Bobo Greybeard

I have a 1979 L82 4-speed Corvette that is Black with an Oyster Leather interior that has only 372** original miles. My father-in-law ordered the car in 78 and took possession of it in 1979. He bought it as a company car and literally only used it for company business for his petroleum engineering company. He is so honest that he would not even drive it to the store for a pack of smokes. When I met my wife in 1997 the vehicle only had 32K miles on it. It also has the AM/FM/CB in it along with power everything and rear speakers. From what I can tell, it is a fairly rare combo of options. Ok now that we have that out of the way, I can get to my question.

I was returning from a trip today from my Mother's , due to a family emergency that happened on Wednesday. It is approximately a 100 miles from Mom's to my house in Tulsa. Since it was a nice day and I had some time to kill, I decided to take the scenic route home at a cruising speed of between 50 and 55 mph instead of taking the turnpike at 80 mph. So I get about 30 miles from Mom's today on the way home and I start hearing an engine noise that sounds like it may be a stuck lifter. I back the speed down to about 40 or 45 and treat the little black beauty gently. After a few miles all hell breaks loose and it is make the most God awful engine noise I have heard. It sounds horrible. So I back down to about 25 and limp it into the next town which was about 2 miles down the road. The vehicle is not leaking any fluid at all, all fluid levels are correct and it never got hot, so there is no blown head gasket. I can not tell by the sound if it is a bent push rod, a wrist pin, or if I have a rod that is knocking.

My question is this, "If it is a Rod or a wrist pin, how much value would I loose if I beefed the motor up to about 400 to 425 hp, while keeping the original matching numbers block and heads." during the engine rebuild. I believe it is strange to have one of these two problems, with a motor that only has 37K miles on it. Then I remember that is sat for 7 years. I am new to all of this as far as original stock vehicles go. We are not wanting to put the car in extremely picky "1000 point" car shows. We will basically just have it in small local shows if any. I absolutely love this car and I have been in love with this car for the 21 1/2 years. I was extremely excited and happy when my father-in-law gave it to me a couple of months ago.

One quick thing, the car sat for about 7 years after I got hurt, up until a couple of months ago. Due to Joe not trusting any of the local mechanics, due to a former tech trying to basically steal the motor out of it, for his own vehicle. The vehicle went down 4 days after I had my career ending injury. He said he only wanted me to work on it, but he would not let me replace the fuel pump, due to me basically having my back broke. LOL

Any suggestions or info is greatly appreciated. Also if we do have to rebuild the motor are there any kits out there that you would recommend. Last but not least what are the specks on the 79 L-82 4 speed Camshaft?

Thanks everyone for any help.

Stay safe,

Bobo

jackson

IIRC L82 cam ... .450"/.460", I 224*/ E 224*

400-425 is a stretch with OE heads ... can be done sure ...You'll spend a lot of $ getting there; having OE heads ported etc Unless you're a quick study & real handy.

FIRST step ... find out what's wrong with L82 ... did YOU switch it off? ... Or did It just quit running? if it was still running when you switched it off, the trouble may not be too bad.

jackson

Bobo OP
download this Free spec sheet for your car from GM

https://www.gmheritagecenter.com/doc...t-Corvette.pdf

Bobo Greybeard

I switched it off myself.

Once I get some Caffeine and Nicotine in me in a few, I will be pulling the Valve covers to see what I can see. I will let you guys know what I find out. Also what is an honest approachable HP rating that I can achieve using the Stock heads? I do not mind going larger springs, and doing a little port and polish work at all.

Thanks for helping a fellow Vette fan out.

Bobo

Bikespace

Black 79 with oyster interior is just about the best looking C3 ever made.

If you do have to rebuild the motor, the "value" of the car is what you get out of it. Make it your own, and enjoy it!

DaveL82

When you first heard the noise it should have been shut down. The L82 with forged pistons tend to use a lot of oil so has the oil level been checked and is there a sign of metal particles on the dip stick.

The L82 is a good base to build on but if the bottom end has a bad bearing or other damage requiring new parts and machining I would pull the motor and put in a more modern version with a roller cam.

My 80 L82 is running a ZZ4 which makes more power and very reliable. More options out there now if you go the option to replace with a crate motor.

Still have my orginal L82 motor but it sits in the corner of the garage.

jackson

I've plenty of options to suggest ... but First ... let's find out which parts are keepers & what're not.
Maybe, at most, you'll need headwork & a great cam. Your inspection results will tell the tale.

? Do you have a $ budget? What?

? You mention you'd been injured ... are you physically capable of heavy car work?

? Do you have the space & time to pull motor & work on it?

cv67

You wont lose any value putting more power into it. Those were a little on the anemic side anyways.

jb78L-82

The L-82 cam is 222 duration, not 224, just for accuracy.

Hydraulic flat tappet
.450 / .460 lift
222/222 duration
114 Lobe Separation Angle

CA-Legal-Vette

First things first: find out what’s wrong. Could be something as simple as the harmonic damper letting go. That makes a hell of a racket. Once you know what’s wrong, you’ll know what needs doing. Doesn’t stop you from doing what you want with respect to adding power.

Bobo Greybeard

I found a couple of push rods that had about 3/8 to 1/2 inch of up and down play in them on the drivers side. I have yet to remove the push rods to look at them due to folks being able to just about water ski down main street here in Oklahoma at the moment. Tomorrow is suppose to be a little better, so I will remove them and inspect tomorrow. I also "felt" about 7 loose rocker arms ( had some side to side play in them, instead of being tight). I am not sure if all of this would of made the noise that I heard yesterday, but I am sure it helped it make some of the noise. I should know more tomorrow.

Thanks for all the help gentleman,

Bobo

jackson

check for bent Push Rods by rolling PR across smooth flat surface such as glass.

you can peek/peer down thru pushrod holes in head but clearly best-viewed by pulling intake manifold.

look for lifters that have spit out their retaining clips/wires/snap rings (examples in below pics)

any MIA clips (& bits/shards thereof) must be accounted for (oil pan & lifter valley) before they get sucked into oil pump.

CA-Legal-Vette

A half inch is a ton of play in a pushrod. Most likely wiped cam lobes. Drain your oil and you’re likely to see a lot of shrapnel.

Capt. Shark

I'm replacing heads and cam.........again and found one of those broken off a new Comp lifter. Thankfully all the pieces in the oil pan were accounted for. That could have been ugly.

As for hurting the value, for years I wouldn't do anything to my 79 L82 4 speed because of it's originality. I have finally realized that particular model is never going to be worth any kind of serious money so have fun with it. Engine came out two years ago for rebuild and now it's out again for aluminum heads and roller cam. The tranny is gone, too, being replaced by a TKO 600 5 speed..

If it were a big block chrome bumper car you could make the don't want to hurt it's value argument. Our particular cars? Not so much so make it yours.

Just my .02

jb78L-82

I have said this before and Will say it again, just because a certain C2 or C3 is valuable today for it originality, do not count out other models like the later C3's becoming much more valuable down the line. In my opinion, that assumption would be a big mistake since the C2's and chrome bumper C3's were not considered much value at one time as well. The Later C3's with the L-82 engine, 4 speed, and gymkhana suspension can very well be considered valuable at some point in OEM condition or numbers matching just like the earlier C3's since these cars were relatively rare production, rare at the time since most folks bought the base cars with automatics and base suspensions, and the L-82 4 speed was right there with all performance cars in the late 70's. I would also include the 80 L-82 auto since it also was extremely rare and the last of the performance SBC Gen 1.

I just read this in Autoweek about the 1988-1991 Nissan 300 ZX Twin Turbo and I quote: (prices of these cars are climbing FAST):

" It wasn't too many years ago when the old car experts told you that the Datsun/Nissan Z Cars, only the first of the range, 240Z, was Collectible"

A group of them just sold between $26,400-$66,000 with low miles and MUST be a manual 5 speed.

"There are multiple lessons to be learned here. First is that lower miles generally means more money. Second, never count out a car that is sporty or well marketed when new. Third, and finally, the experts sometimes just don't know what they are talking about"

Bold Quotes: Autoweek Market Section, May 6, 2019

Beware and cautious folks....................People should do what they want with their cars in my opinion, obviously, but don't do something because you think the car has no value today and will never have any real value since it may not necessarily be true, years down the line.

derekderek

do both. pull the orig engine and do an autopsy on it. get another. build itt yourself out of a C10 pick up or buy a crate engine your call. also rebuild-repair the orig engine. mom 100 miles away. store the 4 speed with the engine and the stock manifolds, etc. you need overdrive anyway.

stingr69

At that mileage the bores should still be serviceable with just a stone hone job which means an overhaul would get you back on the road. All the "good" factory pieces are in the bottom end of that engine and likely still serviceable. Only a tear down will show what must be replaced but more than likely you can reuse a lot of it. The cam and lifters are likely to be trashed so you can replace them or consider other options. The heads could be swapped for a smaller modern combustion chamber and the rest can be left stock for an increase in performance. I would not spend one penny on those smoggy, large chamber, crack prone stock heads. They would go in a bag on a shelf.

Try to save the bores if possible. The cost and complexity of the project goes up drastically if you rebore the block.

More power is nice but it comes at a price.

Bobo Greybeard

I was finally able to get to the root of the problem this afternoon. The rod bearing on the #2 Cylinder was completely missing. I can not even find pcs of it in the oil. ???? Anyway, I am trying to figure out if I need to go ahead and replace all of the rod bearings or leave the others (37K miles on them) and just replace the destroyed rod bearing. I must of done something good in life, because the crank and rod actually do not look bad at all. I am going to replace the oil pump when I put the pan back on it.

Now that we have that figured out. What are your guys thoughts about throwing in a beefer cam, intake and maybe some heads? Do you have any suggestions for someone on a fixed income (disability) ? I am trying to do as much work as possible myself. I was a heavy line tech at a dealership prior to getting my back busted up when a lift malfunctioned.

How does the factory alum intake on the 1979 L-82 stand up against an Air Gap Performer RPM or other lower end performance intakes?

Thank you all.


Bobo


The reason it took me so long to get into it, is my back was killing me and I am just now starting to get moving around. That and we have had record breaking rain and tornadoes (140+ since the 117th) , major flooding. LOL Mother nature does not want me to have any fun.

dmruschell

Agreed. I love my black 79, though mine has the doeskin interior. I was looking for a black 79 with a 4-speed with either oyster or doeskin interior. Luckily, I found one. Unluckily, the engine (L48) needed a rebuild, but that just meant that it was time for more power.

To the OP: I love the cam that is in my 79 4speed: the Lunati Voodoo 268 cam. It will idle steadily at 500rpm, run steadily in 2nd gear at 1,000rpm, and pull to 6,200rpm. I have AFR 180cc heads, but did have Liberty Performance 220cc heads. The cam ran great with both. If I were to do it again, I’d take a long look at Summit brand 165cc (I think) iron heads. They’re Dart Iron Eagles and work great on a 75 I restored with a slightly smaller Voodoo cam. They’ve since changed the specs of the maximum valve lift on those heads to be able to handle the 268 cam (which is why I didn’t put them in my 79 when it needed new heads and went with AFR).

I recommend keeping the original Quadrajet. The original intake, from what I’ve heard, is about as good as an Edelbrock Performer. I’d use it, a Performer EGR, or the GM ZZ4 intake (very similar to the Performer EGR, but made a few extra HP at the top end in a shootout). My 79 has the ZZ4, but the 75 I restored and my wife’s 76 both have the Performer EGR. I doubt one could notice a performance difference on the street.

Today, just to prove to someone that I could, I started off from a light in 4th gear on a slight uphill incline in my 79. I didn’t have any problem lol. Doing that with a 6,200 redline is a nice, streetable engine combo.

Kirk H

I had the same thing happen to my L-82, the rod bearing was gone... but so was the journal. There was a ridge that was easily felt by fingertip so the crank had to be pulled. It turned out to be bent and had to be replaced. I would be very careful measuring the journal before just putting on another bearing and hoping for the best. It will most likely knock. You would need to check clearance with Plastigage but I'm not sure if even that will be enough to ensure a proper fit. Good luck.