Gassers are really popular right now, they look cool and they have a lot of room for creative building. I really enjoy seeing gasser style builds on the table because they are fun cars that border on silly looking. Even though they can have an element of fun to them, you have to remember, everything was done for a reason. Racers don’t do anything to their cars just for fun, they came to win and if it doesn’t make the car go faster, they are really not interested. The idea of racecars looking like show cars is really a modern phenomenon. Even though you can point out the exception from back in the day, most racecars were built to race and no one cared whether they looked like show cars. Measure it with a yardstick, mark it with chalk and cut it with a torch was the rule of the day. So I decided to write a little primer on what is a gasser and what ain’t, er, isn’t. Here’s a list of 20 things you should know when building a gasser. I chose the 1965 NHRA rulebook as a guide and then went a couple of years either way to explain changes.
1. Classes – Those letters on the window mean something, they ain’t there for decoration! Not every car ran A/G (A gas), that was the top of the heap, a light car with lots of horsepower. The class designations are based on the car’s weight divided by cubic inches. The reason guys ran Willys, Austins, and other assorted old coupes, is because they were lighter than the current production cars. That’s why A/G cars are usually old classic coupes with big motors in them. The behemoths of the 50’s are not light and no matter what you do to them short of cutting off all the body panels, they will never be as light is a car from the 30’s or early 40’s. So, if you took the same motor from “Ohio” George’s 33 and put it in a heavier car, it drops a class or so. Superchargers moved you up a class at first, so if you ran your car in B/G and then threw a supercharger on it, you are now in A/G. Then in 1965, they added an “S” to denote a supercharger and you ran in a separate class, such as B/GS. To make things worse, in 66, the doubled the class letter, in this case the “B” to BB/GS, and in 67 they dropped the “S” to BB/G. Classes went from A to H. One of the most famous gassers was the “Flintstone Flyer”, it ran a 292 and weighted 4600 lbs and ran in E/G.
2. Nose Height – Get the nose down! The rules require that the crankshaft centerline be no more than 24 inches from the ground. In 1/24 scale that’s about an inch, not 5 inches. You need to understand the idea behind the high front end, it’s about weight transfer to the rear for traction. The prevalent thinking of the day was to have the car sitting like it would while accelerating, i.e., the back end squatting.
3. Rear Height – Get your butt up! As the 60’s wore on tires got better and taller and the cars began to sit closer to level. The rear was still a little lower than the front, but there was no “cowboy” rake to gassers by 65, and it was never all that prevalent outside the stock classes anyway.
4. Street Legal – These cars fall under the “Street” section of the rules, they must have all the equipment required to drive them on the street and they must be able to start on their own, which means batteries and starters, radiators, lights, and all of that cool stuff. No body modifications unless approved, so watch the chopped tops and no altered wheelbases.
5. Driver – must be in the stock location
6. Roll bars – required
7. Frames – cannot be raised to gain weight transfer (channeling)
8. Bodies – Full fenders required
9. Engines – only one and in the stock location
10. Suspension – Must have one shock per wheel on a functional factory type suspension
11. Interior – NO gutted interiors! Rear seat is optional, buckets can replace front bench, full upholstery required. Cars must have a passenger seat, remember, it’s a street car!
12. Anglias – Anglias can only run a small block Chevys without a supercharger
13. Windows – Can be replaced with plexiglass
13. Windows – Can be replaced with plexiglass
O.K., enough of just the rules, now for the stuff that most guys did or didn’t do. These are the things that most people think cars had on them like they were rules, but they are just common practice or not.
14. Batteries – Big honkin’ truck batteries over the right rear wheel for ballast and to aid in traction. The battery in the trunk puts more weight on the rear tires which improves traction on the launch, it was put over the right (passenger) side because the torque from the driveshaft causes that side of the body to “raise”, the weight helps to keep it down. This torsional motion is what causes drag cars to lift the front left wheel first when they pull a wheelie.
15. Ladder bars – Long “ladder bars” were common in the 60’s to help keep the rear axle from “winding up” on launch and when shifting. In short wheelbase gassers they often connected to the transmission cross member. Until the later 60’s they were made from 1 piece of large square tube and had a pivot on both ends to facilitate rear axle movement in an arc but limit axle twist. The idea comes from the “wishbone” design of 30’s cars and the later habit of hot rodders to put “split ‘bones” on their cars. The “ladder bars” most people think of are a much later design, the long triangle shape with the zig-zag reinforcing that looks like a ladder. These became popularized on “Street Freaks” in the 70’s.
16. Straight Axles – Straight axles on a sky high “gasser” just looks cool! But not as common as you think. By the time the straight axle craze was taking off, the Funny cars were taking over. Early gassers ran stock suspensions and it just so happens that the old 30’s cars had straight axles on them stock. There are light, strong, easy and work really great in a straight line. By the time later body styles were getting in to the gasser act, the class was dying. “Ohio” George modified his Willys chassis to accept a 67 Mustang body, so it had a straight axle. Later gassers looked like little funny cars. The “Street Freaks” movement in the 70’s made people think that all gassers were jacked up to the sky with a straight axle under them, it’s not how it was.
17. Tunnel Ram Intakes – Nope. These are a Pro Stock item, they belong in the 70’s. The first commercially available tunnel ram intake was in ’68, there were some around before then, but they were rare. These were more common on “Street Freaks” than real gassers.
18. White Wall Slicks – White Walls were done by 1962, if your car has anything post 1962 do not put white walls on it, it just looks wrong. I know you can find exceptions out there, but it’s wrong. In 1959 tire makers started making “pinwalls” which are the narrow white wall tires from the 70’s you remember. Everybody had to have them and the “gangster walls” quickly fell out of fashion, then the raised white letter tires took over from there. Another thing to remember, slicks back in the day were recaps, nobody spent the bucks on white walls except the top teams.
19. Modern Stuff – AHHHHH! I hate this! Even factory funny cars didn’t run AN fittings and braided line at this time. Billet fuel pressure regulators came around much later than the gasser era. Big tube welded pro mod headers don’t fit either. Billet valve covers are out, finned covers were the coolest thing ever back then and chrome was king! Billet wheels are out too. Most guys ran steelies, especially on the rear. Real magnesium slotted wheels were common for those that could afford them and Cragar S/S’s came out about 65.
20. Scrub Line – The scrub line is an imaginary line from the bottom of each wheel rim to all of the other wheel rims. Nothing can be below this line and be legal for competition. As a matter of fact, if it’s too close you can’t run. The idea is if you blow a tire the only thing that should make contact with the track is the wheels, anything else is dangerous. No header tubes, no ladder bars, no steering arms, no body panels. Nothing.
Last thing I want to mention, rear bumpers were often hollow tubes that could be filled with water or cement to add weight to “make the minimum”. This way you added weight where it did the most good, water could also “accidently” leak out in the pits after a weigh in. Barbell weights were also common in the trunk of gassers for the same reason.
There’s my little primer on gassers for you, it’s not complete and the rules changed from year to year. I picked 65 because it’s right in the middle of the era. If you have any questions, let me know!
“Rat Fink” Ron