Will it work on my lt1 without causing problems or robbing me of power. Can I get by on 91 as a daily driver and just add some octane booster when I plan to run it hard? I'd appreciate your input.

 

Our premium here in new mexico is 91 due to altitude. It should be higher at lower altitudes, like oakland. Don't you have 93 out there? I'd run the 93 out there. But, if you can scan it for knock, then you can always pump in some 91, scan it, and if it's not pulling any timing due to knock, then your good to go.

Ken R.

 

no we only have 91. lloyd said yes but engine builder guy says ping?

 

Does your engine builder realize the LS2 comes with 11:1 compression from the factory?

 

im in the same boat as you maro boy. My 383 is 11.6:1 and plan on using 91. I was told it should be fine. I think when your around 12.1:1 and above you should watch out

 

it wwould have been 11.78:1 but we went with a thicker gasket for a bit of breathing room. Im hopin for the best its done I just need rockers now.

 

Sounds like you need to learn about quench. And DCR. And get a better engine builder.

 

A lot depends on the cam, heads, and operating conditions. If Lloyd said his combo will work on 91, I'd take his opinion as more credible than someone just guessing. I will say that ageressive timing retard, while it will protect the motor, really kills performance. I disabled the KR on mine long ago and never looked back. However, I have verified the lack of knock and I am careful how mine is operated.

Rich

 

Tad over 13:1 here. With the gm847 I was running pump gas and 38-39 degrees of timing up top.

Only place I had to pull timing and work around knock was down low, mostly below 2k.

 

Go with the Gasket lloyd says to use, your heads flow will be altered by the thicker gasket as well as losing quench. You want piston to head clearance of ~0.31. If your clearance is there and your static compression is under 12:1 you're good to go.

 

Which is why a good engine builder is worth his weight in gold. Your engine and tune must have been spot on, Your engine builder might have been able to fix the knock below 2k with a little prep work on small thing like the spark plugs or maybe a slightly different cam profile. But with a 13:1 motor I'm assuming this car didn't spend much time bellow 2k anyway

 

The motor is apart again (lifter came apart) and I am going to have the chambers opened up a tad.

 

You shouldn't need much I'd try to stick to things that will improve combustion or airflow in the chamber to get that compression down just a little.

 

Like Rich said, lots of factors here. DCR needs to be checked for sure.

 

Tuning can take care of all of that. if he was getting knock at or below 2k all he had to do is either add some fuel in that area or take away some timing in that specific rpm range.