Editor’s Note: This article about the powerplant is just one installment of our El Cheapo street rod build. To see the rest of the articles, click here.
Next up on our $1500.00 rat rod build is marrying the motor and tranny up to the roller we’ve created.
I never go to the trouble, and all the work, of setting up a motor and tranny just to see if I might like it. Oh no! For this reason, picking out the right drive train is like picking out the right woman. Sure, I can pick out one that’s hot and looks good only to be left high and dry. In the case of rat rods or low budget old school rods, it’s even more so. When you’re on a $1,500.00 budget for the entire rod to be completed with, the motor issue becomes a real quest. You can’t go more than five or six hundred at most for a drive train and hope to stay within that budget.
Many people could teach you more than I could about building a hot rod, but few could teach you how to do it cheap. Remember the overall goal: we’re building a super cheap hot rod. Where do you start in finding a motor and transmission both for $500.00? Here is a list some ideas on how to make that happen:
- Watch Craiglist for parts cars or untitled vehicles. You don’t care whether it has a title or not because once you pull the drive train out, you’re either going to sell it piece by piece, or sell it to the crusher as weight for a little extra cash returned back to the budget.
- Check companys with Fleet vehicles. When the older units start to nickel and dime them to death, they will part with those vehicles quick and usually cheap. Old police cars and government vehicles work the same way.
- Insurance totals are yet another avenue for a cheap drive train.
- I have also scored big at recycle yards with cars that are ready to be crushed. The guys on the yard know whether or not the motor is good because they talk to whoever brought it and find out why they brought it.
- Swap meets tend to be high at least in the mornings, but by late afternoon when they’re packing up and the seller knows he has to drag whatever it is home. That’s when they change their tune. I’ve bought older small block Chevy motors for 4 and 5 hundred dollars that way as well.
- Probably the best method I’ve found so far is the market place on Facebook. It seems the most “motivated sellers” post there. I watch the price start to drop after a week or so and most will come down even lower after a conversation. It’s not uncommon to find older Chevy, Ford or Mopar motors in the price range we’re talking about.
However, the most important thing I can tell you about motor and tranny picking is: never buy without hearing the engine run. People in this day and age will look you straight in the eye (while smiling and talking about church) and give you the worst screwing of your life.
In most of the cases of acquiring an engine that we’ve talked about above, it’s as simple as making sure you carry a hot battery with you. If the motor is out of the vehicle you can still make it happen. Just run the positive starter cable to your battery and ground the other side. Aligator clip a wire for the positive post to the ignition side of the distributer and another to the start terminal of the starter and you’re in business.
Along with a hot battery, carry a can of gas. A little priming and you can hear it run long enough to see if its any good. If you buy a motor without the transmission attached and determine to add the transmission later, be sure to rotate the torque converter to see it’s locked in before installing.This works best when shaft is in flex plate and close to motor. Reach under and rotate and you will feel it lock in. Attach the torque converter from underneath to the flex plate.
The reason I go into this song and dance is because if you connect the two without this move it will knock out the front pump in the transmission. Another reason is because with most hot rods you won’t have room to install a tranny after the fact. It will be a super tight fit to say the least.
Now for the fun part! With motor and trans on your hoist or cherry picker, it’s the right time to install the engine mounts and a transmission mount. How these will mount to the frame is unknown until you have it in the hotrod to see where it’s going to sit. Once you hoist it in, this will become clear to you right away. A motor sitting in the cradle can look dwarfed if you sit it low. Another factor to think about in a super-slammed rod is the fact you need to set the total pinion angle of the drivetrain. The big focus for me is to be within six-degrees between the tranny tail shaft and to the rear end. If you set the motor and trans low, it will be hard to get a safe pinion angle. An excessive offset angle from the transmission output shaft and the rearend’s input pinion will wear out components lightning fast.
Once your drive train is in place where you want it, you can measure to see what length brackets you will need to go from the motor to the frame. I have found a piece of 2-inch x 3-inch x 1/8th inch wall thickness tubing works great. We cut them at 8-inches with a square cut on one end, and a 45-degree cut on the other. The square end welds to the factory motor mounts and the 45-degree cut welds to the frame. This gives you plenty of height on the motor and a disconnect at the motor mount itself in case you ever need to pull it. Before welding these in, check with a level from valve cover to valve cover and from back to front. Also run a straight edge with a level sitting on it from the tranny to the rear end. A degree finder would be better to make sure you end up with a maximum of 6 degrees. In the case you don’t have a degree finder, a level will work and you can still check your pinion angle.
A half of a bubble on a 4-foot level is 3-degrees, so you can get pretty close like that. Another reason for the straight edge is to make sure the transmission is in line with the rear end. Not only up and down but also side to side. The back of the tranny will need to be sitting on a jack so you can adjust as needed and to hold it up until you can weld supports from side to side of the frame. This connection will need a tab welded in the center to mount to the transmission mount we talked about earlier. This will also need holes for bolts and nuts in case the tranny ever needs to come out.
Once test fitted on both motor and transmission, the perminant welds can be made to secure all of these connections. Next we move to the driveshaft. You will find that a small mom and pop shop or a small job shop will be much cheaper when getting a driveshaft made or altered. We have a shop that does nothing but driveshafts, but they charge $250.00 to do just one. I drive to a small town near us, about 30 miles away and get it done for $50.00.
Either way you will need the measurement from yoke to yoke if you have these. It’s always good to be sure when buying a transmission to get them to throw in the yoke that goes with it. Same goes for rear ends. Be sure to observe how far the yoke goes up into the tail shaft. It is a slip-fit type joint. Leave 3/4-inch clearance (or more) for those hard to get to hotrods. You will need that to be able to take it in and out easily.
In the next episode will be about cooling and the best way to make that happen – and of course the cheapest way to make that happen – Until next time, happy hot rodding! For more info check us out at ringrods-hotrods.com.