RUST BULLET AUTOMOTIVE



Feature Vehicle:
Bob Shaw's 1987 Dodge/Chevy V6 Raider

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Http://www.4x4wire.com/mitsubishi/projects/bob_shaw/ Short Cuts
April 2000
It looks "slightly modified", but Bob's Raider has something special under the hood!.

Several years ago while having work done on another vehicle (and driving a rental in the meantime), a 1987 Dodge Raider caught Bob Shaw's attention, so he bought it. Bob drove the Raider and used it offroad and found it to be a very good vehicle, if a bit underpowered with the automatic transmission. Then the Mitsubishi 2.6L 4 cyl in the Raider started "acting up": warped and cracked heads along with other common problems. Bob addressed the engine problems (new head, headers, cam, etc) but was still left with the problematic 2.6L. So he got a wild idea..........

With the help of his friend Mike Scott, Bob swapped a Chevy drivetrain into the Raider. Here's how he did it.


The Engine

Bob considered several options for the Raider, including a Chevy engine and transmission mated to the stock Mitsubishi transfer case via a custom output shaft. However, one of the issues with the Raider/Montero line is the 1.92:1 low range, which Bob deemed inadequate for continued trail use. He was fortunate enough to find a complete drivetrain in good condition from a 1989 S-15 Blazer (including transmission and transfer case). The engine is the 4.3 V6 Throttle Body Injection (TBI) model which produces 160 HP in stock form. In order to make this engine fit, Bob and Mike designed and fabricated new engine mounts for the frame, then seated the engine in the bay. They used the stock Chevy motor mounts, but had to flatten one ear so the mounts would sit flush on the Raider frame pads.



The Chevy V6 fits neatly in the Raider engine bay. It almost looks stock! A good fit with plenty of room to work, or add underhood accessories.

With the Chevy V6 wiring harness and ECU in place, Bob found other modifications necessary to make the swap work. These included an all-custom exhaust, two electric fans (12" each pulling air), a new electronic speedometer and tachometer, and a new DRAC (used to control the transmission and speedometer). Bob was able to retain the stock Mitsubishi radiator by modifying the lower outlet to fit the Chevy radiator hose, and he found a union to mate the stock Mitsubishi power steering lines to the Chevy lines off the new pump. To retain "most" of the stock air conditioning unit, Bob used the compressor on the Chevy engine, with Mitsubishi components completing the setup. Finally, a new fuel pump was mounted outside of the stock gas tank, and it was simply bolted to the frame rail.


....and the Drivetrain

Sitting behind the stock 4.3 V6 is GM's venerable 700R4 4-speed automatic transmission. This is a proven and durable unit which utilizes a lockup torque converter, and has a 3.08 1st gear ratio. The transfer case from the Chevy is the NP231CHD (Chevrolet Heavy Duty), and features a low-range reduction of 2.73:1. Bob used the stock transmission mounts, but with minor modification he relocated them to the transfer case. He then modified the transmission shift linkage, and with the help of a new bracket, the linkage was mounted to the transmission where the former mount was.

Bob fabricated a new gas tank skid plate out of heavy duty diamond plate to replace the lighter-duty stock unit.

Bob elected to swap out the Mitsubishi rear axle in favor of a 1985 Toyota rear axle with 4.56 gears and a Detroit Locker. Including the modifications to make this a spring-under axle (like the stock Mitsubishi setup), Bob invested less than the cost of an installed ARB in this rebuilt rear. When I gave him a puzzled look, Bob instinctively explained his reluctance to use an ARB due to reliability concerns: he preferred the positive, maintenance-free Detroit. The 85 Toyota rear axle is the last of the "narrow" axles, and the 86+ Toyota axles are 3" wider - placing them almost identical in width to the Mitsubishi axle. To compensate, Bob used wheels with less backspacing than the front to keep the track width consistent.

The rear axle ratio is numerically lower by 0.06 than the front ring and pinion, yet Bob has not had any problems with binding. Overall, the Raider has a 38:1 crawl ratio, which represents a significant improvement over the stock ratio.

All of this rides on 32x11.50" BFG MT's, with Superwinch manual hubs up front. The suspension has been tweaked with upgraded John Baker torsion bars in the front and rearched spring packs in rear for 2" of lift.

The engine/transmission/transfer case combination is 1" longer than stock. This necessitated a custom mount and crossmember for the transfer case, and the driveshafts both had to be shortened. Bob used a stout Chevy U-joint on the front of the rear driveshaft to mate up to the NP231.

The Interior

Inside, you'd be challenged to distinguish Bob's Raider from any stock Raider. The only visible signs to the astute eye are a transfer case shift lever moved rearward 6" and inboard 3", and the aforementioned speedometer and tach. A small hole for the transfer case lever had to be notched out of the floorboard to mate to the NP231 and allow the full range of motion. Everything else is stock, and it all works! Not being able to leave it alone, though, Bob designed a very sleek sliding mount in the rear cargo area for a toolbox, which makes access very straightforward; and he added cargo holds to the rear door for more functional storage space.

This looks like every other Raider... ...but the speedo, tach, and transfer case lever suggest this one's a bit different. Bob secured his toolbox on sliders bolted to the floor for easy access, and he added some unique cargo holds on the rear door.

So, what did it cost?

I had the opportunity to discuss the work and costs with Bob at length. He and Mike Scott worked at a rather leisurely pace, putting in only "short" weekends over a 3-month period: Bob said this could have been done much quicker had time been devoted to it daily. While working, they designed and fabricated all of the custom mounts, which also extended their time.

As previously mentioned, the completely rebuilt and Detroit-locked Toyota rear axle with new 4.56 gears cost less than buying and having an ARB installed. The entire engine-transmission-transfer case setup with wiring harness and ECM set Bob back $1500. Then he incurred the miscellaneous costs for the speedo, tach, and the materials for his custom mounts. The swap itself (excluding the rear axle) came in right under $2000 - Bob's total was right around $3000 for everything.


And how does it work?

Ok, maybe the "Heartbeat of America" sticker gives it away. Under the Ram hood ornament is a Bowtie, for good measure.

According to Bob, the Raider has not experienced any swap-related problems! He did have to replace the rear main seal, and he wishes he would have known about it before installing the engine: in fact, this is the only item Bob identified as a problem. He obviously gained a great deal of power over the stock 2.6L 4 cyl, but the biggest gain may well be in the gearing: whereas before Bob rode the brakes down hills to control the Raider, he can now idle or even gas the Raider to coax it to move while descending. Onroad, with the lockup torque converter and 4-speed Overdrive, Bob is getting around 20mpg. Following the Raider offroad, one notices how easily it traverses all terrain, with the power and gearing applied through the locked rear end affording more control than stock. So, it has the right combination for serious off-road work while remaining very streetable -- exactly how a conversion of this nature is supposed to work!

 


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