3.5 9.75:1 Puffing blue smoke

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unstable load
Top Dog
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Re: 3.5 9.75:1 Puffing blue smoke

Post by unstable load »

Thank you!


Cheers,
John

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Prophead
Helpful or Confused
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Joined: Thu Jun 16, 2016 7:05 am
Location: Falkirk

Re: 3.5 9.75:1 Puffing blue smoke

Post by Prophead »

Just to complete the tail of this saga I think I have found the route cause of all my smoke wows.

The fuel pressure regulator was incorrectly set delivering about 7psi to my Edelbrock 1404. Having checked the manual i have reset it to the correct 5.5psi. I think the additional fuel pressure was having the biggest effect at WOT, a lot of black smoke, but was ok at other areas of opperation. Hence the confusing decent looking plugs but sooty exhaust. What I think happened was when on the track-day, using a lot of WOT, washed the cylinders clean of their oil. This just happened to effect no8 more than the rest, and it gets carbon build up and caused sticky rings. It also goes towards why it only blue smoked once the engine was fully hot and had been driven a bit.

So, having sorted the fuel delivery out, carbon cleaned the engine, changed the oil back to VR1 racing, adjusted the timing and refreshed ignition, and improved the cooling, I am happy to report that normal operations have resumed. No more blue smoke, no more black smoke, no more using 1ltr oil every 100miles. So glad I didn't start tearing the thing apart.
Porsche 924 GTv8 Track-day car project
Porsche 944 2.5 Lux gone but not forgotten

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