Compression Ratio, help me understand?

[Screamin' Demon]

Alright as we all know a PI head swap on a 96-98 GT will result in a compression ratio to aprrox. 10:1. My question is, is this reliable and safe on a 90,ooo motor gt, hardly abused at all? Will this increase in compression hurt the motor over time or help it? Let me know guys. No blower will be added in case you are wondering. Thanks

 

[GoBabyVroommm]

You'll be fine. Sometimes your compression ratio will change because of the head gaskets your use. The faster you do the PI swap the longer your motor will last. The intake that the 96-98 sucks ballz.

 

[tomustang]

you're putting new parts on your car, it won't make it worse. if you do the swap just brush off the carbon on the pistons. the compression will rise between 10:1 to 10:5.

 

[mrvax]

Just make sure you use the correct grade of fuel to avoid detonation. I also have my timing advanced to 15 degrees BTDC, run 93 octane and never ping.
82,000 and going strong. It's a good engine...change your oil & filter regularly.

 

[Pitch Black]

10.1:1 is perfectly safe.....unless you plan to boost

 

[Stanglover96]

What about with nitrous? Would it be better to get a flip chip and get 2 tunes or what? Also I heard about a bump on the heads that if taken out reduces compression by 1 pt. Is that true?

 

[Blev]

What about with nitrous? Would it be better to get a flip chip and get 2 tunes or what? Also I heard about a bump on the heads that if taken out reduces compression by 1 pt. Is that true?

I don't know anything about a "bump" but I know if you remove the swirl dams it lowers the compression.

 

[kah9911]

Well the swirl dams are kind of like bumps. I would not worry to much about a CR of 10. I think they only take out like .5 also, but your fine at 10. Just run higher octaine and you will make a bit more power.

 

[01TrueBlueCobra]

The only thing different is that you have to run premium gas. Also the Mach 1 is 10.1 compression too. Also make sure you take your short block assembly to a machine shop to have it rebuilt.

 

[Gearbanger 101]

The intake that the 96-98 sucks ballz.

If you're refering to their flow characteristics, yes, the do in fact "suck ballz" but if it's the fact that their all plastic design makes them prone to cracking, up until 2002 model year, PI intakes were all plasic as well. You gotta specify the intake with the aluminum crossover if that's the case.

I don't know anything about a "bump" but I know if you remove the swirl dams it lowers the compression.

Which also makes it brutal on gas. I wouldn't knock em off if I were him.

 

[Pitch Black]

What about with nitrous? Would it be better to get a flip chip and get 2 tunes or what? Also I heard about a bump on the heads that if taken out reduces compression by 1 pt. Is that true?

Nitrous is safe as well. You have to realize that there are many cars out there running a 10.1 CR. Mach 1's, LS1's, etc., all run 10.1:1 CR stock. There are THOUSANDS of LS1's running nitrous without any problem. You don't need to worry about your CR until you boost the engine.

 

[Screamin' Demon]

Well I already have my timing advanced through my chip and I run premium right now currently. Cant wait to have these heads and cams.