I was finally able to get started on Matt's new MS660. I've already run into a couple issues with the BB kit he provided. Keep in mind, this is not from Baileys, so your mileage may vary.
1. The bottom of the exhaust port free-ports when the piston is at TDC. This was corrected in Baileys latest edition.
2. The piston skirts ever so slightly made contact with the case at BDC. It would have been entirely possible to bolt this topend on and start it up. Then the piston grows, it gets longer, and before you know it, boom, you've busted a piston skirt. So I slightly relieved the case for it to clear. This does not hurt the structure of the case, or prevent it from going back to stock.
3. The exhaust port is flat, or worse. It's higher on the one side than in the middle. This means I'll have to raise the exhaust to get a proper shape, which leads to the next issue.
4. The exhaust port is very high. It's at 94° ATDC, much higher than I would ever want one for a work saw. It's going to end up even higher since I have to shape the roof of the port. I'll just have to see how it turns out.
Stock Port Timing
Exhaust - 94° - 172° duration
Transfers - 118° - 124°
Intake - 81° - 162° duration
Blowdown - 24°
Yeah the original OEM top end off that 660 was pretty average. Of course when Brad tidied it up it looked fine. Straight off the bat the MS660 BB kits that I got hold of needed no tidy up work done at all. They are very very impressive kits 
