'76 L82 Cam advice
Thread Starter
Instructor
Joined: Feb 2004
Posts: 207
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From: Laredo Texas
'76 L82 Cam advice
I recently refreshed a motor on a 82k mile L82. The engine had a nice muscle car sound at idle and after seeing the 222 @50 duration I felt that was enough so I swapped in some Promaxx 2181 190 heads with the 64cc chamber along with a .040 gasket, to put me at 9.5:1 CR. Topped it off with some 1.6 RR and a Weiand dual plane intake and a rejetted Quadrajet. Played around with secondaries for best response and total timing is set at 34
I was really hoping for more power honestly lol, it feels good from a dead stop but doesn't have much wow factor from cruise to WOT. The muscle car idle is pretty much gone now. Idles like a tame sedan with chambered exhaust. I guess the old 882 heads were just gone at the valve/seat area giving it a nice idle. Engine runs great but I was aiming towards more sound and performance without losing the really great street manners it has. It's backed by the TH350. What cam would you recommend to bring back that idle and help get more mid-range power? Remember I am using 1.6 RR as well. Thanks!
I was really hoping for more power honestly lol, it feels good from a dead stop but doesn't have much wow factor from cruise to WOT. The muscle car idle is pretty much gone now. Idles like a tame sedan with chambered exhaust. I guess the old 882 heads were just gone at the valve/seat area giving it a nice idle. Engine runs great but I was aiming towards more sound and performance without losing the really great street manners it has. It's backed by the TH350. What cam would you recommend to bring back that idle and help get more mid-range power? Remember I am using 1.6 RR as well. Thanks!
Race Director
Joined: Nov 2006
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From: Sunshine Coast, Queensland, Australia
2025 C3 of the Year Finalist - Modified
2024 C3 of the Year Finalist- Modified
2022 C3 of the Year Finalist - Modified
Cruise-In VIII Veteran
O.K. I'll throw this out there.
my engine in my 77 is nearly identical to yours. flat top pistons, 64 cc combustion chambers. 1.6 -1 rockers. RPM manifold.
However I'm running a manual.
I'm running a Comp Cams Xtreme Energy cam. Part number CL-12-242-2. advertised duration of 268-280.
Likes to idle about 850 RPM. About 13.5 inches of vacuum.
Sounds like it has a Cam in it but not real aggressive. Very streetable. Stong mid range once I finally got my distributor dialed in. (Likes a lot of initial timing).
And they (Comp Cams) claim this is about as much cam you can run with a standard tourqe converter.
Sounds like the heads you have should handle this without modification. With the 1.6-1 rockers, lift should be a tad over .5
my engine in my 77 is nearly identical to yours. flat top pistons, 64 cc combustion chambers. 1.6 -1 rockers. RPM manifold.
However I'm running a manual.
I'm running a Comp Cams Xtreme Energy cam. Part number CL-12-242-2. advertised duration of 268-280.
Likes to idle about 850 RPM. About 13.5 inches of vacuum.
Sounds like it has a Cam in it but not real aggressive. Very streetable. Stong mid range once I finally got my distributor dialed in. (Likes a lot of initial timing).
And they (Comp Cams) claim this is about as much cam you can run with a standard tourqe converter.
Sounds like the heads you have should handle this without modification. With the 1.6-1 rockers, lift should be a tad over .5
Le Mans Master
Joined: May 2007
Posts: 5,021
Likes: 1,120
From: North tonawanda NY
I recently refreshed a motor on a 82k mile L82. The engine had a nice muscle car sound at idle and after seeing the 222 @50 duration I felt that was enough so I swapped in some Promaxx 2181 190 heads with the 64cc chamber along with a .040 gasket, to put me at 9.5:1 CR. Topped it off with some 1.6 RR and a Weiand dual plane intake and a rejetted Quadrajet. Played around with secondaries for best response and total timing is set at 34
I was really hoping for more power honestly lol, it feels good from a dead stop but doesn't have much wow factor from cruise to WOT. The muscle car idle is pretty much gone now. Idles like a tame sedan with chambered exhaust. I guess the old 882 heads were just gone at the valve/seat area giving it a nice idle. Engine runs great but I was aiming towards more sound and performance without losing the really great street manners it has. It's backed by the TH350. What cam would you recommend to bring back that idle and help get more mid-range power? Remember I am using 1.6 RR as well. Thanks!
I was really hoping for more power honestly lol, it feels good from a dead stop but doesn't have much wow factor from cruise to WOT. The muscle car idle is pretty much gone now. Idles like a tame sedan with chambered exhaust. I guess the old 882 heads were just gone at the valve/seat area giving it a nice idle. Engine runs great but I was aiming towards more sound and performance without losing the really great street manners it has. It's backed by the TH350. What cam would you recommend to bring back that idle and help get more mid-range power? Remember I am using 1.6 RR as well. Thanks!
Race Director
Joined: Nov 2006
Posts: 13,199
Likes: 7,796
From: Sunshine Coast, Queensland, Australia
2025 C3 of the Year Finalist - Modified
2024 C3 of the Year Finalist- Modified
2022 C3 of the Year Finalist - Modified
Cruise-In VIII Veteran
Just to say, that Lunati VooDoo cam is very similar in spec to the Xtreme Energy cam I'm running. And my heads are 180 ports as well. But 190's should still run. Biggest thing to look at is your distributor setup. Have you recurved your distributor to match your new heads and compression? You may find a lot of power there. But not a lumpy idle.
Le Mans Master
Joined: Oct 2010
Posts: 6,930
Likes: 845
From: melbourne florida
2023 C3 of the Year Finalist - Modified
Pretty much what I had but I had a thinner head gasket and advanced the stock cam 4 degrees. With an RPM air gap and quick fuel 750 double pumper and 2800 convertor and the timing dialed in it ran really well
My new custom ground Racer Brown cam it's an animal and sounds like it. Just had a hellcat challenger with a loud exhaust slink away from the traffic light, it sounds that bad lol.
My new custom ground Racer Brown cam it's an animal and sounds like it. Just had a hellcat challenger with a loud exhaust slink away from the traffic light, it sounds that bad lol.
Thread Starter
Instructor
Joined: Feb 2004
Posts: 207
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From: Laredo Texas
Thanks for the responses. I am seeing that the stock carburetor, although in perfect working order is jetted too lean for the new setup. I messed with the engine extensively prior to disassembly and carburetor was mixing very well. Now with the new higher flowing heads it is lean on the mixture and I'm sure there's power to be had by jetting up the Q-jet. I am also going to cam it up, I decided to go with the Comp Cams XE262. Just to get that bumpy idle yet still maintain good vacuum and street manners. Should wake up that mid-range as well. Transmission is adjusted properly. downshift occurs at correct time and distributor has been recurved as well. I think the engine just needs a bit more fuel to take advantage of the heads. Want to keep stock stall as well. This is a customer build and just want to meet his expectations. I'll post back once we install cam and jet up the Q-jet. Thanks!
Last edited by Atomic-Punk; Oct 26, 2020 at 12:30 PM.
Team Owner
Joined: Oct 2004
Posts: 81,241
Likes: 3,063
From: altered state
St. Jude Donor '05
First, what rear end gear do you have? Headers?
Is it lacking some power or a lot?
If you had a little gear and were willing to put a small (2800) converter in /650 carb the 280 Isky runs super hard. Midrange is nuts for a little flat tappet
You may need to run a vacuum reservoir. ..the 270 works ok with a taller gear and stock converter .
Specs arent much different but the torque sure is...and sounds good. Not mine but they sound exactly like this one.
Is it lacking some power or a lot?
If you had a little gear and were willing to put a small (2800) converter in /650 carb the 280 Isky runs super hard. Midrange is nuts for a little flat tappet
You may need to run a vacuum reservoir. ..the 270 works ok with a taller gear and stock converter .
Specs arent much different but the torque sure is...and sounds good. Not mine but they sound exactly like this one.
Last edited by cv67; Oct 26, 2020 at 02:38 PM.
Melting Slicks
Joined: Dec 2009
Posts: 3,229
Likes: 656
From: Thunder Bay
Thanks for the responses. I am seeing that the stock carburetor, although in perfect working order is jetted too lean for the new setup. I messed with the engine extensively prior to disassembly and carburetor was mixing very well. Now with the new higher flowing heads it is lean on the mixture and I'm sure there's power to be had by jetting up the Q-jet. I am also going to cam it up, I decided to go with the Comp Cams XE262. Just to get that bumpy idle yet still maintain good vacuum and street manners. Should wake up that mid-range as well. Transmission is adjusted properly. downshift occurs at correct time and distributor has been recurved as well. I think the engine just needs a bit more fuel to take advantage of the heads. Want to keep stock stall as well. This is a customer build and just want to meet his expectations. I'll post back once we install cam and jet up the Q-jet. Thanks!
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