Here we go, 243/247 .653/.656 109+1(lsk lobes) with TFS 215 heads milled to 58cc's and a .040 head gasket. That would put my SCR at 11.58 and my DCR at 8.96. I did not figure in flycutting, how much will that effect my SCR and DCR? Do you think 8.96 is too high of a DCR for 93? This is a Max effort N/A stock bottom end 346 with the exception of doing rod bolts. Any input would be appreciated.

 

TTT for ya.

 

TTT no one?

 

Not enough to worry about. If you really care you can CC your flycuts using a syringe and add that in, but its really not going to be enough to worry about.

 

i think for each cc is around a tenth +/- of a point in compression so that will lower you down some .lets say you will wind up with 2cc relief total so that will drop you down around 2 tenths of a point and i can't remember how much dcr that will lower you but i think you will be o.k on 93.that should be a very strong combo and those heads will still have pretty good velocity so you may be on the high side but you can always take out a couple *if you have some knock.

 

Yeah, but im more worried about my DCR at 8.9. I still want to run on pump gas and not have to pull a bunch of timing because of KR.

 

What i want to do isnt for the faint of heart, thats for sure. i was going to do a solid roller set on with a set of PRC heads, but it cost to swap everything over for what you get was too much for me. I would rather spend the money on a good set of heads.

 

I would say you are pushing the limits of 93. If you have a source of good 93 you might be alright. Most say 8.6 or 8.7 is the limit for 91 so I imagine 93 can't be too far behind but I think you might be alright. You can always just add in a couple gallons of 101 if you have to.

 

i know im pushing it a little. I know there has to be people out there running 8.7 or higher DCR that can give me some input.

 

ttt...

 

I'd think that's on the ragged edge.. in summer heat.. I dunno. If you had a forged motor with good pistons, I'd say try it, but with stock pistons, it doesn't take much detonation to cook the ring lands off one.

I'd try not milling the heads that much, or go with a thicker head gasket at a minimum.... or just do a 100 unleaded/93 mix and go ahead as you've planned.

 

well, im going to go with the .040 head gasket for the better quench, But would you recommend only going with a 60cc chamber? that would put me at SCR 11.275 and DCR at 8.73

 

or would it be better to go with the 58cc chambers and go with a 110 or 111 LSA. Can someone explain the effects of valve events play in this?

 

Two Tough *******

 

The 60 cc route sounds better IMO.