Re: XD3P or MDI Motor for Mahindra CL / CJ340 Finally, I made up my mind on a MDI engine for my CL340.
It was a tough decision and took me a couple of months to reconcile all the facts.
Let’s start with what were my choices. Option 1: Resurrect the existing stock XDP 4.90 by overhauling it with new sleeves and rings.
From my past experience, XDP 4.90 in the CL340 with the stock 5.375 axel ratio has good amount of torque when it comes to hard surface climbs. It has great engine braking on declines of any gradient or surface type. However, on sand/soft surface climbs, where you need momentum, the XDP 4.90 is a non-performer. It needs a good run up (on 3rd gear) to get the speed and start the climb. While you are near the summit of the climb, there is a good chance of being out of power, requiring you to shift to a lower gear. This would result in loss of momentum and the wheels would sink into the sand/soft surface.
Overhauling my stock XDP would have costed me about Rs.20,000 including labour and parts. Most natural trails in Gurgaon/NCR are sandy trails. The XDP 4.90 was always at a disadvantage in these trails. Though overhauling is the most cost effective option, it would be a compromise when it comes to offroadability in NCR. Moreover after the overhaul, if I keep pushing the engine, there is a good chance of it breaking down again. Option 2: Replace my engine with the legendary XD3P salvaged from military scraps.
Since, new/less used XD3P are rare to find, I will have to salvage the engine from military disposals and overhaul it. There is a cult that swears by the XD3P. This 72 BHP engine is known for its ruggedness and durability and has got everything you need to offroad in the Gurgaon/NCR terrains. It is smooth and refined, weighs slightly more than an XDP 4.90, has good engine braking and is a near perfect fit on the CL340. To make things better you don’t need to change the crown/pinion (You can continue with the stock CL340 axel ratio of 5.375).
The engine will cost me about Rs.15,000-18,000 in salvage condition. I will have to spend about Rs.20,000 on the overhaul including the parts and the transplant labor would be about Rs.7,000. All in all, about Rs.43,000-45,000. Overhauling a XD3P needs skill. There is no guarantee that the engine would be perfect after the overhaul. However, the XD3P is notorious for its overheating problem. In the Delhi summers, this would only add to the misery. Option 3: The MDI
Some say ‘MDI is what the doctor prescribed for offroading’. This 63 BHP engine is very reliable and built on technology of 1990’s (unlike XD3P which is of 70’s vintage technology). It isvery low on maintenance and is known to deliver a good mileage (not that you are bothered when you use it only for offroading). Add to that, the good low end torque, which is a must for sandy climbs.
A 2-3 year old engine would cost about Rs.65,000 with the turbo charger. (The source of this engine is always questionable. Let’s not start a debate on that). With the new engine, the crown pinion will have to be changed to an axel ratio of 4.27 (or 4.88) which shall cost about Rs.5,000. Others sundries - assembly parts including, new mountings will cost Rs.5,000-6,000 and labour of about Rs.10,000. All in all, about Rs.85,000!
Now the tough question, what to choose from the 3 options.
The “restorer” in me always wanted to keep the vehicle as original/stock as possible. Since, I use the vehicle exclusively for offroading, living with the resurrected XDP 4.9, would be big compromise. Hence, the option of overhauling the stock XDP 4.9 is out. Moreover, I would be able to sell the XDP as scrap for about Rs.8,000 and part fund the new engine.
Which left me with 2 opinions, XD3P or the MDI.
I tested both engines (MDI and XD3P on a short wheel base vehicles) on similar terrains. On sand climbs, both the engines performed quite well and were able to negotiate all types of climbs with ease (my stock XDP 4.90 would have struggled on these climbs).
However, MDI was the winner when it came to stop and start on a sand climb. While at the middle of a soft surface climb, I had to stop, realign and start again, the XD3P found it difficult to generate momentum from the start position. I had to reverse a few feet and build momentum to clear the remaining obstacle. The MDI on the same obstacle had no such challenge and took off from where I had to stop. If you go back to comparing the tech specs, the MDI has a very good low end torque when compared with the XD3P. On sand, what you need is low end torque.
When it came to declines, the XD3P was well behaved than the MDI. The reason could also be attributed to the fact that both vehicles had different axel ratios. XD3P had 4.88 and the MDI had 4.27. However, it’s a known fact that the MDI has less engine braking than the XD3P.
On the high way, the XD3Ps showed who is the boss. It delivers 72 BHP as compared to 63 BHP of MDI. I know of people who claim that their XD3P can go up to 150 kms per hour. While offroading you don’t need such speeds nor do these vehicles have the brakes to manage such speeds.
When it comes to maintenance, the MDI is said to be maintenance free as compared to the XD3P. The overhauled XD3P has an ‘OTR Only’ life expectancy of about 10,000-15,000kms. No guarantee that it will not have mid-term breakdown. Where as a MDI can be trouble-free for the next 60,000kms (assuming I get a 2010 or 2011 engine).
Being a modern engine, MDI has integrated provisions for creature comforts like power clutch. Though my CL340 never had a power clutch, power breaks or power steering, I have always longed for these comforts.
I finally made up my mind. MDI made more sense. I don’t have the time to spend on supervising the overhaul nor do I have the time to spend on regular mechanic visits. What I need is an OTR ready engine which is maintenance free, has a good low end torque and can last me the next 5 years. The extra Rs.35,000 on the MDI would be worth it! |