L79 vs L46
Thread Starter
CF Community Team
Joined: Mar 2007
Posts: 9,339
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From: Delaware
St. Jude Donor '25
L79 vs L46
Fellas,
I have owned my 68 L79 since 1985. I also have a 69 L46. The 69 is a very original side exhaust coupe waiting for a mild restoration. Other than driving it to it's storage area 10 years ago, I have never run it (I know, long wait..3 kids, mortgage, private schools, blah blah blah). What should I expect as far as performance and how should it compare to my 68 L79? I believe they both have the same rear (3.70). Both engines are 100% stock.
Keep in mind I never drive the 68 like I did back in the day, but I remember it ran like a raped ape.
Thnaks, John
I have owned my 68 L79 since 1985. I also have a 69 L46. The 69 is a very original side exhaust coupe waiting for a mild restoration. Other than driving it to it's storage area 10 years ago, I have never run it (I know, long wait..3 kids, mortgage, private schools, blah blah blah). What should I expect as far as performance and how should it compare to my 68 L79? I believe they both have the same rear (3.70). Both engines are 100% stock.
Keep in mind I never drive the 68 like I did back in the day, but I remember it ran like a raped ape.
Thnaks, John
Last edited by avalonjohn; May 12, 2017 at 01:51 PM.
Burning Brakes
Joined: Oct 2012
Posts: 1,152
Likes: 252
The L46 has a tick more torque from the displacement increase but they are the same otherwise.
http://www.superchevy.com/how-to/eng...-dyno-testing/
http://www.superchevy.com/how-to/eng...-dyno-testing/
Thread Starter
CF Community Team
Joined: Mar 2007
Posts: 9,339
Likes: 360
From: Delaware
St. Jude Donor '25
The L46 has a tick more torque from the displacement increase but they are the same otherwise.
http://www.superchevy.com/how-to/eng...-dyno-testing/
http://www.superchevy.com/how-to/eng...-dyno-testing/
Burning Brakes
Joined: Oct 2012
Posts: 1,152
Likes: 252
It started back in 68 when the L79 got an AIR pump and the C2 L79 did not have one, people back in the day used that as justification to say their C2 327 as better. We all now know the AIR pump doesn't consume any meaningful power. The change of carb also contributed to the rumor.
L46 = L79 with stroke increase
L82 = L46 with lower CR and less CFM head flow
ZQ3 = 69-70 L48
71-80 L48 = 69-70 L48 with lower CR and less CFM head flow
L76 = L79 with a lesser cam
so...
you can turn an L82 in an equivalent L46 with a head swap (the L82 cam has 4 more degrees advance but close enough)
you can turn a late L48 into an equivalent early L48 with a head swap (the pistons are slightly different but close enough)
You can turn a L79 into a L46 with a 3.48" crank and pistons (carb was different but close enough)
you can turn a L79 into a L76 with a cam change
Last edited by Dynra Rockets; May 13, 2017 at 06:39 AM.
Thread Starter
CF Community Team
Joined: Mar 2007
Posts: 9,339
Likes: 360
From: Delaware
St. Jude Donor '25
Thats an old wives tale spread by people that do not know any better but want to sound knowledgeable.
It started back in 68 when the L79 got an AIR pump and the C2 L79 did not have one, people back in the day used that as justification to say their C2 327 as better. We all now know the AIR pump doesn't consume any meaningful power. The change of carb also contributed to the rumor.
L46 = L79 with stroke increase
L82 = L46 with lower CR and less CFM head flow
ZQ3 = 69-70 L48
71-80 L48 = 69-70 L48 with lower CR and less CFM head flow
L76 = L79 with a lesser cam
so...
you can turn an L82 in an equivalent L46 with a head swap (the L82 can has 4 more degrees advance but close enough)
you can turn a late L48 into an equivalent early L48 with a head swap (the pistons are slightly different but close enough)
You can turn a L79 into a L46 with a 3.48" crank and pistons (carb was different but close enough)
you can turn a L79 into a L76 with a cam change
It started back in 68 when the L79 got an AIR pump and the C2 L79 did not have one, people back in the day used that as justification to say their C2 327 as better. We all now know the AIR pump doesn't consume any meaningful power. The change of carb also contributed to the rumor.
L46 = L79 with stroke increase
L82 = L46 with lower CR and less CFM head flow
ZQ3 = 69-70 L48
71-80 L48 = 69-70 L48 with lower CR and less CFM head flow
L76 = L79 with a lesser cam
so...
you can turn an L82 in an equivalent L46 with a head swap (the L82 can has 4 more degrees advance but close enough)
you can turn a late L48 into an equivalent early L48 with a head swap (the pistons are slightly different but close enough)
You can turn a L79 into a L46 with a 3.48" crank and pistons (carb was different but close enough)
you can turn a L79 into a L76 with a cam change
Stay safe, john
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Burning Brakes
Joined: Oct 2012
Posts: 1,152
Likes: 252
Agreed on "not equivalent", two totally different specifications (L79), not an apples to apples comparison. That '67 327 had much more compression and a better cam the the 8.5:1 and mild cam of the '72. I would expect that 327 to rev more eagerly! Even the base 327 (L30) with the same .390/.410 camshaft spec would have revved more eagerly than the 72 L48 due to much more compression. While displacement is fantastic, I'll take the 2 more pts of CR over 23 cubes any day.
Last edited by Dynra Rockets; May 13, 2017 at 10:02 AM.
Melting Slicks
Joined: Jan 2012
Posts: 3,041
Likes: 505
From: myrtle beach sc
Army
The 68 Corvette L-79 had the cast iron intake manifold and Quadrajet carb like the L-46.
I think that the 327 would rev faster due to a smaller 10 1/2" flywheel, but it does not have the torque of the 350. Mine was very "dead" until you got over 2,200 RPM's. I use to rev it up to 6,300 RPM,s sometimes. Lou.
I think that the 327 would rev faster due to a smaller 10 1/2" flywheel, but it does not have the torque of the 350. Mine was very "dead" until you got over 2,200 RPM's. I use to rev it up to 6,300 RPM,s sometimes. Lou.
7th Gear
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From: NYC
The L46 has a tick more torque from the displacement increase but they are the same otherwise.
http://www.superchevy.com/how-to/eng...-dyno-testing/
http://www.superchevy.com/how-to/eng...-dyno-testing/
Is my vette stock?? HAHA
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