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Compression results - White Smoke, need some input..


Guest nosoupforyou

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Guest nosoupforyou

Car is running in AEM v2, new 62mm single, nee walboro 255 and stock pump, new 850cc injectors, new r154 trans, fresh rebuild on motor, new NGK 3330s at .026, fresh 10w-40 full synthetic oil.

 

Took it to 160mph on a 15lb test pull the other night. (12.5AFR @ WOT)

 

Ever since I have white smoke at idle out of the exhaust, intake breather and turbo/exhaust side.

 

Compression test @ 3/4 operating temp.

 

Cyl 1 # - 165

Cyl 2 # - 160

Cyl 3 # - 170

Cyl 4 # - 165

Cyl 5 # - 150

Cyl 6 # - 130

 

Which worries me because there is only 5k on the motor.

 

It runs good. Idles good. Boosts fine.

 

I did notice an oil puddle underneath the turbo on some brackets. So maybe turbo seals? Its pure white smoke. Sometimes on start up it looks like a damn fog machine. Then after you drive it for 15min it practically goes away..

 

Help?? What route should I take?

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12.5 afr is abit lean especially considering RON rating on pump gas in the states are low.

As for the white smoke could be turbo seal as you are finding a oil puddle it would be a good place to investigate first

Standard pressure:1,079 kPa (11.0 kgf/cm2, 156 psi) or more Minimum pressure:883 kPa (9.0 kgf/cm2, 128 psi)

Difference between each cylinder:98 kPa (1.0 kgf/cm2, 14 psi) or less(d) If the cylinder compression in 1 or more cylinders is low,pour a small amount of engine oil into the cylinder through the^spark plug^hole and repeat compression test on the cylinder with low compression.If adding oil helps the compression, it is likely that the piston rings and/or cylinder bore are probablyworn or damaged.If pressure stays low, a valve may be sticking orseating improper, or there may be leakage past the gasket.

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Guest nosoupforyou

Did an oil change this morning. Went from 15w-50 synthetic (25psi at idle, 50psi at wot) to 10w-40 synthetic and now it's running 50psi idle and up to 90psi WOT. Does this have to do with compression or the turbo aswell?

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Guest nosoupforyou

No i havent done a leak down test yet.

 

And its a precision 6152.

 

Also concerned about my new 75psi oil at idle since i switched oil weights..

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No i havent done a leak down test yet.

 

And its a precision 6152.

 

Also concerned about my new 75psi oil at idle since i switched oil weights..

 

Your far better off running the 10W40 than the 10W50, as you have seen the pressure has come up to about where it should be, the heavier oil will tend to stress the oil pump at high RPM and also i suspect the reason for the lower pressure at WOT is down to the oil being over pressure is keeping the oil pressure relief valve open.

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Guest nosoupforyou

Alright thanks for the insight on the oil!

 

As far as my motor, i'm suspecting rings to do a badly fouled plug in the same cylinder. What should my WOT be at? 11? I was told to be at 12.5 over 5psi, as i'm only tuned to 15psi at the moment. I'd love a solid tune to upload or build off of. I'm trying to learn as I go, youtube videos, forums. But I didn't start with a solid tune or know anyone with a known working tune to adjust off of. Its AEM v2. Is there sticky to download basic or known working tunes based of certain builds?(bpu, single swap, etc)?

 

- - - Updated - - -

 

I also ordered a garret, 67mm, .60/.68 T4 ball bearing turbo.

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I think you need to go and do some in depth reading on the subject of mapping, fuelling and AFRs are all to do with engine loadings as well as boost, there is no concrete AFR for a given load, there are a lot of factors that govern what any one engine will tolerate in the way of fuelling and timing advance, things like compression ratio, squish, valve timing and boost pressure all play a part in influencing how the engine behaves,

Saying that an engine needs 12.5 at over 5psi is not the advice you should be listening to, most tuner's/mappers will aim for an AFR in the region of 11.2 to 11.8 at full load, however this can vary, there is quite a bit more to it.

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I think you need to go and do some in depth reading on the subject of mapping, fuelling and AFRs are all to do with engine loadings as well as boost, there is no concrete AFR for a given load, there are a lot of factors that govern what any one engine will tolerate in the way of fuelling and timing advance, things like compression ratio, squish, valve timing and boost pressure all play a part in influencing how the engine behaves,

Saying that an engine needs 12.5 at over 5psi is not the advice you should be listening to, most tuner's/mappers will aim for an AFR in the region of 11.2 to 11.8 at full load, however this can vary, there is quite a bit more to it.

 

:yeahthat:

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I think you need to go and do some in depth reading on the subject of mapping, fuelling and AFRs are all to do with engine loadings as well as boost, there is no concrete AFR for a given load, there are a lot of factors that govern what any one engine will tolerate in the way of fuelling and timing advance, things like compression ratio, squish, valve timing and boost pressure all play a part in influencing how the engine behaves,

Saying that an engine needs 12.5 at over 5psi is not the advice you should be listening to, most tuner's/mappers will aim for an AFR in the region of 11.2 to 11.8 at full load, however this can vary, there is quite a bit more to it.

 

Good post/advise.

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