Shop called me yesterday after doing a test drive and said the engine was starting to scatter around 4000rpm when you stand on it. They brought it back and checked the compression and it was down to 70-90psi in all 8 cylinders where as previously it was 150-175psi in all cylinders. They did a leak down test and all cylinders showed 30-40% leak down (no previous numbers). The breather in the valve cover is full of oil and the plugs are black. He dumped some marvel mystery oil in a cylinder and checked again and nothing changed. Their thoughts are that when I was trying to get it to start previoulsy that I washed the cylinders down and the rings are toast and it needs new rings, hopefully, and they want $4500-5000.
I'm a bit skeptical. When I was trying to get it to crank I didn't try to crank it for more than 60-90secs total. I don't think that's enough to wash the cylinders down and the rings to not seal but maybe I'm wrong. I'm also wondering if maybe the valves were set when the engine was cold and once it warms up it's hanging the valves open and bleeding off compression. We are going to go ahead and pick it up tomorrow and we are going to do some of the test ourselves. We are planning a hot and cold compression test as well as dumping some 50w oil into a cylinder and retesting compression and leak down with that to try and isolate the issue.
I'm not knocking the shop as they've been great to work with and they've done awesome work. My brother in law and I built the motor so they are just helping us out but the price they are quoting me for putting new rings in is ridiculous. I can buy, and have found, assembled short blocks for $2500 that I can swap my top end on to it. Heck I've found 347 long blocks for what they are quoting me. I'm just looking for some ideas or thoughts that would cause all cylinders to suddenly lose all compression at the same time. That just seems strange to me.
I'm a bit skeptical. When I was trying to get it to crank I didn't try to crank it for more than 60-90secs total. I don't think that's enough to wash the cylinders down and the rings to not seal but maybe I'm wrong. I'm also wondering if maybe the valves were set when the engine was cold and once it warms up it's hanging the valves open and bleeding off compression. We are going to go ahead and pick it up tomorrow and we are going to do some of the test ourselves. We are planning a hot and cold compression test as well as dumping some 50w oil into a cylinder and retesting compression and leak down with that to try and isolate the issue.
I'm not knocking the shop as they've been great to work with and they've done awesome work. My brother in law and I built the motor so they are just helping us out but the price they are quoting me for putting new rings in is ridiculous. I can buy, and have found, assembled short blocks for $2500 that I can swap my top end on to it. Heck I've found 347 long blocks for what they are quoting me. I'm just looking for some ideas or thoughts that would cause all cylinders to suddenly lose all compression at the same time. That just seems strange to me.
