The 360 build that has more turns than Willow Springs
The machinist bored the engine to .028 over to see if the rust pits in the cylinders would clean up. They are still there in 2 cylinders so this will go .040 over.
I'm okay with that.
Now, onto piston selection. That is another thing to deal with.
I don't want to deal with a compression ratio so high that I am obligated to use Premium fuel all the time. Most of the cars out back sit for weeks, sometimes months and with the way that our California gas goes bad so quickly, I don't want the car to run like crap until I burn all the crappy gas out. Keep in mind, we only have 91 octane premium here.
The Speed Pro pistons that were in the engine were flat tops with 5 cc valve reliefs. The compression height was 1.660". Assuming the deck clearance was .010, this put me at over 10.5 to 1 with these #308 iron heads. I do not want to be that high with an iron head.
Speed Pro also has pistons with an 18 cc dish that drop the compression ratio by about 1.3 points. This will put the CR around 9.2 if the deck clearance is around .010.
The thing with that is, the popular Keith Black 107 piston has a compression height of 1.675. That extra .015 will make a difference in the compression ratio. This makes me wonder where the Speed Pro and the KB pistons actually DO end up at TDC.
I can only assume that you'd have to mock up a piston & rod in a block with the crank in place to actually know what to expect for deck clearance.
The machinist bored the engine to .028 over to see if the rust pits in the cylinders would clean up. They are still there in 2 cylinders so this will go .040 over.
I'm okay with that.
Now, onto piston selection. That is another thing to deal with.
I don't want to deal with a compression ratio so high that I am obligated to use Premium fuel all the time. Most of the cars out back sit for weeks, sometimes months and with the way that our California gas goes bad so quickly, I don't want the car to run like crap until I burn all the crappy gas out. Keep in mind, we only have 91 octane premium here.
The Speed Pro pistons that were in the engine were flat tops with 5 cc valve reliefs. The compression height was 1.660". Assuming the deck clearance was .010, this put me at over 10.5 to 1 with these #308 iron heads. I do not want to be that high with an iron head.
Speed Pro also has pistons with an 18 cc dish that drop the compression ratio by about 1.3 points. This will put the CR around 9.2 if the deck clearance is around .010.
The thing with that is, the popular Keith Black 107 piston has a compression height of 1.675. That extra .015 will make a difference in the compression ratio. This makes me wonder where the Speed Pro and the KB pistons actually DO end up at TDC.
I can only assume that you'd have to mock up a piston & rod in a block with the crank in place to actually know what to expect for deck clearance.