[jeepbug]

Originally Posted by mustag

I am continuing with the stock KMT-90 gear box and the T18 double lever transfer case. My existing clutch was changed a year earlier, hence did not require a replacement either.

The engine transplant job was done at Hukkum Singh’s workshop in Mayapuri. The total labour cost including replacement of crown pinion, transfer case & steering overhaul was Rs.10,000 and took 5 days to complete.



Like all repair work, the engine transplant too requires quite some follow up and supervision at the workshop. Since, Kapil was also getting his engine changed at Hukkum’s; he took over the responsibility of the follow up and supervision.

Thanks, Kapil Anand for all the help. This would not have been possible without you.

Hello Brother jeeper i am sailing in the same boat these days confused butween xd3p and mdi3200tc reading your post has definately made me go in for the 3200tc but i will be thankful to you if help me with the following questions.
How many days work is this swap at hukam singh workshop, he is recommended by harjeev many times.
Were any chassis strenghting recommended,? and what gear are you using .
how did it fare on the otr if you did one,

thanks.
regards to kapil anand

[mustag]

Originally Posted by jeepbug

Hello Brother jeeper i am sailing in the same boat these days confused butween xd3p and mdi3200tc reading your post has definately made me go in for the 3200tc but i will be thankful to you if help me with the following questions.
How many days work is this swap at hukam singh workshop, he is recommended by harjeev many times.
Were any chassis strenghting recommended,? and what gear are you using .
how did it fare on the otr if you did one,

thanks.
regards to kapil anand

I am quite happy with the MDI in terms of its offroad performamce. I am able to do climbs that I could only dream of with an XDP. The MDI and the XD3P are quite similar in terms of offroad performance. However, what you get with the MDI is a trouble free engine and some add on creature comforts.[/COLOR]

Hukkum Singh took about a week for the engine transplant. If you speak to people you would realize that there are enough admirers of Hukkum Singh and at the same time enough who despise him. I am quite happy with his work. His prices are quite reasonable and has been prompt in delivery (at least with me when I compare him with other Mayapuri mechanics).

The chassis did not require any reinforcement. However, new engine mountings (costing about Rs.700) had to be welded on the chassis to accommodate the new engine.

Regards,

Rahul

[mustag]

Originally Posted by desertfox

LEts see how your new engine performs, If there is an OTR this Sunday bring your Jeep we will go out to the Behrampur trail, I have not driven my MM550 for ages now looking forward to some slush and mud after all these rains.

Shahid,

These days, we have an OTR every weekend.

For the past couple of years, we have not been using the Behrampur trail since most of our members have outgrown it in terms of its challengers. The Bandwadi trail has enough challenges in terms of articulation. Badshapur offers a good challenges on sandy uphills.

Regards,

Rahul

[mustag]

Originally Posted by Samurai

I am running MDI with 4.88 and I can do 90 degree turns in 4th gear. So it is not a good thing. I am planning to change to 4.27 as a result. The DI with 4.88 is too much for offroading too. The obstacle that required 2nd low in XDP & 5.38, now I can do in 3rd low with DI & 4.88 ratio.

I can’t agree any better on the 4.88. I used have 5.38 as stock on the CL340. It’s a great ratio to crawl over declines. But quite useless if you are doing soft surface climbs. I am happy with the 4.27 that’s now matted with the MDI

Originally Posted by Samurai

BTW, you are driving a CJ340 powered with MDI engine, and still on drum brakes? Now that you have hanging pedals and brake booster, spend a little more and switch over to disk brakes.

I am still running on my stock drum brakes connected to the new boosters. However, I must confess, I am not happy with this brake arrangement. As of now the brake system has not stabilized after the engine transplant. Moreover, Drum brakes have an inherent problem of getting jammed each time they get into water. I intend to shift to disk brakes soon. Now that I have the brake boosters, I might need to spend about 9-10K for the disk brakes.

[dhanushs]

Originally Posted by Sutripta

I have a (unsubstantiated) theory as to why it is so, but would like others opinion on my observation first.

An old post, but, can you please shed some light on it?

[Sutripta]

^^^
First of all does anyone agree with my observation?

Regards
Sutripta

[dhanushs]

Originally Posted by Sutripta

^^^
First of all does anyone agree with my observation?

Regards
Sutripta

I agree. Also, I have somehow noticed that XDP to have slightly better torque @idling speeds. Taking off in 2nd gear in plain roads is easier in an XDP, where as while going up an incline, the XDP looses its breath long before the XD3 does. Would appreciate comments on the first part as well..

[Samurai]

Saw this just now.

Originally Posted by Sutripta

My take: The XD3 had far better torque compared to the XDP if the test was climbing ghat roads. In acceleration on level roads, there was hardly anything between them. Seems contradictory, doesn't it!?

No, it is not contradictory. Not if one understands torque.

Originally Posted by Samurai

Remember, torque is the minimum force required to make the wheel turn.

I said this 5 years back, and have repeated it many times. But I will elaborate a bit this time.

1) Hold a pen loosely in your hand. Ask a small kid to rotate it slowly. As you can imagine, she or he can do it easily. Let's say the kid required X amount of force to rotate the pen, so X is torque applied here (minimum force to rotate).

2) Now ask a normal adult male to rotate the same loosely held pen at the same speed. He too will rotate the pen, but won't be able to use more force than the kid since the pen will start rotating when same X amount of force is applied.

3) Now get the world's strongest man to rotate the pen at the same speed. He will obviously rotate the pen, but won't be able to use more force than the kid or the normal adult male since the pen will start rotating when same X amount of force is applied.

In other words, the torque required to rotate the loosely held pen remains the same no matter which person turns it. That means, on a level road XDP and DI will use the same amount of torque to turn the wheels. The additional torque available with DI won't come into play at all.

Now hold the pen tighter:

1) The kid won't be able to turn the pen at all. The kid doesn't have the force required to turn the pen. Not enough torque.

2) The adult male is able to turn with some difficulty. Call this minimum force required to turn as Y.

3) The world's strongest man can still turn it easily, he can easily deliver force Y.

As the force required to turn the wheel increases, the additional torque comes into play. That is why DI does better than XDP in climbs or while pulling heavy loads.

There is another way to look at it, from the traction point of view. Smoother/slippery surfaces offer less traction, rough/harsh surfaces offer more traction. If your apply more force than necessary to turn the wheel, the tyre will start spinning. This will happen at lot less force in smoother/slippery surfaces, and will take lot more force in rough/harsh surfaces. The minimum force required to spin the tyre (remember the pen) is the torque that will be delivered by the engine, no matter how much reserve force is available.

This is the reason why lowly XDP can do all well as CRDe in slushy terrains. The additional torque available with CDRe is useless if the terrain offers traction that can be overcome using XDP, for either climbing or for spinning wheels.

Originally Posted by Sutripta

I have a (unsubstantiated) theory as to why it is so, but would like others opinion on my observation first.

It is science, why is it unsubstantiated?

[dhanushs]

Originally Posted by Samurai

No, it is not contradictory. Not if one understands torque.

Sharath, considering on-road, traction is not of a concern, better torque should mean better acceleration on flat stretches, as well as on inclines.. right?

I guess what Sutripta tries to say is the XDP vs XD3 feel is almost similar on flat stretches, but, on inclines it behaves very differently. That - is contradictory.

[Samurai]

Originally Posted by dhanushs

Sharath, considering on-road, traction is not of a concern, better torque should mean better acceleration on flat stretches, as well as on inclines.. right?

If you are talking acceleration, are you talking torque or rate of torque? I thought speed was a function of power rather than torque, isn't? Help me out here, I am no mechanical engineer.

XDP has more horsepower than DI, but has less torque than DI.

[Blue Thunder]

Originally Posted by Samurai

... I will elaborate a bit this time.
...

Thanks, Samurai, for the simple but amply clear example to help illustrate the points about torque.

Originally Posted by dhanushs

...better torque should mean better acceleration on flat stretches.....

For better acceleration (on flat stretches), I guess, you would need better power (than torque). Torque always peaks at a lower RPM than power. When you want better acceleration, then you need more "energy" at the higher RPM band, and this "energy" is power.

['72 Bullet]

That doesn't really explain it either. XDP is supposed to be about 62 bhp while XD3P is supposed to be 73. Isn't it?

[Samurai]

I was comparing DI vs XDP. While I am clear on torque, the power is still not very clear to me.

[Sutripta]

Originally Posted by dhanushs

Sharath, considering on-road, traction is not of a concern, better torque should mean better acceleration on flat stretches, as well as on inclines.. right?

I guess what Sutripta tries to say is the XDP vs XD3 feel is almost similar on flat stretches, but, on inclines it behaves very differently. That - is contradictory.

Thanks Dhanush.

My feeling:- In the XD3, the governing system is arranged so that even if you stomp on the accelerator, fuel supply is increased slowly. As if you are being very gentle with the accelerator.

It would be interesting to compare HP figures for the XD3 on an inertial and brake dyno.

Regards
Sutripta