How to Build a Cheap Hot Rod Rat Rod

By Driverinmyhead

So you've been to the car shows and maybe even seen a cool early Hot Rod on the streets.....and you are BITTEN by the bug! Now What?

Instructions

Difficulty: Moderately Challenging

 

Things You’ll Need:

Step1

First, Be honest with yourself. Are you handy? Can you wield a wrench? Yes, I said WEILD! Secondly, do you have a space to work? Finally.... what about cash? If you are low on bucks... no problem. We can fix that. If you aren't handy, take a college class or local course on basic mechanics, welding and fabrication. If you don't have a place to work, you will need one.

 

Step2

If you CAN work on cars and DO have a place to work and at least SOME cash... we can begin. First, we need a frame. Go through the classifieds, online message boards and local clubs. Also Junk yards and scouting out rural areas works. ANY old frame will work, but ideally you want something from the 30's or older. As straight and rust free as you can find. If you can't find one... a local steel supply will work. Rectangular 2x4 steel tubing makes a NICE early frame. Buy around 16-20 feet of it. You can have them cut it into 2 lengths of 8 or 10 feet. Most old cars from the 20's and 30's were on a wheelbase of 90 to 110 feet, so plan accordingly. You will need welding skills or have it welded together. It will need to be welded together like a ladder. Perfectly square and level. One cross member at the front, maybe 2 or so in the middle (an x is best) and one in the back. Width depends on the body, so plan ahead! A flat ladder over two axles will ride high like a 4x4.. so a "kick-up" in the back is necessary. It looks like a "Z" when the frame is laid on it's side. That way the frame under the body is lower than the frame over the axle.

 

Step3

Next, you will need axles. Front and rear. Measure your rear width or rear body width. The axle can be wider than the frame (should be). Any old rear end will work, but stuff from the late 50's through late 70's is best. Looks are secondary and bolt pattern of the wheels is important if you want to run nice custom rims. A Leaf Spring rear axle is best.. easier to modify. But it depends on price. The rear-end will need a spring. Coil springs, coil over shocks and leaf springs are easiest. Leaf springs can be transverse (from side to side of the tires) or parallel. Parallel will require the frame to be low again behind the axle. Coils and coil over shocks are easiest so we will concentrate on them. Weld upper cups or mounts on the rear cross member (ladder rung) and lower mounts or cups to the axle housing. Locate the axle with radius rods, torsion bars, ladder bars or a split wishbone (early cars had a triangular link called wish-bones). The front axle can be a straight axle or independent suspension., A straight axle is cheapest... and can come from another old car or be purchased new. Independent suspension is a better design, but requires more welding and mechanical know how. Popular types are Mustang II/ Pinto, AMC Pacer and Corvair. A straight axle uses an axle, parallel or transverse leaf spring(s) spindles that pivot and Hairpin rod, wishbone or a 4 link system. Most of these items are available new.. and at least the exploded view will give you a pattern for using old parts. The cheapest way is to buy a late 40's, early 50's chevy or Ford pick up. This will give you a front end that is straight axle, with most parts needed. The cab and frame are a bonus and can also be used. At this point.. once welded together and designed by you... it is a rolling chassis.

 

Step4

Now it's time for a body. Are you LUCKY? Do you have a body or a line on one? If not... fiberglass is forgiving, lightweight and CHEAP. Making your own is an option... but the cheapest BY FAR... is an old pick up truck cab. For FUN... you can practice chopping the top before you cut it off for good! You can carve up the pick up body until it resembles and old bucket roadster. Mount it on your frame using common sense.... and it's almost there! Wahhhh Hoo! This will allow you to use doors that open, the dash, etc.

 

Step5

It LOOKS like a Hot Rod... but won't move under it's own power. Time for a drive train. Engine is as Engine does. Pick anything. But choose wisely. Maybe a 396 Chevy Big Block, Chrysler Hemi or Ford 351 Sounds good... but it could blow all of your budget and THEN some. If you already have the block and heads or it's worn out... consider selling it to finance a runner. The old chevy 350, ford 302 and Mopar 318, 340 and 360 are all common and cheap! A small 4 banger will scoot that little roller skate around too. You are building a GLORIFIED Go-Cart..... big Blocks aren't necessary and furthermore... might rip the car apart! Go cheap and running well. Mount it (hopefully with good trans) over the front of the frame. Measure and weld in motor mounts. A cradle mount works well... or side mounts are best. You will need a driveshaft.... they can be cut down easily (I don't recommend doing it yourself). WOW!

 

Step6

It LOOKS like it will run. Might even start! Now it's safety time. Safety for the car and you. You will need wiring, basic yes. You also need a radiator, Brakes, Lights and guages. You need steering from the box to the linkage and a steering column with wheel. You need to get the BEAST running and hook up brake and gas pedals. Safety for you...... well that's UP TO YOU. You NEED a seat, your SHOULD HAVE seat belts. Get it?

 

Step7

Make an assessment of everything. Condition of the brakes, and whether they actually work. So on and so forth through the entire vehicle. Check all systems and take her for a test spin. The very BEST idea is a truck and trailer. Borrowed, or yours. Take the car to a HUGE parking lot or out in the middle of nowhere. Try it out. Take it easy and see if she boils over, if she leaks, won't stop, won't start, etc. If she passes the maiden voyage... 'TIL DEATH DO YOU PART! GOOD LUCK.