I feel your pain!
Mine wasn't a Turner engine although I wish I had gone for a full engine from Turners as i've heard nothing but praise for them so far...
I got all my bits for the engine rebuild from Turners (Cam, Followers, Push Rods, Oil Pump Gears, gaskets etc) & have had no problem with these. My problem as been with the block - head bolt threads pulling out over time & 3 head gasket failures in 30k miles. I bought a top hat block, pistons , crank etc from a guy who builds engines for TVR track cars etc. Lesson learned for me was that it's not straight forward to just machine top hats into an old engine block as the block needs to be fully tested. I had a chat with V8 Tuners who I just bought my ARP studs from & they were saying a lot of blocks come in that are no good for rebuilding due to being overheated & stressed (as soon as they start machining it becomes apparent the material is too soft). As already said, many RV8's are available for re-manufacture because they've been taken out of a scrapper - usually due to engine failure in the first place.
Hope you can get somewhere with Turners, I would imagine they want to protect their reputation. Trouble is, with engines, there are so many other factors that can cause early failure so proper investigation with Turners would be the best plan IMO. The warranty is often dubious as often it's dependent on many other components being renewed during fitting. Remember my indie saying Turners small print stated something like the entire cooling system needed renewing when fitting to get the full warranty.
Mine wasn't a Turner engine although I wish I had gone for a full engine from Turners as i've heard nothing but praise for them so far...
I got all my bits for the engine rebuild from Turners (Cam, Followers, Push Rods, Oil Pump Gears, gaskets etc) & have had no problem with these. My problem as been with the block - head bolt threads pulling out over time & 3 head gasket failures in 30k miles. I bought a top hat block, pistons , crank etc from a guy who builds engines for TVR track cars etc. Lesson learned for me was that it's not straight forward to just machine top hats into an old engine block as the block needs to be fully tested. I had a chat with V8 Tuners who I just bought my ARP studs from & they were saying a lot of blocks come in that are no good for rebuilding due to being overheated & stressed (as soon as they start machining it becomes apparent the material is too soft). As already said, many RV8's are available for re-manufacture because they've been taken out of a scrapper - usually due to engine failure in the first place.
Hope you can get somewhere with Turners, I would imagine they want to protect their reputation. Trouble is, with engines, there are so many other factors that can cause early failure so proper investigation with Turners would be the best plan IMO. The warranty is often dubious as often it's dependent on many other components being renewed during fitting. Remember my indie saying Turners small print stated something like the entire cooling system needed renewing when fitting to get the full warranty.