Engine Knocking - Can't figure it out
#1
Engine Knocking - Can't figure it out
This is the 4th time this car has been on the dyno in 3 weeks due to various testing with plugs, BAS, and timing changes. This time was on a DynaPack at Synapse which seems like a lot more stress on the motor than a dynojet. I only added a deg in timing at 25-26 psi which added 20whp up top and 712whp. I only made 4 runs and started hearing knocking at idle. I checked out the head and its fine. Compression is 230 across all four and oil level was perfect. I drove it home with no issues, no smoke, no changes at all with driveability. It sounds like rod knock for sure but won't know until I test oil pressure. I'm not sure what would have caused this except one idea...
All last week I thought I had spark blowout which might have been pre-ignition which is hard on rod bearings. Maybe today was it, although I had clean runs. Maybe my 1000 mile old AMSOIL 10w30 ran thin from all the abuse the past couple months at 20-28 psi on E85. I dont know. I think im going to run an oil analysis as well.
Timing was as 10 deg peak torque 6400rpms and 14 deg 8200-8500 rpms @ 28 psi. Boost was only at 25.5-26 psi at redline.
http://www.youtube.com/watch?v=PIlXF...LKG8TFTjo5tNkg
Last pull before the knocking started. This was only at 25-26 psi. She sounded good, and was just starting to wake up and showed no idication of breaking during mid pull.
All last week I thought I had spark blowout which might have been pre-ignition which is hard on rod bearings. Maybe today was it, although I had clean runs. Maybe my 1000 mile old AMSOIL 10w30 ran thin from all the abuse the past couple months at 20-28 psi on E85. I dont know. I think im going to run an oil analysis as well.
Timing was as 10 deg peak torque 6400rpms and 14 deg 8200-8500 rpms @ 28 psi. Boost was only at 25.5-26 psi at redline.
http://www.youtube.com/watch?v=PIlXF...LKG8TFTjo5tNkg
Last pull before the knocking started. This was only at 25-26 psi. She sounded good, and was just starting to wake up and showed no idication of breaking during mid pull.
#2
Ign timing looks on par given the conditions, obviously there is more than just peak timing numbers though. Did Morgan or Steve take a glance at the tune, and give an opinion at all? I've also heard of people hearing rod knock type of sounds, and it was something completely different, so hope for the best, it may not be the worst case.
#5
I drove it home since I was only a couple miles down the road. Its parked and under the microscope now. You would think that this far in the game I'd have an oil pressure gauge SMH.
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#8
Im going to drop the pan tonight. How can I test a spun bearing with the rod caps on ? I dont want to start pulling off caps if I dont have to. Chances are, the crank is scuffed up from a spun bearing. We will see.