Street Stock Chassis Build up

Jim Ott

 

In this article I plan to explain all the things I feel necessary that are required to do to build a safe reliable and competitive car to race in the Hobby or Street Stock Division. Most of these principles can be applied to just about any class using a stock type chassis.

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First and foremost you need to acquire a decent sound body and frame. For this article we will be building a street stock type car using a 1985 Oldsmobile Cutlass. In case you are unfamiliar with this type of car, it is what is referred to as a GM “G –body” or the “Metric” chassis. There are other models that GM offered with the same platform, such as the Chevy Monte Carlo, Buick Regal, Pontiac Grand-Prix, Chevy Malibu, Pontiac Lemans, and even the El-Camino were built on the “G-body” chassis from 1978 until 1988 depending on the model. Although these cars are getting somewhat scarce I have had little trouble finding no less than six prospective cars in the last six months of which I bought all of them and resold one. I paid no more than $180.00 for any of them, so they are out there and you can get them cheap. As a side note you can probably forget going to the auto wrecking yard or your local “you pull it” as they likely won’t have any, but it might not hurt to call ahead anyway. We located ours by posting wanted ads on the internet but there maybe local buy and sell newspapers you can try. What ever car you end up with there maybe a secondary market for the parts you do not use and eBay is the place to try to sell them.

 

When you get your new “gem” home the first thing you are going to need to do is to immediately start the process of stripping the car. The first problem area is the glass! Do you bash it out or go to the local auto glass shop and have the windows pulled? Your call but broken glass is a pain to clean up and is hazardous to you health. Once you get the glass dealt with it’s time to go nuts! Start with the seats, then the carpet and under padding junk. The dash board should be next along with all the interior panels and roof liner. For you folks that live in the northern part of the country, this is when you discover the nasty holes in the floors from road salt and winter driving!

 

After you have the inside gutted you can proceed to start dismantling the rest of the car. We chose to pull the front clip off of the vehicle before we removed the drive train. This makes everything allot easier when pulling the motor and transmission. Try to keep all of the fasteners in a box, tub, or big ole coffee can because depending on the rules at your track you may need to put some of this stuff back on your car. You did read the Rule Book for your track right? At this point it maybe more beneficial to look at removing the engine and transmission as lifting the body off with these items out of the way is clearly easier. The next thing to be disconnected is anything that ties the body to the frame such as the steering column, brake lines, parking brake cables and exhaust. After that you can remove the dozen or so body mount bolts and you should be ready to lift the body from the frame. We had access to a forklift so this was real easy, but if you have done a real good job of stripping your body out removing can be handled by a half dozen able bodied volunteers (this will require a few beers gratuity for each participant) and once the body is pulled you will probably call it a day. This will depend on how much beer your volunteers help you dispose of!

At this point you should now have an extremely messy shop with a greasy frame and a skeleton of body and loads of parts kicking around. This is the time to make note of any floor work or body work that your shell will need as well as any chassis repairs that are required. We chose to set the body aside and concentrate on the frame and chassis components as you can count on spending allot of time in this area. Our chassis had some twenty plus years of accumulated grease and oil stuck to it. Here is where the pressure washer comes in real handy to blast this mess off before you go any further. We used a hot water unit to really clean the frame as hot water can remove the factory rust proofing paint called E-coat. You are going to be surprised at all the things you discover! I was completely amazed any of the factory welds were holding up as they were absolutely hideous. Most of the welds showed signs of poor fusion due to porosity and there was bits of MIG wire everywhere. If you have ever been stabbed by a piece of .045 welding wire you will undoubtedly understand why it might be a good idea to go ahead and grind all of this junk off your frame.

The next step is a vital one to building a stout race car and in my mind should not be skipped. You are going to go over the chassis and re-weld every factory weld you can find. To do this we used a small arc welder (stick) using 3/32” 6013 electrodes. The reason for stick welding is that is more tolerant of impurities trapped in the substandard weld joints that were done at the factory. The 6013 will also not burn in too deep causing holes in the frame. I did try to use the MIG welder but this left behind some pretty poor results, and I was quite pleased with the quality of weld the 6013 left. We took the time at this point to fabricate and weld in some stiffening plates to reinforce the arches over the rear axle and to add rigidity to the area of the upper spring mounts. We also chopped off the tail end of the OEM frame rails and replaced it with 2”x4”x1/8” wall rectangular tubing. To do this first cap the stock frame rail with a piece of 1/8” plate where you cut it off. Now you have a decent point to attach the rectangle tubing to. REMEMBER check your rules to make sure this is allowed! Almost all of the welding was done in the flat position to yield a good strong weld joint so this is going to mean flipping the chassis and probably a couple of volunteers (and some beer!) to help with this chore. You can grind and blend your weld joints for a better appearance if you choose to do so as we did. By now you should have relatively clean frame with some nice looking welds and some nice looking reinforcements ready for paint. I might need to mention that we decided not to sandblast the frame as after pressure washing it didn’t look like it was going to be necessary. If you think it should by all means go ahead it can only give a better looking frame, although that money could be spent elsewhere.

For the paint we used tractor paint that we purchased from TSC as it is decent stuff and after some thinning sprays on nicely. It is also very cost effective (read cheap) and results in some pretty good looking paint jobs. Red oxide primer was used to cover the frame as a base coat before we apply the finish color. We are going to finish the frame in a light color as this will help to show damage from collisions on the track. The paint will usually crack were the steel underneath is bent giving you a nice visual indicator. Some people choose to powder coat their frames and roll cages, however it has been my experience that this might not be the best approach to covering your frame. Powder coating gives you fabulous results until the frame needs repairing. It can be tough to remove for weld prep and if any thing is left behind it will undoubtedly spoil your weld especially if you are going to use a MIG welder for frame or chassis repairs. It is also impossible to touch up and get good results, so for a street stocker I recommend enamel paint.

 

 

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 In the next Installment we will be looking at re-assembling the body to the frame and getting ready to install the precut and notched roll cage that was purchased from CSC Racing Products Inc. You can find their website at http://www.cscracing.com/