California 91 octane to be exact.

I know LT1s can better handle compression due to the reverse flow cooling... But is the factory C.R. pretty much all you can run without risking detonation? If not, how much compression can you run and still have a little bit of wiggle room -to be safe?

 

Just as long as you DCR is below 9.0:1 you should be fine.

 

It has to do with a lot of things.... where is Valle Vista in Ca? What are you planning to build?

Bret

 

I'm running a CR close to 12:1 and I run on 93 octane without any problems. I don't know how else to help except to give a comparison.

 

Head/cam 383 is what I've been planning on, although I haven't rulled out a 355.

Valle Vista is in the SoCal desert about 20 miles west of Palm Springs.

 

So it's still hot there?

 

A big radiator(3 core) and Evans coolant ya could get away with 8.8-9.0-1 DCR.
I talked to a guy in Vegas that is running 9.6-1 on the street in an Impy on pump gas,but I ain't that brave.

 

Summer can reach highs of 105-108 degrees on the hottest days... In winter, usually 60-70 degrees.

But yeah, it's pretty hot here in the summer months.

 

Sorry for asking or jacking the thread, but what does DCR stand for?

 

I felt like asking, so no worries. I'm imagining/guessing it may stand for Dynamic Compression Ratio? At least from the context of what they're saying it must be the compression ratio when all factors are considered.

Of course that's all a guess so we'll see what it really means when they reply

 

Yes that's what it stands for. Do a search on that to learn some more.

I would actually cut the DCR back to at the most 8.5:1 where you are, and probably put it around 8.3:1.

Bret

 

Sweet... I guessed what the D stood for.


So what DCR do you think (guessing) my stock motor is getting in this climate? You're saying I wouldn't be able to bump it up a little?

 

IF YA GOT COOLING ya can have it at 8.5+ but ya better have the cooling system jam up and jelly tight.

 

I'll have to remember that one.

 

How much cooling do you need? Especially in a hot climate. I was shooting for 8.7 dcr with rp purple ice and cowl hood and around 20% coolant (the rest distilled water) and a 160* thermostat.

Is the above considered to be enough to run a dcr that high?