NC700 - Honda FIT (JAZZ) component sharing

[Mi_ka]

I did some part numbers net diving and I found that the NC700 engine shares these components with the Honda Fit (Honda Jazz over here) 1.3 engine:

1. Connecting Rods listed for Insight and Civic Hybrid
2. Piston Rings
3. Pinston Pins
4. Con.rod bearings
5. Con.rod Bolts

Valves, valve springs, seats or other less important component numbers do not match.
Of course many other small parts (roller bearings/nuts/bolts/ashers etc) match to other Honda bikes/cars as usual with every manufacturer's parts bins but I have not found any other main component coherence.

Since I have always envied car engine longevity, I am glad for the automotive mentality that should mean ultra long engine life for the NC besides great mpg. I could not care less if my bike's engine comes from a MotoGP bike, a tricycle tractor or an helicopter as long as it does what I want it to.

 

[Bug Dr.]

I'm with ya on the last point. I couldn't care less if people want to call my engine "half of a Jazz". It's not powerful, noisy and doesn't vibrate when idling.......and I'm cool with all of that. I don't ride bikes for show and I don't polish chrome. I've ridden many bikes and this one is one of my favorite because it's simple, efficient and quiet. For me, it's about going places economically and safely with a reliable machine. This bike suits all of my needs.

I'm still working on finding the correct ergonomics and luggage combinations for my style of travel and budget. I have no doubt that the aftermarket will provide me with all of the goodies to make this bike a worthy travel companion for many years.

Simplify! Simplify! Simplify! - Henry David Thoreau
Mike

 

[wozza]

Yep ditto the above comments. I think what Honda is doing is brilliant.

 

[Garnet]

But why oh why didn't they use the hydraulic valve lifters from the Jazz?????? This would have been the perfect bike for car-like near zero maintenance that would have given.

 

[Mi_ka]

But why oh why didn't they use the hydraulic valve lifters from the Jazz?????? This would have been the perfect bike for car-like near zero maintenance that would have given.

I guess that besides the obvious "cost factor" of embedded plumbing that one may think:
- NC oil pump supplies much smaller quantity than the car engine and this could mean quite few seconds of clackity-clack until oil pressure/volume builds up to properly supply the lifters depending on oil viscosity in conjunction to temperature
- Hydraulic lifters mass affects total friction up there as the bike engine will be rotating higher in the rpm spectrum much more often than the car
- Hydraulic lifters going bad are a much more difficult and maybe expensive issue to solve than current simple system

My 2 (euro) cents...

 

[Old Can Ride]

I did some part numbers net diving and I found that the NC700 engine shares these components with the Honda Fit (Honda Jazz over here) 1.3 engine:

1. Connecting Rods listed for Insight and Civic Hybrid
2. Piston Rings
3. Pinston Pins
4. Con.rod bearings
5. Con.rod Bolts

Valves, valve springs, seats or other less important component numbers do not match.
Of course many other small parts (roller bearings/nuts/bolts/ashers etc) match to other Honda bikes/cars as usual with every manufacturer's parts bins but I have not found any other main component coherence.

Since I have always envied car engine longevity, I am glad for the automotive mentality that should mean ultra long engine life for the NC besides great mpg. I could not care less if my bike's engine comes from a MotoGP bike, a tricycle tractor or an helicopter as long as it does what I want it to.

Happy with the tappets on the bike. Easy to adjust and keep cost down.

 

[Mr_Krabs]

But why oh why didn't they use the hydraulic valve lifters from the Jazz?????? This would have been the perfect bike for car-like near zero maintenance that would have given.

The lower revving nature of this engine like the cars would have the valves virtually not moving past the first valve adjustment. And usually then after the break in the valves haven't moved passed out of spec. Even with solid lifters valve life and frequent adjustments wouldn't be an issue anyways.

Plus who told you the Fit/Jazz has hydraulic lifters?

valve clearance - Unofficial Honda FIT Forums

Looks solid and has adjusters to me.

Most people probably don't realize Honda's have solid tappets because they never really need adjustment except if you're constantly revving and racing the engines. But during normal use the valves don't really recede much at all.

 

[Old Can Ride]

The lower revving nature of this engine like the cars would have the valves virtually not moving past the first valve adjustment. And usually then after the break in the valves haven't moved passed out of spec. Even with solid lifters valve life and frequent adjustments wouldn't be an issue anyways.

Plus who told you the Fit/Jazz has hydraulic lifters?

valve clearance - Unofficial Honda FIT Forums

Looks solid and has adjusters to me.

Most people probably don't realize Honda's have solid tappets because they never really need adjustment except if you're constantly revving and racing the engines. But during normal use the valves don't really recede much at all.

"during normal use the valves don't really recede much at all"

Bingo, you just nailed it solid!!!!!!!!!

 

[Garnet]

Wow, I never realized how antiquated the Jazz/Fit engine is. 2 valves per cylinder, no variable cam timing and jam nut adjusters, the only thing that's not from the 80's is the chain drive. I'm not saying that any of that proven simple technology is a bad thing, but virtually every new automotive engine in the last 10ish years is much more advanced than that and still super reliable. The average Corolla owner expects to get several hundred thousand miles from their engine with only the occasional oil change at the cheapest shop they can find.

Anyway, back to the topic at hand. Thanks for putting those numbers up. I didn't thinks there where any Jazz/Fit parts in our bikes, I thought it was just automotive design that was used.

 

[dduelin]

I did some part numbers net diving and I found that the NC700 engine shares these components with the Honda Fit (Honda Jazz over here) 1.3 engine:

1. Connecting Rods listed for Insight and Civic Hybrid
2. Piston Rings
3. Pinston Pins
4. Con.rod bearings
5. Con.rod Bolts

Valves, valve springs, seats or other less important component numbers do not match.
Of course many other small parts (roller bearings/nuts/bolts/ashers etc) match to other Honda bikes/cars as usual with every manufacturer's parts bins but I have not found any other main component coherence.

Since I have always envied car engine longevity, I am glad for the automotive mentality that should mean ultra long engine life for the NC besides great mpg. I could not care less if my bike's engine comes from a MotoGP bike, a tricycle tractor or an helicopter as long as it does what I want it to.

Add boat motors to the list. Honda's Jazz/Fit L series engine shares some rotating parts and castings with Honda 75 and 90 hp outboard motors.

 

[Mi_ka]

Add boat motors to the list. Honda's Jazz/Fit L series engine shares some rotating parts and castings with Honda 75 and 90 hp outboard motors.

That's a bonus for super rainy weather reliability!

Wow, I never realized how antiquated the Jazz/Fit engine is. 2 valves per cylinder, no variable cam timing and jam nut adjusters, the only thing that's not from the 80's is the chain drive.

Many versions in the L engine family - one is the 8-valver. God is in the detail: The Truly Amazing Honda Fit/Jazz
The bottom line is that depending the use and expected/designed gas flow, a 2 valved cylinder may have many benefits over a multi valve one. But it needs cutting edge technology to come out with a simple looking 8-valver producing excellent efficiency. Fine details evolution.
I would love it if MotoGuzzi redesigned its classic 1100 2-valver cylinder to become super efficient instead of pursuing horsepower by pushing 4 valve air/oil-cooled designs to their limits.

 

[Fuzzy]

that's a bonus for super rainy weather reliability! :d

l o l
.......

 

[Mr_Krabs]

Wow, I never realized how antiquated the Jazz/Fit engine is. 2 valves per cylinder, no variable cam timing and jam nut adjusters, the only thing that's not from the 80's is the chain drive. I'm not saying that any of that proven simple technology is a bad thing, but virtually every new automotive engine in the last 10ish years is much more advanced than that and still super reliable. The average Corolla owner expects to get several hundred thousand miles from their engine with only the occasional oil change at the cheapest shop they can find.

Anyway, back to the topic at hand. Thanks for putting those numbers up. I didn't thinks there where any Jazz/Fit parts in our bikes, I thought it was just automotive design that was used.

The thing with all that whizbang variable phase, timing lift and duration stuff is that it contributes nothing to the real life efficiency of the engine. In fact what they're generally used for is to lower the torque curve on a high RPM tuned engine. Before this trickled down to everyday cars the technology was first pioneered in racing cars and motorcycles. These had engines tuned to output very high power for their displacement.

In fact they had this high power small displacement thing down pretty well in even in the 1980's. If you check the power specs of the average carburetted AIR COOLED fixed timing 750cc super sport bike in the 1980's like the GSX-R 750 it had 106 hp waay back in 1985 and now nearly 30 years later where are we? The 2014 GSX-R 750 has 123 hp.

So no gigantic leap in peak power but if you ever rode one of those old bikes you knew they only made power in a very narrow 2000 rpm band at the very top. Very finicky to ride compared to the wide powerband offered by newer variable timing and valving technology, albeit offered only in the 1000cc version which is known as having a very flat torque curve.

So getting back to cars, if you keep a naturally torquey engine design you don't need all that fancy technology in order to have a wide powerband. If you want very high peak outputs but useable torque ratings you need variable cam timing in order to extend the torque curve lower. This of course is at the expense of engine efficiency. So it really is better to keep the simpler design. It's not outdated, it's simply proven.

 

[Mi_ka]

From what I understand you need state of the art technology to properly select the best possible combination of curvature of intake ports vs profile vs valve design vs many other simple looking sub-mm details that affect gasses circulation and all combined give this excellent efficiency to this engine. In the older days this design perfection was less flexible to achieve and we must never forget the slow reactions of what are the presently running production procedures of each company.

In the NC we see in production the combustion study of the L-engine family which was performed 10 years ago by the car department. I understand that the motorcycle department designed a motorcycle engine around this proven car combustion cylinder design aiming for best mpg while embedding some motorcycle spice to evade the "electric motor" feeling (I hate this in current BMWs 800s).

I am glad that Honda dared to make this bike. It was a bold move, took well the motorcycle folks conservative negative criticism and finally gave us what we want: A real life bike.

These days I study the DCT which is the real mechanological gem of the NC series.
Not because of any engineering novelty but because of well thought reliable component layout in the severe space and EMF interference constraints of a normal size everyday motorcycle.

 

[mez]

Beware, old thread resurection.

Does someone know if the NC also shares the same pistons with the Jazz/Fit? I am asking because the 1300cc Jazz/Fit has a 73x80 bore-stroke and the 1500 has 73x89.4.

 

[L.B.S.]

Beware, old thread resurection.

Does someone know if the NC also shares the same pistons with the Jazz/Fit? I am asking because the 1300cc Jazz/Fit has a 73x80 bore-stroke and the 1500 has 73x89.4.

Any particular reason for the curiousity, mez? For the record, no, I don't believe the pistons are shared. I think it's the connecting rods, bolts and bearings, piston rings and pins, that they share in common.


Edit:

D'oh! Mi_ka said this in the very first post in this (his) very thread, lol

 

[mez]

Any particular reason for the curiousity, mez? For the record, no, I don't believe the pistons are shared.

Well curiosity killed the cat, not the biker!

The L15 engine has more stroke, this could be an outcome of different connecting rods or different pistons or maybe both.

Now if we do the math then 73x89.4 on a 2-cylinder engine..(drum-roll)..745cc sounds familiar? For some it could mean nothing, for others it could mean a potential upgrade.

 

[670cc]

745cc sounds familiar but Honda "upgraded" the NC700 to the NC750 by increasing the bore, not the stroke.

A long stroke NC750 would have been cool.

 

[mez]

745cc sounds familiar but Honda "upgraded" the NC700 to the NC750 by increasing the bore, not the stroke.

A long stroke NC750 would have been cool.

Indeed and this is quite puzzlling. In sence that, if Honda alrady had a simple sollution for upgrading the NC, why go the other way.

Or maybe this is only my view of things (which quite probably is)!

 

[MZ5]

The only way to increase the stroke is to increase the crank throw length, and therefore increase the operating diameter of the crank. Maybe they didn't have enough room left to do that in the NC crankcase? That would make boring the only option. Or, maybe it's more economical to make different pistons vs. making different crankshafts? IDK.