Originally Posted by TomTDM
Can Anyone guide me in selecting the proper cyl ratio 17:1, 18:1, 19:1 for Detroit 671-JT engines. I have been getting different answers. I have heard that if I use 19:1 ratio vs 17:1 that the engines will not smoke as much!
The specs available to me show the 6-71TI as 17:1. I have heard that you can increase the compression ratio to make them smoke less but that requires rebuilding the engine. If you install block heaters they will still smoke some but not nearly as bad. Even engines in good shape will smoke on start-up. If it clears up after they are warmed up then they probably don't need an overhaul.