Don, considering that this is the protype TA block, I could not be more pleased!:biggrin:
Initially we made some changes that were incorporated into the production block. I have had NO issues with it.
Based upon my stack of time slips, I have over 400 total runs with the TA block.
Cool down between rounds is great, I imagine that with alcohol you have a hard time just getting to operating temp.
It's not that bad really. To keep oil contamination down at idle and light throttle, I use a relatively lean mixture. The lean mixture keeps the engine at a temp a little cooler than with gas, but with enough idle time it can get over 210 where I would turn the fan on and it cools down real fast. I like to leave the line at around 160.