Open transfer port jugs. Spine sharpening


Well-Known Member
Local time
11:54 AM
Jul 13, 2021
To get the most performance out of these motors you must maximized fuel mix flow and exhaust flow. To do this we take away the restrictions that come stock with these motors. This is accomplished by porting exhaust and intake ports and cleaning up transfer windows. One must also portmatch the flanges, gaskets, and case to jug transfers. After doing all of these things you will have double the performace of the stock setup. One more step I found helpful on open transfer port jugs is sharpening the spine that seperates the tranfer ports into 2 ports. The bottom of the spine where it matches to the case comes stock with a flat, blunt edge. When the exhaust stroke forces the air/ fuel mix up from the case into the transfer ports it hits the spines blunt edge and deflects flow. by sharpening the spines blunt bottom edge into an even point will create a smoother air fuel transfer into the tranfer ports. You may not think its much but remember the smoother you can make flow within these motors the more performance you are going to get out of them. Every small thing counts Here is a crappy drawing to thoes of you who are visual learners.