clock service for 62

[Gene M.]

Re: clock hands

Tony, The hands are just a tight fit on the pins. I use a small pice of metal with about a 1/16 inch slot in the end (de burred) to gently lift off the hands. To put the minute and hour hand back on I use my fingers to start then the same fabricated tool with tape warped around slotted end to not scratch the delicate hands. The second hand is taped on using the handle of a small Craftsman screwdriver, very gently. Take your time and the job is easy.

[Joe L.]

Re: clock internals of 62 vs 70

Tony----

All Corvette standard movement clock mechanisms were manufactured by J.W. Borg, so that's what the "Borg" inscription on your clock refers to. The rest of it, I can't identify, but it may be a plant identification code and manufacturers model code.

As I understand it, when J.W. Borg got out of the automotive clock business, they transferred all of their parts inventory and tooling to Instrument Services, Inc. of Roscoe, Illinois. ISI continued to manufacture some clocks and, as I am told, even supplied GM service parts with certain Corvette service clocks. They remain the only 'factory authorized' service center for Borg clocks to this day.

Many years ago, I had a long, early-Friday-morning-at-Bloomington conversation with the owner of ISI, although I can't recall his name. I found this conversation very interesting and enlightening----I could tell that this man KNEW AUTOMOTIVE CLOCKS and I always love talking to folks who really know what they're talking about. I asked him about rebuilding an original Corvette clock mechanism and he told me that he didn't recommend it. He said that mechanical automotive clock mechanisms, "tick-tocks" as he referred to them, couldn't be reliably rebuilt without performing a "granfather clock-type" restoration effort which is impractical for an automotive clock. He recommended converting to a quartz movement, but I told him that I did not want to convert my original clock. He understood that and said that he had reproduction 69 clocks fitted with quartz movements. I asked him how close they were to the original in appearance and he told me that they were made on the original tooling and were exact. I bought one and later compared its face to my original; turns out he was right; they were EXACTLY the same.

Later, I decided to have my original clock rebuilt. I sent it to one of the popular instrument repair specialists who shall remain nameless. Clock came back in beautiful condition and worked perfectly----for a while. Then it gave up. Well, I was more determined than ever to make this mechanical movement work. I sought out and found an old-fashioned clock repair shop in Oakland, CA about 30 miles from where I live. I visited the shop and it was JUST WHAT I WAS LOOKING FOR! Very old-fashioned with dozens and dozens of various clocks, mostly automotive types, sitting on racks being tested after repair. Best yet, the shop was staffed with two really old timers who were busy at work with their jewelers eyepieces repairing clocks. No quartz movements sold or serviced here! I'd found THE PLACE! One of the fellows came over to me and accepted my clock for service. He told me that it would take at least a month, since they had a lot of work ahead of me and they test the clocks for at least two weeks on the rack after repair in order to thoroughly test and calibrate it. Sounded great to me.

When I got the clock back, it looked fine. I installed it in the car and it worked fine. Kept PERFECT time----for about 6 months. Then it quit again. Maybe that fellow at Bloomington knew what he was talking about, after all.

Of course, I'll tackle about any automotive service operation. I thought, maybe I should try this myself? Then I thought better of it. I just don't think that I have the ability of the popular Corvette clock servicer. And, I know damn well that I'll NEVER know more about automotive clocks than those two old men in Oakland.

[Terry M.]

Re: clock internals of 62 vs 70

Some years back - perhaps 10 to 15 years - I had the clock in my 1970 repaired by Instrument Services in Roscoe. It still works. I recomment them. Everything Joe says about their knowledge is correct.

I had the advantage of delivering and picking up my clock. Seeing their shop was a trip not to be forgotten. There were 3 or 4 employees who were as knowledgable as the owner.

I co-authored a story for "The Restorer" on the visit. As far as I know they have been repairing "tick-tock" movements for years. Terry McManmon

[Tony H.]

Re: clock internals of 62 vs 70

Terry/Joe,

In the time that the mechanically restored clock has been installed in your Vettes, is the battery connected year-round or do you use a battery disconnect when the caris not driven (storage)? How many miles has car been driven since the clock was installed? I suspect the clocks would last longer if battery disconnect were used whenever the car is not in use to save on wear and tear on the internals. Would you and wnyone else please comment on this notion?

Tony

[Joe L.]

Re: clock internals of 62 vs 70

Tony----

I've never used a battery disconnect switch or disconnected the battery. On the west coast where I live there are usually days year round when I can drive the car, so it's not practical to disconnect the battery. As far as a disconnect switch goes, there exists only one type Corvette for which installation of a disconnect switch is impractical or impossible. That type Corvette is a late 69 with side terminal battery. On late 69s with side terminal battery, the battery posts are on the forward side of the battery, facing the passenger compartment.

[Terry M.]

Re: clock internals of 62 vs 70

Tony,

I live in the midwest where Corvette activity is limited by the weather.

In the 10-15 years I have had the clock since repair the battery is disconnected while the car is in storage. That has been 4 to 6 months each year for winter, but I once had it in storage for 16 months.

During that time (obviously while the car was not in storage) I put on about 5k miles and the car got a Duntov (it took 3 regionals to get 97 and a fourth regional to get PV), Bow Tie, Bloomington Gold, Survivor, Benchmark, several Gold Spinners, a Triple Crown and Founders award. The clock always worked and kept/keeps correct time. In fairness, I trailered it to almost all those events except the for the Founders, for which it must be driven. I got everything except the Founders before 1994 and have driven it since, so most of that 5k has been in the last 5 years. Some of that driving has been to meet the requirements for the 5th Star Bow Tie award.

The only thing I have to do is set the time BEFORE I connect the battery. That way the time adjustment does not change. If that needs more explaination ask.

Terry

[Jack H.]

Re: clock internals of 62 vs 70

YES! I rebuilt the clock in my '71 using a quartz kit. Nothing fit as the instructions suggested it should. The kit had a 'help' number to call and talk to tech's a Borg. They told me there were several running changes (gear size, Etc.). I was curious as to why kits weren't specific.

Helpful tech indicated stuff sat in bins at GM, so just having the year of the car wasn't enough info. Then, there's the issue of whether or not the clock was changed somewhere along the line with a service spare. And that's why they put the 'help' number in the instruction sheet.

My '71 should have been one rev and it was actually the earlier '70 model internals. After consultation (original apart and tech on phone), they sent me correct substitute gears to make the kit work on my clock. Nice, helpful!

[James F.]

Re: clock internals of 62 vs 70

FWIW Department: When I had my '56 clock rebuilt by a clocksmith located in Vermont, it came back with a red tag reading: "Warning-never install an electic clock in a car without an in-line fuse." The 12 Volt clock requires a 1 amp fuse. The 6 volt clock requires a 3 amp inline fuse. I ask him about this, he said he sees many clocks with the little rewind coil burnt up. New ones are hard to come by. When the car battery is in a discharged condition, it may have enough power to close the points but not to open them. If the points stay closed, the coil heats up, could burn out. Points are easy to be fixed coils not so.

[Ian McGuffin]

Re: 1970 LT1 hp rating

Thanks for the responses to my question. It would seem that none of you would give any credence to the claim of underrating by GM.

I realize that the 370 rating was SAE gross. For comparative purposes, I've read that one can estimate net at around 80% of gross, which for this engine would work out to about 300. Is that reasonable?

Ian

[Duke W.]

Re: 1970 LT1 hp rating

Yes, the 80 percent of gross equals net is a good "rule of thumb", however, in a 1992 SAE paper on the new LT1 small block the authors stated that the new LT1 made more net horsepower than any small block ever built, so the "vintage" 1970 LT-1 must have been a bit weaker, though it's not clear if Chevrolet Engineering ever measured the '70 LT-1 with the modern SAE net methodology.

I also always wondered if the '64-'65 L-84 FI engine really made 375 gross with 23 cubic inches less displacement. Maybe so. I've run numerous smallblock engine simulations and with the same configuration (heads, cam, induction, exhaust) a 327 makes about the same peak power as a 350, but at about ten percent higher revs. The 350 will make more power through out the range because of its greater torque, except at the very top end. Because of its longer stroke and higher piston speed at any given revs, the 350 will run out of breath sooner, but if the 327 is geared about ten percent shorter both should accelerate about the same and have the same top speed.

The same analogy would apply to a 302 versus a 327 assuming you could keep the valve gear together. The bottom line is that more displacement means more torque, and it's torque that makes driving pleasurable.

The last time I say this quote it was attributed to a Mercedes Benz engineer, but I'm sure someone else came up with it before: "People buy horsepower, but they like torque".

Duke

[Roberto L.]

Re: 1970 LT1 hp rating

That last sentence is very good! We all talk about big horse power but in the real/every day world in the street a low end torque car is very satisfaying. For fast driving/racing LT-1 and BB are really fantastic but old base engine 350 is a good option with low end bandwith, not so much revs above 5K and big sense of power in the streets, net or gross... All my best, Roberto, NCRS #30019, RMC