|Great Rover Rebuild of 2002
In The Beginning
Soon after getting the Series IIa on the road it became apparent that the vehicle had a serious lack of power climbing highway grades. The highway from Pearl City to Mililani on the H-3 is a 55mph zone that the Rover struggled to climb at 35mph. It was able to cruise 55-60 mph on the flats, but it just had no oomph going uphill. I also had a real bad hesitation. From an idle or low cruise if I put the pedal to the floor it would almost stall. So pulling away from a light or working through the gears trying to accelerate on a highway onramp could be a real problem. I was averaging 6-8mpg. On the plus side, other then the hesitation I didn’t have any problems offroading.
I started going over all the basics of the Rover 2.25l engine. The PO had installed a Weber 1bbl carb, but every thing else was stock. I had a leaded 8:1 head, Lucas 25d dizzy, and stock coil. I ran hi-octane petrol. My compression was 125-130 in all cylinders. It was low for the 8:1 head, but at least it was even across all four. The dizzy was loose, but no real wobble or warping in the shaft. The weight springs seemed week also.
Mark I Mods:
So the first thing I did was to contact Mini-Mania and order a new 25d dizzy. At the same time I talked to Bill at Great Basin Rovers and ordered a Petronix ignition and a high voltage sport coil. I ordered a new genuine cap and rotor from Rovers North and went to a local parts supplier and got an Accell 8mm wire kit. The wire kit came with boots, ends and 3-foot sections of wire. You cut them to length and attach the ends. I installed all the new components, adjusted the timing, and started fiddling with the carb adjustments. This resulted in a smoother running engine, and the mileage increased to around 10mpg. But I had no improvement in the hill climb or the hesitation.
Mark II Mods:
I decided to do some major work to the engine. I asked questions on the LRO and Mendo email lists, read the Rovers North and Aardvarks Guns and Rovers BBSes, spoke to fellow Rover owners, and researched all the different ‘performance’ web sites I could find. I decided to get an ACR Stage I head and cam, Weber 32/36 DVG carb with K&N filter, Pierce 2 bbl intake, Clifford exhaust header, 2” exhaust, Flowmaster muffler, and new genuine followers, lifters and timing components.
I spent a weekend doing the over haul. It was a pretty straightforward procedure. After getting everything set up it was time to road test. My test climb to Mililani I could do at 49mph. Mile mileage got to around 11-12mpg. The real improvement came in the flats, she would accelerate and easily handle 75mph. But the hesitation was still there and it was running way too rich. I started fiddling around with the jetting on the Weber. But no matter what I did, I couldn’t get it leaned out.
September rolled around and it was time to ship the Rover to Seattle. We took leave en-route during the move, so didn’t arrive ourselves until October 15th. We picked up the Rover in Seattle and I drove her around to Bremerton. The highway from Tacoma to Bremerton is 20 miles of rolling hills and mostly a 60mph zone. A couple of these hills were so steep that the rover was only able to hit 40-45mph climbing them. The National Guard unit in Washington that I joined sometimes drills at Yakima Firing Center, which is east of the Cascade Range. After leaving Seattle heading east on I-90 I climb from sea level to 3000 feet in 25 miles. The last 4 miles before the pass is a climb of 1200 feet. This is all in a 65mph zone. The Rover was straining in 3rd gear and 30mph to get through the pass.
A fellow member of the LRO email list let me borrow a CO analyzer. I used this and a large assortment of Weber jets from Pierce and was finally able to get the carb running correctly. Mileage reached 15mpg, but still couldn’t climb hills at speed. Hesitation was better, but still there and noticeable.
Mark III Mods:
I had to decide what I wanted to do next. With the exception of the low compression, every system with the engine was in top notch condition. I was not interested in building a 100mph Series Rover, but I did want to have the ability to drive 60-65mph. I also wanted to keep the off road ability of the stock machine. I was still running stock 4.7 gears and had a Fairey overdrive. The gearing was there, but the engine just couldn’t pull overdrive. So I started looking at all of my options.
1. Get a 2.5l 5 bearing short block and install all of my ACR components. This would have been the easiest by far to accomplish, but I wasn’t sure it would be enough. I would hate to spend the time doing the work and be hardly any better off then I was.
2. Get a 2.5l td, 200tdi, or 300tdi diesel. I really liked the idea of doing a diesel conversion. The low-end torque would allow me to swap to 4.1 gears with out having to worry too much about off road-ability, would be able to better pull on the hills, and provide better fuel milage. Plus I think diesels are just plain cool. Problem is the availability in the US, especially the Tdi’s. Options 1 and 2 would allow for a pretty straight forward swap. I would be sticking with Rover parts, and there is a large experience base for doing these swaps.
3. Get a GM Iron Duke or Rob Davis Cross Flow.
4. Get a GM straight 6.
5. Get a GM 4.3 vortec v-6.
6. Get a GM small block.
7. Get a GM 6.2 or 6.5 diesel.
I was looking at GM engines because I am familiar with working on them and I felt they were more common as far as engine availability, stock parts, and after market support. Plus Scotty’s Adapter makes a plate that will allow a Series tranny to bolt up to a GM engine. The four cylinders would make an easy swap also, with the Rob Davis engine being the better option. I have spoken with the owner of a IIa 109 ambulance that has done this conversion and he raves about the available power. It is a pretty expensive option though.
There are people that are using the 6 and 8 cylinder engines with the Series transmission and transfer case, but I was really worried about breaking something. So I started looking at using a different tranny and t-case. The Dana 18 transfer case has a right hand offset front and rear drive shaft similar to the Rover case. The Dana 18 was used in 1947-71 Jeeps and 1960’s International Scouts. Advance Adapters and Novak Adapters make adapter plates that will mount the Dana 18 to a variety of GM transmission. In the Jeep community, a small block and GM tranny, mated to a Dana 18 is a pretty common setup. Warn used to build an overdrive for the Dana 18 and they are still available used. Advanced Adapters purchased the tooling and rights to the OD and are still making them new. The transfer case and overdrive are reportedly able to handle 300+ horsepower. Parts are still available for the t-case. This really seemed to be the way to go. Now to decide upon the engine. I felt that based on overall length a straight six was not an option. I wanted a diesel, but they were outrageously expensive rebuilt and I couldn’t find one used anywhere. So the 4.3l or small block? A friend did a 4.3l swap into a Jeep Scrambler. He used the 700R4 tranny mated to a Dana 300, but it was a very nice conversion. Edelbrock makes a 4bbl intake and there are tons of carbs, cams, ignitions, and headers for them. They have a great power curve, good fuel economy, and could be found in a wide variety of GM vehicles. With this and the size of the engine I really felt that it would be the perfect engine for the 88.
Then one day I found out that Navy Scrap in Bremerton had a scale and only charged $5 to weigh a vehicle. With the roll bar, soft-top, front bumper, winch, spare tire, half tank of fuel, and no driver on board she tipped the scales at 3980lbs. This is about 1000lbs over stock. Add in my weight, the tools that I normally carry, and any other gear it’s no wonder she couldn’t get out of her own way going up hill. Hmmm, maybe I needed to go v-8 after all. I was talking about this with some people when a friend offered me a 327. Well, the decision was pretty much made for me.
So I started the search for a SM465 transmission and Dana 18 transfer case. I located the transmission down in Oregon and a Dana 18 in Pennsylvania. I went down and picked up the tranny and sent the money to have the t-case shipped. I started doing internet searches to see if I could find a used overdrive. I stumbled upon one site that had a 1984 ¾ ton GMC pickup with a 6.2 diesel and they were only asking $1000. I called the phone number immediately. The vehicle only had 100k miles on it, ran strong, but the body was rough. The owner basically just wanted to get rid of the vehicle and didn’t realize that the engine alone was worth 1500-2k. I spent that night re-evaluating my engine choices. I made up my mind, I wanted a diesel. So the next weekend, I drove back down to Oregon to tow the GMC home.
After getting back home I drove the vehicle around a bit to check out all the rest of the systems. Power brakes, power steering, and charging system where all working properly. The clutch on the AC compressor was shot, but everything else was looking good. This meant that I was able to get a whole bunch of auxiliary systems that I would need for the swap and the engine, all for less then the cost of a new or rebuilt engine.