Hi, This is my first post here, but I've been reading these forums for a couple of years now. I recently installed a rebuilt 5.7 long block in my boat to replace one of the engines that had low compression due to a leaking riser gasket. I broke in the flat tappet cam with 15w40 and a bottle of EOS by running it 2000-2500 rpm's for 20 minutes. I changed the oil and filter, then followed the rebuilder's recommendations on breaking in the engine. At this point everything is good with the engine.
After the 10 hour break in, I was able bring the RPM's up and plane off the boat. When running at 3000 rpm's the oil pressure on the new engine started at 50 psi, then slowly dropped and settled at 25 psi. If you let this engine cool down for a bit the oil pressure is back up to 50 psi, then the pressure drops once the oil heats up again. This is with Quicksilver 25w40 conventional oil and a bit of zddplus for the zinc.
I decided to see if 20w50 would bump up the oil pressure a bit. The oil that came out of the engine didn't look good, it was a glittery metallic bronze color. I also cut open the filter and found it filled with silver metal flakes. I know this engine is toast and needs be rebuilt...again. The weird thing is this engine runs perfectly and its not making any noises. What would cause this failure? I always thought you would get a knocking noise when the bearings were going.
Thanks, Sean
After the 10 hour break in, I was able bring the RPM's up and plane off the boat. When running at 3000 rpm's the oil pressure on the new engine started at 50 psi, then slowly dropped and settled at 25 psi. If you let this engine cool down for a bit the oil pressure is back up to 50 psi, then the pressure drops once the oil heats up again. This is with Quicksilver 25w40 conventional oil and a bit of zddplus for the zinc.
I decided to see if 20w50 would bump up the oil pressure a bit. The oil that came out of the engine didn't look good, it was a glittery metallic bronze color. I also cut open the filter and found it filled with silver metal flakes. I know this engine is toast and needs be rebuilt...again. The weird thing is this engine runs perfectly and its not making any noises. What would cause this failure? I always thought you would get a knocking noise when the bearings were going.
Thanks, Sean