Converters, Measurements and Dial Calipers – Oh My!

Converters, Measurements and Dial Calipers – Oh My!

It’s a bit funny but I have probably explained the following procedure to a few friends a half-dozen times in the last few weeks. And honestly unless you too are a diehard drag racer using a GM style automatic transmission and converter setup, the information here is probably worthless. But then again, to a lot of those that do use that setup there seems to be a huge mystery to this procedure. Actually it’s all rather simple. Why this might apply to some of the latest GM stuff, I am specifically talking about Powerglides, TH350s and TH400 transmissions. And this procedure should be used every time you have the transmission serviced or maintenance on the converter performed. You should also use it if you are changing the flexplate for the engine or the bell housing/transmission case.

First things first. The convertor has to be seated properly in the transmission before anything else can happen. I like to call it the  “3-step drop”. What needs to happen is that as you place the converter in the transmission, you need to make sure that the splines of the transmission are engaging the internal splines of the converter and that the converter hub properly seats within the drive tangs of the transmission fluid pump. It’s actually pretty easy although some converters can be a real bear getting them to make that final seating. What you will feel is that the converter “drops” or moves back further on the input shaft as you rotate the converter back and forth. The first drop is almost negligible and is simply the converter hub aligning itself with the outer portion of the transmission pump. The next drop is significant and typically moves the converter back about 1/2″, this indicates that those splines have now engaged each other. The last and final drop again is about 1/2″ and will be the hub engaging the fluid pump tangs. Now at this point, the converter is completely engaged in the transmission but if you were to run it this way, you would find that you will destroy your transmission pump in quick order. This brings up the procedure that needs to be used. With the transmission installed in the car and bolted up properly to the engine, it is time to take a measurement. Depending on the combination of flexplate, the thickness of the converter mounting pads, the bell housing or transmission case and whether a rear engine plate is used, this measurement needs to end up being somewhere between .125 and .187. With the converter still pushed back into the transmission, we want to measure the distance between the flexplate and the mounting pads of the converter. The easiest way I have found to do this is to take a set of feeler gauges and insert a stack of them until the stack is just snug between the measurement points. One you have that measurement, you can then take a dial caliper and measure the thickness of the stack or lacking a dial caliper, you can add up the feeler gauges. This measurement will be the distance between the flexplate and the mounting pads of the converter. As an example, let us say the measurement is .234 – well that is a little bit too much as if we were to pull the converter forward and simply bolt it to the flexplate, we would run the risk of pulling the converter hub out of the drive tangs for the fluid pump and in turn we would have an inoperable transmission. What we need to do is a little bit of math. If our desired minimum clearance is .125, we deduct that from the measured distance, which in this case is .234. That leaves us with .109 as the excess distance. We now need to find some hardened washers or spacers to take up the extra clearance. Using the dial calipers again, we should be able to find washers that come close. Again as an example lets say we find 3 washers that are .090 in depth – three are required for the GM transmissions and we want to make sure that they are all the same. That still leaves us with .019 extra clearance but if we add that to our desired .125, we come up with .144 which is well within the maximum amount of .187. We can now bolt the converter to the flexplate with the .090 washers between them and we have the proper clearance for the transmission to fully perform its job function.

The Joys of Hot Rod Wiring

The Joys of Hot Rod Wiring

There’s nothing like rebuilding your hot rod save for that wiring job you now have to take on. In my case this is Elvira right now and with the circuits that I am changing, adding and deleting all at once, the wiring looks like a colorful pile of spaghetti – and I don’t like spaghetti, just ask the missus. I cannot remember really which car was the first that I even worked on as far as the wiring but an early one that I remember was my mom’s car. I was slowly taking the car over and had added a couple of gauges to the car, one of those oil and ammeter combination deals. Everything worked just fine until she was shopping one day and the car refused to start. After getting a mechanic to look at the car, it seems that one of the wire connections I had made to the ammeter had failed which cut all of the battery power to the car. Not long after this, I learned how to properly crimp a wire connector – squeezing it with a pair of pliers just doesn’t get the job done.

 

Over the years I have added different electrical items to cars including gauges, ignition systems, stereo units, speakers and fuel pumps. I have wired hot rods from the ground up; they didn’t have the first piece of cable in them and when I finished there was an operational vehicle with all of it’s electrical functions functioning. One car that I am still a little proud of was a NHRA/IHRA stocker. It was basically a complete wiring job from front to back but just to throw me a curve ball, the owner wanted his power windows to work. They still do. I am lucky in that I grew up in the phone system so Basic Electricity was actually a course I took at one time and that as the job situation required, I became very familiar with different kinds of electrical components. I learned that assembling things in certain ways, connecting the circuits and using special bits and pieces as you needed let you customize a solution to obtain the results that you want. I was also trained to read electrical schematics and can normally follow the flow of a circuit from A-Z. One of the most recent wiring jobs I performed was on the Monza. If you have looked at any of the photos of the car when it was first purchased, you can tell that the wiring job in it was more of a miss than a hit. The car had everything from 110v light switches in it to solid house wiring. Grounds were simply holes drilled in any roll cage pipe that was close by. Simply put, electrical wiring in a vehicle, whether a race car or not escapes a lot of people. These same people can assemble a race engine, weld a complete chassis together and tune the daylights out of a race car but tell them they have to wire it and they will give you every excuse in the book not to do it.

So back to Elvira. Right now I have about 99% of her wiring completed right now. I have moved some components around a bit which has resulted in shortening the wiring to them and in other cases I am making improvements in the way I connected something before. I have also run a total copper ground system in the car to reduce the amount of electrical resistance that might have been in the frame. While the chrome moly frame was a convenient point to make ground connections, I have learned that it is certainly not the best route to take. I have also added additional grounding to some components in an attempt to reduce any resistance in those particular circuits. I am not sure any of this is going to make the car perform better but at least I will know that each circuit will be at it’s best. There is also some additional items that I am adding that I did not run before and of course these needed wiring connections too. I hope to have all of the wiring completed over the coming week and once everything is tested I will be ready give Elvira her final test firing.

Le Mans

Le Mans

I just finished watching a documentary on Steve McQueen and the making of his movie – Le Mans. The name of this is Steve McQueen & Le Mans. As anyone who is familiar with the movie would know, I paraphrase one of the most moving lines in the movie as the tag line for my site –

“racing is life, everything else is just waiting….”

During the documentary, Steve’s wife of the time Neile Adams makes a comment that during the making of the movie, Steve lost everything, his soul, his family and friends,  maybe so. Steve never raced again after the movie was completed; the desire to do so was gone and without that you endanger not only yourself but others around you, so I respect him greatly for his decision. What he might have never known and I wish there was a way to tell him, was that he created a legion of men who understand, who really understand that “When you’re racing, it’s life. Anything that happens before or after is just waiting.….”

I attended the movie “Le Mans” the very first weekend it was shown in 1971, the movie and Steve changed the way I thought and felt about motor racing. My career, what there was of it, my family and friends, all the things that make me – me ~ all move to a little place somewhere else in my psyche when I step into my racing car. At that moment and until I step out, it is only man and machine. It always has been and it always will be like that for me. Thank you Steve

Project Introduction

Project Introduction

Roughly about 46 years ago, I purchased my first 1955 Chevy. It was a pure stock, 4 door model with a 265 cubic inch motor and automatic transmission. The purpose of the car was for my girlfriend to have something to drive back and forth to school. I think we paid $175 for the car from a used car lot, but the car had vacuum windshield wipers on it and she hated driving it whenever it rained so it didn’t stay around too long. We had some fun cleaning it up and drove it for most of that summer and there’s no doubt that it was actually a pretty decent car.

Next up was a mess of a car that was a combination of sheet-metal and attending paint colors that all combined summed up the next ‘55 Chevy we owned. This one was actually spotted by my wife who was that girlfriend in the previous paragraph, not too long after we had seen the Two Lane Blacktop movie. And of course I was just positive I could turn it into that car on the screen. This particular car had parts from just about anything and everything that you could imagine. Wood 2×4’s were used under the bucket seats that came from something unknown so that you could see out the windshield and the radio was haunted. Kind of like that Christine movie thing, it would turn itself on and off, change stations, play weird songs, all of it very strange. The motivation for this one was a 350/4 speed Muncie transmission deal. The car was actually pretty quick and we enjoyed driving it around although I am sure the seven different paint colors on it made other motorists rather nervous. My wife and I still talk about the times that we would take our baby son to the drive-in, put a blanket on the hood and set him between us. We were dead-broke most of the time, but it sure is funny how we still managed to have a good time. I enjoyed that car probably more than any other that I have ever owned. Of course sometimes those long rear views can have a touch of romantic nonsense that can make it seem better than it really was at the time but none the less, we were doing a-okay.

A bit later on I had the notion that I wanted a full time drag car and the ‘55 was going to be it. We put a hotter cam in the engine, cut two coils off the front end (no, I don’t know why!), replaced the side glass with plexiglass and that was about the extent of the modifications. I would fire up the car on Saturday morning to check it out while every lawnmower in the neighborhood was running, but within about 15 minutes I would have another visit from the local authorities, compliments of a really nice neighbor down the street. We flat towed the car to the drag strip and normally spent our day there chasing one problem or the other. Most of the time the car ran great in the driveway at home, but by the time we got it to the strip we had used up all of our luck. After about one summer of this, I had tired of the “fun” and we had also decided to sell our place and move. The real estate person suggested that we might have better luck if we ditched the weird looking car in the driveway, so I pulled the engine then towed it to a local junkyard and turned over the title. The house sold just a few weeks later, but I’ll never know if getting rid of the car had anything to do with it or not.

So that brings us up to now and how did I manage to end up with another ‘55 Chevy? Well, about 20 years ago I thought that getting into street rodding would be fun, but I wasn’t quite ready to make the jump into the really old vintage tin stuff. However, the 50’s stuff was looking like fun so I found a ‘49 Ford. The only problem I ever had with it was that I wanted it to be a ‘55 Chevy. That’s just a bit difficult as you might imagine. So after having done very little with the ‘49, I decided it was time to sell it and just let the whole street rod type deal go by the wayside. I placed an ad in the local trader paper and to my surprise was contacted almost immediately. During the transaction, I was asked why I was selling the car and I simply said that I really wanted a ‘55 Chevy, but that I also knew that anything decent was completely out of my price range. The person that was buying the ‘49 surprised me by telling me that they happened to own one and wanted to sell it too. We worked out a trade of cars at that point and I found myself owning my third and final 1955 Chevy. This one is a 210 model, 2 door post ~ identical to the model used in the Two Lane Blacktop movie (and of course American Graffiti). I cannot believe my luck in finding one of these and while it certainly is in need of work, it’s no worse that the Ford that I let go, besides, it’s a ‘55 Chevy!!

The build plans call for a large motor, automatic, decent performance that can maybe cruise to the ice cream shop yet do some fun duty at the strip on a Friday night. My wife accused me one time of being a teenager that had never grown up – she’s actually dead right and there’s no arguing the point. But she’s also that same pretty girlfriend that I bought that first ‘55 for -so I think we’re going to be a-okay.

Project Details

Project Details

Over a period of time the project objectives for this car have changed in my mind, sometimes flowing back and forth. Should it be an all-out drag car or should it be a street/strip car or even something in-between? I am not sure I will really know until the car is about done but obviously some choices are going to dictate how the car will be used.

Another item is while I reference the car that was featured in the movie “Two Lane Blacktop”, I am not building a clone of that car but rather a car that was maybe inspired by the movie car and the movie itself. I am not sure how many times I have viewed the movie since it originally came out but I can say that I know most of the details about the movie. The other piece of that is that the movie actually says a lot more than one might notice at first glance. It might look like a B-movie made for the drive-in theaters of the time but to me it actually shows a microcosm of life back in the late ’60s and early ’70s. Things were a real mess back then, a bad political war and youthful unrest were just the tips of the problems. Driving a car across the country with a few bucks in your pocket and making a couple of dollars racing it along the way – just motoristic escapism? I am not sure but it didn’t seem like a bad idea at the time.

So yes, now at a later stage of my own life, the ’55 represents something maybe missed, longed for or at the very least, some fun that I think I should have had back then. It’s my last build, that I am sure of and how it turns out is yet to be seen. My hope is that I finally finish a build somewhat quickly as I feel that time is not exactly on my side anymore, so there is some urgency in it but with a dollop of wanting to enjoy it too.