(By Loren Krussow) – Among those projects that we keep around but don’t make much steady progress on are a couple that are serious back-burner dwellers. They either have little pressing need for completion or are on the more creative side where there is a new challenge or thing to invent at each turn, and we’d go nuts if we tried to do it on a schedule. The cheapo mid-engine car conversion is one of the latter.
We’re not talking about taking a motor out of the front and putting it in the rear for improved handling sports-car style, rather just a good ol’ juvenile Little Red Wagon-type, let’s-do-a-wheelie drag exhibition car. Admit it, you’ve thought about it. Maybe when you were 13, but still. We all know that if you really want to launch a car with the wheels in the air (and perhaps one shouldn’t) all you need is power and traction, but isn’t it fun to look at something different like an old Wild Bill Shrewsberry creation? I bet it would be even more fun to drive on the street to cruises and rod runs, whatever, if it could be made streetable.
Half of the bench-race sessions I’ve ever been in where mid-engine conversions were discussed have some guy holding a beer pitching the plan, “Just find an old mid-engine Pantera, get its transaxle…” and that would almost make sense for a sports car.While Panteras and their mid-mount drivelines are rare, various styles of the neat, compact trans-and-diff in a single unit called the transaxle are available used (such as from a Corvair) or new from a number of manufacturers, including those developed as offshoots of the sand car scene which can be “flipped” for either rear- or mid-engine use. All are for independent suspension only and not meant for drag cars.Priced from around $8,000 for the uncommon used Ford GT Ricardo unit to the mid-teens and up for a new aftermarket Mendeola, the V8-intended units are all way too expensive for me…and don’t quite fit the vibe I’m going for here.
The Olds Toronado V8/front drive automatic transaxle is another oft-mentioned possibility that has the attraction of low cost. These units orient the engine in the normal front-back position and use a heavy chain to connect to the transmission and differential which is placed alongside. These are questionable for HD use, put the engine too far back for my needs, and result in a wide package. Fitting big tires under fenders requires severe narrowing of the independent axle shafts. I’ve seen axles taken down to less than six inches long, and following a vehicle so-equipped on a highway one night I observed it to be nearly undrivable at speeds over 50 mph. Not for me.
While the original Little Red Wagon placed the engine against the pickup cab and connected the transmission output directly to the diff yoke in the style of contemporary slingshot dragsters, other drag exhibition cars have put the motor further back and up where it can be seen easier and used
what’s called a V-drive.
The engine gets mounted backwards, wherever the builder chooses to put it as long as it’s high enough to clear the rear axle. A driveshaft runs toward the front of the car and into a simple two-gear box of the style used in rear-engine prop-drive boats (and still available from Casale). A second driveshaft runs rearward at a slight angle to the first, back to a rear live-axle which can be suspended conventionally. Off-road racing vehicles may also use this setup where unusual engine placements may be necessary for a proper flight-though-the-air center of gravity, so we imagine they are a tough unit.Cost is again a factor (if less so), plus the need for two driveshafts running through the middle of the car. It’s not quite what I’m looking for, but close.
I once spoke with a couple of good friends who happen to be competent fabricators (Ron and Ray Weaver) and with my financial requirements it was suggested I obtain a portion of the driveline from a heavy-duty 4×4 truck. The engine would be mounted ahead of the rear axle, a driveshaft would run to a transfer case at the back of the car, then another forward to the front axle from the 4×4, now used as a rear. The transfer case would use no rear output. I have an old Dana 60 front end acquired partly with that thought in mind but discovered that size-wise there were some problems with the differential case shape. Dana 60s are really big.
After much additional thought and the production of a small pile of painstakingly designed-and-machined parts which didn’t work, I have come upon the following usable (I hope) plan which is similar but a little more elegant.
A normal manual transmission (in this case an A-833 four-speed from an ‘80s Chevy truck) and 9-inch Ford rearend are positioned to be as close as possible to each other to minimize engine height and the distance between crankshaft and mainshaft centerlines. The trans is mounted upside-down for that reason, and the differential is also inverted for proper rotation and to get the pinion up. The engine ends up a bit forward from the axle where it should help provide reasonable street balance. The transmission will send power via a driveshaft to a fabricated parallel gear box built using old truck transmission parts and mounted at the rear of the car, where from a second counter-rotating shaft goes forward to the suspended live axle. All these upside-down components will require a pressure-oiling system to reach gears and bearings that are now high-and-dry, with sump levels set below any shaft seals via outflow ports which will drain to a separate reservoir.
The photo shows some very dirty old parts including a junkyard-sourced Lakewood steel bellhousing modified for the new trans orientation and its’ proximity to the rear axle, as viewed from above at the rear. This results in a pretty tight setup which should someday fit nicely in the bed of a sixties-era El Camino. Picture big-block power with EFI Hillborn injection and drag-boat-style exhaust headers, and likely 15” Cragars.
There are still plenty of challenges to face in this on-again/off-again project but it’s satisfying some old urges and getting simpler all the time. Anybody else have an idea for a car build that they would like to do, but perhaps would be better-advised not to? I’d say, think about it some more. You might not want to get old wondering what may have happened if you’d tried it and succeeded.
