Will running rich screw up a new engine?

[sam-131]

hmm well the a bit of a caffale going on here runing it on rich will not do any harm besides carbon build up and fouling the pulgs which is really nothin to worry about if you getting the car tuned later down the track

as for run in time 1000k's try droping two zeros off that

as for running rich glazing the bores

i have personally watched a 322 (308 bored) run on 2 stroke 25:1 motie mix and jet's richer then richie rich for it's run in and yet this engine to this date is still running strong (we ran 2 stroke because we ran out of fuel about in 10mins running the cam in)

just think how long are the piston rings gonna be up there at say 4000rpm or let one 3000rpm

[Robbos_Toyotas]

running too rich and letting it idle/ run for short periods of time will wash your bores and glaze them. In turn, cutting down the life of your motor.

give it a run on the highway, it wont be running rich enough to do damage there.

[Robbos_Toyotas]

hmm well the a bit of a caffale going on here runing it on rich will not do any harm besides carbon build up and fouling the pulgs which is really nothin to worry about if you getting the car tuned later down the track

as for run in time 1000k's try droping two zeros off that

as for running rich glazing the bores

i have personally watched a 322 (308 bored) run on 2 stroke 25:1 motie mix and jet's richer then richie rich for it's run in and yet this engine to this date is still running strong (we ran 2 stroke because we ran out of fuel about in 10mins running the cam in)

just think how long are the piston rings gonna be up there at say 4000rpm or let one 3000rpm

I believe a "brand new" motor should do AT LEAST 2000km before it gets hammered. Even at this, i bet the rings arent bedded 100%

[oldcorollas]

I believe a "brand new" motor should do AT LEAST 2000km before it gets hammered. Even at this, i bet the rings arent bedded 100%

exactly!!

this is why many motors don't bed in early... no pressure behind the rings to puch them into the bores... there is no reason to take it easy on a motor for 2000km...

all you need to do is see what factories do to run their engines in before sending them out the door

[sam-131]

what exactly do you call "brand new"

well i have ran in every engine i have owned like so and i have seen and heard engines and cars worth more the house's ran in like so one example is the pavtec boys they seems to be one of the leading mechine/engine shops they have run in everything from 18rg's to lotus's in like so

so yeh you can be the judge but the stats seem to point some were

[30psi 4agte]

Ah i run my engines in for about 500km but the are built precise.

The thing you need to worry about most is bedding in the rings! driving down a steep hill and backing off throttle in a high gear will thow the rings out into the bore.
Do this 5 or so times along with normal ( light) driving will bed them in sweet!

[urantia]

hmmm interesting stuff. I just rebuilt a motor and told the owner to give it full throttle up to 80-100km in top gear and let off the throttle until it slows down to about 40. Do that about 10-12 times then take it easy for awhile. And we'll change out that running in oil for some better stuff once the kays get up there abit more. So far so good. But this is my first rebuild and don't exactly have alot of experience to draw from in this area.

[30psi 4agte]

slowing down from 100 will do it too.
Dont know about full throttle though.

[TooF]

ive always been a believer in the run the enigne up and do a few engine breaking runs to bed the rings up on the bore.

realistically all the hone is rubbed off the bore pretty quickly its not like it is going to stay there for 1000km.

give it a few engine breaking runs as suggested before me. about 200km of medium driving. drop the oil out of it. put real oil in and head on down to the dyno.

["Z" UTE]

tooch, what injectors are you running now? Is your o2 sensor working? The Wolf map should be all good for a "STANDARD" 3S-GTE. If you are washing the bores with fuel now, how are larger injectors going to effect it? Fit the larger injectors just before the Dyno tune.

cheers Chuck

[tooch]

Chuck: Stock injectors for now, the larger ones are going in when I get the 'final' tune done. I have booked the car in for a light tune next week, just to run the car in and get around in it, till I stick the larger ones in, and possibly the bigger cams I have here. The o2 sensor was working in my old engine, so I don't think it's died yet. The only other thing that might make it run rich is the removal of TVIS, and possibly the fact that this engine has no EGR, whereas the standard Aus spec ones did? Not sure if EGR would make any difference tho. The only other thing is that the compression has been slightly lowered, not sure how that would affect things though....

[boxh34d]

Although it has kind of been answered already, I'll still stick my 2 bobs in.
Running pig rich on an old engine is not a good thing, on a new one, i would consider it critical.
Petrol is a solvent, it thins the oil in the bores, and washes them clean. Also, as petrol is highly combustable ( derr ), you can end up with a sump that has little in the way of oil, as its all been burnt.

As for running in, its very simmilar to giving the engine a good 'de cobwebbing'. Hill work is best. As 30 psi 4AGTE has said, good solid engine breaking, and medium throttle acceleration i have found to work wonders for removing 'cobwebs', and is what i have always been told by those i consider knowledgable.

[cibvr4]

In regards to running in, I had a 4K race engine built for my Corolla last year and i got the car back 3 days before an event i wanted to do. When i asked about running it in i was told to drive it like i stole it! No need to go easy, the harder you drive it the better. I was also told that over time it would losen up and rev more freely and provide more power. This advice was from a professional engine builder.

I've also had a couple of stock reco engine in a few different cars over the years, and the advice i got on both occasions was to avoid high revving and vary the speed constantly for the first 500km.

So, there is obviosuly different "best practise" running in procedures depending on how the engine has been built.

[TooF]

or the otherside of it.. more conservative builders may be reccomending the take it very easy on it approach as if you say to most people "you need to give it a bit of a flogging" they will go on a mission to blow it up. and the builder is more concerned about the idiot blowing something up (even if its a component they didnt work on) less hassles the better. then the slight loss in compression by rings not seating perfectly

where your race engine builder knows that "give it a bit of stick" to someone that knows a bit more about engines means give it some stick but dont work on destroying it. and hence rings get better bedded in ?


remember for your average re-ring and fresh bearings job on a vn commodore the enigne might be fine but jsut about everything else in the car is preobaly about to fall off. hence the reco man dosent want to have deal with the idiot client coming back after his gearbox failed when flogging the bejesus out of his new engine.. despite the fact that the engine builder didnt touch the gearbox he just dosent want the hassles ?

edit: and if the owner takes it easy for 1000km then starts flogging it. the gearbox falling out in the customers mind becomes less the engine builders fault and hence less hassles for the engine builder ?

[CrUZida]

As Stu has pointed out, Motoman.

This is how he reckons to do it, and this is how I plan to run in my motor (when I build it...)

On a Dyno:
Warm the engine up
completely !!

Then, using 4th gear:

Do Three 1/2 Throttle dyno runs from
40% - 60% of your engine's max rpm
Let it Cool Down For About 15 Minutes

Do Three 3/4 Throttle dyno runs from
40% - 80% of your engine's max rpm
Let it Cool Down For About 15 Minutes

Do Three Full Throttle dyno runs from
30% - 100% of your engine's max rpm
Let it Cool Down For About 15 Minutes
Go For It !!

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