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I believe in 78 the horsepower difference was only 20+ between the l48 and l82, BUT if you can find a cheap aluminum intake and port it then you could almost increase HP by 25-30 percent, match that with a decent working carb and you will be close to 300 ponies providing the engine is healthy.
WOW!!!
No chance what-so-ever that happens from an intake port match and swap.
Everyone only wishes it was that easy........195HP is plenty weak.......but even this small number....25-30% equates to an increase of darn close to 50-60HP.........you're gonna need more cam and/or better heads to go along with your aluminum intake to make that happen.......the good news though......add headers and pick the correct cam and head combo......50-60 extra HP is not only EASY to achieve but really the baseline of what you should expect. 100HP extra is also quite possible if you do it all at once.
But really......there is no solid reason to give a single extra bit of consideration to an L82 car or it's differing pieces from this period over an L48. I'd pick the best example I could find of either model ........the motor would come in as no serious consideration at all......both are so weak by modern standard that neither survives a resto-mod anyway which is what we're talking in this quest for more power..
In beach analogy .......The L48 is the 98 pound weakling and for the owners of L82s that want to highlight their MORE powerful optioned engine.......it's the equivalent of the 99-100pd weakling pointing out his weakling competition on Muscle beach. Technically stronger than the other under hood weakling........hardly makes something impressive when it's surrounded by actual strength on the street these days. Fact is the world today sees the L82 in the exact same light as the L48.......too weak to power a sports car.......definitely not up to the expectation of the name plate "Corvette".
If porting a 50 buck intake would net any measurable gain, everybody would be doing it. Now, if you port a couple of holes for nitrous injectors, maybe net 25%. And the 98 lb weakling can take the 100 lb weakling under 3500 rpm's. Better torque curve. Or should I say less horrible torque curve?
And the 98 lb weakling can take the 100 lb weakling under 3500 rpm's. Better torque curve. Or should I say less horrible torque curve?
unless the L82 is a 3.70 car :-)
If you must keep the L48 camshaft then in order to get the engine to perform you have to focus on torque. The camshaft simply will not allow enough air in to make power over 4300 rpm on a 350.
Increasing the CR by using 58cc heads is a great start.
Last edited by Dynra Rockets; 12-17-2017 at 04:16 PM.
No chance what-so-ever that happens from an intake port match and swap.
Everyone only wishes it was that easy........195HP is plenty weak.......but even this small number....25-30% equates to an increase of darn close to 50-60HP.........you're gonna need more cam and/or better heads to go along with your aluminum intake to make that happen.......the good news though......add headers and pick the correct cam and head combo......50-60 extra HP is not only EASY to achieve but really the baseline of what you should expect. 100HP extra is also quite possible if you do it all at once.
But really......there is no solid reason to give a single extra bit of consideration to an L82 car or it's differing pieces from this period over an L48. I'd pick the best example I could find of either model ........the motor would come in as no serious consideration at all......both are so weak by modern standard that neither survives a resto-mod anyway which is what we're talking in this quest for more power..
In beach analogy .......The L48 is the 98 pound weakling and for the owners of L82s that want to highlight their MORE powerful optioned engine.......it's the equivalent of the 99-100pd weakling pointing out his weakling competition on Muscle beach. Technically stronger than the other under hood weakling........hardly makes something impressive when it's surrounded by actual strength on the street these days. Fact is the world today sees the L82 in the exact same light as the L48.......too weak to power a sports car.......definitely not up to the expectation of the name plate "Corvette".
You did not read my other posts, nor did you read the original posters. I told him to pop the heads off...basicically pitch them in the garbage. Original poster said he was going to change exaust, heads and cam....so you honestly think that changing the heads, cam, intake, and exaust isnt going to make a 25-30 percent increase in horsepower??? I say do it just to make the car perform better and make it more fun to drive. I didnt even touch on the price factor of making it worth more like the original poster was asking.
You did not read my other posts, nor did you read the original posters. I told him to pop the heads off...basicically pitch them in the garbage. Original poster said he was going to change exaust, heads and cam....so you honestly think that changing the heads, cam, intake, and exaust isnt going to make a 25-30 percent increase in horsepower??? I say do it just to make the car perform better and make it more fun to drive. I didnt even touch on the price factor of making it worth more like the original poster was asking.
My advice is pull the intake and get a better performance one at least....it will increase power and fun quite a bit. If your so inclined, pop the heads off and port match them to the new intake gasgets, then port match the intake to gasgets as well....the gain in power alone will help sell the car for sure!!! Other then the price of intake, its a cheap, great power gain!!! All you need is a decent drill or dremel with a couple good grinding bits. Check youtube, lots of good how to videos.
this is what you said. pull heads and port match them to a better intake.
I believe in 78 the horsepower difference was only 20+ between the l48 and l82, BUT if you can find a cheap alluminum intake and port it then you could almost increase HP by 25-30 percent, match that with a decent working carb and you will be close to 300 ponies providing the engine is healthy.
then you repeated yourself and threw in a rather optimistic power increase...nobody said anything about heads til later in the thread.
I'm wondering if I should add the usual intake, exhaust, heads and cam or is it worth it?
My car needs an interior and paint and I will probably not have it very long. I want to correct the problems and hopefully someday trade up to a chrome bumper car.
I guess I'm asking, is it worth adding performance to a 2 bolt main L48 and make it perform better? Or should I leave it stock?
Which will have more value when I sell it? A performance motor or a stock motor?
I know I'll have more fun if it performs better and I guess if I keep all the parts they can always be put back on and make it stock again.
Just looking for opinions.
With a 78, it won't make much difference what you sell it for. Just puts the buyers in two groups.
78's don't command great money, and c3's are down in value in general that I can tell.
With a 78, it won't make much difference what you sell it for. Just puts the buyers in two groups.
78's don't command great money, and c3's are down in value in general that I can tell.
I would never do anything with these cars or any others based on a value proposition.....don't spend money on most cars if you want to MAKE money or break even....usually does not happen.....
I would never do anything with these cars or any others based on a value proposition.....don't spend money on most cars if you want to MAKE money or break even....usually does not happen.....
Cars generally cost money.
Flipping rare cars can pay, but even those fluctuate like the Dow Jones.
My opinion if you're planning to buy a chrome bumpers. Please keep your 78 as is and don't overspend. Keep your money for the chrome bumper one and it will be a project will not end . This is my 77 I bought
fiberglass bumpers so it will look like the chrome ones
then you repeated yourself and threw in a rather optimistic power increase...nobody said anything about heads til later in the thread.
Poster already said they are changing all the parts...in doing so, he could actually almost DOUBLE the horsepower. 350HP is not hard to make on a 350...furthermore....you will deffinately add 25-30 percent from the original 180hp to the entire package by doing some extra machining.
And the original poster said he was going to swap them.
If porting a 50 buck intake would net any measurable gain, everybody would be doing it. Now, if you port a couple of holes for nitrous injectors, maybe net 25%. And the 98 lb weakling can take the 100 lb weakling under 3500 rpm's. Better torque curve. Or should I say less horrible torque curve?
Just to be clear since this subject comes up often:
NO, the stock L-48 CANNOT take a Stock L-82 in any form regardless if a 4 speed L-48 or an automatic......This comes up periodically..just to keep mythology from creeping into these discussions
Fact and documented in many forms from the magazine tests of the day and my own personal experience driving 78/79 L-48/L-82's 4 speeds and autos:
1978/79 0-60 MPH L-82 4 speed (which came with 3.70 gears)-6.5 seconds
1978/1979 L-82 Auto (with 3.55 gears)-6.6 seconds
1978/79 Base L-48 4 speed and Auto 0-60 mph 7.8-8.2 seconds
It's not even close, guys! The L-48's were MUCH slower than stock L-82's....1.5 sec differential between a stock L-82 versus an L-48 from 0-60 MPH is an eternity......
Posting your dyno numbers for your L82 or L48 doesn’t add much to the discussion. The only legit use for a dyno is comparing before and after dyno runs on the same engine, under the same conditions. You guys should understand that...
Just to be clear since this subject comes up often:
NO, the stock L-48 CANNOT take a Stock L-82 in any form regardless if a 4 speed L-48 or an automatic......This comes up periodically..just to keep mythology from creeping into these discussions
Fact and documented in many forms from the magazine tests of the day and my own personal experience driving 78/79 L-48/L-82's 4 speeds and autos:
1978/79 0-60 MPH L-82 4 speed (which came with 3.70 gears)-6.5 seconds
1978/1979 L-82 Auto (with 3.55 gears)-6.6 seconds
1978/79 Base L-48 4 speed and Auto 0-60 mph 7.8-8.2 seconds
It's not even close, guys! The L-48's were MUCH slower than stock L-82's....1.5 sec differential between a stock L-82 versus an L-48 from 0-60 MPH is an eternity......
Back "in-th-day" this might have been a discussion.......today it's just laughable and more than just a tad ridiculous to even talk about.
NOBODY is going to be satisfied with the stock L82 or L48 powered Corvette........I'd sooner drive a damned PRIUS. AT least when driving something this slow AND it looks the part ....... it can claim honest MPG Champ status.
The L82 powered Corvette just like it's L48 counterpart...... is DEAD SLOW and delivers all the gas mialge you'd typically expect from a
kick *** fast high end exotic.......there is absolutely NO REASON to prefer an L82 over the L48 today........both are truly horrible without enough difference between them to argue for keeping one or the other "stock". Fact is it's awfully hard to find one that is "stock" today and when you do it's not ruining as well as it did when new anyway....imagine how horrible this car runs when you find it.
Corvettes are not supposed to be DOGS on acceleration......and there is no good reason to accept 220HP with any more enthusiasm than you would be willing to accept 195HP.
Back "in-th-day" this might have been a discussion.......today it's just laughable and more than just a tad ridiculous to even talk about.
NOBODY is going to be satisfied with the stock L82 or L48 powered Corvette........I'd sooner drive a damned PRIUS. AT least when driving something this slow AND it looks the part ....... it can claim honest MPG Champ status.
The L82 powered Corvette just like it's L48 counterpart...... is DEAD SLOW and delivers all the gas mialge you'd typically expect from a
kick *** fast high end exotic.......there is absolutely NO REASON to prefer an L82 over the L48 today........both are truly horrible without enough difference between them to argue for keeping one or the other "stock". Fact is it's awfully hard to find one that is "stock" today and when you do it's not ruining as well as it did when new anyway....imagine how horrible this car runs when you find it.
Corvettes are not supposed to be DOGS on acceleration......and there is no good reason to accept 220HP with any more enthusiasm than you would be willing to accept 195HP.
No argument about today!!!!......just making sure mythology, as I said, does not creep into the memory about the 2 being equal, BACK IN THE DAY....nothing more, nothing less......
My rebuilt/upgraded 355 L-82 450+ Gross HP would smoke a 1970 LT-1 370 gross HP.....It still cannot compete with many bone stock modern sports cars...my 10 Z06 will smoke the 78 L-82 even today....without breaking a sweat......
No argument about today!!!!......just making sure mythology, as I said, does not creep into the memory about the 2 being equal, BACK IN THE DAY....nothing more, nothing less......
My rebuilt/upgraded 355 L-82 450+ Gross HP would smoke a 1970 LT-1 370 gross HP.....It still cannot compete with many bone stock modern sports cars...my 10 Z06 will smoke the 78 L-82 even today....without breaking a sweat......
$5K with top of the line parts (no budget parts) using OEM L-82 forged crankshaft,L-82 forged rods, and L-82 aluminum intake. Everything else was new except Holley 4175 carb and OEM distributor. AFR heads, Howard roller cam, JE forged Racing pistons (10.2:1 compression), oil pump, fuel pump, new RAM HDX clutch kit etc...bottom end professional machined and rebuilt
With a C3 chassis and drivetrain, you need about 600+ gross hp to keep up with modern sports car. PaulDana on the forum with his 427 SBC 79 C3 with 650+ Gross HP is faster than most modern sports cars but that is what it takes plus extensive chassis mods and tuning......but it can be done!
$5K with top of the line parts (no budget parts) using OEM L-82 forged crankshaft,L-82 forged rods, and L-82 aluminum intake. Everything else was new except Holley 4175 carb and OEM distributor. AFR heads, Howard roller cam, JE forged Racing pistons (10.2:1 compression), oil pump, fuel pump, new RAM HDX clutch kit etc...bottom end professional machined and rebuilt
With a C3 chassis and drivetrain, you need about 600+ gross hp to keep up with modern sports car. PaulDana on the forum with his 427 SBC 79 C3 with 650+ Gross HP is faster than most modern sports cars but that is what it takes plus extensive chassis mods and tuning......but it can be done!
Thank you for the info
Do you think after you set up, this procharger will work?
No argument about today!!!!......just making sure mythology, as I said, does not creep into the memory about the 2 being equal, BACK IN THE DAY....nothing more, nothing less......
My rebuilt/upgraded 355 L-82 450+ Gross HP would smoke a 1970 LT-1 370 gross HP.....It still cannot compete with many bone stock modern sports cars...my 10 Z06 will smoke the 78 L-82 even today....without breaking a sweat......
Actually.....you just made another point for me.
Today.....near 50 years after that first 1968 and 35 years after that last '82 left the factory....... your odds of finding a C3 of any year with a motor still in "like new configuration" and running well........is a pretty rare occurance in all but those few cars where "matching #s" original still exsits and make sense to maintain.
Your car sounds like mine........today on it's 3rd engine another crate motor that replaced the 2nd.......and yes the power levels have mirrored more modern expectations. 20 years ago a roller cam 350 chevy crate motor was the way to get the over 300HP that was "perforfmance" level power in the 1990s. Today it's a 430HP 383 that came with a dyno sheet that suggests it's really making closer to 455HP.......and if I stiil have the car 20 years from now......who knows......maybe an electric swap happens .........but the point is easy enough to see anyway.
In any C3 you might want to buy today.......unless advertised as Matching #s........ it's unlikely to have a weak L82 or L48........it's almost an embarrassment to acknowledge "code" designation for engines better suited to work at the bottom of a lake as boat anchors.
12-17-2017, 02:04 PM
unless the L82 is a 3.70 car :-)
.........but the point is easy enough to see anyway.