Originally Posted by
bkhart
I have found the Super Tigres respond well to porting. I had a tired old Italian S .40 and after porting and a new ring it turned a 10X6 MA on 5% at 15,000 rpm with the first version of the swing muffler. I made an adapter to use the .60 size swing muffler on it and it turned 15,400 rpm. The Super Tigres are one of my favorites. I have also gotten great results porting the ST S .61.s as well.
Regards, Bill
Just about any engine will benefit from porting. I haven't done any aircraft engines yet, but I did a Picco .28 buggy engine recently. The biggest changes I made were boring the crank out .75mm and increasing the induction port probably 15 degrees or so. It is a stout engine in stock form, but it gets to be quite the beast when modified. I look forward to doing the SuperTigres. I will probably do one of my GS 45s first. I have an S45 ring that does 14,700-14,900 on a 10x6 APC and silent muffler. The smaller swing mufflers are loud and rob some power. I like the idea of using a larger muffler - I've found substantial gains by using larger mufflers on smaller engines. My little Enya .30 gained almost 1800rpm by using a .46 sized muffler on it - and it only has about 150 degrees of exhaust timing.