Going through my engine draws(yes I have more than one) I started pulling out my examples of ST60's . One of them that I picked up along the way looks brand new/unrun , it has a blue anodized venturi (apprx. .200") with the NV acting as the retaining device . I removed the head and back plate for a look see. The head looks stock like some older ones I have( deep hemi chamber with a squish band apprx .150"wide. It has a gold colored plug (Idle bar type). The crank looks like it has more counter weight than the others and the discharge end of the center hole is hand radiused. Stroke measures .860" and bore is .946" or so. On the intake side of the engine, two round holes are in the skirt of the piston that match with two holes in the sleeve below the normal square holes for intake. I have not put a degree wheel and dial indicator on engine to map out port and crank timing but the eyeball says a slight delay on exh opening and a slight advance on closeing of the exh might be present. This thing looks like it has never run the crank has a slight gold irridite look to it .  Any Idea who might have done these mods, would like to know so I could contact for running info and what to expect performance wise. Thanx in advance.

Good job on the pictures, Gordon! You did all the resizing and compression yourself? Or was it the 13 year old kid down the street? 

Nothing engraved on the case or head? Many tuners do that. GMA vibro-engraved "GMA" on the side of the head. I have a Big Jim ST .60, and it has "L" on one side of the bypass and "J" on the other (LJ for "Large Jim"), and LJ on the front side of the head. I have a few Tom Lay engines, and they have "T&L" engraved on one lug and a serial number on the other. I believe Randy engraves something on his reworks; dunno about others, but it's likely. I don't know who else might have done ST .60bb reworks, back in the day.

Regarding the holes in the liner and piston...lots of older engines had similar holes. I think McCoy .60's, and maybe OS MAX III's. But the holes were in the piston skirt, certainly not above the wristpin bosses. So, that looks maybe stock, or maybe not, to me. It should do a fair job of cooling the piston crown from underside, but as for power, probably not.  I am pretty sure Perry Ports are not like that. I have an engine with PP's, and that is not even close to similar. I'll have to ponder which engine that would be, and then find it. With PP's, you can look in the exhaust and see some extra bypass sorta things. These on your .60, you wouldn't be able to see from the open exhaust stack.    Steve 

Since you didn't mention the head having the conical head fins (like my LJ ST .60), I'm sure it's not one of the last ones. Those did have Perry Ports from the factory. I'm not sure if that's a good thing or not, but Colin Pickard did a test report on one in SN a long time ago, and said it gave very good power and fuel economy for a ST .60. Maybe because of the PP's. But I also read that some tuners plugged the PP's with JB Weld. I think he ref'd to it as a "K" model, but I don't know why. Those were made about the time World Engines was going Tango Union and ST's were soon to be sold as Como's by Indy R/C.  Steve

I will reassemble this thing and test it. I plan on trying it with two different heads. One head looks like all the other stock small hemi style with wide squish band, the other looks like a nearly full bore dia. hemi cut head with a baffle clearance slot,very little squish if any. I guess this might be similar to what people call the Big Jim hemi style. I am going to use a 10/22 mix of fuel (50-50 on syn- cas oil mix). Not sure what prop to use after break in but will use a 10-4 for initial run in to keep load down on fresh engine.  Was thinking of useing a 12-6 for testing there after. If someone has more knowledge please feel free to chim in to shorten my learning curve and prevent reinvention of the wheel.

Hi Gordon

Don't use a 10 x 4 for breakin, use a 12 x 4 or 12 x 5 the ST doesn't like to rev as high as a 10 x 4 will, and at least 2 people have done rod damage with a 10 x 4 at breakin, The ST 60 you have runs very well on a 13 x 6 or 13 x 5
 by the way that is a perforated piston porting arrangment on the motor, I have done that many times with engines

Regards
Randy