Running in a motor. opinions?

[jeffro ra28]

At idle there is insufficient oil-throw off to lubricate the pistons, rings and camshaft lobes when the oil is cold and prolonged idling should therefore be avoided.
In the initial driving period u should accelerate the car several times from 60 to 80 kmph in top gear at full thorttle(automatics in 2nd at lower speed). this will provide sufficient gas loading to build up pressure behind the top rings to ensure gas tight sealing against the cylinder walls.
Prolonged high speeds and low speed lugging should be avoided.
To much of running constant speeds is bad for bedding-in.

"Home Brand" actually make engine oil, hehe best run in oil out.

http://forums.toymods.org.au/index.p...3694msg_603694

[ghost]

I've done just over 100km on my new engine and haven't gone over 3500rpm or boosted over a few psi. I'm using Valvoline running in oil and was considering running for at least 500km before changing, but I may consider replacing the oil and filter much sooner.

I have heard that varying the rpm was the most important thing to do rather than sitting on steady rpm for ages. I remember being told by my mechanic to drive my RX7 this way for a while until it was run in. Hope I havn't been too easy on my motor and glazed the bore!?!
Hopefully not!
My neighbour freaked out at the smoke that it produced for the first two minutes and kept saying there was a problem and it was a pity my other neighbour who is a mobile mechanic wasn't home as he could tell me what to do. He almost had me panicking but I kept telling myself that this was normal and it would go away. And it did much to my relief.

Any other wise experienced engine builders able to confirm this rough break in method?

[Starfire]

You can never change your engine oil too often. Ever. When running in an engine you could change it every day if you like (probably not required though) but after 20km or so is reasonable.

The two main points to running in an engine is bedding in the piston rings and work hardening/bedding in the camshafts.

The rings benefit the most from being thrashed pretty hard, but not at constant revs. Motorsport (motorkhana, track day, hills thrash) are the best way to get that done. The quicker you do it the better the seal and less oil you will use.

The camshafts benefit the most from working in the middle of the rev range. At low rpm the load on the tip of the cam lobe is the highest with oil pressure low. At high rpm the face of the cam lobe cops a hiding. Mid range evens out the loads as much as possible.

If you are building a basically stock motor the run in is pretty standard. Baby it for a little bit (keep the revs above 2000 and avoid idling though) for the first few km. Change the oil. Give it a bit of a thrash, again varying the revs and avoiding redline and idle.

For a monster with big cams and crazy compression and/or boost the best option is to run it in in stages.

Put a stock head on your new bottom end. Run that in with a pretty hard thrashing. Change the head over to your new one. If you have a really crazy cam use stock valve springs as these will reduce the load on the new cam till it has had a chance to work harden. Once that has bedded in for a few hundred km put in the hardcore springs. Wind up the boost

Aust: if you are concerned by oil usage change your oil and then keep an eye on how much it is using in the next few days. It is normal for an internal combustion engine to use a fair bit of oil during the early part of run in when the rings arent sealing with the cyl. correctly. All engines use some oil as part of their normal operation.

If you still think that your engine is using too much oil take it back to the place that put it toghether or get it compression tested.

Cheers,

Terry

[JustCallMeOrlando]

as far as the rich when warming up thing goes.. motors just seem to need it.
when tuning mine by hand, it just idled and ran better with a certain amount of enrichment when cold....

As far as I know this is due to not enough of the fuel vaporizing and burning correctly when the engine is not up to temperature, so you add some fuel so even though the ratio remains roughly the same, the right amount of combustible fuel is still delivered.

[Starfire]

As far as I know this is due to not enough of the fuel vaporizing and burning correctly when the engine is not up to temperature, so you add some fuel so even though the ratio remains roughly the same, the right amount of combustible fuel is still delivered.

Same principal as a choke on a carbie.

[sw20r]

This is what i've heard.

Once the engine is in let it idle for 5-10minutes, dump the oil and filter.

Let it warm up again for a few minutes, and drive on a stretch of road for 500m through all gears from 2nd to 5th starting at 30 going to 65-75% throttle max (almost trashing it but not quite..)

come back around and do the same 2-3 times.
Once more at upto 90%-100% but easing in.
Cruise back home in medium revs 3-4K rpm.

After 3rd oil change, Boost upto 5,000RPM at 70% load (so the ecu doesnt go too rich) and on the freeway give it 100% in 5th gear from 60-90kms. And just vary the gears down+upshifting like your changing lanes

[Starfire]

IDLE IS BAD.

At idle there is very little oil pressure and the most load on the tips of the cam lobes. The pressure in the cyl. is at a minimum so they are not sealing correctly.

Try to keep a minimum of 1500 RPM and vary it up and down as you sit there.

[gearb0x]

IF ur not loading the motor free reving will be worse than idling as the piston rings will wear faster but not seal properly.

I allways keep load on an engine im running in, and only idle enough to warm up (bedding in new cams is suposed to be a different story, but i havent done that yet)

[Starfire]

Oh yeah definately avoid sitting... If you have to sit there though keep the revs above the idle range.

[Aust162]

Ok, i just changed the oil and filter. it looks as though its used about 300-600mls max of oil. (i get some really strange readings on my dipstick for some reason)

I will see how it goes now. keeping a close eye on it.

The motor has a stock standard head (rebuild) and a forged bottom end.

[ghost]

I change my oil and filter today after 250km of running in.
The oil looked like some midnight metallic black paint. It was FULL of suspended metal particles.
When I poured the oil out of the drip tray it looked like I had been gold panning.
Lots of medium sized particles.
I am very glad I didn't leave that in the engine for a further 750km!!

[Aust162]

I change my oil and filter today after 250km of running in.
The oil looked like some midnight metallic black paint. It was FULL of suspended metal particles.
When I poured the oil out of the drip tray it looked like I had been gold panning.
Lots of medium sized particles.
I am very glad I didn't leave that in the engine for a further 750km!!

Yeah, thats pretty much what my oil looked like. it looked nice and golden on the dip stick, but it was actually black. the oil i poored out of the filter looked like metallic paint. i cut my filter open with tin-snips and it had a couple of larger metal flakes, not much.

I wish i had changed it eariler...the guys who assembled the motor said to leave it for 1000kms.

[ghost]

This is after 250km running in.
Would you leave this in your engine for 1000km?!

Suspended particles


Some of the larger particles


Bottom of the pan

[Aust162]

Nice pics there.

I'd have to say my oil didnt look as bad as that though

[sam-131]

wtf mate if i found a bit of steel that size i would be thinking hard about were it came off that carnt be good that oil looks like the oil i dumped out of a sized/rod out the side the block 304 i had had

has it still got compression?
it looks like it been making dry steel on steel contact did prime the engine befor starting it?