blue smoke
Posted: Tue Oct 25, 2022 5:00 pm
I have a 4ag I've recently put back together. I used Tomei 264.8.15 cams, intake and exhaust. I used weisco pistons, used, with rings, rods, and new rod bearings. The seller of the pistons was unsure of the compression ratio, thought it might be 10:1. He said the engine he'd installed them in spun a crank bearing and he lost enthusiasm for the project. He thought maybe 150 miles on the pistons, but I suspect more, looking at carbon. Pistons looked good, rings looked good, had sharp edges. All assembled and running. Engine is showing 215-220# compression without the butterfly open, warm engine, on all 4 cylinders. Engine shows 195-210# on cold compression test.
Problem is this. I was driving on the interstate at about 4k in 5th, went to slow down for traffic, downshifted, and was enveloped in a cloud of blue smoke. Further playing/testing on back roads shows blue noticeable smoke on hard acceleration. Engine sounds good, pulls hard to redline, and shows good compression. I am running 93 octane fuel. Any idea as to cause of this embarrassment?
Problem is this. I was driving on the interstate at about 4k in 5th, went to slow down for traffic, downshifted, and was enveloped in a cloud of blue smoke. Further playing/testing on back roads shows blue noticeable smoke on hard acceleration. Engine sounds good, pulls hard to redline, and shows good compression. I am running 93 octane fuel. Any idea as to cause of this embarrassment?