Does anyone know of an example of a head modification to a gas engine? The modified head that was created for the Thundertiger 1.2 makes a lot of sense when trying to alter the compression ratio. MVVS used to make a .61 engine that came with 2 heads one for glow and the other with a contra-piston for diesel (I have one around here somewhere I'll post a pic of). The diesel head had a two piece "button" design. That two piece head concept might be another way to change the combustion chamber for comression ratio.

I'm wondering if the RC boat guys have designed a bolt on head modification...anyone know?

Check out Dave's Discount Motors, they sell racing parts for scooters....

Tim I was thinking of selling but that fell thru so I am starting to make mufflers to have ready to sell. What the plan is , is to make up a bunch and take orders for others and build them on sertain days , instead of being in the shop every day . So if you want some I am still building them just not 24-7 like I have been. Whwn I get some piled up I will turn the sale page back on on my site, I am currently buildy some for the mac engine today.

Ralph,

Thanks for that input. These guys look like they know what they're doing.
Now I've just got to figure out how to get the 14:1 compression ration they're claiming.

It looks like they're bolting the head on but I don't have a clue whether there is enough material in the cylinder wall to drill and tap for the bolts.

There isn't...They use long bolts...Also a compression release from a chainsaw...

Ken...how are you doing on the Supertiger conversion? Thanks Capt,n

getting there doing some 2300