134cc Mac's

[mcbob]

Tom,

Old mate old buddy of mine i see you responded to a ad by Rick on the pistons used in the open 100cc engines and read this ..............

The 100cc open rod is from the chrome bore 895C saw, the 125cc version is from the chrome bore Superpro 125C saw. Chrome bore 101s also used the same Super Pro 125C rod with the same wrist pin, thrust washers, clips, and a +.110" forged piston.
Those rods are heavy junk compared to the billet titanium rods some of the vintage karts run now.
The 895C is a gear drive saw.

Now in this engine did Mac use the 101 cylinder and was it a rebore and then chromed you might be kind enough to enlighten me more

Mc Bob.

[Tom Smith]

Bob, Blocks were cast without the iron bore liner, finished machined and ported etc, and then the bore was chromed the same way the saw blocks were done. Mike Savin was the engineer at Mcculloch who designed the special pistons and they were made by Forgedtrue. Burco marketed the same design of piston for the 100cc open Macs. I don't know about the 135cc pistons except Wiseco made some big ones also, Burco may have sold the 135cc pistons also. Information about these last Savin 101 motors isn't real well established because there were not thousands of them produced. Savin also designed special sand cast heads but the fins were too close together so they didn't cool very well. If you think about it about all they did was make a Mcculloch 820. Tom

[mcbob]

Thanks Tom now i understand ..................

Mc Bob.