Synthetic Myths

[Birdman]

can't you see the pic,,

it's a "HARLEY DAVIDSON"

Oh I can see that. It's the model I was asking about.
I ride motorbikes too, remember?

Here's one of mine I made earlier!! It's a....(you tell me!)

 

[Dieselman]

Oh I can see that. It's the model I was asking about.
I ride motorbikes too, remember?

Here's one of mine I made earlier!! It's a....(you tell me!)

At a guess it's a Yamaha take off Harley Fat Boy.

If that's your house, that sure looks an interesting place.

 

[COUPE FREAK]

Oh I can see that. It's the model I was asking about.
I ride motorbikes too, remember?

Here's one of mine I made earlier!! It's a....(you tell me!)

hd rip=off,, vulcan 1500,, ?? not sure,, they all look about the same,,

FL is the model designation,, 1979 1200cc,, mine's not quite standard though,,

 

[Birdman]

OK C-Freak - close, but no cigar! Besides, aren't Harley's just Indian rip-offs? Clue: it's an 1800 twin with piston bores bigger than a North American Mustang so they say. I guess that gives it away.

Here's another 'guess what' ride, taken from the other side of the courtyard.
(Btw the moderator is being ver-r-y-y lenient with us, dontcha think?? )

 

[COUPE FREAK]

sorry,, no idea,, not very well up on new models,, living in the past,, if it was a 70's or 80's model ,, i'd have more chance,,

 

[Birdman]

OK, they do all look the same, except this one! It's a Honda VTX1800C FWIW.
Faster than most 911s to 60 but a bit slower thereafter.
The red one's an Aprilia Falco SL1000 - a twin.

I guess I should stop now before the moderator packs me off to a bikers forum and bans me from here til Easter

 

[steptoe]

Those bikes are fine for a sunny sunday hour ride -

if you want to be in the saddle a littlelonger, you'll need a real bike .

 

[COUPE FREAK]

nice bikes beemers,, especially like the 1200c,, ie james bond one,,

was that a sunday when you took the pic's,,

 

[TKB13]

The same really applies to car engines.

Rather than thrashing an engine I would go for revving the engine at full load (steep hill, heavy load) several times for the first twenty miles or so. This will definately reduce bore glaze and will ensure the piston rings seat well into the cylinders.

I'm with Birdman here, have to totally disagree that a new engine should be subjected to heavy loading to assist running-in. Fast, yes (within reason of course) but under light load always. Should never be allowed to 'labour'. Opinion only of course, but no-one will change my mind.

 

[Dieselman]

I'm with Birdman here, have to totally disagree that a new engine should be subjected to heavy loading to assist running-in. Fast, yes (within reason of course) but under light load always. Should never be allowed to 'labour'. Opinion only of course, but no-one will change my mind.

Consider this.
When an engine is revved higher it creates heat which is bad for new components.
Also what to you think creates the good seal between the rings and the bores? Cylinder pressure, which will be greatest when the engine is working harder, not faster.

Another point to consider is that all new engines pass oil by the rings until they seat properly. The oil is what causes glazing. Once cylinders are glazed the rings can never seat unless the liners are glaze busted.

It has been known for a long time that a gentle same speed cruise is the worst way to run an engine in. The engine speed should be constantly varied and should not sit at a constant rpm.


http://www.mototuneusa.com/break_in_secrets.htm

 

[jgevers]

Consider this.
When an engine is revved higher it creates heat which is bad for new components.
Also what to you think creates the good seal between the rings and the bores? Cylinder pressure, which will be greatest when the engine is working harder, not faster.

Another point to consider is that all new engines pass oil by the rings until they seat properly. The oil is what causes glazing. Once cylinders are glazed the rings can never seat unless the liners are glaze busted.

It has been known for a long time that a gentle same speed cruise is the worst way to run an engine in. The engine speed should be constantly varied and should not sit at a constant rpm.


http://www.mototuneusa.com/break_in_secrets.htm

You're right. I order to get an engine to seal well (better than 95% on a leak down test) the running in should be done at varying speeds and loads. In the first hour or so be very carefull with revs (I keep them between 2 and 3 thousand revs) but high loads for short periods.

The result of gentle, low load running in (I speak from experience) seems to produce engines that have higher cylinder leakage, lower torque/power and higher oil consumption.

Cheers

 

[Birdman]

Consider this.

It has been known for a long time that a gentle same speed cruise is the worst way to run an engine in. The engine speed should be constantly varied and should not sit at a constant rpm.

http://www.mototuneusa.com/break_in_secrets.htm

Couldn't help noticing the link is to a performance biking site

I read the linked page with interest because it's backed up empirically.

There is a difference between bikes and cars in that modern high-revving bikes (10 - 14 000 rpm) have factory coatings on the cylinder bores and pistons, and these coatings must chemically react with each other during the run-in period for the pistons to bed-in correctly. High temperature/pressure combinations over the first 200 miles or so are needed to do this. So it is not just a "wear" issue but also a chemical reaction laying down a new micro-coating on piston and bore. If the rider doesn't create the neccessary conditions for high temperatures/pressures during the early run-in miles this change will never happen and the engine will under-perform and eat oil over the whole of its remaining life. Which, it may surprise people to know, can run to over 100 000 miles before repair even on these screamers!

So high-performance bikers needs to be a bit more demanding on their engine than car drivers during the run-in period (HD and other cruiser owners don't need to read this, it will only serve to alarm!).

 

[tamrsoft]

I recently dug this up from the Times-online motoring advice forum, I cannot believe any engine in reasonable order consumes this much. Did he not follow the run-in techniques discussed in this article. Probably the reason we cannot see the bimmer in front is because of the smoke screen. I use only a fraction of a litre in between 6000 miles oil changes. All down to a good Synthetic.


Q - I am baffled by the quantity of engine oil my BMW 520 (51 reg, 104,000 miles) consumes, right from its early days. I seem to put in a litre of oil every week. Is this normal? There does not seem to be any leakag.? Smit Bharadwaj, Ashford


A - BMW’s listed oil consumption figure is around 500 miles to the litre and you are doing about 500 miles a week, so the consumption is acceptable. Modern engines run on low viscosity oils, which improve starting, and emissions, but they do seem to burn more readily in some engines and hence oil consumption is higher. High-speed motoring tends to use more oil, and at 500 miles a week, my guess is that a lot of your driving is on motorways. You have managed an impressive 104,000 miles and with regular oil and filter changes the engine should have lots of life left, but do keep checking that oil level – you’ll only run out once.

 

[nigel cross]

Seems like a great get out clause, ( abit like normal wear and tear). I have had a couple of Beemers before and they didn't use oil anything like that.

 

[Birdman]

Q - I am baffled by the quantity of engine oil my BMW 520 (51 reg, 104,000 miles) consumes, right from its early days. I seem to put in a litre of oil every week. Is this normal? There does not seem to be any leakag.? Smit Bharadwaj, Ashford

There is a huge discrepancy between what we expect from experience by way of oil consumption and the manufacturer's published figures.

My guess is that the discrepancies aren't due to poor manufacturing but rather to what happens after the car gets onto the public roads. As far as oil consumption goes, treating an engine too gently during the run-in period can cause more problems than treating it harshly.

That could be an explanation for your excessive oil consumption.

BMW did for a while produce coated bores (a different technology from and not relevant to my earlier post re bike coatings) that failed when exposed to certain fuel additives which caused excessive bore wear, galloping oil consumption and in extreme cases engine seizure. But that isn't the source of the problem here as it was cured by BMW in the nineties. Some cars had several warranty replacements before BMW identified the cause and stopped coating its cylinders.

 

[COUPE FREAK]

500 miles to the ltr of oil,, it must be smoking like a diesel,, i'd get shot of the car,, sounds like the engines knackered,, apart from being expensive you'll be under the bonnet all the time,, checking the oil level,,

my little ford ka that i used to thrash up and down to london on a weekly basis,, 500 mile round trip,, never used a drop,, plus various other cars,, bmw,, saab,, volvo,, etc i've owned never used anything like the ammount of oil you're using,, and the cars were'nt new,, all 100.000 plus miles on their clocks,,

if it's using a ltr for 500 miles either the bores are shot or it's sucking oil past the valve guides,,

car's use oil not use it up,,

 

[Dieselman]

Couldn't help noticing the link is to a performance biking site

I read the linked page with interest because it's backed up empirically.

There is a difference between bikes and cars in that modern high-revving bikes (10 - 14 000 rpm) have factory coatings on the cylinder bores and pistons, and these coatings must chemically react with each other during the run-in period for the pistons to bed-in correctly. High temperature/pressure combinations over the first 200 miles or so are needed to do this. So it is not just a "wear" issue but also a chemical reaction laying down a new micro-coating on piston and bore. If the rider doesn't create the neccessary conditions for high temperatures/pressures during the early run-in miles this change will never happen and the engine will under-perform and eat oil over the whole of its remaining life. Which, it may surprise people to know, can run to over 100 000 miles before repair even on these screamers!

So high-performance bikers needs to be a bit more demanding on their engine than car drivers during the run-in period (HD and other cruiser owners don't need to read this, it will only serve to alarm!).

The issue isn't one of premature wear, it is one of blow-by.
The principles of ring sealing are the same irrespective of engine type. The cylinder pressure forces the rings out to the cylinder and creates a good seal.

The article clearly states that the principle applies to all cylinder types made of different materials whether coated or not, it even mentions lawnmowers.

I know of a new Volvo truck that the driver was meticulasly running in and was complaining of high fuel consumption and low power. Volvo sent out their regional technican who took out the truck fully laden and absolutly caned it.
Problem solved.

If that was the wrong thing to do why would he do that?

 

[Birdman]

You think it's not about "wear". Read this!

http://www.thedieselstop.com/contents/getitems.php3?Breaking in a Diesel Engine

I think there may perhaps be a difference of opinion here!

 

[jgevers]

You think it's not about "wear". Read this!

http://www.thedieselstop.com/contents/getitems.php3?Breaking in a Diesel Engine

I think there may perhaps be a difference of opinion here!

Probably. Although I agree with 'Jay' with loading to a certain extent, the large American diesel engines do not rev as much as the smaller European ones. In my opinion high revs in the first few hundred miles (heat cycles) is a no-no. Although the plasma type honing that holds more oil on/in the bores for superior sealing and first fill oil are pretty good at not leaving glazed oil deposits, the engine block still has to 'settle'. The first few heat cycles allows the crank to 'settle' in the block. At high revs (4-7K) the new crank bearings will allow premature wear and clearance which results in lower oil pressure.

Jay's idea of 'flash deposits' might be true in a low reving engine (I still doubt it though) seems strange as piston rings are very sharp and the higher the load the more they scrape. The glazing of bores that we see as a result of inadequate loading can normally be removed by 'caning' the engine. This shows the effect of the scraper rings.

As with everything, 'excessive' is too much. With new engines, be it race, rally or road, if we run them in on the road rather than engine dyno, we use varying loads for the first approximate 200 miles between 2 and 3 thousand revs. After that we add an extra 500 revs every 70 odd miles. The main thing to remember is varying loads and engine speeds. A long stint on the motorway at 70 miles an hour seems to produce rotten engines that drink oil, and have lower torque/power output.

The reason why we do it this way is that it has proven to produce engines with almost no oil consumption, best sealing which results in having the compression that we set out to have and less fuel dilution in the oil, and ergo, produce the best torque/power.

Oh, and we change the oil after approximately 1000 miles even when the manufacturer doesn't reccomend it anymore but that might be a bit anal.

Cheers

 

[big x]

You think it's not about "wear". Read this!

http://www.thedieselstop.com/contents/getitems.php3?Breaking in a Diesel Engine

I think there may perhaps be a difference of opinion here!

Whilst interesting I don't think stoneage American truck engines have much in common with modern hi tech car diesels.
There are hardly any diesel cars stateside.

adam