Rat piston; Ace cylinder

[JPark]

It seems to me that, as long as you use the Rat head, there should be no problem with using a Rat piston in an Ace cylinder. The nominal spec for compression [atmospheric] for the Rat is 5.5:1 and the Ace is 6.5:1 as recall. The difference is that the Ace exhaust port is at 32mm and the rat is 30mm which should up the compression to just under 6:1.

I know; the Dykes ring life is short[er] but the Toad uses the same top ring with the second ring probably there to take over when the top ring gets worn. Is there anything else I'm missing about this combo?

[dirty_rat]

I've run a model 93 Rat piston in an Ace cylinder many times (using either a Webco head or the Rat head) without any problems.

[JPark]

Thanks. That's what I was hoping to hear.