What's the difference between L48 and L82?
Hey guys... what was the difference between the L48 motor and an L82? I know the 82 had more power, but what was the difference?
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Originally Posted by MarkBullis
(Post 1576548269)
Hey guys... what was the difference between the L48 motor and an L82? I know the 82 had more power, but what was the difference?
Crank L82-forged L48-cast Pistons L82-forged L48-cast Intake L82-Alum L48-iron Cam L82-performance L48-std (performace is just a generalization the L82 cam is a higher perf cam than the L48 but in comparison to aftermarket cams isnt all that splendid) Valves L82-large L48-small Block L82-4bolt L48-2bolt Compression L82-8.9:1 L48-8.2:1 (1978) there are other changes for example in 78 the L82 exhaust was 2 1/2" while the L48 was 2 1/4" (IIRC) |
Originally Posted by MarkBullis
(Post 1576548269)
Hey guys... what was the difference between the L48 motor and an L82? I know the 82 had more power, but what was the difference?
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L34
:cheers: |
Originally Posted by 10caipirinhas
(Post 1576548798)
L34
:cheers: |
The Rods and Oil pan are also different.
Plus the Aluminum valve covers. |
completely different, L-82 was a true performance engine. L48 was a nice station wagon engine
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Originally Posted by 7t9l82
(Post 1576553220)
completely different, L-82 was a tuned down smog engine. L48 was even more so
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In 1978, dual snorkel vs. single
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All of the above with the correction that both intake manifolds are cast iron. Exhaust after the manifolds on a 73 is 2 1/2 inches versus 2 inches on an L-48. Intake and exhaust valves are different and lift and duration of the cam are greater on the L-82. The iron block castings are identical. Tach redline is greater on the L-82 (5600 w/o AC on the L-82 versus 5300 L-82). Rear ends installed at least in 1973 tended to be greater in L-82 4 speed cars such as the GS4 3.70 which resulted in more revolutions to the rear wheels per crankshaft revolution. :cheers:
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Originally Posted by 68AIR
(Post 1576553608)
All of the above with the correction that both intake manifolds are cast iron.
L-48s, cast-iron 78/79 |
both sucked. one just worse then the other....
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ha ha! both sucked. ha ha! wait a minute what am i laughing at i have an l 48. wahaaaaaaaaaa!
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"L-82 was a true performance engine" haha
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Originally Posted by fauxrs
(Post 1576548686)
The differences probably vary by year but essentially boils down to the following:
there are other changes for example in 78 the L82 exhaust was 2 1/2" while the L48 was 2 1/4" (IIRC) Check out your webpage out of curiosity...you did some serious work on that 78. Looks great! What's your background...engineer? Nice display of data in tables. You must have a penchant for detail. :cool: |
Originally Posted by Evil Empire
(Post 1576560605)
"L-82 was a true performance engine" haha
http://www.superchevy.com/technical/...ver/index.html Quote-"In stock trim on our dyno, the 9.0:1 L82 produced 313 flywheel (gross) horsepower at 5,500 rpm and 355 lb-ft of torque at 3,800 rpm. The engine produced adequate torque relative to the horsepower rating, but it wasn't exactly what you'd describe as earth-shattering." The L-82 will easily make 400 HP by changing the heads and cam-not hard. The 70/71 LT-1 was 330/350/370-The mid range LT-1 had 37 more HP-Not earth Shattering 350-313=37 Gross HP gain! In Net HP that difference is probably about 10-12 HP Net! The 1972 LT-1 had 255 Net HP and the 1973 L-82 has 255-Wow! 74 L-82 with true duals 250 Net HP. A 78/79/80 L-82 will certainly make 250-255 Net HP with a true dual 2.5 inch exhaust (more with headers) and no cat. Is the LT-1 a better engine-certainly but not by much! This same kind of nonsense is probagated about the 427 435 Gross HP big blocks. Yes they are fast for their day but so was the L-82 but it does not stand a chance against a modern LS3 not to mention an LS7 Z06-not even close. Different eras! Hopefull, this information will put to rest that the L-82 is some knid of "dog" compared to the "high horsepower" SB engines of the late 60's/early 70's-it simply is not true. |
Originally Posted by fauxrs
(Post 1576548686)
The differences probably vary by year but essentially boils down to the following:
Crank L82-forged L48-cast Pistons L82-forged L48-cast Intake L82-Alum L48-iron Cam L82-performance L48-std (performace is just a generalization the L82 cam is a higher perf cam than the L48 but in comparison to aftermarket cams isnt all that splendid) Valves L82-large L48-small Block L82-4bolt L48-2bolt Compression L82-8.9:1 L48-8.2:1 (1978) there are other changes for example in 78 the L82 exhaust was 2 1/2" while the L48 was 2 1/4" (IIRC) |
On my 78 L-82 the fifth digit of the VIN number is a 4 but a 77 it is an X:
Decoding VIN Numbers Do you need to determine if you Corvette is really an L-82? Here's a simple way to decode your VIN number. However, this only works for 1973 - 1980 Corvettes. First, here are a few facts about VIN numbers: Each Corvette has a unique Vehicle Identification Number and they are assigned in sequence, starting with one, during production. The last 6 digits of the VIN make the Corvette unique. This number is the Production Sequence Number. Position Description Code 1 General Motors Division 1 = Chevrolet 2 Car line or series Z = Corvette 3 - 4 Body style 37 = Two door coupe (1973-1977) 67 = Two door convertible 87 = Two door coupe (1978-1980) 5 Engine type 1973: J = L48; 350ci, 190hp T = L82; 350ci, 250hp Z = LS4; 454ci, 275hp 1974: J = L48; 350ci, 195hp T = L82; 350ci, 250hp Z = LS4; 454ci, 270hp 1975: J = L48; 350ci, 165hp T = L82; 350ci, 205hp 1976: L = L48; 350ci, 180hp X = L82; 350ci, 210hp 1977: L = L48; 350ci, 180hp X = L82; 350ci, 210hp 1978: L = L48;350ci, 175hp, 185hp 4 = L82; 350ci, 220hp 1979: 8 = L48; 350ci, 195hp 4 = L82; 350ci, 225hp 1980: H = LG4; 305ci, 180hp 8 = L48; 350ci, 190hp 6 = L82; 350ci |
L-48s did not have smog pumps (Xcept CA and high altitude)
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Originally Posted by 98MustGT
(Post 1576564248)
L-48s did not have smog pumps (Xcept CA and high altitude)
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