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camshaft specs for 79 Corvette L82

General engine tech -- Drag Racing to Circle Track

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Belgian1979
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camshaft specs for 79 Corvette L82

Post by Belgian1979 »

Can someone provide me with the original camshaft specs of a 1979 Corvette L82 version?

Thanks
F-BIRD'88
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Re: camshaft specs for 79 Corvette L82

Post by F-BIRD'88 »

222/222 @.050" .450"/.460" lift 115/113 centers 114 LSA

A lot of aftermarket replacements list it as 224/224 @.050"
You can still buy this cam from GMPP 3896962
Last edited by F-BIRD'88 on Fri Apr 16, 2021 5:11 am, edited 1 time in total.
induction apprentice
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Re: camshaft specs for 79 Corvette L82

Post by induction apprentice »

I did know the answer to this at one time as I used to use alot of them back in the day. They make a surprising amount of power for something so tame.

My guess as my memory will probably lie by now. Is...

222 int dur @.050"
112 seperation
.480" lift but likely exh side.
Int lift would be more likely in the .460" range?

Anyway, thats how I remember it.
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Re: camshaft specs for 79 Corvette L82

Post by Belgian1979 »

Thanks
Which lifters (brand/type) with that GMPP cam?
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Re: camshaft specs for 79 Corvette L82

Post by F-BIRD'88 »

Any normal sbc hyd lifter Ht817 (sealed power speed pro)
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Re: camshaft specs for 79 Corvette L82

Post by novadude »

I always thought that cam was likely driven by emissions requirements, as it seems less-than-ideal for a 9:1 engine. Plus, they had the design left over from the original application which was 11:1 CR (and likely a better fit). I'm guessing it was a case of just using what was already in the design library that still met late-70s emissions standards.

IMO, You could probably pick up a lot of torque and some power with something in the 214-218 deg @ 0.050 range on a 108-110 LSA and not give up any driveabilty over the stock cam.
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Re: camshaft specs for 79 Corvette L82

Post by F-BIRD'88 »

You can pick up a lot of low mid if you advance this cam by 8 degrees from 115/113 centers to 107/121 centers (114LSA) when in engines with a lower compression ratio.
You trade off a small amount of peak horsepoeer for a good bit of low end torque where most mild stuff needs it.
A new intake C/L of anywhere from 107 to 110 deg works well for better low end.

Especially auto transmission. Yes this same cam was used in the L46 350-350 hp 11:1 cr 1969 Corvette with 4 speed and bias ply tires of the day..
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Re: camshaft specs for 79 Corvette L82

Post by Belgian1979 »

I know a lot more power is to be had. However this is not a maximum effort type of deal. I'm slamming together a stock type engine with leftover parts to pass tech inspection as a sort of plan B. As soon as the inspection is over, it's coming back out and the current engine goes back in. In fact the original 225 hp is more than enough for this goal. I'm going to put an original carb, airfilter and exhaust manifolds on it.
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Re: camshaft specs for 79 Corvette L82

Post by rebelyell »

novadude wrote: Fri Apr 16, 2021 8:41 am I always thought that cam was likely driven by emissions requirements, as it seems less-than-ideal for a 9:1 engine. Plus, they had the design left over from the original application which was 11:1 CR (and likely a better fit). I'm guessing it was a case of just using what was already in the design library that still met late-70s emissions standards.

IMO, You could probably pick up a lot of torque and some power with something in the 214-218 deg @ 0.050 range on a 108-110 LSA and not give up any driveabilty over the stock cam.
^^^^THIS^^^^
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Re: camshaft specs for 79 Corvette L82

Post by NewbVetteGuy »

I get what you're trying to do. Go get any of the "classic"/ "nostalgia" copies available. I looked at a couple a few years back and they seem to have less seat-to-seat/ adv durations vs. the OEM L82 cam, but finding info on the ADV / seat-to-seat durations for that cam is NOT easy... -I chucked mine in the recycle bin a couple of years back or I'd give it to you for shipping to Belgium...

My understanding is that it's the cam from the 11:1 L46 but with 3 degrees of retard ground in and slapped in an 8.9:1 actual static CR engine. ;-(

I've heard 346/340 quoted as the seat to seat duration before in a couple places, but that number seems crazy.
I've also found 284/278 @ 0.008" as the point for the ADV duration. (No idea on 0.006".)

I found one guy on CorvetteForum who claims to have measured it as 292/288 @ 0.006". Another guy claimed 290 intake ADV duration so any of those numbers seem reasonable.

-Something like a 6.61 DCR. *Barf-Emoji-Goes-Here*.


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Re: camshaft specs for 79 Corvette L82

Post by NewbVetteGuy »

novadude wrote: Fri Apr 16, 2021 8:41 am I always thought that cam was likely driven by emissions requirements, as it seems less-than-ideal for a 9:1 engine. Plus, they had the design left over from the original application which was 11:1 CR (and likely a better fit). I'm guessing it was a case of just using what was already in the design library that still met late-70s emissions standards.

IMO, You could probably pick up a lot of torque and some power with something in the 214-218 deg @ 0.050 range on a 108-110 LSA and not give up any driveabilty over the stock cam.
It 100% was. Emissions and cost (just reuse the L46 lobes!).

Less DCR = Less Heat and LESS NOX. Heat up those cats, then when you're passing a bit of fuel out the exhaust, inject some O2 ala the A.I.R. / SMOG pump to initiate a 2nd burn in the manifolds.

-Then the ignition timing is super retarded because of all the EGR so even less torque.
Then the timing chain stretches out and the rubber on the teeth starts to fall off and the timing gets REALLY retarded and the torque gets REALLY terrible. (My 79 L82 had 14.4k miles on it and all the rubber still on the upper cam sprocket and still couldn't manage a burn-out; a DOG off the line. Gutless even with the cats removed and true dual exhaust.)


One of the greatest candidates for a cam swap, IMHO. (And a head swap with the 624 crack-if-you-look-at-them heads...)
-A really pretty solid bottom end with a terrible cam and heads that are destined to crack.

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Re: camshaft specs for 79 Corvette L82

Post by F-BIRD'88 »

GM and most aftermarket replacements list the SAE seat duration @.006" valve. 291-287 or 292-288.

.006" @the valve (SAE) is .004" at the lifter.

but .006" @ the lifter (Comp etc) will be sbout +/- 7-8 ° LESS
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Re: camshaft specs for 79 Corvette L82

Post by 68maliblue »

Do you have to run the factory L82 cam? If not you might be better off with the 350 HO cam p/n 24502476 at 212int/222 exh @.050. Still has a GM part number on it but would run much better with 8.5:1 compression or whatever the 79 L-82 had.
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Re: camshaft specs for 79 Corvette L82

Post by Belgian1979 »

induction apprentice wrote: Fri Apr 16, 2021 5:10 am I did know the answer to this at one time as I used to use alot of them back in the day. They make a surprising amount of power for something so tame.

My guess as my memory will probably lie by now. Is...

222 int dur @.050"
112 seperation
.480" lift but likely exh side.
Int lift would be more likely in the .460" range?

Anyway, thats how I remember it.
Is that lobe lift? I assume no or none of the regular 180 cc intake runner heads would be able to work with that lobe...
I also need to replace the heads. I located a pair of smog heads but they are in Amsterdam and questionable condition wise. Might be better to replace it by a new steel head. I went over parts in Summit but all heads are out of stock. As a matter of fact a lot of parts are. Issues with supplies because of Covid???
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Re: camshaft specs for 79 Corvette L82

Post by F-BIRD'88 »

Possibily a good candidate for a ported modded 305 head to replace the crappy and crack prone oem 462624 or 882 stock head if you A, want more compression, B. Want more power/torque at low cost. Stock appearance to an inspector. other than the end identifier. (Finish chamber to 62 cc ish depending on desired CR and headgasket choice..) Should be able to source and refurbish locally.
A 1.94/1.60 valve set in these works very well.

Effective...
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