20VE both have fairly linear powerbands. The power delivery of both engines are more similar to that of the FA20. That doesn't mean I don't think the Honda engines aren't fantastic, they make great power, it's just not my ideal power output. However, given the choice between the FA20/3S-GE/SR20VE like delivery and the erratic variable lift engines with an additional dallop of power, I still think it's silly not take the F20C or K20A which have between 10-30HP more than the previously mentioned engines. Then again... emissions and efficiency need to be assessed, too? Aye, it's a hard choice. But given our current day choices in a new car, it's a FA20 or... something turbo charged, right?

[Superhatch]

What you need were Toda Vtec killer cams. It basically swaps the Vtec lobe so it's on all the time. There are also guys who would take the K24A1 out of a CRV (which you can get for super cheap..300-400 usually) and add the K20A2 valvetrain and put down solid numbers. An average dyno would be 200/180 and along with some elbow grease you could pay about $800 for that motor.

Also, I'd say the K and B series engines were much different in their power delivery. Yes there was a noticeable gain even in the Ks but it was a much smoother progression than the sharp break of the B series. So much that many people didn't like the K series when they came out because they were too smooth.

[chrisl]

Originally Posted by ThisIsChrisKim

I've personally never been a fan of cars with variable lift. That jekyll and hyde low-RPM/high-RPM behavior was always a turn off for me.

They don't all have a dramatic change from low to high RPM. Check out the engine in the Porsche Cayman, which has VVT and 2-stage lift on the intake side. Look how flat the torque curve is (within 15 lb-ft of peak from 2300rpm onwards! From a N/A engine!)- there's no jekyll and hyde behavior here:

[DarkSunrise]

Wow the shape of that torque curve looks very reminiscent of the FA20, just scaled higher.

- Torque peak at 2500 rpm
- Torque dip from 3200-4500 rpm
- Flat torque from 4500-6500 rpm
- Power drops off at 6500 rpm
- 7400 rpm redline

[fatoni]

Originally Posted by ThisIsChrisKim

I've personally never been a fan of cars with variable lift. That jekyll and hyde low-RPM/high-RPM behavior was always a turn off for me.

Making the same amount of power over a linear curve of powerband is preferable to the erratic behavior of an engine with variable lift. 2ZZ-GE is also similar in that regard. I feel as if the high-RPM power is too big a trade off for the horrendous low-end power. Luckily, the other famous DOHC VTEC engine (NSX's C32B) doesn't exhibit that on/off behavior of the B and K series engines.

im pretty sure the reason vtec exists is to negate what you are blaming it for causing.

[chrisl]

Originally Posted by DarkSunrise

Wow the shape of that torque curve looks very reminiscent of the FA20, just scaled higher.

- Torque peak at 2500 rpm
- Torque dip from 3200-4500 rpm
- Flat torque from 4500-6500 rpm
- Power drops off at 6500 rpm
- 7400 rpm redline

Yep - I've always found it pretty neat how qualitatively similar the Cayman and BRZ torque curves are - they really do look like nearly the same engine rescaled. The Cayman S has pretty much the same shape as well (but scaled even higher). The torque dip around 3.5k is noticeable, though not too bad on the CS. Note that both the Cayman curve I posted above and this CS curve are from the old (pre-2009) engine, but the new one also looks pretty similar, just with a bit of extra power.




As a point of comparison, here's the new one:

[WolfpackS2k]

Originally Posted by ThisIsChrisKim

I've personally never been a fan of cars with variable lift. That jekyll and hyde low-RPM/high-RPM behavior was always a turn off for me.

Making the same amount of power over a linear curve of powerband is preferable to the erratic behavior of an engine with variable lift. 2ZZ-GE is also similar in that regard. I feel as if the high-RPM power is too big a trade off for the horrendous low-end power. Luckily, the other famous DOHC VTEC engine (NSX's C32B) doesn't exhibit that on/off behavior of the B and K series engines.

It's not an issue when you're driving on a track. Unless there are some very low speed turns if driven properly the engine will never come off the larger high lift cam. As an aside, it's also worth noting that Honda's VTEC system is bulletproof. There has never been a warranty claim made on the system, ever. And after 300k miles I can say that I haven't had a single issue with VTEC on my Integra. Truly amazing.

[ThisIsChrisKim]

Originally Posted by fatoni

im pretty sure the reason vtec exists is to negate what you are blaming it for causing.

I wonder what the difference is in newer cars (say like our FA20) single cam profile versus a VTEC 2-stage lift cam profile on a K or F series engine. The reason for the 2-stage lift is to improve idle as the primary function but also to provide improved responsiveness at low-RPM, but for some reason, didn't most of those engines have lesser torque at a given RPM than their less performance oriented counterparts (ie. 1ZZ vs. 2ZZ; B18A vs. B18B, etc)?

The F20/F22 have less torque in the low-RPM range than the FA20 does at similar RPM.

Originally Posted by WolfpackS2k

It's not an issue when you're driving on a track. Unless there are some very low speed turns if driven properly the engine will never come off the larger high lift cam. As an aside, it's also worth noting that Honda's VTEC system is bulletproof. There has never been a warranty claim made on the system, ever. And after 300k miles I can say that I haven't had a single issue with VTEC on my Integra. Truly amazing.

Yeah, Honda does have super reliable engines. I've always been blown away by that.

Originally Posted by chrisl

They don't all have a dramatic change from low to high RPM. Check out the engine in the Porsche Cayman, which has VVT and 2-stage lift on the intake side. Look how flat the torque curve is (within 15 lb-ft of peak from 2300rpm onwards! From a N/A engine!)- there's no jekyll and hyde behavior here:

That's really interesting. I wonder if being a 6-cylinder engine helps negate that jekyll and hyde power delivery? Or maybe the cam profile switch is just so much more gradual (the low-high profile is much less aggressive than on the K and F series engines).