Camshaft question
Le Mans Master
Joined: May 2007
Posts: 5,025
Likes: 1,120
From: North tonawanda NY
Because we are debating amunst ourselves.. My understanding is the l82 became less and less powerful and what started out as a good choice cam wise for older engines became less viable and ideal on the later lower compression smog motors.
Melting Slicks
Joined: Dec 2009
Posts: 3,233
Likes: 657
From: Thunder Bay
Yes, that's exactly what you want to do. Actually the better solution is to increase the compression. The advertised compression ratio was 8.9:1. With the factory camshaft you end up with a dynamic compression ratio of about 6:1. The L-82 was a dog the way it came from the factory and it was purely the result of mismatched parts. I had that cam in a '78 Monza with a 350 but the compression was around 10.5:1 and it worked great! But it was way too much cam for the L-82 the way the factory built it. Not sure what the heck they were thinking.
Burning Brakes
Joined: Aug 2007
Posts: 897
Likes: 245
From: Green Valley Ca
Yes, that's exactly what you want to do. Actually the better solution is to increase the compression. The advertised compression ratio was 8.9:1. With the factory camshaft you end up with a dynamic compression ratio of about 6:1. The L-82 was a dog the way it came from the factory and it was purely the result of mismatched parts. I had that cam in a '78 Monza with a 350 but the compression was around 10.5:1 and it worked great! But it was way too much cam for the L-82 the way the factory built it. Not sure what the heck they were thinking.
Le Mans Master
Joined: Oct 2010
Posts: 6,936
Likes: 848
From: melbourne florida
2023 C3 of the Year Finalist - Modified
It didn't take much work ,headers exhaust, distributor set up carb tweaked to run high 13s. That wasn't too shabby in it's day.
Throw some aftermarket 64 cc heads on an L82 with the simple recipe above and you will see a big improvement.
I run an SSH-24 RACER BROWN CAM with 110 lsa and it's a very strong runner. It's an old school design that should hold up for a long time plus it's zero spark ground. It's not mass produced made by one guy one at a time.
I went with a guy that ground stuff for me 40 yrs ago.
Throw some aftermarket 64 cc heads on an L82 with the simple recipe above and you will see a big improvement.
I run an SSH-24 RACER BROWN CAM with 110 lsa and it's a very strong runner. It's an old school design that should hold up for a long time plus it's zero spark ground. It's not mass produced made by one guy one at a time.
I went with a guy that ground stuff for me 40 yrs ago.
Le Mans Master
Joined: May 2007
Posts: 5,025
Likes: 1,120
From: North tonawanda NY
And the xr270 hr is also small
at 224/218@50
GM 8100/8.1L 8-Cyl. 2001-Present
Chevy 496
RPM Range
1200-5200
Lifter Type
Hydraulic Roller
Int. Duration Advertised (Deg)
270
Exh. Duration @ .050 in. (Deg)
224
Exh. Duration Advertised (Deg)
276
Int. Duration @ .050 in. (Deg)
218
Usage
Street/Performance
Quantity
Sold individually
Lobe Separation (Deg)
114
Exhaust Valve Lift with Factory Rocker Arm Ratio (
0.51
Intake Valve Lift with Factory Rocker Arm Ratio (i
0.51
Valve Lift with Factory Rocker Arm Ratio
0.510 int./0.510 exh.
Advertised Duration
270 int./276 exh.
Computer-Controlled Compatible
No
Valve Springs Required
Yes
Cam Style
Hydraulic roller tappet
Exhaust Duration at 050 inch Lift
224
Intake Duration at 050 inch Lift
218
Duration at 050 inch Lift
218 int./224 exh.
Advertised Intake Duration
270
Advertised Exhaust Duration
276
Basic Operating RPM Range
1,200-5,200
Grind Number
CB8 XR270 HR14
Exhaust Valve Lift
0.51 in (12.954 mm)
Intake Valve Lift
0.51 in (12.954 mm)
Manufacturer's Part Number:
46-422-9
Shipping Weight:
11.1
Package Height:
2.8
Package Depth:
24.5
Package Width:
3.2
at 224/218@50
GM 8100/8.1L 8-Cyl. 2001-Present
- Produces Better Throttle Response
- Produces Top Engine Horsepower
- Delivers Increased Engine Vacuum
- 1 Year Limited Warranty
Best in performance applications, aftermarket intake and exhaust recommended.
Specifications:
Engine Make/SizeChevy 496
RPM Range
1200-5200
Lifter Type
Hydraulic Roller
Int. Duration Advertised (Deg)
270
Exh. Duration @ .050 in. (Deg)
224
Exh. Duration Advertised (Deg)
276
Int. Duration @ .050 in. (Deg)
218
Usage
Street/Performance
Quantity
Sold individually
Lobe Separation (Deg)
114
Exhaust Valve Lift with Factory Rocker Arm Ratio (
0.51
Intake Valve Lift with Factory Rocker Arm Ratio (i
0.51
Valve Lift with Factory Rocker Arm Ratio
0.510 int./0.510 exh.
Advertised Duration
270 int./276 exh.
Computer-Controlled Compatible
No
Valve Springs Required
Yes
Cam Style
Hydraulic roller tappet
Exhaust Duration at 050 inch Lift
224
Intake Duration at 050 inch Lift
218
Duration at 050 inch Lift
218 int./224 exh.
Advertised Intake Duration
270
Advertised Exhaust Duration
276
Basic Operating RPM Range
1,200-5,200
Grind Number
CB8 XR270 HR14
Exhaust Valve Lift
0.51 in (12.954 mm)
Intake Valve Lift
0.51 in (12.954 mm)
Manufacturer's Part Number:
46-422-9
Shipping Weight:
11.1
Package Height:
2.8
Package Depth:
24.5
Package Width:
3.2
