Clubjazz - Honda Jazz & HR-V Forums
Honda Jazz Forums => Honda Jazz Mk3 2015 - 2020 => Topic started by: JazzMusic on March 09, 2020, 09:51:27 AM
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Does the 1.5 have a chain or a timing belt? I hope it doesn't have a timing belt running in the engine oil.
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Does the 1.5 have a chain or a timing belt? I hope it doesn't have a timing belt running in the engine oil.
As far as I know, no Honda engine since early 2000's ( when 2006 Civic and 2003 Jazz came out ) used a timing belt, they went over to chains. What is wrong with chain running in engine oil like on every other engine, including high performance motorbikes do, do you thing it should have its own oil supply ? I have no doubt at all that given oil change at recommended intervals that the chain will last >200,000 miles, Ozzie had a Jazz that did and he never mentioned timing chain, although IIRC the aircon compressor did pack up about 200K.
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I hope it doesn't have a timing belt running in the engine oil.
JazzMusic says a Timing BELT running in engine oil (My italics in quote).
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I hope it doesn't have a timing belt running in the engine oil.
JazzMusic says a Timing BELT running in engine oil (My italics in quote).
Ooops, my bad.
seems timing belts in oil are even better than chains............... described as 'engine lifetime rated'... ( previously the preserve of chains ) it is normally the chain tensioners that go bad though especially on motorbikes where there is less room to get them in...
@JazzMusic have you had bad experience with belts in oil ?
https://www.ngfeurope.com/~/media/NGF%20Europe/Site%20Content/News/Automotive%20Design%20Europe%20Feature.ashx
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I thought it was only the 1L 3 cylinder turbo engine which had the belt-in-oil. I think all the 1.5L are still chain cam.
FWIW, the service interval for camshaft and oil pump drive belts on the 1L is 6 years/75,000 miles for UK... and it's a big, and hence expensive, job. Must say, I don't fancy the idea at all.
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I trust timing belts and even more chains (at least in a Honda but certainly not in a European car :)). Running a timing belt in the oil is pretty new for Honda, the 1.0 turbo (Civic) uses it. I'm not saying it's wrong but I just want to avoid them until they've proved ok (for >200k miles). They require a special oil. I prefer using the oil I want. :)
TB on a 4 cyl is not as bad as on a V6. I usually extend the intervall up to 100 years. The risk is on my side but a TB is a very strong part unless it's exposed to oil and dirt.
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L series such as 1.3 and 1.5 have timing chain, naturally aspirated for Jazz or turbocharged for Civic.
The 1.0t is a P series, and it has wet timing belt.
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I thought it was only the 1L 3 cylinder turbo engine which had the belt-in-oil. I think all the 1.5L are still chain cam.
FWIW, the service interval for camshaft and oil pump drive belts on the 1L is 6 years/75,000 miles for UK... and it's a big, and hence expensive, job. Must say, I don't fancy the idea at all.
And if you don't use the correct oil - to specification , the belt may break See Ford turbos 1.0...
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I drove my son's 1.0 Ecoboost Fiesta on the weekend and thought how nice it is to drive, so much more powerful and flexible than my 1.2 mk2 Jazz.
It made me wonder why Honda didn't put their 1.0 turbo in the Jazz or even if I should consider buying a 1.0 Civic next but I think I've gone off the idea after reading these comments as I like to keep cars for the long term.
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And if you don't use the correct oil - to specification , the belt may break See Ford turbos 1.0...
That's my point. Wet timing belts are planned obsolescence and undesired dependency.
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I drove my son's 1.0 Ecoboost Fiesta on the weekend and thought how nice it is to drive, so much more powerful and flexible than my 1.2 mk2 Jazz.
It made me wonder why Honda didn't put their 1.0 turbo in the Jazz
Under the WLTP test regime the 1.3 Jazz is significantly more economical (around15%) than the turbo Fiesta. The 3 cylinder turbos showed up well on the older NEDC test cycle but not in real world driving.
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I trust timing belts and even more chains (at least in a Honda but certainly not in a European car :)). Running a timing belt in the oil is pretty new for Honda, the 1.0 turbo (Civic) uses it. I'm not saying it's wrong but I just want to avoid them until they've proved ok (for >200k miles). They require a special oil. I prefer using the oil I want. :)
There are 4 generations of timing belts.
1° generation, chloroprene, born in the late sixties and used in lots of ohc engines
2° generation, polichloroplene and fiberglass and called HSN, used since the nineties, made to last 5-6 years or 90-100000 miles. If you have a 2010 Renault Clio, you have an HSN belt.
3° generation, HT (High tenacity), initially made for VW diesels with the "Pump Duse" injection system. This kind of belt had to bear high mechanical stresses coming from these engines (the camshaft has to push both valves and the pump-injector), so the rubber is a high idrogenated HNBR polymer with high strenght fiberglass inside and ptfe on the surface. Used in a 1.9 or 2.0 TDI engine this belt last 5-6 years and 100000miles, used in a Ford 1.6tdci common rail engine can last 200000 miles and 10 years.
4° generation, wet belts patented by Dayco.
Ford and PSA use Dayco wet timing belt since 2013. "Wet" means that the belt is in contact with oil vapour (this is enough for lubrication), and they set the manteinance every 10 years or 150000 miles. As I can read, they do not set a particular oil, their user manuals write only about ACEA type and SAE grade.
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Under the WLTP test regime the 1.3 Jazz is significantly more economical (around15%) than the turbo Fiesta. The 3 cylinder turbos showed up well on the older NEDC test cycle but not in real world driving.
According to Spritmonitor, the average consumption of a 100hp 1.0 Fiesta is 6,4 liters per 100km, while a 100hp Jazz is 5,8 liters per 100km. The difference in the real driving is 0,6 liters, about 10%.
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I drove my son's 1.0 Ecoboost Fiesta on the weekend and thought how nice it is to drive, so much more powerful and flexible than my 1.2 mk2 Jazz.
It made me wonder why Honda didn't put their 1.0 turbo in the Jazz
Under the WLTP test regime the 1.3 Jazz is significantly more economical (around15%) than the turbo Fiesta. The 3 cylinder turbos showed up well on the older NEDC test cycle but not in real world driving.
I recall the other problem with turbo engines is that the real life emissions tend to be higher than those during the controlled testing.
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I recall the other problem with turbo engines is that the real life emissions tend to be higher than those during the controlled testing.
Also naturally aspirated engines have this "problem", even if less than turbocharged.
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I recall the other problem with turbo engines is that the real life emissions tend to be higher than those during the controlled testing.
Also naturally aspirated engines have this "problem", even if less than turbocharged.
Isn't it the higher combustion temperature of forced induction engines ( due to higher CR and leaner mixture ) that increases the Nox emissions though ?
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The matter is complex.
NOx come from very high temperatures, this is true.
Diesel engines have a great NOx production, even if the average temperature in the diesel cycle is low (they take a lot of time for warming up, this means that cylinder walls and the head are not in contact for a long time with hot gas); the problem comes from the type of combustion because the fuel burns in the same time in the whole cylinder space, so you have a very short moment when temperatures are very high (nox production) and a long period when temps are lower (expansion). This is also why diesel engines produce particulate matter: fuel starts burning during the knock, quite all fuel burns completely except from bigger drops that stop burning because temperatures fall down. Common rail try to solve this problems using multiple injections, no more one or two big knocks but more little knocks, the idea is to have four or five small peaks and no more one or two big peaks, and smaller size fuel spray.
Petrol engines produces a very lower amount of nox, except from ones in the 80ies without catalytic converter. These small engines, produced by Fiat and Peugeot (Fire and TU series) used a lean burn mixture (18-20:1) to gain good economy, but they had to abandon this strategy when the european commission decided to use fuel injection and catalytic converters, that need a stoichmetric mixture 14,7:1. Thats why that kind of engines were quite bad with electronic fuel injection and cats: fluid flux, manifolds and sparkplug position were ok for lean burn, not for stoichometric run mode, so engeneers had to understand how to re-arrange the engine settings.
Petrol engines have a different combustion process from diesel, the combustion spreads from the spark to the farest part of the cylinder, average temperatures are much higher than diesel but peak temperatures are lower. NOx production is lower because only small part of time and area reach so high temperatures to combine nitrogenum with oxigen. This is true in low power conditions, but if you push the gas pedal then temperatures would rise quickly, too much heat for pistons, valves, manifolds, turbo and cats, so engeneers have to cool the combustion process adding fuel to the mixture; it's quite a paradox but the air-fuel mixture does not heat so much during compression thanks to the liquid fuel evaporation, this process needs energy. And considering that there is low oxygen inside the cylinder, the next combustion process will not produce more heat than a stoichometric combustion. Some turbocharged engines (as BMW) use water spray injection inside the inlet manifold: water evaporates before and during compression and helps keeping temperatures low.
Without enriching the AF ratio, petrol engines would break by wear because pistons, piston rings, valves and valve rings would run over their temperature limits; so part of the fuel, when you push the gas pedal, goes to to wet cylinder walls, the piston head and valves and so to cool them. This happens in every petrol engine, naturally aspirated or turbocharged, and you can check it with a simple EOBD tool following real time the AFR number; you will see that in cruising mode the AFR will be 14,7:1 (or 1, depending by how the software shows it), but this number will fall every time you push the gas pedal more than half path (is path correct?). Clearly, if an engine runs out of the stoichometric condition, the catalytic converter will run poor because it needs a precise balance of elements, some parts of residual oxygen, some of Nox, some of HC and CO, and the 14,7:1 is the best for it; enriching the AFR, the cat will get less oxygen and more HC and CO, so emissions will raise, especially carbon oxides and unburned fuel.
That's why a 100hp 1.0t Ford has bigger real consumption than a 100hp 1.3 NA Honda; when you push the gas, the Ford engine gives more torque, but it must enrich more than the Honda; supercharged engines can run leaner only in stratified charge (direct fuel injection), but in average they run with a richer AFR.
Anyway, both naturally aspirated and forced induction engines enrich the AFR, even if NA do it much less; the only way to limit this problem is to reduce specific power and specific torque, and now we understand why american engines usually have big displacement and low power: a 2500cc NA engine will have less AFR enrichment than a 1.0turbo giving 200nm torque and 140hp... If USA rules want to strongly push the gas pedal during the test, a 2500 NA will be much better than a 1.0T for emissions. And this is why hybrid vehicles like toyotas and I-MMD hondas use underpowered atkinson engines: when they run, they often do it with a widely open butterfly valve to reduce pumping losses, and since they have to run with low emissions and this needs low enrichment, they will have low specific torque and power to raise reliability and reduce emissions.