PerformanceTrucks.net Forums

GM Engine & Exhaust Performance EFI | GEN I/GEN II/GEN III/GEN IV Engines |Small Block | Big Block |

5.3 vs 243 Heads...Confusion

Thread Tools
 
Search this Thread
 
Old Jun 1, 2007 | 06:56 AM
  #11  
nighthawk08's Avatar
nighthawk08
TECH Resident
 
Joined: Nov 2006
Posts: 881
Likes: 1
From: San Antonio
Default
does anyone know the piston to deck height in these engines?
Reply
0
Old Jun 1, 2007 | 07:03 AM
  #12  
nighthawk08's Avatar
nighthawk08
TECH Resident
 
Joined: Nov 2006
Posts: 881
Likes: 1
From: San Antonio
Default
Originally Posted by pbraxton
and i was curious why the new 5.3's are making better numbers with those heads.
the new 5.3's have flat top pistons and 9.9:1 compression, ls6 based heads, 90 mm TB/intake manifold and a slightly larger cam. these are the factors producing more power.
Reply
0
Old Jun 1, 2007 | 07:06 AM
  #13  
ChevyThunder17's Avatar
ChevyThunder17
TECH Resident
iTrader: (45)
 
Joined: Nov 2001
Posts: 959
Likes: 1
From: Michigan, the land of cold
Default
I *think* the piston protrudes .008" out of the deck, similar to the 5.7's. I'm not sure though.
Reply
0
Old Jun 1, 2007 | 07:12 AM
  #14  
tdrumm's Avatar
tdrumm
TECH Addict
iTrader: (18)
 
Joined: Oct 2003
Posts: 2,373
Likes: 0
From: Northeast, NJ
Default
Bore 3.78 gasket bore 3.91
Stroke 3.62
Chamber Vol 58.8
Compression Height -0.008
Piston dish Vol 7
Gasket thickness 0.045

Displacement volume -1.471179387
Gasket Volume 8.854378301

Swept Volume 665.7086726
Compression Volume 73.18319891

Compression Ratio 10.09646862
Reply
0
Old Jun 1, 2007 | 07:13 AM
  #15  
tdrumm's Avatar
tdrumm
TECH Addict
iTrader: (18)
 
Joined: Oct 2003
Posts: 2,373
Likes: 0
From: Northeast, NJ
Default
Originally Posted by ChevyThunder17
I *think* the piston protrudes .008" out of the deck, similar to the 5.7's. I'm not sure though.
Yep, I measured mine with a bridge when I had the heads off.
Reply
0
Old Jun 1, 2007 | 08:55 AM
  #16  
ChevyThunder17's Avatar
ChevyThunder17
TECH Resident
iTrader: (45)
 
Joined: Nov 2001
Posts: 959
Likes: 1
From: Michigan, the land of cold
Default
Originally Posted by tdrumm
Bore 3.78 gasket bore 3.91
Stroke 3.62
Chamber Vol 58.8
Compression Height -0.008
Piston dish Vol 7
Gasket thickness 0.045

Displacement volume -1.471179387
Gasket Volume 8.854378301

Swept Volume 665.7086726
Compression Volume 73.18319891

Compression Ratio 10.09646862
Yep, I did +.008 for the deck height, didn't click the negative. Twice.
Reply
0
Old Jun 1, 2007 | 09:15 AM
  #17  
.T.'s Avatar
.T.
TECH Resident
 
Joined: Jun 2005
Posts: 810
Likes: 0
From: Taxachusetts
Default
Originally Posted by colyneedsv8
the new 5.3's have flat top pistons and 9.9:1 compression, ls6 based heads, 90 mm TB/intake manifold and a slightly larger cam. these are the factors producing more power.
Temporary here but, where'd you find that detailed info?
Reply
0
Old Jun 1, 2007 | 09:21 AM
  #18  
tdrumm's Avatar
tdrumm
TECH Addict
iTrader: (18)
 
Joined: Oct 2003
Posts: 2,373
Likes: 0
From: Northeast, NJ
Default
Originally Posted by ChevyThunder17
Yep, I did +.008 for the deck height, didn't click the negative. Twice.
Using a + for deck height in my calculator makes the CR even lower, still not sure how you are getting 10.3:1??
Reply
0
Old Jun 1, 2007 | 09:46 AM
  #19  
ChevyThunder17's Avatar
ChevyThunder17
TECH Resident
iTrader: (45)
 
Joined: Nov 2001
Posts: 959
Likes: 1
From: Michigan, the land of cold
Default
Originally Posted by tdrumm
Unported LS6 heads milled down to 58.8cc chambers with a 3.910 bore x .045 thick gasket on a stock 5.3 shortblock will net you ~10.0:1 compression.
And, I misread this... I saw 3.910 bore, not 3.910 head gasket diameter.
Reply
0
Old Jun 1, 2007 | 10:17 AM
  #20  
tdrumm's Avatar
tdrumm
TECH Addict
iTrader: (18)
 
Joined: Oct 2003
Posts: 2,373
Likes: 0
From: Northeast, NJ
Default
Originally Posted by ChevyThunder17
And, I misread this... I saw 3.910 bore, not 3.910 head gasket diameter.
That'll do it.
Reply
0



Advanced Search

All times are GMT -5. The time now is 06:14 AM.