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The True Exploits of a Yenko Stinger
by Merle Grabhorn

Merle Grabhorn
Merle Grabhorn
Owasso, OK
grabhorn@busprod.com

     
After I had just graduated from college during the 70's, a friend and I began search for a slow car to race in the lower AHRA classes figuring that it would not be that hard or expensive to be competitive. To give you an idea of how this story will go, let me first tell you that my friend was an American Indian by the name of Charlie Crazyhorse or CC for short. Because of his native American ability to live off the land and scout around locating elusive things like deer or buffalo, he had this ability to find the damnedest things. In hunting for the elusive slow car, he scouted up a gem! He found a Yenko Stinger!

You probably know that Yenko put out a series of super muscle cars, but Yenko put out a few unusual ones too! A Yenko Stinger was a 1965 Corvair that Yenko built primarily for SCCA road racing. The standard Corvair 164 cubic inch flat 6 was rated at a mere 90 to 110 hp. The Stinger was conservatively rated at 180 hp and probably kicked out something over 200 hp. When CC had me come and look at the car, I nearly died. The Stinger came stock with fiberglass decklid and rear deck spoiler, functional airscoops, headers, sported a 3:55 posi, with a close ratio 4 speed transaxle. The car even had a rollcage and plastic side windows. Even more amazing was the carburation set up. The Stinger had 4 Webber 1 bbl carbs on a cross ram induction manifold with the carbs on the right side feeding in big long tubes across the engine to the left cylinder bank and vice versa. The owner had ordered the Stinger from Yenko, had certification papers to prove that the was indeed a production car and described in full detail all the options.

This was the only Yenko Stinger I have ever seen. I have seen only a few pictures of others in sports car racing magazines. The owner, who had purchased it for racing, hadn't raced it for several years and his wife was making his life miserable about it taking up garage space. He offered to sell it to us for a mere $1,000. We bought it on the spot, with me contributing every penny that I had to my name, exactly $500. Boy, do I wish I had that car now. On the collector's market, I have been told that a pristine Stinger is worth as much as 50 times that or more and that only two Webber Stingers were ever made. I don't know if this is true or not, but I don't doubt it.

The class that the Stinger would go into was V/SO F-2 (pronounced Vee Stock Optional-Formula 2) with a record index of about 17 seconds, something we knew this car could do in a walk. Our problem was, we didn't know beans about an air-cooled Corvair motor and were really perplexed with the really complicated induction system. Neither of us knew anything about Webbers and until this time I had only seen them in pictures. We had no earthly idea how to synchronize 'em, tune 'em. etc. The rest of the motor was equally mystifying.

We managed to get the Stinger running although it really staggered and kicked dense clouds of black smoke as it idled. There was no doubt that the Stinger had a wild cam, but the carbs were really messed up and we couldn't get them right. CC and I took it outside of town where street racers had conveniently marked a quarter mile and made a pass. By CC's wrist watch, we turned about 16 to 16.5, at least a half to a full second under the index. And this was with two of us in the car with it severely out of tune and pouring black smoke like a crashing airplane. We knew we had a winner, we just had to figure out how to fix it.

Since we were still in our early twenties we were not willing to let well enough alone. We decided to *engineer* the car a little better. We had that *need for speed* desire that overwhelmed everything else. In looking back, I now realize the error in our thinking. The car was a winner as it was, and we didn't take advantage of that simple fact.

CC immediately went on a hunting party for some way to find a sponsor. Of course, both of us being flat busted was part of the reason CC went searching. And CC came through again, in the most amazing manner.

CC got the name of a garage where the owner, named Bob Walter, had been a Corvair Specialist for the local Chevy dealership for many years. CC was told that this guy knew more about Corvairs than God himself. When we drove up to this really ramshackle, unpainted shop, we thought we died. In the weeds, behind this unpainted and run down shop, must have been 20, 30, no, maybe a 100 Corvairs. CC and I figured that this must be the equivalent of an Elephant Graveyard, only for Corvairs. Also, what was interesting was the total lack of customers at this garage. Tall grass was growing through the cracks in the driveway. CC had been told that Bob was a bit eccentric, but we didn't really know how eccentric he really was until later. He didn't have any customers!

We went in, and there was Bob and his helper. His shop was amazing, with tons of Corvair parts, such as motors, fenders, transaxles, etc. stacked to the ceiling. There were tiny, narrow, impossible, dark little trails between these piles. It was like a junkyard, only it was inside.

His helper, we immediately nicknamed Snaggle Tooth as he had exactly 4 teeth, sort of scattered at random in the front of his mouth. He also had a glass eye that looked off into the dark corners of the garage or at the floor or ceiling at the worse possible times. Only later would we learn that Snaggle Tooth's glass eye would pop out from time to time and go bouncing across the floor of the garage, giving CC and me terrible nightmares. I was chased by that eyeball for years afterwards in my nightmares. And Bob was not much better-sort of tall, unkempt, and equally wild-eyed. We were to find out much latter that Bob, although uneducated, was a mechanical genius and an inventor. He had invented a good number of automotive tools and other things, got patents, sold them to different companies, and was making a really comfortable living off the royalties. Unfortunately, like many people of this nature, he was eccentric. No, to be honest, he was crazy.

We told Bob what we wanted to do with the Stinger. He was fascinated by our plans and decided that he wanted to help. Bob firmly believed that the Corvair was the worlds ultimate car and that Ralph Nader was the devil incarnate for destroying its reputation. Anything that could be done to bring the *status* of the Corvair up in the world, Bob was willing to do. And brother, let me tell you that this was only the beginning. Bob was so disappointed that Ralph Nader had forced Chevy to discontinue the Corvair, he (meaning Bob) was driven to drink! CC and I never realized that Bob was drunk until we saw him sober once!

Being an inventor and a serious drinker, he had all sorts of unusual friends who were also inventors, (and serious drinkers!) It seems that certain types of personalities always congregate together and this was the perfect example. Of course, CC and I, were not unusual in the least, you understand.

What CC and I wanted to do, as part of our hop up ideas, was build up potential energy for the launch by installing a super heavy flywheel, something that was O.K. in the rule book. Only problem was that we felt we would not only burn clutches and pressure plates up, but we would pound the main bearings out in a hurry. We also thought that the transaxle would break under the severe pounding.

*No (expletive deleted) problem* says Bob. *We'll (expletive deleted) soak the (expletive deleted) clutches in (expletive deleted) rubbing alcohol and they'll (expletive deleted) grab like a (expletive deleted). I'll (expletive deleted) change 'em every other (expletive deleted) pass.* Bob had a very colorful but somewhat limited vocabulary that got even more colorful as a function of his drinking. He volunteered to pull the engine after every racing week end and replace the bearings-no small job in a Corvair. He had transaxles to spare if we needed them. Even more astounding was the help he got from his buddies.

They would all meet at Walt's shop, get in a state of intoxication, and theorize and design ways to make the Stinger go faster. These guys were something else. Bob built us a flywheel that weighed well over 50 lb., maybe closer to 75 or even 100 lbs. One of his buddies made a pattern for the flywheel, took it to a foundry and had it cast. He then built a lathe at Walt's shop (I'M NOT MAKING THIS UP) to finish it. They even worked out a way to get the ring gear on by cooling the fly wheel with dry ice. It contracted, they slipped the ring gear over it, and when the flywheel expanded, it had an intense friction fit. Spot welding was the final safety feature. (HONEST, I'M NOT MAKING ANY OF THIS UP-IF I TOLD YOU SOME OF THE THINGS THEY DID YOU WOULD CALL ME A LIAR-THE STORY IS UNBELIEVEABLE AS IT IS AND I WAS THERE!) They built up the springs in the pressure plate, modified a truck clutch to work in the car, and in general did wonders to the car. Since the Stinger engine was air cooled, they fabricated pulleys to turn the engine fan slower and free up even more horsepower. My God, they went through every inch of that motor and custom fabricated individual pushrods, custom fit them for each cylinder and valve, and on, and on, and on. They cast and hand fitted each individual bearing to each main and rod journal out of babbit metal. When they balanced the motor, they fought about differences as little as a thousandth of a gram and where to remove the metal. They put as much effort into this car as is put into Pro Stock Cars or Top Fuel Dragsters.

What we found was the racers dream. A group of mechanical geniuses who worked for the pure pleasure of solving problems. And they did it for free. There was only one problem. Like many geniuses, they were never satisfied with the final product and kept modifying and modifying and we could never get the damn thing to the track. On the other hand, this wasn't costing CC or me any money so we just sat back and watched. I can even begin to guess what it would have cost to do what we were doing if we paid someone to do it. AHRA rules were pretty loose on what you could do to a class car to hop it up and these guys did it all. I think we had the ultimate Corvair.

CCs final hunting and scouting expedition found some 12" slicks on 12" rims from a quarter midget racer that actually fit the Stinger. The stock Stinger tires were 13 inch chevy and were not anywhere as wide. When these were installed, the Stinger looked about like a go-kart with these huge tires on the back. The aspect of those midget tires was so small that the Stinger looked like it was constantly driving uphill, however, it probably changed the 3.55 ratio up to about 3.90 to 4.11. The 3.55 was the max you could get in a Corvair transaxle. However, these guys were in the process of building a mill and designing gear cutters to fix that problem. That part was never completed due to what happened next.

The Stinger, such as it was, was ready to race, about a half an hour before the gates opened for tech on the very morning of the AHRA record race so we never got a chance to test it except to start it at the shop. It didn't take long to realize with that super heavy flywheel, and the bumped up compression, the Stinger was not only hard to start, but it took forever to build up rpm.

When we got to the track with this car, we were objects of derision. We had a really funny looking Corvair (covered with Bird Poop because it was in Walt's Garage so long), and all sorts of strange doo-dads on it. The webbers had carburetor heat shields obviously fabricated from K-Mart cookie sheets. The headers had been altered and looked something like 6 tangled trombones wrapped with asbestos. Stock Corvair exhaust manifolds pointed to the front of the car. These headers also pointed to the front but were bent into a real basket of snakes as they twisted towards the rear of the car. Bob and his buddies had determined the optimum lengths for each cylinder and fabricated them. These guys should have been designers for Hooker. Also, this was really before anybody thought of heat wrapping headers to help exhaust scavenging, I might add-Bob and his friends were really ahead of their time- AGAIN, I AM NOT MAKING ANY OF THIS UP.

We passed tech, although barely. We got more head shaking and *I don't know about this* and more questions as to *What in the hell is this?* than you can imagine. We had the AHRA rule book in hand and we fought about three hours to pass tech. Most of the time, all you did was fill out a piece of paper and that was it. AHRA was pretty loose. It was only by the grace of all the Yenko paperwork that we proved this was a *production* vehicle. I think they passed us because they were certain the Corvair would Crater when we started it.

We were set to go. CC and I flipped to see who got to make the first pass and I won. Bob, and his friends, who came out with us in the *Support Truck* celebrated by proceeding to commune with the Spirits.

I started the Stinger and let me tell you, that six sounded as husky as a small block V-8. It didn't have this high pitched six sound, but a deep throated popping rumble-stumble totally unlike a six. You know how a wild cam and open exhausts sounds. Really, really sweet. If sound alone was enough to win first place, we had it hands down. Oh yeah, this was a bad boy, really, really baaaaad.

I finally staged the Stinger and built up rpm, figuring that there ought to be plenty of power in this Corvair...

There was!

When I dumped the clutch, about 6500 -7000 rpm, the Stinger launched like a Fuel Dragster!!!!! With a Corvair front to back ratio of 70% rear and 30% front, coupled with the independent rear suspension, slicks, and all that energy stored in the flywheel, the front wheels went about 2 feet into the air and the whole damn car leaped over the staging beams! The ass-end of the car actually wanted to get out in front and lead. I actually whiplashed my neck. The bolts holding the seats in the floor broke, and I damn near flew into the back seat. I'm not kidding! I've never felt a launch like that in my life and I've been in some 8.90 cars. I can only guess that this type of launch can only be felt in a Funny Car or Dragster.

By the time I hit second gear, the fan belt came off the pulley, freeing up more horse power. Hell, the only thing I had to hang on to was the steering wheel and that spindly Corvair shifter that I actually bent when I went flying backwards. That Corvair went through the traps with an E.T. of 12.2 and 110 mph, more than five seconds under the index! Of course, by the time I hit fourth gear, the rpm was way down because of the heavy fly wheel and the car was actually slowing down. In fact, the Corvair was decidedly squirlly at that speed and gave the feeling that the back end really wanted to be in front all the time!

I got back in the pits and Bob literally fell out of his truck, due to a combination of drink and excitement. He pulled the welder out, and fixed the seat, scorching wholly h*ll out of the seat and setting the carpet on fire several times. He stuck his foot on the shifter and bent it back into position. We were certainly high tech. CC made the next pass with an equally astounding wheel stand and a similar E.T. (With the same sore neck, broken welds, trip to the back seat and a bent shifter.) We had turned in a time that was incredible for a Corvair and in fact would have been incredible for some of the Muscle Cars at the track. We were in ecstasy.

Unfortunately, the officials were not. We got jerked immediately. First order of business was to check the fuel. It was clean. They put us on the scales. We were O.K. They put the jar on the cylinders to check cubic inches. It went on and on until they finally said, *Pull the heads, tear down the motor, you can't be legal.* That was the Red Flag for Bob. The one thing that really got his goat was someone who doubted his honesty. Of course, tearing down a Corvair is not something you can do very well unless you have the engine out of the car. And, it doesn't come out of the top, it drops out of the bottom. The officials knew that, and Bob knew they knew it which made him madder yet. The combination of being called a cheater, and being forced to due a difficult task to prove that he was honest was it. Bob clearly told the officials where they could go, how they could go there, and what bizarre biological feats they could expect to perform on themselves, while on the way. His being very well lubricated due to drink didn't help.

We, of course, were thrown out.

And that was the end for us and Bob. He wanted nothing to do with any organization that doubted his integrity, particularly having to do with Corvairs. Since this whole thing was our idea, we were responsible, and were told to take the car and get the Hell out of his sight. He never wanted to see us again!

CC and I were despondent. We were busted. We had an outstanding car, but no money, and we didn't have the knowledge, tools, or experience to keep this car in top form. We couldn't take it out to the track because we had been blackballed due to Walt's drinking. We could have run the car in AHRA H or I Hot Rod Class or even E or F/Gas class and made it work, but that was impossible due to being blackballed. We didn't have the money or even a way to tow to another track. (We had used Walt's homemade trailer and his truck to get us to the track-perhaps another reason we were objects of laughter. You had to see his rig to believe it.)

However, a week or so later, a guy called us up and wanted to buy the Stinger. He offered $5,000 cash on the spot, a 5 to 1 return on our money. We took it. Our buyer had realized something that we didn't, the car was an obvious sleeper for street racing if you made a few cosmetic changes. A well known street racer bought it thinking he could make a killing. Instead the car almost killed him. The flywheel let go in a grenade like explosion that actually tore the back end off the car and shotgunned the car beside him with shrapnel. The fuel line was cut and the car flamed. It was gone. And, incidently, I have not been back to that particular race track since. I'm sort of afraid that somebody will remember that Corvair and Bob.

So, although you probably don't believe this story, I SWEAR EVERY WORD IS TRUE. I just hope that your venture into class racing will be a little more successful than mine.

(Some names have been changed to protect Merle from having recurring nightmares about bouncing eyeballs chasing him. -Michael)
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Michael:

Here are just some final thoughts that you may want to include if you put the Stinger story on *The Staging Light*. Although the story is funny, the Stinger honestly obtained an E.T. of 12.2.

The E.T. of 12.2 for a Corvair does not sound very impressive by today's standard with many street driven vehicles of today able to obtain much better. So, here is a little perspective:

For a 2,800lb Corvair (including driver) to optain an E.T. of 12.2 requires a NET horsepower of about 300 at the rear wheels. This can be confirmed by anyone checking into the HP/Wt programs that abound on the net. This means the motor actually grossed more horsepower because of mechanical losses such as clutch slippage, and so forth. Dragstrip Plus estimates a gross of 375 HP for the combination-while I would haved guessed around 330 HP as a good number.

For a 164 CI flat six to put out 330 HP is a Horsepower per Cubic Inch ratio of 2.01 HP/CI. If the higher number is to be believed then the ratio is 2.28 HP/CI.

Present NHRA 500 CI Prostock motors are estimated to put about about 1100 to 1200 HP for 500 cubic inches or 2.2 HP/CI to 2.4 HP/CI.

So, to put it into perspective, Bob and his buddies managed to obtain horsepower per cubic inch displacement darn close to what is being obtained for the normally aspirated Prostock racing engines of today. An amazing accomplishment! If the higher 2.28 number is to believed, then that accomplishment would be equal to producing 800 hp from a small block 350 and 1270 hp from a 454! Try those numbers in a 3500 lb Camaro!

In closing, one of Bob's drinking buddies was a chemist who talked about *chemical supercharging* with *laughing gas*. Something that I never heard of at the time so I laughed it off. We now know what that is-Nitrous. Further, the Corvair Sypder was turbocharged and Walt had a number of turbochargers from deceased Spyders. They planned to step up to *chemical supercharging* and the turbo... which makes me wonder:

What would have been the ultimate E.T. for this car?

Merle Grabhorn
grabhorn@busprod.com

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