I thought I'd answered the question of why I continued to have a problem from over-heating but to be even more clear, here goes.
1) Right out-of-the-box was first my ignorance of the fact that the LT1 is a "reverse flow engine". Without going into all that that term means I'll just say that all my placements, coolant flow and nearly everything else associated with the cooling system from when the water exits the engine to when it is returned was WRONG! Nothing earth shattering was needed to correct it but my assumptions were simply 180˚ out from what I should have done, if I'd known.
Not being an engine guru beyond level 101 I had relied on you guys to fill me in on these incidental details.
2) After correcting that fundamental issue (reverse-flow) the problem was lessened but still not fully solved. Although I could run easily on the street it took two more weekends of track-days to finally enjoy myself accomplishing hard runs on the track without paying most of my attention to the heat gage. Between each visit to the track I worked to increase the air flow to the radiator. Seeing improvement each go-around, I gained confidence that I was working in the right direction and in a final attack created the solution.
I'm not sure how or where I'll generate any more air-flow to the radiator if what I've done now isn't sufficient to keep things running cool on a 100˚ day next summer but running at VIR last Thanksgiving with the ambient temperature of 80˚+ the problem seems to have been solved.
Solved but not without some heartbreak! Tomorrow I'll start the process to reconstruct (rather than purchase) a road course oil pan with increased oil capacity and a gated oil pump resevor to insure nothing is starved for oil come this spring. It seems that my tests on the way to discovering the reasons for overheating took a tole on the bearings and rings requiring some internal replacements along those lines during the next month.
In the photographs you can see what I did to direct every molecule of fresh air to the radiator. 1) encased the rad with a full housing on both sides of the car capturing air from the two side pods as well as the two body panel inlets above the pods. Originally these two side inlets supplied air to the in-take manifold. And 2) I created a new air filter box and mounted it beneath the roll bar cowling. Now the engine receives fresh air directly from two previously existent inlets positioned behind my head at the front of the roll bar encircled cowling. Works perfectly when except when driving around town without a helmet the constant sucking noise in my ears is distracting. It's not an issue when I have a helmet on.
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IMG_2441.jpg [ 63.14 KiB | Viewed 894 times ]