Engine dipstick markings

[wilf]

Anyone know how much oil is represented between the two marks on the dipstick?

[MikeParker]

Anyone know how much oil is represented between the two marks on the dipstick?

I would certainly be interested to know! Not much help..

[trunt]

Usually a quart?

[dasadrew]

On 4th June 2020 my oil was exactly at MIN and, to get it to MAX I added 400ml
On 12th December 2020 it was just slightly under MIN and, to get it to MAX I added 500ml

I must admit I'm not too impressed with the oil consumption, although the engine had still only done 4000km so maybe it's still running in?

[wilf]

Thanks Drew, very helpful

Maybe your engine needs a hard workout to get those rings fully bedded?

[MikeParker]

On 4th June 2020 my oil was exactly at MIN and, to get it to MAX I added 400ml
On 12th December 2020 it was just slightly under MIN and, to get it to MAX I added 500ml

I must admit I'm not too impressed with the oil consumption, although the engine had still only done 4000km so maybe it's still running in?

May be worth putting in a catch can just in case it is oil being blown out of the breather like mine.
Mike

[dasadrew]

There's no sign of oil anywhere around the engine apart from the occasional drip in the oil pump area. No blue smoke out of the exhaust. Not sure how much consumption is "to be expected". Most of my Stag motoring is short runs. s the response to the question in this thread has been quite limited, I wonder how many actualy do measure the cc's going in between changes!

[wilf]

That was why I wanted to know - to guage the oil consumption. My guess at the moment is around 1000 miles/pint, which I think would be quite acceptable. But I would like to be slightly more scientific about it.

[jbuckl]

There's no sign of oil anywhere around the engine apart from the occasional drip in the oil pump area. No blue smoke out of the exhaust. Not sure how much consumption is "to be expected". Most of my Stag motoring is short runs. s the response to the question in this thread has been quite limited, I wonder how many actualy do measure the cc's going in between changes!

1000 miles per pint is fine.

If the oil consumption is less than half that…. It’s probably being diluted by fuel. (!)

Always worth smelling the oil …. Fuel in oil is a pretty distinctive aroma.

Sounds as if your engines situation is at the other end of the spectrum though. (Oh & leaks!)

Bore hone pattern / depth & valve guide fit are the usual culprits for excess oil consumption.

Worth checking how much blowby there is… disconnect breather hose…. Although there are no numbers for that…it’s a bit subjective tbh.

[dasadrew]

Further to my post above, here were the km readings

125292 km rebuild finished and oil filled for first time
128418 km 1100ml added to bring back to max after 3126 km
130098 km 400ml added to bring back to max after 1680 km
132490 km 500ml added to bring back to max after 2392 km

7198 km, 2000ml
4500 miles, 3.5 pints

1300 miles per pint (unless I've slipped on the calculation)

[wilf]

Another facet of Stag paranoia?

[Motorsport Micky]

You have to take positive steps after a rebuild or running in a new engine. With race engines about 20 mins on a rolling road does the job, tell the operator you are bedding the rings and he'll "load "the engine as the car runs on the rollers increasing the roller resistance within the grip capabilities of the tyres, and watching the engine temperature to avoid overheating.
There's a lot of hooey talked about "an Italian tuneup" or "drive it like you stole it" neither of which helps the rings bed in, the rings need running in the BMEP range (google it) Brake Mean Effective Pressure. This is running the engine in the rev range (under load) where the downward power stroke of the piston exerts maximum outward pressure on the piston rings. This allows the rings to "gouge" complimentary grooves (no panic, we are talking microscopic levels) into the cylinder bore walls improving piston ring sealing and oil deposit scraping off, and commonly occurs around the maximum torque of the engine and not in the higher ranges where the tacho needle is bending around the tacho stop pin !..goodbye any aberrant Italians who use cars for bank robberies !
You can carry this out yourself whilst driving on public roads but to develop the maximum pressure which expands the piston rings and forces them into contact with the cylinder walls you need to be in top gear and be giving it full throttle, being in 4th or 5th gear on a part throttle don't cut the mustard. The long uphill gradients on motorways are good for this, (loading the engine) in 4th gear at about 2500 revs (below max torque but allowing an operating range) and give it full throttle holding the pedal hard against the floor... without lifting, until the revs get to 4000 then drop off the throttle and do it again, and again, and again, until you reach the top of the gradient. On the next junction come off and repeat the exercise on the other side of the road Motorway/Autostrada whatever as you return to your start point. I would carry this out weekly for about a month. As previously said on race cars we do it on a rolling road and it can take 20 mins or more loading the cars revs on the rollers and applying maximum torque, or on models which are MOT, taxed and tested about 200 miles on public roads.

Don't confuse bedding in with wearing the engine out, without the rings gouging out the material from the cylinder bores the engine will not give the best mpg or power, under a microscope the patterns on the rings and cylinder bores are complimentary and giving the best gas seal and oil removal from the upper cylinder preventing glazing and burning. My road car tows a 1700 kg caravan about 2000 miles a year and it's max torque is between 45 and 55mph and after a seasons caravan use inadvertently carrying out BMEP running when towing, it's performance is always improved.

Micky

[jbuckl]

IIRC, running in on a performance engine dyno was 10 hours at 50% load…. And they hated wasting dyno hours.

[Motorsport Micky]

IIRC, running in on a performance engine dyno was 10 hours at 50% load…. And they hated wasting dyno hours.

Yeahhh ? that sort of comment doesn't reflect the economics of making a living from selling dyno hours on a rolling road does it ?
A day spent bedding in rings can still be charged the same as a day carrying out power runs and maximising the efficiencies. Those would be done on a car on the rollers even if it wasn't a race unit, it still needs timing to be maximised and it's efficiencies checked. To give you an idea I've only been charged £50 for bedding in rings which reflects the time spent on the rollers which is less on race engines, because the fit of piston to liners is greater because of the requirement to develop full power almost instantly.
The rest of the engine can be catered for on the public roads as said above ( on models which are MOT, taxed and tested (hence road cars not race) about 200 miles on public roads.), or If you are driving the 200 miles you can bed the rings in at the same time. The important thing is to not rev it's nuts off but load the engine and run it full throttle in it's BMEP range, but I'll gladly bow to superior knowledge.

Micky

[flying farmer]

My last 2000 mile round trip to France used about a pint of oil.
The previous one used about 4 pints.

I discovered the reason on my last rolling road session, the small puddle of oil beneath the car came from a faulty oil cooler take off plate which i have since replaced, or maybe towing the trailer tent helped this time?