Well, I had the privilege of getting my '73 L-82 totally dialed in by Lars last week. He really worked his magic and the car finally runs like I remember. But just a bit of background...

I literally learned how to drive on this car. My uncle ordered it new and waited 6 months for it to arrive at a small Chevy dealer in Southern IL. It was a stripper except for the L-82, close ratio 4 speed, tilt/tele steering wheel, HD battery, and power steering. Oh, and it still has the original AM-FM. He also ordered the aluminum wheels but was told he couldn't get them due to "manufacturing issues". He traded in a '70 Chevelle SS with a 396, cowl induction, and a 4 speed slathered in Fathom Blue, white vinyl top and white vinyl interior. He took me out one day and nailed the throttle in that car. My 11 year old self was never the same. For some reason, the memory of riding shotgun in that Chevelle remains to this day. I felt like a king. Anyway, once the '73 Vette was delivered to my uncle, it rocked my world. The body and presence was something I had not experienced before. I thought it was an exotic super car. Once I turned 15 he taught me how to manual shift a performance sports car. He even let me drive it from San Diego to Vegas on my learner's permit! I took the car to my senior prom and drove it in Homecoming parades in college. Lots of lasting memories.

Over the years, the car was driven less and less. To this day, it only has 39,000 original miles. While the body and interior are close to factory original, the mechanicals didn't age so well. So I jumped at the chance to acquire the car last summer, and quickly found it was needy. My son and I waded into the great abyss of "restoration". We did brakes, fuel pump, exhaust, spark plugs/wires/coil, carb rebuild, power steering rebuild, fluid changes, etc. But it still didn't run like I remember it used to. Ran ok but my 2011 Miata would smoke it in a drag race. I knew something was still missing.

Not long after getting the Vette in hand, I discovered this forum. On one of my newby posts, people started mentioning Lars. I didn't know who this one name person was. I'd heard of Cher, Bono, Prince, etc but never this guy. Well, I was able to visit Lars' garage last week and he did his thing on my Vette. I only live 12 miles away. The place is tucked away in a typical suburban neighborhood and the garage is awesome. Trust me on that.

Here's what he did while I intently watched. Not the most technical description, but I think you'll get the idea:

1. He discovered my throttle linkage was not set up right. The throttle cable was attached to the "truck position" on the carburetor lever and it didn't have enough range of action to open the secondaries. So I've been using the primaries only, even at WOT. He repositioned the cable to allow all four barrels to show up when needed. Now I hear 'em (and feel 'em).
2. The vacuum advance actuator on the distributor was too restrictive. It didn't allow any advance at all. So he replaced that module as well. While he was at it, he checked the distributor weight springs. Again, they were too stiff. He replaced by feel so they had the ability to open up and do their job at higher rpm.
3. Once he did all that, he was ready to time the car. He checked it at idle as well as up and down the rev range. Nailed it first try using two timing guns. The car runs much smoother now.

Well, the car runs much better and is bit more angry. It actually pulls strong and has enough torque to break the wheels loose. The seat of pants difference is amazing. So it was incredibly fortunate for me to not just have a rebuilt carb with new plugs/wires, but to have someone with Lars' experience see it on the engine and tune the whole system together. I know guys like Lars are very rare and hard to come by, but now I see that tuning an older car like this takes experience, feel, and knowledge that is quickly disappearing. I'd encourage you to do more than a simple carb rebuild and tune up. There's more to it than that.
Thank you Lars

 

Great story about your car. And wonderful to hear Lars got her purring again!
Thanks much for taking the time to write this all up.

 

Thanks for sharing your story - the basis for future, great memories for you and your son. Lars rebuilt the carb on my 1973 L82 and I have tuned it according to his papers. It is a blast to drive! We are lucky to have him and others with the same knowledge/experience in our "corvette" life.

Fran

 

Nice story, well told. (You are one lucky guy!)

 

Nice write-up, Craig! I can add a few details to the tuning process we went through:

As I promote here on the Forum, tuning these cars is all in the details and the small things. In addition to seeing that the throttle cable was installed in the incorrect position on the throttle lever, we also saw that the throttle cable bracket was bent a little forward. A cable bracket that is angled forward will limit throttle cable travel. So we gave it a quick smack with a 5-pound hammer to bend it back towards the firewall a little bit. I call this the "5 hp hammer tuning trick."

When we looked at the vacuum advance system, we noticed a couple of things: First, the vacuum advance was hooked up to a "ported" vacuum source on the carb. This works well for reducing emissions at idle, but it does not contribute anything to good throttle response or good quality idle. Then, as you noted, we tested the vacuum advance control unit and found that it did not meet the "2-inch rule" for pulling it its full advance range at a vacuum spec 2 inches numerically lower than the vacuum the engine is pulling at idle. In fact, it wasn't even close. The unit we found in my stash met the "2-inch rule" requirement, and we then installed a limiter on it to limit its range to 12 degrees of vacuum timing.

With a good vacuum advance system installed, we then set the total timing to 36 degrees, "all-in" at 3000 rpm, which resulted in initial timing at idle coming in at a perfect 15 degree spec. With the 12-degree vacuum advance hooked up to manifold vacuum, the engine then idled at a very nice 27 degrees of advance. This allowed us to actually back off the idle speed screw a bit, and we could then re-balance the idle mixture setting for a perfect idle with great off-idle throttle response. The entire process took 2 beers and was a lot of fun!

Good to hear the car is now running as it should and that you're having some fun with it!!


Lars

 

 

Hello All
4-Vettes I am also in Australia (south island), I am in the throws of gathering parts and information to do a rebuild on my 75 L-82 (62000mls). I am reluctant to send my Carb to Lars due to the ridiculous postage costs these days.
I am going with Howard's Hyd Roller Cam (1144-12), Trick Flow Heads (DH175) Ceramic Headers, Edelbrock 2101Manifold, 2.5" crossover SS Exhaust.
I will decide on re-bore etc after the engine is pulled down.
Do you know of any good and reputable companies in Australia to go over my Carb?
I also have an Edelbock 2701, so have the option of just changing the Carb to a Holley..... I don't really want to do this as I would like to keep the Carb and original air cleaner.
Thanks in anticipation.

 

Hi Trev. Let's just say hijacking a thread is kinda considered a no no on here. Lot's of us on here from Australia. And yes I've even travelled to others homes to help them out.
Consider starting a thread on help in Australia, or simply shoot me a PM.
Thanks. Doc.