running rich whilst breaking engine in

wee-jo

wee-jo

Member +
looking for some advice on the engine run in process.

I recently rebuilt my forged engine and I was advised to get a base map put on it after 100-200 miles. Is this neccesary? The only concern I have is that the a/f ratio is quite high, the aem gauge reads 14-15 constantly and I'm worried it will do damage to the engine being that rich.

Is there anyway to reduce the richness without getting it mapped or would you recommend mapping asap? The car runs a td04 with walbro fuel pump and a rrfpr.

Any info would be appreciated.
 
M

Mikey4410

Member +
you can run a td-04 up to 15 psi with standard ecu,rrfpr,fcd,etc and supporting mods.u can get it mapped but dont have to at all.

mine reads 14.8 ish when cruising/idle and mines rich and runs at 11.8-12.0 on full boost standard ct9 16 psi. im running 3 bar fuel pressure

hope this info helps
 
wee-jo

wee-jo

Member +
Sorry guys I got muddled up, yeah it runs lean off boost at 15 on the a/f gauge. My issue is that in order for it to pass the brake test aspect of the mot it would need to idle for a while. The garage is not comfortable letting it idle for a long period of time because they recommend driving it under load straight away without a stop/start driving style.

What would you guys recommend doing?
 
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Murray

Member +
Skalabala said:
You want it rich to wash the bores. 100 miles is fine. But you have to boost it in high gear.
Click to expand...

No you dont, misleading info right there. Bore wash is bad

For pootling around the ecu will swing back and forth from anywhere between 13-15 afr.
For an mot my car idles for about 5 mins and gets switched off. that includes the brake tests and emmisions.
 
wee-jo

wee-jo

Member +
Murray said:
No you dont, misleading info right there. Bore wash is bad

For pootling around the ecu will swing back and forth from anywhere between 13-15 afr.
For an mot my car idles for about 5 mins and gets switched off. that includes the brake tests and emmisions.
Click to expand...

Thanks Murray. So its ok to let it idle for a short while during the mot? Think the guys in the garage are paranoid they will break it if they keep turning it on & off without driving it over long distances.
 
Rory

Rory

Lifer
It just goes to show the folk doing MOT's have no idea what there doing with an internal combustion engine...

It will be fine for a few minutes, they wont need to switch it off and on a few times, once is enough to check the required things needed.

Your AFR will be fine for running in, if your in any doubt pop up to PHQ and see Russ for a quick run on the dyno.
 
wee-jo

wee-jo

Member +
Thanks Rory. No I mean they haven't said that they need to keep turning it on/off during the mot, what I mean is they have concerns over turning it on, moving short distance then turning off again. They want to turn it on and just go with minimal interuptions.

Also would I be right in thinking that you only come on boost gradually when you are in 4th and 5th gear?
 
S

Skalabala

Member +
Murray said:
No you dont, misleading info right there. Bore wash is bad
Click to expand...

Lean is bad for bedding in rings. A little bore wash is nothing wrong with.
And oily sleeves is also not good for bedding in rings. It is like wanting to bed rings using a good oil.
And the extra fuel cools the pistons slightly, and that is what you want.
We are the only ones that have not blown plenty engines on the track. 1.5 years on one engine!!
 
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Murray

Member +
Skalabala said:
Lean is bad for bedding in rings. A little bore wash is nothing wrong with.
And oily sleeves is also not good for bedding in rings. It is like wanting to bed rings using a good oil.
And the extra fuel cools the pistons slightly, and that is what you want.
We are the only ones that have not blown plenty engines on the track. 1.5 years on one engine!!
Click to expand...

So you would rather have excess fuel contaminating your oil rather than an ecu toyota themselves have developed?
Rorys engine has been in his GT for 4/5 years used and abused, and geuss what ecu it was running to be run in?
 
Rory

Rory

Lifer
Murray said:
So you would rather have excess fuel contaminating your oil rather than an ecu toyota themselves have developed?
Rorys engine has been in his GT for 5/6 years used and abused, and geuss what ecu it was running to be run in?
Click to expand...

Edited Muzzy..

As for fueling, you dont want rich or lean, you want it right!!

weejo - You want to boost it from the word go, dont baby it or all you will do is glaze the bores which is no use to seating the rings. But please make sure the fueling and ignition is checked before you go hooning around!
 
wee-jo

wee-jo

Member +
Cheers for the info guys. The problem is people have differing opinions when it comes to running engines in. It seems logical that the only way to get used to boost after the engine is run in would be to boost it during the running in process. I'm just worried about the engine destroying itself and 4k worth of engine lying on the road.

What would a safe level of boost be on the td04 to break in the engine without killing it at the same time?
 
Rory

Rory

Lifer
Ask yourself this, "IF" the engine were to let go, would you want it doing within a few miles of a rebuild or after a couple of weeks of pussy footing around waiting to play with it?

Anyway, run the stock ECU at 0.6 bar or so and you should be fine. But as ive said above have it checked on the dyno to be safe.

Me i run my car in per the link Adam linked. 35,000 miles (5/6 year old motor now!) later and its still pulling strong. ;)
 
A

AdamB

Member +
0.6 bar would be safe enough, if your running external wastegate you might have to change the spring.

Ideally the only thing that could let go would be bearings or piston rings, unless something was not torqued correctly or machining process was poor.
 
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