1937 Chevy Coupe Gasser--1965 NHRA Rules

[dusty_shelf]

As mentioned in my member intro, I intend to get back into modeling with the build of a 1937 Chevy Coupe gasser using the 1965 NHRA Drag Rules as a guide.  I am going with the AMT Chevrolet Coupe kit (#6579).  Under the hood will be the 421 dual quad taken from the AMT 1962 Catalina.  Go Poncho power!  The motor will be augmented by pieces from the Revell Pontiac 421 Parts Paks offer.  If I have done my math correctly, the Chevy Coupe would be running in Class A.

As a backstory, the build will reflect the efforts of one man working out of his own barn/garage with no sponsor or financial backing.  Most of the parts will be scrounged from local junkyards or purchased from a small automotive shop in his area.

In reading over the 1965 NHRA Drag rules, I came across two that have me a bit puzzled.  Perhaps some of the members can clarify.  The first is in regard to lifting the body or frame to gain weight transfer to the rear wheels, which is prohibited.  Is this not what is typically done with gassers creating the nose-in-the-air look?

The second rule deals with the fuel tank, which it is recommended be fit in front of the motor.  Safety regulations require those mounted in front of the grille be protected by a bumper, the frame, or the body as a safeguard against low-speed collision.  I have seen countless cars, both kit and real, that have the tank fully exposed on the front of the car/truck.  Different set of drag rules?  I want to be sure my build is correct for the class and year.

One last question is about the original gas tank.  Would its removal be permitted or does it go against the rule prohibiting the lightening of the car by gutting or cutting body panels?  I would surmise the latter since the rules would have one retain the factory weight of the car with only a few modifications allowed.

I have begun modification and super-detailing of the factory frame and hope to have some photos soon.  Still waiting on delivery of some styrene tubing and other items.

[larman]

Check out http://www.georgeklass.net/index.html, great reference for vintage drag cars. There are a lot of '37/'38 Chevys in the Gasser section.These are actual pictures of cars from the time, not modern interpretations. His pics cover from the mid 50's up to the early 70's.If I were building a gasser from the AMT '37, I would probably use a smaller Moon tank in front of the radiator and either use the stock grille or the cool smoothed out, one piece drag version, included in the kit. To be honest, that kit pretty much has decent stuff to build a gasser right in the box.If you use the drag front end, maybe lower it just a little, or you could modify the stock one. I like the idea of an SD 421, people think everyone always used Chevy motors in Chevys, but in that time period an SD Pontiac motor would be highly desirable and I have seen more than one '37/'38  or  Tri-5 Chevy with Pontiac power. I would probably leave the stock gas tank too.I try to build my drag cars as authentic as I can, usually in the time frame of '64-'68, so I understand you wanting to sweat the details, but it seems that there was a lot of leeway from track to track with rules, especially the smaller ones. HTH.....

[Ace-Garageguy]

6 hours ago, dusty_shelf said:

...In reading over the 1965 NHRA Drag rules, I came across two that have me a bit puzzled.  Perhaps some of the members can clarify.  The first is in regard to lifting the body or frame to gain weight transfer to the rear wheels, which is prohibited.  Is this not what is typically done with gassers creating the nose-in-the-air look?

The second rule deals with the fuel tank, which it is recommended be fit in front of the motor.  Safety regulations require those mounted in front of the grille be protected by a bumper, the frame, or the body as a safeguard against low-speed collision.  I have seen countless cars, both kit and real, that have the tank fully exposed on the front of the car/truck.  Different set of drag rules?  I want to be sure my build is correct for the class and year.

One last question is about the original gas tank.  Would its removal be permitted or does it go against the rule prohibiting the lightening of the car by gutting or cutting body panels?  I would surmise the latter since the rules would have one retain the factory weight of the car with only a few modifications allowed...

The wording of the rules can seem to be a little ambiguous, as could be the interpretation by a car builder. The prohibition against "raising the car body or frame to gain weight transfer to the rear wheels" can be sidestepped by the builder claiming the car wasn't lifted to gain weight-transfer specifically, but simply has to sit as high as it does in order to reasonably clear tall rear slicks, traction-aiding devices like ladder bars on the rear, etc.

Somewhere along the line (and I should know exactly when, as we've been over this enough times), a rule was instituted limiting the center of the nose of the crankshaft to a maximum of 24" off the pavement. This was partly done to counter some of the stupid-high-nose cars that were built, and which became wildly unstable at speed. There was also a rule requiring rocker panels to be more-or-less level with the car at rest, though I'll be dammed if I can find it right now.

In general, build what you see in period photos and check the dates the photos supposedly represent. You can't go far wrong that way. Period cars generally sat level at rest, or close to it. The characteristic nose-high attitude that many "nostalgia" builders go for these days is just flat wrong for cars raced under national sanctioning bodies' rules back then (though you'll occasionally see a period dork running one in a non-sanctioned event). The trend towards stupid-nose-high developed due to a widespread misinterpretation of photos of the in-period cars' attitudes at launch, when the nose does in fact come up significantly.

One thing to remember that's not obvious and a lot of folks miss...in '65 and '66, the rules required the rear fenders to entirely cover the width of the tires. This was relaxed in '67.

[dusty_shelf]

Larry---

Thanks for the reply.  Your input is most welcomed.

The George Klass site is one of the first I bookmarked.  Wonderful vintage photos!  Will definitely use it for reference. I also have bookmarked PDFs of the 1937/38 Chevrolet shop and body manuals with great drawings and details.  Trying to get my research down before diving into the build.

---Mike

[dusty_shelf]

Bill---

Thank you for your very informative reply.  This is what I hoped to learn from the forum.  I will keep in mind as I build the suggestions you have offered.  I am getting a clearer picture of where I am going with the gasser.

---Mike

[Snake45]

25 minutes ago, Ace-Garageguy said:

There was also a rule requiring rocker panels to be more-or-less level with the car at rest, though I'll be dammed if I can find it right now.

A similar rule stipulated that a line running from the bottom edge of the body should run no higher than the centerline of each axle, nor no lower than the lower edge of the wheel rim. Many cars seem to have fudged the upper limit a slight bit, but if you stay in those guidelines, you can achieve "the look" quite nicely. 

[larman]

2 hours ago, Ace-Garageguy said:

The characteristic nose-high attitude that many "nostalgia" builders go for these days is just flat wrong for cars raced under national sanctioning bodies' rules back then (though you'll occasionally see a period dork running one in a non-sanctioned event). The trend towards stupid-nose-high developed due to a widespread misinterpretation of photos of the in-period cars' attitudes at launch, when the nose does in fact come up significantly.

 

Amen to that!!

[Muncie]

In addition to rules changes already mentioned, tire and chassis technology were going through a big change in 1965.  The new wrinkle wall style drag slicks started showing up and offered a lot more traction.  It just wasn't as necessary to raise the front end to get a car to hook up.  The front ends started coming down and gas class cars started running a more level attitude.  You'll see some of both in 1965 but the extreme lifted front suspensions were mostly gone.

Looking forward to watching the progress on your coupe - love the Pontiac

Edited August 6, 2019 by Muncie

[Ace-Garageguy]

Here's a little vid for inspiration. Though the specific clips aren't dated, I'd opine they're from about '65-'68. There's a '37 Chevy that sits just slightly nose-high at rest, but when it launches, it's easy to see the nose come up under hard acceleration. Generally note the level or slightly-nose-high stance of the cars at rest. Sky-high noses were never the norm. And pay attention to the angle the rocker panels make with the ground. I think people get confused when they see the front fenders sitting high over the smaller front tires, but don't realize somehow that the rear of the cars are raised to clear big slicks, and the cars are high, but basically level at rest...not stupid-nose-high. And you can definitely see a trend towards slight nose-down static attitudes as the wrinkle-wall slicks Muncie mentioned came into play, and trap speeds were high enough to make nose-high cars virtually undrivable at the end of a run. Cars with the rear slicks extending well outside the rear fenders would be '67 and later, according to the NHRA rulebooks.

 

Edited August 6, 2019 by Ace-Garageguy

[espo]

3 hours ago, Ace-Garageguy said:

Here's a little vid for inspiration. Though the specific clips aren't dated, I'd opine they're from about '65-'68. There's a '37 Chevy that sits just slightly nose-high at rest, but when it launches, it's easy to see the nose come up under hard acceleration. Generally note the level or slightly-nose-high stance of the cars at rest. Sky-high noses were never the norm. And pay attention to the angle the rocker panels make with the ground. I think people get confused when they see the front fenders sitting high over the smaller front tires, but don't realize somehow that the rear of the cars are raised to clear big slicks, and the cars are high, but basically level at rest...not stupid-nose-high. And you can definitely see a trend towards slight nose-down static attitudes as the wrinkle-wall slicks Muncie mentioned came into play, and trap speeds were high enough to make nose-high cars virtually undrivable at the end of a run. Cars with the rear slicks extending well outside the rear fenders would be '67 and later, according to the NHRA rulebooks.

 

Great link. I really enjoyed the music also. Nothing like Booker T & the MG's , Hip Hugger and Green Onions were my favorites.   

[dusty_shelf]

Just received the Revell 421 SD Parts Paks motor and accessories.  All I can say is it is BLAH_BLAH_BLAH_BLAH!  Incomplete injection on several parts; sink marks; flashing; and excessive chrome plating.  I removed the chrome using bleach and was further surprised to see the poor quality plastic used.  It looks like the transparent plastic used in glow-in-the-dark kits and even has a yellow/green tint to it.  I will be lucky if I can use any of the parts.  Live and learn.

I have the gasser video bookmarked as well and will reference it often.  As some of you members pointed out, the high nose was NOT the norm.  When you consider the larger rear wheels and the lift needed to clear the wheel wells and fenders, and the much smaller wheels up front, it does give the illusion of a high nose.  Looking at how close to parallel the rocker panels are to the ground tells the story.

[Snake45]

I used to work with a guy who had crewed on a Willys gasser in the '60s. I asked him once if they sat so high for "weight transfer," and he told me, "Naw, it was mainly so we could crawl around underneath 'em and work on 'em between rounds if we had to without having to jack 'em up." 

[Ace-Garageguy]

3 hours ago, dusty_shelf said:

Just received the Revell 421 SD Parts Paks motor and accessories.  All I can say is it is BLAH_BLAH_BLAH_BLAH!  Incomplete injection on several parts; sink marks; flashing; and excessive chrome plating.  I removed the chrome using bleach and was further surprised to see the poor quality plastic used.  It looks like the transparent plastic used in glow-in-the-dark kits and even has a yellow/green tint to it.  I will be lucky if I can use any of the parts.  Live and learn...

Sorry to hear that. I have a bunch of those that are just fine, but another bunch that were short-shotted with bad sinks like you describe. It's a crappshoot if you'll get a good one or not, as the reissues in the yellow packaging had very spotty quality.

There's another Pontiac, a nice one, in the vintage AMT parts-pack #8158.  There are 4 engines in the 8158 kit...the Poncho, a Chrysler FirePower 392 hemi, a Corvair, and a front-blown smallblock Chebby, plus custom bumpers and grilles, and the engines are not plated.

https://www.ebay.com/itm/AMT-ERTL-1-25-BLUEPRINTER-PARTS-PACK-MODEL-KIT-8158-1993-NOS-VINTAGE/202749858390?epid=1600605512&hash=item2f34d55256:g:d84AAOSwV7NdECqU

Edited August 6, 2019 by Ace-Garageguy