Overboosted. Now what? - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

S13Eye · 06-11-2006, 02:48 AM

I recently got done swapping an engine into my car. During the swap i installed a Greddy Profec B Spec-II boost controller, which worked fine for a cople boost cycles. It soon failed, and my S13 SR20 over-boosted. It was still reading pressure, and i had last-boost on so it recorded the max pressure. Its bad - just over 25 psi. Mostly stock fuel system, except for Walbro pump and cleaned injectors, T25, and a front mount IC. No blow off valve. The fuel tank was drained, and whatever remained was diluted with 5 gallons of 102 octane gas. The engine has a total of maybe 10 miles on it since it was swapped.

The head gasket is not blown, but it now smokes white after running for about 30 seconds. Compression is fine, and there is no froth in the coolant. I'm assuming the turbo is damaged. There are fine metal shavings in the oil. Some have collected in the head, and there are also some in the oil pan. No chunks though. These shavings are not sticking to a magnet. They don't look like brass, so its most likely not bearing shells. Oil pressure is fine. Hopefully its just the oil pump thats broken and its eating away at the front cover.

The engine needs to be torn down. What should i be looking for? Is there anything i will have to replace for sure, aside from the turbo and oil pump? How would you go about cleaning out the oil passages? The bearing shells are most likely damaged. Overall the engine runs great, its just a timebomb at this point. Any input is appreciated. Yes, its a stupid mistake, but you would be suprised at how little power difference there is between a healthy 10psi, and 25psi of hot air.

Edit: Spark plugs show no sign of coolant consumption. The engine is losing coolant. There is no white smoke comming out the crankcase vent. It seems the smoking starts once the exhaust piping gets hot.

06-11-2006, 02:48 AM	#1
S13Eye Zilvia Member Join Date: Feb 2006 Location: Los Angeles Age: 40 Posts: 190 Trader Rating: (0) Feedback Score: 0 reviews	Overboosted. Now what? I recently got done swapping an engine into my car. During the swap i installed a Greddy Profec B Spec-II boost controller, which worked fine for a cople boost cycles. It soon failed, and my S13 SR20 over-boosted. It was still reading pressure, and i had last-boost on so it recorded the max pressure. Its bad - just over 25 psi. Mostly stock fuel system, except for Walbro pump and cleaned injectors, T25, and a front mount IC. No blow off valve. The fuel tank was drained, and whatever remained was diluted with 5 gallons of 102 octane gas. The engine has a total of maybe 10 miles on it since it was swapped. The head gasket is not blown, but it now smokes white after running for about 30 seconds. Compression is fine, and there is no froth in the coolant. I'm assuming the turbo is damaged. There are fine metal shavings in the oil. Some have collected in the head, and there are also some in the oil pan. No chunks though. These shavings are not sticking to a magnet. They don't look like brass, so its most likely not bearing shells. Oil pressure is fine. Hopefully its just the oil pump thats broken and its eating away at the front cover. The engine needs to be torn down. What should i be looking for? Is there anything i will have to replace for sure, aside from the turbo and oil pump? How would you go about cleaning out the oil passages? The bearing shells are most likely damaged. Overall the engine runs great, its just a timebomb at this point. Any input is appreciated. Yes, its a stupid mistake, but you would be suprised at how little power difference there is between a healthy 10psi, and 25psi of hot air. Edit: Spark plugs show no sign of coolant consumption. The engine is losing coolant. There is no white smoke comming out the crankcase vent. It seems the smoking starts once the exhaust piping gets hot.