Power Recommendations Needed….
Thread Starter
Pro
Joined: Dec 2004
Posts: 534
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From: Connecticut
Power Recommendations Needed….
I have a 1978 L-82 with a 4 speed. I have true dual exhaust and edelbrock intake. Everything else is stock. I’m looking for a way to add some more power without replacing the heads.
Is there a replacement cam that I can use that will provide more power and allow me to keep everything else as is and also not have a problem with vaccum? If so, please recommend which cam and lifters if needed I should use.
Thank you
Is there a replacement cam that I can use that will provide more power and allow me to keep everything else as is and also not have a problem with vaccum? If so, please recommend which cam and lifters if needed I should use.
Thank you
Melting Slicks
Joined: Mar 2007
Posts: 2,100
Likes: 12
From: Frederick Maryland
Call Summit Racing and talk to their techs. Tell them what you have and what you want out of the car and they'll give you solid recommendations on what mix of parts will accomplish that.
Burning Brakes
Joined: Dec 2005
Posts: 992
Likes: 56
From: Baldwinsville, NY
If I had a second chance.
I did a vortec head & cam change last summer. I may be wrong, but most of the power came from the increased CR with the smaller head chamber volume plus the new seals (intake, head, valve stem).
The cam & intake just complete the system.
The L82 has larger cam then the L48 and larger then the one I installed.
If I could do it again I would use standard cast iron SB heads with 64 or 67 cc chambers and paint it the blue engine color.
The Scoggin Dickey vortec kit was priced right for me at that time.
You might think about your budget.
Some one on the forum can help with the head selection.
The cam & intake just complete the system.
The L82 has larger cam then the L48 and larger then the one I installed.
If I could do it again I would use standard cast iron SB heads with 64 or 67 cc chambers and paint it the blue engine color.
The Scoggin Dickey vortec kit was priced right for me at that time.
You might think about your budget.
Some one on the forum can help with the head selection.
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
The stock L-82 cam (P/N 3896962) is a pretty healthy one with .450/.460 lift which is about the limit of your stock springs. Any aftermarket cam wouldn't be able lift much higher without a spring swap, and we start thinking about piston/valve clearance once we get up around .500 lift. Newer cams have a more aggressive ramp which might produce somewhat more midrange power - but I strongly doubt it would be significant.
I respect not wanting to change the heads, but frankly they're the weakest point of the engine. The L-82 heads are lousy; something like 165cc intake runners a "smog"-style chambers, and the flow tops out around 200/130 # .500 lift, although realistically they level out at .400 lift. There's no reason to change the cam if the heads won't flow.
Moving to an aftermarket head gives you the option to bump the compression by moving from a 76 to 64cc chamber - about a 1 point bump - and something that will BREATHE with that L-82 cam. If that's really not an option, then I would enjoy the car as-is vs. trying to chase more power. Possibly invest in a tune to get the most out of it possible.
I respect not wanting to change the heads, but frankly they're the weakest point of the engine. The L-82 heads are lousy; something like 165cc intake runners a "smog"-style chambers, and the flow tops out around 200/130 # .500 lift, although realistically they level out at .400 lift. There's no reason to change the cam if the heads won't flow.
Moving to an aftermarket head gives you the option to bump the compression by moving from a 76 to 64cc chamber - about a 1 point bump - and something that will BREATHE with that L-82 cam. If that's really not an option, then I would enjoy the car as-is vs. trying to chase more power. Possibly invest in a tune to get the most out of it possible.
Thread Starter
Pro
Joined: Dec 2004
Posts: 534
Likes: 2
From: Connecticut
The stock L-82 cam (P/N 3896962) is a pretty healthy one with .450/.460 lift which is about the limit of your stock springs. Any aftermarket cam wouldn't be able lift much higher without a spring swap, and we start thinking about piston/valve clearance once we get up around .500 lift. Newer cams have a more aggressive ramp which might produce somewhat more midrange power - but I strongly doubt it would be significant.
I respect not wanting to change the heads, but frankly they're the weakest point of the engine. The L-82 heads are lousy; something like 165cc intake runners a "smog"-style chambers, and the flow tops out around 200/130 # .500 lift, although realistically they level out at .400 lift. There's no reason to change the cam if the heads won't flow.
Moving to an aftermarket head gives you the option to bump the compression by moving from a 76 to 64cc chamber - about a 1 point bump - and something that will BREATHE with that L-82 cam. If that's really not an option, then I would enjoy the car as-is vs. trying to chase more power. Possibly invest in a tune to get the most out of it possible.
I respect not wanting to change the heads, but frankly they're the weakest point of the engine. The L-82 heads are lousy; something like 165cc intake runners a "smog"-style chambers, and the flow tops out around 200/130 # .500 lift, although realistically they level out at .400 lift. There's no reason to change the cam if the heads won't flow.
Moving to an aftermarket head gives you the option to bump the compression by moving from a 76 to 64cc chamber - about a 1 point bump - and something that will BREATHE with that L-82 cam. If that's really not an option, then I would enjoy the car as-is vs. trying to chase more power. Possibly invest in a tune to get the most out of it possible.
What heads would you recommend?
Race Director
Joined: May 2005
Posts: 10,674
Likes: 122
From: Millington Illinois
St. Jude Donor '08-'09
The stock L-82 cam (P/N 3896962) is a pretty healthy one with .450/.460 lift which is about the limit of your stock springs. Any aftermarket cam wouldn't be able lift much higher without a spring swap, and we start thinking about piston/valve clearance once we get up around .500 lift. Newer cams have a more aggressive ramp which might produce somewhat more midrange power - but I strongly doubt it would be significant.
I respect not wanting to change the heads, but frankly they're the weakest point of the engine. The L-82 heads are lousy; something like 165cc intake runners a "smog"-style chambers, and the flow tops out around 200/130 # .500 lift, although realistically they level out at .400 lift. There's no reason to change the cam if the heads won't flow.
Moving to an aftermarket head gives you the option to bump the compression by moving from a 76 to 64cc chamber - about a 1 point bump - and something that will BREATHE with that L-82 cam. If that's really not an option, then I would enjoy the car as-is vs. trying to chase more power. Possibly invest in a tune to get the most out of it possible.
I respect not wanting to change the heads, but frankly they're the weakest point of the engine. The L-82 heads are lousy; something like 165cc intake runners a "smog"-style chambers, and the flow tops out around 200/130 # .500 lift, although realistically they level out at .400 lift. There's no reason to change the cam if the heads won't flow.
Moving to an aftermarket head gives you the option to bump the compression by moving from a 76 to 64cc chamber - about a 1 point bump - and something that will BREATHE with that L-82 cam. If that's really not an option, then I would enjoy the car as-is vs. trying to chase more power. Possibly invest in a tune to get the most out of it possible.
Head recomendation, AFR 195 eliminators, 65 cc, straight plug. standard springs. 1.6 full roller rockers to get a little more lift and duration to feed those heads. This gasket. http://summitracing.com/parts/FPP-1094/
Last edited by 63mako; Jun 16, 2009 at 01:39 PM.
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
This becomes a budget discussion 
The very best bang-for-the-buck setup for the L-82 is below, but this will require an intake swap as well.
If you want a stock-style head it really comes down to $$$; you're looking for a 180cc head with a 64 cc chamber - and there's a bunch. If you post a budget, I'll give a few thoughts.
The very best bang-for-the-buck setup for the L-82 is below, but this will require an intake swap as well.
- GMPP Vortecs (P/N 12558060), $600
- GMPP Self-aligning stamped-steel rockers (P/N 12495490), $60
- Edelbrock Performer EPS intake (P/N 2716), $185
- Center-bolt valvecovers (used), around $30
- Gasket set, etc. An .028 or .015 compressed thickness gasket will significantly reduce your quench which adds power and detonation resistance.
If you want a stock-style head it really comes down to $$$; you're looking for a 180cc head with a 64 cc chamber - and there's a bunch. If you post a budget, I'll give a few thoughts.
Last edited by billla; Jun 16, 2009 at 01:26 PM.
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
I should probably add that a set of headers would be a fairly significant change as well - ESPECIALLY after a head change. There's right around 350HP/350TQ at the flywheel with an upgraded L-82
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Race Director
Joined: May 2005
Posts: 10,674
Likes: 122
From: Millington Illinois
St. Jude Donor '08-'09
Headers would be a big plus. The 180 is a good match but I would go with the 195's. Always think of future upgrades. Don't think the increased cc will be a problem.
Thread Starter
Pro
Joined: Dec 2004
Posts: 534
Likes: 2
From: Connecticut
This becomes a budget discussion
The very best bang-for-the-buck setup for the L-82 is below, but this will require an intake swap as well.
If you want a stock-style head it really comes down to $$$; you're looking for a 180cc head with a 64 cc chamber - and there's a bunch. If you post a budget, I'll give a few thoughts.
The very best bang-for-the-buck setup for the L-82 is below, but this will require an intake swap as well.
- GMPP Vortecs (P/N 12558060), $600
- GMPP Self-aligning stamped-steel rockers (P/N 12495490), $60
- Edelbrock Performer EPS intake (P/N 2716), $185
- Center-bolt valvecovers (used), around $30
- Gasket set, etc. An .028 or .015 compressed thickness gasket will significantly reduce your quench which adds power and detonation resistance.
If you want a stock-style head it really comes down to $$$; you're looking for a 180cc head with a 64 cc chamber - and there's a bunch. If you post a budget, I'll give a few thoughts.
Last edited by DO2G; Jun 16, 2009 at 02:08 PM.
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
You may get a recommendation to take your heads off and home port them. You can do a decent job of this at home, but it needs to be done carefully and I really don't recommend it. There are porters that will do this on iron heads, but they're fairly pricey and you'd still have those smog chambers.
This is one of those situations where something costs N dollars and there's really no shortcut
Thread Starter
Pro
Joined: Dec 2004
Posts: 534
Likes: 2
From: Connecticut
Is there anything else needed besides what you have below? Will this set-up work with a stock hood?
The very best bang-for-the-buck setup for the L-82 is below, but this will require an intake swap as well.
GMPP Vortecs (P/N 12558060), $600
GMPP Self-aligning stamped-steel rockers (P/N 12495490), $60
Edelbrock Performer EPS intake (P/N 2716), $185
Center-bolt valvecovers (used), around $30
Gasket set, etc. An .028 or .015 compressed thickness gasket will significantly reduce your quench which adds power and detonation resistance.
The very best bang-for-the-buck setup for the L-82 is below, but this will require an intake swap as well.
GMPP Vortecs (P/N 12558060), $600
GMPP Self-aligning stamped-steel rockers (P/N 12495490), $60
Edelbrock Performer EPS intake (P/N 2716), $185
Center-bolt valvecovers (used), around $30
Gasket set, etc. An .028 or .015 compressed thickness gasket will significantly reduce your quench which adds power and detonation resistance.
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
I've found that for mild 350s (<= 1HP/CID at the flywheel) anything larger than 180cc makes for poorer low- to mid-range throttle response. It doesn't show up on the dyno, but it does show up driving. Just one guy's opinion
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
I understand that this requires a drop-base air cleaner and/or a shorter filter. There are always a few odds-and-ends with these kinds of swaps, but I can't think of anything major missing.
Melting Slicks
Joined: May 2006
Posts: 2,590
Likes: 403
From: Nashville TN
St. Jude Donor '09
I'm doing the same research now for my L48. If you go the Vortec route, this combo from SDPARTS might work. They have an RPM version too, but the intake is square bore, so your Q-jet will not bolt right on w/o an adapter plate. Not sure what the verdict is on using adapter plates . . . maybe others could comment.
Edelbrock has a new E-Street series head that has pretty good flow #s and you can get for about $850 at SDPARTS E-Street.
Edelbrock has a new E-Street series head that has pretty good flow #s and you can get for about $850 at SDPARTS E-Street.
Thread Starter
Pro
Joined: Dec 2004
Posts: 534
Likes: 2
From: Connecticut
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
News Flash The August Hot Rod has an OUTSTANDING comparo between the Vortec and the E-Streets.
Flow is about the same until > .400 lift where the E-Streets peak out at 228/162 vs. 216/148 for the Vortecs. On a relatively mild 383, the E-streets made about 20TQ and 7 HP more. On a mild 350 with a milder cam, the difference would be smaller - but it makes the E Streets a GREAT choice for a low-buck head where a Vortec isn't desired for whatever reason. Price-wise it's kind of a wash when you factor in the cost of the new intake required for the Vortecs.
Great catch, redman 76!
The August Hot Rod has an OUTSTANDING comparo between the Vortec and the E-Streets.Flow is about the same until > .400 lift where the E-Streets peak out at 228/162 vs. 216/148 for the Vortecs. On a relatively mild 383, the E-streets made about 20TQ and 7 HP more. On a mild 350 with a milder cam, the difference would be smaller - but it makes the E Streets a GREAT choice for a low-buck head where a Vortec isn't desired for whatever reason. Price-wise it's kind of a wash when you factor in the cost of the new intake required for the Vortecs.
Great catch, redman 76!
Melting Slicks
Joined: May 2006
Posts: 2,590
Likes: 403
From: Nashville TN
St. Jude Donor '09
I haven't seen the Hod Rod comparison. I'll have to grab a copy. . . thanks! I was wanting a head that could work good with a 383 eventually, but wasn't as $$$ as AFR (wish I could afford). I was almost sold on the Vortec upgrade, but since the cost was the same for what I'm replacing, I'm thinking the aluminum heads will serve me better so I can eventally get a little more compression and HP with them.
DO2g . . . I asked the exact same question with the exact same budget ($500). One suggestion was to replace the rear gears with something a little higher like 3.55 or 3.70. I'm still going to do that, but waiting until I can get OD tranny like the 200-4R. I HAAAATE my smog heads.
DO2g . . . I asked the exact same question with the exact same budget ($500). One suggestion was to replace the rear gears with something a little higher like 3.55 or 3.70. I'm still going to do that, but waiting until I can get OD tranny like the 200-4R. I HAAAATE my smog heads.