heads and compression ratio issues
Thread Starter
Le Mans Master
Joined: Nov 2003
Posts: 8,004
Likes: 250
From: Tampa Fl
St. Jude Donor '12-'13-'14
heads and compression ratio issues
You guys with higher compression ratios than stock, what's your car like in the summer and winter, any issues with detenation, and what spark plugs are you using. I know the new C6s are at 11:1, but im interested us C5ers
answer this in the thread reply:
what type of heads you have
what is the compression ratio
what size cam
is it a daily driver
what type of octane and fuel do you use.
I think alot can be learned here from these issues
answer this in the thread reply:
what type of heads you have
what is the compression ratio
what size cam
is it a daily driver
what type of octane and fuel do you use.
I think alot can be learned here from these issues
Safety Car
Joined: May 2000
Posts: 4,821
Likes: 347
From: Albuquerque NM
I am running the MMS Stage II x heads. These are 5.3 heads, milled for even more squeeze, giving 11.3:1 compression. I am running a mild cam, 218/218 duration, .556/.556 lift, with a 114 LSA. It was tuned and ran great at sea level on 93 octane gas. I now run it on the best available here, 91 octane. 91 works great here, at 5,000+ altitude. I run LS1edit tuning and have no KR with 28 to 30 degrees advance @ WOT. This is an every day driver, not a weekend warrior.
This combo is not too wild for 93 octane gas at sea level, I could run 24 to 26 degrees timing, no problem. Sea level and 91 gas... probably too much comression for that.
If I had to choose between adding compression and adding timing, I'd add the compression. It makes your engine more efficient, givng better part throttle response, better gas mileage, less emissions, and yes, more HP! The LSx heads are very good, they thrive on compression. Chevy seems to agree, the LS6 went to 10.6:1 and now the LS2 going to 11.1:1.
This combo is not too wild for 93 octane gas at sea level, I could run 24 to 26 degrees timing, no problem. Sea level and 91 gas... probably too much comression for that.
If I had to choose between adding compression and adding timing, I'd add the compression. It makes your engine more efficient, givng better part throttle response, better gas mileage, less emissions, and yes, more HP! The LSx heads are very good, they thrive on compression. Chevy seems to agree, the LS6 went to 10.6:1 and now the LS2 going to 11.1:1.
Racer
Joined: Mar 1999
Posts: 413
Likes: 0
From: Pennsville, NJ
Phil,
Here is the setup I'm currently installing:
AFR 205 heads milled .024 for 62cc chambers
Cometic .040 head gaskets
This combo will give 11:1 CR
I bought AFR's cam (part #6016) which is basically a CompCam XER 224/228 .581/.588 114+1.
According to others on LS1TECH, this is a very streetable and powerful combination. I hope so!
I use my car as a daily driver, except in bad weather (1996 Bronco), but I do tolerate less than BMW comfort...
Here is the setup I'm currently installing:
AFR 205 heads milled .024 for 62cc chambers
Cometic .040 head gaskets
This combo will give 11:1 CR
I bought AFR's cam (part #6016) which is basically a CompCam XER 224/228 .581/.588 114+1.
According to others on LS1TECH, this is a very streetable and powerful combination. I hope so!
I use my car as a daily driver, except in bad weather (1996 Bronco), but I do tolerate less than BMW comfort...
Safety Car
Joined: Mar 2002
Posts: 3,556
Likes: 2
11.2-1 LS6 CNC Lingenfelters here with a Cartek H-Cam in the WORST area for power. It is always hot, and worse the humidity!
Still no KR on my beast. LS1 edited and dyno tuned during the summer in S.Fl.and makes 423-417 RWHP in 85-95 degree weather with 99-100+ IAT's and tuned mild. It is sea level (but the air is full of water) and I run 93 octane with the fans and a 160 thermo to keep the coolant below 200 degrees. On the highway during the summer it never gets above 178.
I have thought of putting a little torco octane boost as insurance bringing it to 94 octane during the summer 90-100+ weather, but that would be just for making sure all my horses show up to play.
I do run one range colder NGK plugs and headers w/o the goofy factory cats.
Still no KR on my beast. LS1 edited and dyno tuned during the summer in S.Fl.and makes 423-417 RWHP in 85-95 degree weather with 99-100+ IAT's and tuned mild. It is sea level (but the air is full of water) and I run 93 octane with the fans and a 160 thermo to keep the coolant below 200 degrees. On the highway during the summer it never gets above 178.
I have thought of putting a little torco octane boost as insurance bringing it to 94 octane during the summer 90-100+ weather, but that would be just for making sure all my horses show up to play.
I do run one range colder NGK plugs and headers w/o the goofy factory cats.
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Le Mans Master
Joined: Jan 2002
Posts: 7,275
Likes: 19
From: Camden County NJ
Check with Chris@East Coast Supercharging for my specs. I believe he has my at 11:1......I just write the checks and have no clue. Ask him for Barry's aka BT-01-Vette setup. If memory serves me correctly I have AFR 205 heads milled to 59cc and a G5x-3 cam. Now what ever the hell this means I have no idea 
I just know that when I step on the gas my smile is bigger. Oh yeah I run on 93 octane. It's not a daily driver but she is no garage queen either at just under 40k miles on my 01 Coupe
I just know that when I step on the gas my smile is bigger. Oh yeah I run on 93 octane. It's not a daily driver but she is no garage queen either at just under 40k miles on my 01 Coupe
Thread Starter
Le Mans Master
Joined: Nov 2003
Posts: 8,004
Likes: 250
From: Tampa Fl
St. Jude Donor '12-'13-'14
BT, Ill have to call chris and find out.
Miamidave, One day I hope to return to Florida in the next couple of years and not have to worry about the car pinging or Knock retard. Your poor summer weather conditions are ideal for a ping or a KR, and im glad to hear at 11.2:1 your not getting anything on 93 octane.
great info so far
Miamidave, One day I hope to return to Florida in the next couple of years and not have to worry about the car pinging or Knock retard. Your poor summer weather conditions are ideal for a ping or a KR, and im glad to hear at 11.2:1 your not getting anything on 93 octane.
great info so far
Safety Car
Joined: Mar 2002
Posts: 3,556
Likes: 2
I have a great tuner. Back to back dyno runs on sweltering days 
I was shocked!
Further info I also have the standard LS1 oil from the PCV in my intake (thanks GM you douchebags!) and plan on getting one of those catch cans for further added power insurance. But I figure that also reduces octane a tad as well-but still no pings
I was shocked! Further info I also have the standard LS1 oil from the PCV in my intake (thanks GM you douchebags!) and plan on getting one of those catch cans for further added power insurance. But I figure that also reduces octane a tad as well-but still no pings
Thread Starter
Le Mans Master
Joined: Nov 2003
Posts: 8,004
Likes: 250
From: Tampa Fl
St. Jude Donor '12-'13-'14
I bought a pair of used port and polished 5.3l heads. The kids said they are GTP heads with 2.02 and 1.57 valves milled .015. I called GTP and im shipping them down to them for a rebuild even if they are not GTP, they will be like new when I get them back. I dont want more that 11:1 compression.
The 5.3l heads with the TR224 should put me right where I want to be at 400-410 RWHP. I only want to buy rear tires once a year
The 5.3l heads with the TR224 should put me right where I want to be at 400-410 RWHP. I only want to buy rear tires once a year
Melting Slicks
Joined: Feb 2002
Posts: 2,613
Likes: 0
From: Winston Salem NC
Originally Posted by phils C5 vette
I bought a pair of used port and polished 5.3l heads. The kids said they are GTP heads with 2.02 and 1.57 valves milled .015. I called GTP and im shipping them down to them for a rebuild even if they are not GTP, they will be like new when I get them back. I dont want more that 11:1 compression.
The 5.3l heads with the TR224 should put me right where I want to be at 400-410 RWHP. I only want to buy rear tires once a year
The 5.3l heads with the TR224 should put me right where I want to be at 400-410 RWHP. I only want to buy rear tires once a year
I believe your heads with stock gaskets will give you about 11.2 CR. Since your having them worked on they should CC them to be sure.
Safety Car
Joined: Aug 2000
Posts: 4,537
Likes: 84
From: St. Joseph MO
Cruise-In III Veteran
Cruise-In IV Veteran
Patriot Stage 2 6.0 Liter heads with 59cc chambers. Cometic gaskets. I think it calculated to 11.25 compression ratio. Running a 224/0.581/112 cam. No problems at all with 91 or 92 octane and 27 degrees of timing. Weathers nice then it gets driven 2-3 days per week to work. Still get 28mpg on the highway to 
Le Mans Master
Joined: Dec 2003
Posts: 7,506
Likes: 0
From: Hillsborough NJ
Originally Posted by BT-01-vette
Check with Chris@East Coast Supercharging for my specs. I believe he has my at 11:1......I just write the checks and have no clue. Ask him for Barry's aka BT-01-Vette setup. If memory serves me correctly I have AFR 205 heads milled to 59cc and a G5x-3 cam. Now what ever the hell this means I have no idea I just know that when I step on the gas my smile is bigger. Oh yeah I run on 93 octane. It's not a daily driver but she is no garage queen either at just under 40k miles on my 01 Coupe
I just know that when I step on the gas my smile is bigger. Oh yeah I run on 93 octane. It's not a daily driver but she is no garage queen either at just under 40k miles on my 01 Coupe ...well, handing out the cash to Chris 
). I don't know if adding the Fast 90mm intake and NW 90mm TB will make any difference, other than making me wait just a bit longer for it to warm up. 
Thread Starter
Le Mans Master
Joined: Nov 2003
Posts: 8,004
Likes: 250
From: Tampa Fl
St. Jude Donor '12-'13-'14
I had the LS6 manifold put on last year with the rest of the bolt ons. Ill stick with it. I dont need to squeeze everything out of the car. I just want to make sure it has just a little more kick than the stockers