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Skinners Sprint Micra

Aren't you meant to use a 'bed in' oil, that has zinc, or is it magnesium , soft **** added to it to help break stuff in?
 
pork said:
Aren't you meant to use a 'bed in' oil, that has zinc, or is it magnesium , soft #### added to it to help break stuff in?
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I think that's mainly for breaking in new cams/flat tappets on big blocks.

I just use cheap mineral frequently for the first few hundred and till its fully bedded n sealed then use any type afterwards.
 
pollyp said:
I think that's mainly for breaking in new cams/flat tappets on big blocks.

I just use cheap mineral frequently for the first few hundred and till its fully bedded n sealed then use any type afterwards.
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I was jus trying to look smart after watching blokes on that fast and loud program break in their engines ;)

Your right, they were big block v8's too
 
pollyp said:
Barely. It depends on the bore finish & bedding procedure, my forged pistons took at least 1.5k till it stopped smoking and 7k till the pistons weren't pooling oil.
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I'm more than happy with the engineering in it, if it's good enough for them as they say.

Iv never had an engine that smoked, but on an island 36 miles long 1,000 miles is annual mileage for my and not really practical :)
 
Paul, (Pollyp), your bedding in isn't really representative of what an engine 'should' take to bed in though sadly :(

A decent diamond honed block with new rings will seat in very quickly. 500miles should be plenty to ensure good bed in on a fresh engine before swapping over to a semi-synth/fully-synth.

We all have our favorites , I use Millers CRO.
 
Low Rider said:
Paul, (Pollyp), your bedding in isn't really representative of what an engine 'should' take to bed in though sadly :(

A decent diamond honed block with new rings will seat in very quickly. 500miles should be plenty to ensure good bed in on a fresh engine before swapping over to a semi-synth/fully-synth.

We all have our favorites , I use Millers CRO.
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Indeed mine is not the norm, hence i mentioned its dependent on number of variables.

Factory engines are built consistantly close to a standardised quality control so that they're all the same. Some cars are even initially bedded in at the factory on a dyno in a standardised procedure thats been developed by the engineers.
This ensures all the cars are delivered almost exactly the same and perhaps close to 100% bedded (depends on company) and so a final minimum break in distance of few hundred miles is suitable as a guide.

For engines that are hand rebuilt and bedded on uncontrolled public roads and weather, each one are unique and takes a different time to reach a point where the rings seal at their best against the bores with the highest compression and lowest oil consumption. So here you have to constantly monitor the engines condition throughout breakin till all the signs show the rings have reached its peak performance then its ready to run and can optionally run fully synth to slow down the wear rate and keep it at thar sweet spot for longer.
 
I've built several engines over the years and my local machine shop do the rebores etc and each one has been fine after a few hundred miles of gentle driving. I've never had oil pooling on the pistons or measurable oil consumption.

gentle driving up to 3k for the first 500 miles then slowly increase revs over the next 500
 
Bit closer to where I need to be:

Engine bays painted up gloss black and cleaned out.

Sills and underside ground back and oxide painted ready for underseal in the week.

Found I need a fresh drivers side cv joint!

Engine is bolted to the 3.8:1 box and is in the engine bay :)
 
Low Rider said:
Paul, (Pollyp), your bedding in isn't really representative of what an engine 'should' take to bed in though sadly :(

A decent diamond honed block with new rings will seat in very quickly. 500miles should be plenty to ensure good bed in on a fresh engine before swapping over to a semi-synth/fully-synth.

We all have our favorites , I use Millers CRO.
Click to expand...
would you be able to shorten that time on an track for example? continual speed change and rev monitoring? How would a motorsports team do it? I have seen this guy who breaks in bikes by opening the throttle up with control in rev at increments. The pushing power expands the rings causing the friction more effectively. Is this stuff a dark art or just lots of people cocking it up? Surely if you get it done right when the bores are done the seal should be near perfect? Also could you not just run in an engine with just a weekend trip to like nottingham and back in one go? haha ALL the questions. Could skinner just continually drive around the island for a day or two?
 
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SirChris said:
would you be able to shorten that time on an track for example? continual speed change and rev monitoring? How would a motorsports team do it?
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We warm it up at 2,000-2,500 rpm for 10 or so minutes so its thoroughly warmed through. Then load it on a dyno so we can monitor it.
If the map aint right... breaking an engine in on a bad or insufficient tune aint good. But they're race engines. They're built to scream hours on end

Theres no right way to break an engine in :) I reckon a day or two of steady driving should be fine. Checking plugs for air/fuel mix the old fashioned way
 
h701micra said:
We warm it up at 2,000-2,500 rpm for 10 or so minutes so its thoroughly warmed through. Then load it on a dyno so we can monitor it.
If the map aint right... breaking an engine in on a bad or insufficient tune aint good. But they're race engines. They're built to scream hours on end

Theres no right way to break an engine in :) I reckon a day or two of steady driving should be fine. Checking plugs for air/fuel mix the old fashioned way
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Yeah theres no right way, but there obviously is methods which do work better than others... if nissan made me a micra engine which lasted 280 thou, then they must of bedded in the engine somehow? Correctly...
 
They do initial bench bedding in I'm sure and the new owners does the last couple of hundred miles.
Bedding in methods can affect an engines peak performance too according to the Internet :)
 
@Skinner_87 I figured you might be interested in this sort of chat, please tell me to shut up otherwise.

@h701micra so once again the internet ssays stuff.. people dont really know then? well it must have a lot to do with peak performance, you are making a 'air tight' seal with the rings. bedding in creates this ability so, winging it wont do anything but problems. @pollyp did you compression test your bedding process at various intervals, seems like something you would do. results?
 
SirChris said:
would you be able to shorten that time on an track for example? continual speed change and rev monitoring? How would a motorsports team do it? I have seen this guy who breaks in bikes by opening the throttle up with control in rev at increments. The pushing power expands the rings causing the friction more effectively. Is this stuff a dark art or just lots of people cocking it up? Surely if you get it done right when the bores are done the seal should be near perfect? Also could you not just run in an engine with just a weekend trip to like nottingham and back in one go? haha ALL the questions. Could skinner just continually drive around the island for a day or two?
Click to expand...

checking and building the engine to precise clean tolerances is obviously the first essential key step.
next a controlled environment like an empty clear racetrack or road is the best place to break-in an engine with undisturbed controlled loading/unloading of the rings to ensure the best seal, economy & reliability.
finally constant monitoring of the engine & oils condition throughout the whole thing with frequent oil changes will tell you how it's going.

read this motoman break-in guide
http://www.mototuneusa.com/break_in_secrets.htm
 
SirChris said:
@pollyp did you compression test your bedding process at various intervals, seems like something you would do. results?
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yes, you know me, of course. frequently measured compression after each run every day & inspected the cylinders condition with an endoscope. I've even videoed the whole 1500m process.

http://micra.org.uk/threads/pollymobiles-rebuild.35251/page-83#post-600310

the forged piston setup on mine's obviously a different case to say break-in a stock engine and there was also afew oil leak mistakes that I later resolved. I also tried fitting stiffer JE oil ring expanders and replaced stem seals but it still burnt oil for awhile.
posted a history of the compression during the procedures here.
http://micra.org.uk/threads/pollymobiles-rebuild.35251/page-91#post-622118

5snc.jpg


it took me ages to break-in but (this might only be in my case with these racing forged pistons) the best fix to my leaky oil ring was after I pushed her on a trackday in Feb and she sealed alot better.
 
SirChris said:
@Skinner_87 I figured you might be interested in this sort of chat, please tell me to shut up otherwise.

@h701micra so once again the internet ssays stuff.. people dont really know then?
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But then on the other side I see why people don't give it such effort. The main reason being if your engine is honed properly and rings properly gapped etc then they're already gonna be near on perfect.
We get the specs from a company who has spent alot of time researching the engine. That's why I'd say you only need a couple hundred miles if that. All depends on how the engine is built
 
See that is why my mind was blown with pauls. I said this previously, if they are machined to the spec of the manufacturers suggestion of the new pistons and rings then they are like the near perfect attributes to create the best seal. You shouldnt need much but get it warm and give it a few foot to floor love blaps down the motorway with equal deaccel scenarios.?
 
Whatever happens. I will give my engine, pistons, metal H/G and rings to someone who knows what they are doing. I may just give someone the car so they can bed it in too... if it dont seal its not my issue then. * plus I dont want to have to spend countless amounts of money fixing my mistakes.

@Skinner_87 what has your engine makers said? ** engine builders, god i speak like a muppet
 
SirChris said:
Whatever happens. I will give my engine, pistons, metal H/G and rings to someone who knows what they are doing. I may just give someone the car so they can bed it in too... if it dont seal its not my issue then. * plus I dont want to have to spend countless amounts of money fixing my mistakes.

@Skinner_87 what has your engine makers said? ** engine builders, god i speak like a muppet
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The machine work was done by Matt's engineer so i've 100% faith there.

My engine builders my dad, time served at Datsun/BMW & i've never seen any problems with anything he's built up :)
 
Skinner_87 said:
The machine work was done by Matt's engineer so i've 100% faith there.

My engine builders my dad, time served at Datsun/BMW & i've never seen any problems with anything he's built up :)
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sorry mate i wasnt implying urs aint going to work. I was wondering what has been suggested to you?
 
SirChris said:
sorry mate i wasnt implying urs aint going to work. I was wondering what has been suggested to you?
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didnt read it like that at all mate, no worries.

Rings were gapped as per the engineers specs.

And the plans just to start up on the drive for 20 / 30 mins to get it warm, check for leaks, burn the chemicals of the exhaust wrap.

Then 350 / 400 miles of as smooth as i can drive up to 3k.

then build up the revs by 500 rpm until the week of the hill climb. Then change the oil & filter and give it some proper beans
 
We all have our own methods. I change oil & filter within the first 50miles, then again at 500mile intervals before switching over to a synthetic oil.

Regardless of break-in methodology, that first oil change is the most important one as it's likely to be full of the most deposits you'll want to get rid of.
 
Low Rider said:
We all have our own methods. I change oil & filter within the first 50miles, then again at 500mile intervals before switching over to a synthetic oil.

Regardless of break-in methodology, that first oil change is the most important one as it's likely to be full of the most deposits you'll want to get rid of.
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Hopefully the magnetic sump plug will prove its worth too! :)
 
I want 100 from my CG13 for now, cant get more because of the gearbox :).

@h701micra mentioned something about the gearbox I have being rather sought after for racing/sprints ect?
 

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