Jap Engine Warm Up

[Simon Davey]

So, by the time I've let her run on the choke, faffed about getting gloves on, down to the gate and on the road, it's about three minutes. 

I just can't help but take those rev's to 7k as I head away from the farm. 

Red line is 10.5k.

 

Should I really be keeping it under 4k for a while longer? 

Edited November 8, 2024 by Simon Davey

[Mississippi Bullfrog]

Personally I let my engines get up to full operating temperature before giving them the beans. Modern oils are very good but I'm still old school about letting the oil get hot before getting enthusiastic with the throttle. Equally though, you don't want to let the engine labour when cold. 

[Simon Davey]

1 hour ago, Mississippi Bullfrog said:

Personally I let my engines get up to full operating temperature before giving them the beans. Modern oils are very good but I'm still old school about letting the oil get hot before getting enthusiastic with the throttle. Equally though, you don't want to let the engine labour when cold. 

 

This is how I'm thinking, I should probably give it a little longer. 

My temp gauge is utterly useless, only hovers above the low mark in the summer heat, unless I cane it then stop. The fans kick in, as and when expected though, so no issues with overheating. 

Edited November 8, 2024 by Simon Davey

[Mississippi Bullfrog]

I saw an interesting survey on car reliability recently. One thing that has always puzzled me is how cars that use the same parts come out totally differently in reliabilty surveys. For example, Skoda, Seat, VW and Audi share many components, yet Skoda come out well in reliability surveys, Seat a bit lower, VW much lower and Audi even worse. The conclusion is that it's down to the owners, in terms of how the cars are driven and maintained. Skoda owners tend not to hammer their cars and look after them. VW & Audi drivers - well, no need to say more.

[Simon Davey]

That's very interesting, and not something that can be argued with. 

[RideWithStyles]

Depends on the bike and what you put in it.

 

nakeds take a little longer to heat up.

Oil,air, water cooling engines have an impact as to how quickly it gains or loses heat.

old engines with massive ports/passage ways and thinner jackets/walls made huge difference. 

Grade/type/spec/additive package of oil, including its level of degradation at that time. Thinner and more good synthetics additives the better it is at cold and hot temperatures than say a random semi with huge base stock and no additional - generally.

the great thing about carbs it that they already told you when the engine was good to go as they are awkward and hesitant till they’re good and give it some more revs. electronic injection and good ecu mapping (old Hondas and ktms of a old era were shite in this regard) takes that away, so good now the rider has no idea when is right or not so you could just do a burn out from stone cold if you so wished unless you had a s1000rr which the bike would not allow you rev past a certain rev until it reached a parameter.

 

Neighbour of mine is old school return biker- nice enough guy, modern ktm but goes about it like the old days.

lets it sits on idle for about 10-20mins, turns it off, goes back inside to get changed, comes back 10-15min later, starts up again and lets idle for about 7 or so min and starts to struggle to wheel it out of the tight gate. 
takes a few moments more to be able to mount the bike then zooms off…not the best for that bike as they are designed to get gone straight away on the starter with a little sympathy for a mile or so. Very much the opposite to what my bike wants.

 

design, manufacturing and materials are extremely good these days so the likely hood of bad damage is way less than it used to be but not impossible regardless. personally I’d still be careful and still go easy for a few miles.

Edited November 8, 2024 by RideWithStyles

[husoi]

Keep in mind that while the engine is warming up so do the tyres.

[Simon Davey]

3 hours ago, husoi said:

Keep in mind that while the engine is warming up so do the tyres.

It takes me longer to switch on, than it does for my tyres to warm up. 

[Stu]

Just start and ride! 

 

You are doing more harm leaving the bike to idle than you are riding 

 

The majority of engine wear is done in the first few sencods of starting the bike and once the oil is flowing all is good 

 

By the time you get to your favourite roads the engine will be more than warm enough 

[Geordie Oldie]

Any vehicle I own I wait until it has reached temperature before I howk it.

 

Company vehicles are a different matter.

[RideWithStyles]

A person I know in the early days with previous employer would let the team to place bets on who would kill or it would “die on” their use with the pool car (carver) / company car. Reason was quite logical, it encouraged them to go quickly about places (not breaking the law -thats on you), incentives to be competitive with others and have fun….that what he said.

the other reason was because the “list of choices they were allowed were shite” the person in charge of company cars had no idea on what accounts as a remotely a nice car to use or live with , to add insult mostly of those shite cars were just as if not more expensive that something nice so like I said the person in charge of that was a complete incompetent fool.

 

so the mission was to use it hard in the hope you pushed it just far enough that it went pop in someone else’s use/care. Then hopefully could get something else Much better.

lets just say a lot of tyres and brakes got used up even discounting track days on it and got the unofficial medal of the most “used and expensive” car award amongst the branch ranks.

the conversations with said manager as to while it was using consumables so quickly was amusing apparently.

Edited November 15, 2024 by RideWithStyles

[Gerontious]

My engine temp indicator is 3 bars. I wait until 1 bar is showing then will ride down the hill. It’s always at 2 bars by the turn into the next road and take it gently as there’s a series of fairly brutal speed humps. Just a smidge over tickover. By the time I’m over the final on I’m in 3 bars then it’s uphill to the main road. It’s no big deal being a bit patient and following the advice of the owners manual. I’m never in that much of a rush. It’s a 20 to the top of the hill so it hardly matters anyway.

Edited November 16, 2024 by Gerontious

[Egon247]

With the car (haven't actually used the bike yet, its still in bits!) i wait until the coolant is up to temperature before giving a boot full. Its an alfa TBI engine and parts are expensive/hard to get/hard to get AT so i treat it with kid gloves until its warmed up. Even then, i still cant use all the performance as there's usually other people in the way!

Mechanical sympathy is the way forward in my head. But I'm an engineer so i kinda figure that its part of my job to mot take things up to 11 on startup. 

There's a thing called a bathtub curve, where the probability of failure is high to begin with, calms down to a sensible level, then as it gets older it goes back up again - hence it looks like a bathtub, i tend to look at things like that. If i push the start button and it doesn't go bang, I'm onto a winner.

 

[Mississippi Bullfrog]

5 minutes ago, Egon247 said:

 

There's a thing called a bathtub curve, where the probability of failure is high to begin with, calms down to a sensible level, then as it gets older it goes back up again - hence it looks like a bathtub, i tend to look at things like that. If i push the start button and it doesn't go bang, I'm onto a winner.

 

Sounds like the story of my life. I'm definitely in the latter upward curve. 

[Tinkicker]

No engine likes large sudden temperature fluctuations.  This is because some parts are lighter, smaller or by their nature are forced to heat and cool far quicker than its neighbours.

 

Sudden fluctuations affect the running clearances within the engine.  Pistons, rings and exhaust valves are most prone to heat very quickly and as a result of heat expansion, often run on the ragged edge of zero clearance to their more sturdy neighbours when the engine is cold.  Also, running a cold engine hard leads to fretting between block face and head face, with premature head gasket failure possible.  Heads and blocks can also warp due to uneven temperature expansion.

 

I have built literally hundreds of bus engines and seen all of this very regularly.  All due to the severe duty cycle a bus engine has to put up with.  Stop and start, from idle to full throttle for a minute, then back to idle again.  Then foot flat down again.  Was not a problem back in the day as a bus engine was typically around 11 ltrs with a lazy power curve and had a lot of mass preventing sharp temp spikes.

 

These days, the typical single decker bus will have a turbcharged, 4 cylinder of around 3 to 4 litres.  This means the engine has to work far harder and rev higher.

Naturally the engines blow very regularly.  It is rare to see a modern bus engine last more than 8000 hours.  It should last 30,000 hrs.

Even how you treat your engine when warm has consequences.

 

In answer to the OP.  No engine should be run flat out until it has reached its specified operating temperature.

 

A well known axiom in engineering circles..... " engines dont die, they are murdered".

Edited November 16, 2024 by Tinkicker

[JRH]

1 hour ago, Mississippi Bullfrog said:

Sounds like the story of my life. I'm definitely in the latter upward curve. 

I resemble that remark.

[Egon247]

2 hours ago, JRH said:

I resemble that remark.

I'm already on my way back up the curve.  

Interesting avatar, JRH. I have a signed copy of the hogfather on my shelf

[Stu]

6 hours ago, Tinkicker said:

No engine likes large sudden temperature fluctuations.  This is because some parts are lighter, smaller or by their nature are forced to heat and cool far quicker than its neighbours.

 

Sudden fluctuations affect the running clearances within the engine.  Pistons, rings and exhaust valves are most prone to heat very quickly and as a result of heat expansion, often run on the ragged edge of zero clearance to their more sturdy neighbours when the engine is cold.  Also, running a cold engine hard leads to fretting between block face and head face, with premature head gasket failure possible.  Heads and blocks can also warp due to uneven temperature expansion.

 

I have built literally hundreds of bus engines and seen all of this very regularly.  All due to the severe duty cycle a bus engine has to put up with.  Stop and start, from idle to full throttle for a minute, then back to idle again.  Then foot flat down again.  Was not a problem back in the day as a bus engine was typically around 11 ltrs with a lazy power curve and had a lot of mass preventing sharp temp spikes.

 

These days, the typical single decker bus will have a turbcharged, 4 cylinder of around 3 to 4 litres.  This means the engine has to work far harder and rev higher.

Naturally the engines blow very regularly.  It is rare to see a modern bus engine last more than 8000 hours.  It should last 30,000 hrs.

Even how you treat your engine when warm has consequences.

 

In answer to the OP.  No engine should be run flat out until it has reached its specified operating temperature.

 

A well known axiom in engineering circles..... " engines dont die, they are murdered".

 

It doesn't help the fact that drivers plant the throttle from stone cold to build the air pressure up 

 

Time and time again I see this at work! 

 

I think the largest engine we have in a bus not is about 6 ltrs! All euro 6 that run rather hot!