[Jay S]

IRC a guy can cut .070 off pretty easy on those 6x-8. I think the chamber is a little narrower than some other heads, makes them a little more friendly to mill some extra off, .070 would be removing almost 14 cc’s. I think .040” off gets it down into 6x-4 range, if you were going to bother having them machined I would at least go .050”, that would get the compression into the mid 8s.

If you pick a good cam, the upper 7 SCR can be workable, certainly would rather be higher, I think upper 7s would ok for a cruiser though. Steve C mentioned I use dynamic compression designing cams, which is correct. On something really low compression I would suggest working backwards and pick a profile from intake closing targets. I also would not suggest starting with DCR first, I would look at V/P index’s first then work your way to DCR. The DCR on that low of compression will give you a false reading compared to what most people try to run. The compression is so low, if your not careful you will end up with a very tiny cam, likely to small for the head flow you have.. Go to big and it will be a gas guzzling slug. For that upper 7s static compression I would try to get the V/P (using that Wallace DCR calculator) around 120 from as correct as possible .006” tappet intake closings, that should end up in the upper 50s lower 60s for the intake closing. I also recall that the Crower cam Cliff R likes with lower compression is the 60240. It is 270* and has a intake closing of about 67. The Lunati Voodoos are more aggressive, dealing with something really low compression I would rather use something like them. The way those lunati’s are ground the little Lunati 262 voodoo (702) actually has nearly the identical intake closing as the 60240. With the lower compression I would rather run the smaller 701 (255 adv duration) than the 702 (262) or the Crower (270). But both the 702 or the 60240 cams are about as big as you would want to use. Bigger than those the engine will start acting sluggish. Bullet has a Ultradyne grind that is listed as a H00 that would be inbetween the 701 and 702 lunati’s , probably be my first pick, and on a 110 LSA instead of the 112s. I think it would build some more compression and might get better milage