Compression ratio

I had them milled for 8cc, I should have gone 10 or 12, or should've done alot of things like use those 2.5 rods.. ;) That's the beauty though, always learning. It's a good strong runner. There's no comparison to the old 170. I've got no regrets at all. There's always next time :) I didn't check lavron's math looking back on his thread when he came up with 12.863cc. 1.417"R .276"H is 1.74 cu inches or 28.51349 cc's. It doesn't really matter imo unless you have to use off the shelf pistons. It's like that other Hoosier said, pmuller9, custom pistons.

Those 28cc's pistons may be good for a lower duration street cam or a turbo 250 build, if they'll hold up. I know nothing about turbo builds other than lower compression and a good head gasket seal.

They'll put you at 8.6 scr/7.3 dcr with that cam @ 4*, zero deck, those rods, 54cc chambers and a .045" gasket. Or 8.8/7.45 with a fomoco composite .032" gasket. With the Felpro gasket and 48cc's it top's out at just over 9.1/7.7, maximum ~9.4/7.9 w/ .032" gasket and that cam.

Even with a 248/256 110 advanced 4 degrees you'd only be @ ~9.15/8.1 w/ a .045" gasket and zero deck. I'm sure it would be reliable and sh*t and get right now but you'd be leaving a lot of power on the table I bet.
 
I'm decently going off the shelf parts that's why some sacrafices are being made. I think I'll deal with a log head if I want that aluminum I'll just build a different engine. That being said 8- 10 cc dish should be perfect just gotta pull the head and check the chamber cc and deck hight. I'm ready to get great on my hands and put down the hammers and dolly's for awhile
 
I would have to look back at my own post but I was just using whatever numbers Silvolite printed because I can hardly add 2+2 :roll: So however it turns out I will most likely be ok I was trying to run a conservative compression ratio and first and foremost was wanting to eliminate the piston shortfall.

Hopefully one day I will have the motor back from the machine shop and can see how it is all going to work.

See Ya,
Mike
 
six shooter maverick":6yk2zhk7 said:
I'm decently going off the shelf parts that's why some sacrafices are being made. I think I'll deal with a log head if I want that aluminum I'll just build a different engine. That being said 8- 10 cc dish should be perfect just gotta pull the head and check the chamber cc and deck hight. I'm ready to get great on my hands and put down the hammers and dolly's for awhile
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You will be on the high side for a DCR.
Instead of the Clay 264/274 use the Schneider 270/280 which has almost the same .050" duration specs (214/222) and will give you a lower DCR.

Have you located a source for the 5.990" long connecting rod?
 
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