I fairly new to the LS series of motors. I have been playing with the older SBC for years.

I'm wondering how the LS series relates to DCR. I know in the old SBC motors is that 8.4 is about as high as you can go on 93 octane before race gas is needed. A few buddies of mine have gotten by with 8.6, but their tune was spot on!

I have been searching here and it seems that DCR is not talked about as much as it is on other sites.


For ones that know something of DCR, how does the LS handle DCR? How high have some of you guys gone on 93 octane?

 

If my calculations are correct, my DCR is around 8.59 and CR is 10.35 .

I have 58cc heads with a .04 headgasket and the cam in my sig. I have no issues running 93 octane and every once in awhile i run 89 without issues... Tuning was a little difficult but it runs like a champ now..


From my understanding to be able to run high DCR you need to have pretty good heads, Not being able to get the hot exhaust gasses created by the CR/DCR is what causes detonation...

 

Most of the info that I've seen about DCR here has been up in the Internal Engine section...I'll bet that if you searched that section for "DCR" or "Dynamic Comression Ratio", you'd find more info than you would in this section. I remember finding links to DCR calculators there too...