14 Interference (Parts 2 and 3)

Since I believe that the worst thing that you can do to a vehicle is to not drive it regularly, I try to drive the hot rod to work at least once a week.

On one of these trips, I heard a loud snap, then the engine started to backfire through the carburetor under load. By removing one plug wire at a time, I was able to determine that the problem was in number three cylinder. When I removed the valve cover, I found that the exhaust rocker arm on #3 was broken in half.

 I bought three rocker arms (two of Egge Machine # 44000, the type that broke, and one #44001).  One was hand filed for clearance as mentioned in Chapter 9, installed on the right rocker shaft, and reinstalled on the engine. (Nailhead Buick cylinders are numbered  1, 3, 5, 7 on the right bank and 2,4,6,8 on the left.)
 

Less than 1,000 miles later, the #3 exhaust rocker arm broke again.

Less than 500 miles later, the #3 exhaust rocker arm broke a third time.

Thinking that the problem was that the rocker was hitting the edge of the (larger diameter) Kenne-Bell valve spring retainer, I decided to keep the Kenne-Bell cam, but install a stock head on the right bank until I was able to determine how to fix the problem.

 I found a stock 425 head with rocker assembly at Wheatbelt Antique Auto, a Buick specialist in Carrier, OK. When it arrived, the UPS driver was the first and only delivery person to acknowledge the sign in the empty planter along side of the front porch which read "Please place deliveries here". I had to reach down two feet into the clay pot and lift the heavy sucker out of there. After that ordeal, installing it on the right side of the engine was relatively easy. For nearly three years, there have been no further problems with the right bank valve train.

Recently the engine developed a miss and an intermittent tick on the left side. Because I don't know all of the peculiarities of Nailhead Buick engines, I decided to find  someone who had experience building them to see if we could find a permanent fix.  Most of the builders I talked to had never worked on a Nailhead.

Ryan at Ryan's Rod Service said he had some experience with Nailheads, and he knew an expert to go to if he ran into trouble.   
                  

I asked him to degree the cam at 113°ATDC ± 1° per the cam card and check out the miss problem . (The cam was originally installed straight up at 118°ATDC, 5° retarded from where it should have been.)

This engine was built following  the 1997 series of articles in Street Rodder written by Doc  Frohmader. There was an error in Part 6 (June 1997) describing advancing the cam to the 2A marks. However, the particular and peculiar crankshaft gear that we both used is marked in camshaft degrees, not crankshaft degrees. The cam should be advanced to the 4A marks. On page 60 of the magazine, the photo caption on the left hand photo is correct.

A minor problem cropped up when reinstalling the timing cover. The original rope  front crankshaft seal and stamped  steel retaining ring  had been removed and replaced with a more modern nitrile lip type seal sourced  from Carmen Faso at  J&C's Parts in North Tonawanda, NY. Carmen is not on the internet. TA Performance in Scottsdale, AZ  lists a neoprene seal part number TA 1514 but that number does not cross to any other manufacturer. The source article did not mention an application. A little digging on http://www.v8buick.com  revealed that a National 474272 seal, an SKF 19786 seal or a Chicago Rawhide 19786 seal will work. I still don't know the application. Getting this solved took way more time than it should have.

After correcting the cam to crank timing, Ryan removed the left valve cover and discovered a broken rocker arm on number two intake valve. According to his sources, Nailheads with non-stock cams break rocker arms because of incorrect valve train geometry. That makes sense because of the complexity of the valve train. However, they said that the rockers will break when the pushrods are too short, which is counterintuitive.

Ryan installed one of the filed  rocker arms from  the modified head  I had removed from the right side. The pushrod was reused. If another rocker arm breaks, the plan is to order Smith Brothers adjustable pushrods and install them with the adjustment end near the lifter (upside down) for easier adjustment. The intake manifold and valley cover will need to be removed to adjust them, but it should only have to be done once.

 

13 Sounds

I was recently reminded of a chapter of the coupe history that happened ten years ago.

For Fathers' Day of 2002, Suzanne asked me if I Wanted a stereo for the hot rod. I said that I did,so we went to Car Toys to listen to their demo systems. As much as I love music, my hearing is not good enough to tell the difference between entry level and top quality sound. We settled on a Pioneer receiver, amplifier and 6 CD changer.

The salesman was a kid in his late teens. I described the business coupe and told him that there was no room for any of the equipment anywhere except behind the seat. He tried to listen to me, but it was clear from his glazed eyes and fidgiting that he had no clue what I was saying. He suggested that we look at the car. As we were walking toward it, he said "It's not a Honda. I don't know what to do with it." He went back inside the store and got an installer who knew where to place the units and speakers.

When the installation was done, the technician could not get the remote to work except by aiming it under the seat directly at the receiver. I returned the signal relay and kept the stereo. After all, changing the station was no more distracting than dialing a cell phone.

I later mentioned the problem to a salesman at SoundTrack. He tod me that home remote stereo systems operate on 12 volts. I said "Oh, do they?' and asked what I would need to use a home system in a car. I bought a single zone IR repeater system, a minisensor and a micro flasher. When I installed it, the system worked but the flasher beam was too narrow for reliable use in a car. I traded the flasher for a larger unit and the system has worked flawlessly ever since. The stereo remote is Velcroed to the car seat and aimed at the sensor under the dash. The sensor sends a signal by wire to thr repeater which operates the flasher aimed at the stereo.

Rube Goldberg yes, but I havent rearended anyone while changing CDs.

12 Disengagement (Part 2)

Although the realization might come a little late, I usually figure out when it's time to hire professional help.

The first time the coupe went to a local shop called "Gasoline Alley", it was running way too rich. The car was built at sea level and the carburetor jetting was way off for operation at 5280 feet. The owner of the shop knew AFBs inside out. When he finished with the carburetors, he claimed that they would pass Colorado emissions testing. They didn't have to because the car is too old, but the man knew how to brag. I will say the coupe ran 100% better.

Early in 2002, the clutch started to go out of adjustment. Each time I adjusted the master cylinder actuating rod, it improved for a few drives, then got worse. Eventually I ran out of adjustment. In four attempts, I spent a total of ten hours trying to vacuum bleed the clutch mechanism with no success.

I had the car towed to Gasoline Alley. They examined the clutch hydraulic system and found it was contaminated with thousands of rubber chunks.

We had used a hose on the remote fill reservoir which wasn't compatible with brake fluid. The brake fluid attacked the inside of the hose and eventually caused it to disintegrate.
Gasoline Alley had to remove the driveshaft, transmission and bellhousing and replace the hydraulic throwout bearing, master cylinder and the connecting hoses. Since we replaced all of the expensive parts, we replaced the reservoir too. This time we used brake hose from the reservoir to the master cylinder.

The second time we drove the car to "Hot Times, Kool Cars" (the annual firefighters car show to benefit Children's Hospital Burn Unit), the bearing in the Corvette left wheel support banjo seized. As much fun as it is to drive the hot rod, it's extremely embarrassing to the leave a car show with your car on the back of a roll back tow truck. There wasn't enough room in the cab to duck down so no one could see us. We took the '39 directly to Gasoline Alley, then rode home in the roll back.

Gasoline Alley didn't have a tool to disassemble the banjo and didn't want to use my homemade one. They sent the part to a Corvette specialist for repair. Shortly after I got the car back, an intermittent clunking sound started coming from the right rear. When they realigned the rear, they didn't get the pivot bolt tight enough. The bolt worked loose allowing the pivot end of the banjo to bang against the mounting bracket.

I fixed this at home, but I learned that it pays to check the work of every shop, even those with a sterling reputation.