Ed's 77 Terex 72-41

[56wrench]

these are all the reasons i suggested the possibility of patching up what you have. it may be easier and faster

 

[Bluox]

these are all the reasons i suggested the possibility of patching up what you have. it may be easier and faster

Roger that plus when you get done you know what you have.
Bob

 

[mountainguyed67]

So you people aren’t willing to help? Or the questions aren’t answerable right now?

 

[mountainguyed67]

these are all the reasons i suggested the possibility of patching up what you have. it may be easier and faster

I would only do that if I converted it to a turbo in the process. This is the heaviest model machine with this engine, making it the worst horsepower to weight ratio. Plus it’s at elevation, 5,300 feet.

 

[Welder Dave]

If it had a problem developing with one cylinder would certainly affect it's power output. I think other posters are trying to help you avoid opening a big can of worms. A proper rebuild should restore the engine to full power. There may be other ways to increase the power a little without requiring a turbo.

 

[mountainguyed67]

I’m listening to you guys, I haven’t jumped on the purchase. I’m not getting enough interaction though.

 

[mountainguyed67]

A proper rebuild should restore the engine to full power.

Agreed, but I’m saying I don’t think I will be happy with that.

 

[56wrench]

but you will not be happy if you cobble together an unknown engine combination and it or the trans grenades. with more power than designed for, you may find a weak link somewhere else in the drivetrain. on a machine that is getting harder to get parts for that is a chance i personally would not take. just pointing that out. ultimately its your call

 

[kshansen]

but you will not be happy if you cobble together an unknown engine combination and it or the trans grenades. with more power than designed for, you may find a weak link somewhere else in the drivetrain. on a machine that is getting harder to get parts for that is a chance i personally would not take. just pointing that out. ultimately its your call

Agree with 56, not knowing how much safety margin the original components were built with I would be concerned that boosting the power would shorten the life of those pieces. Remember even if the original design had a 15% safety factor in the design that was when ever thing was new!

If a nice fresh engine is still not going to be where you need power wise maybe you are trying to do too big of a job with too small a machine?

Like they used to say where I worked "You can't put 10 tons of sh!t in a 5 ton truck and expect it to last!"

As for not getting answers to some of those questions, like I said due to the fact that there are many different ways to spec a 4-71 to try to make definite statements about the adapting one to replace another can be something of a mine field especially without having them sitting next to each other. Also due to the age of both these engine the chance some one has made a change to them since that tag was put on at the factory also adds to the problem.

Just the fact that on most of those engines the tag is on the valve cover adds a layer of unknowns, is the valve cover even the right one for the engine it is on?

 

[Nige]

OP was saying that the machine is up in the hills @ 5300ft ASL.
Anyone have an approximate idea what is the altitude rating of a 4-71 before the fuel system has to start getting tweaked.?
I have no idea but in my experience most big yellow engines are generally good for at least 5,000ft before derating. In many cases significantly more than that.

 

[Birken Vogt]

Non-turbo usually they lose power fast at that elevation. However, I think if that is the case, they will show a lot of black smoke if you get into it. If there is not black smoke then power is simply being limited by fuel quantity injected (injector PN in DD case).

 

[mountainguyed67]

Just the fact that on most of those engines the tag is on the valve cover adds a layer of unknowns, is the valve cover even the right one for the engine it is on?

The model number is also stamped on the side of the block, I need to match them next time.

 

[mountainguyed67]

Non-turbo usually they lose power fast at that elevation. However, I think if that is the case, they will show a lot of black smoke if you get into it. If there is not black smoke then power is simply being limited by fuel quantity injected (injector PN in DD case).

You can see the smoke here.

 

[mountainguyed67]

If a nice fresh engine is still not going to be where you need power wise maybe you are trying to do too big of a job with too small a machine?

You seem to be missing some of what I said. The next smaller model machine has the same engine.

 

[Bluox]

You can see the smoke here.

that smoke is from the bad piston in your engine.
bob

 

[mountainguyed67]

This was before it got bad, or at least before it got really bad.

 

[mountainguyed67]

You seem to be missing some of what I said. The next smaller model machine has the same engine.

My searches show the next smaller machine is 3,500 lbs lighter, and has a payload 5,000 lbs less.

 

[Bluox]

Here is all I got , If your motor do have N 65 injectors it should be a 150 HP. motor.
It's pulling that bad piston I bet its only putting out around 100 HP.
If You lucked out so far you may not have ruined the block.
At your alt. the derate should only be 3-6 HP. depending on the temp.
If the motor you are looking at is indeed a fire pump it may be 250 HP. + and like the marine engines it is heat exchanger cooled ,you missed the loader keel cooler part.
Since your loader has a radiator it won't cool much over a 150 HP.
I truly think your best bet would be over haul your motor .
But its your zoo and your monkeys so carry on.
Good luck
Bob

 

[mountainguyed67]

Here is all I got , If your motor do have N 65 injectors it should be a 150 HP. motor.

Terex calls it a 160.

At your alt. the derate should only be 3-6 HP. depending on the temp.

I don’t understand this. Alt = alternator?

like the marine engines it is heat exchanger cooled ,you missed the loader keel cooler part.

I didn’t miss it, that’s one of my questions that didn’t get answered. I asked if it was a different block, and could I still bolt the water pump to it.

Since your loader has a radiator it won't cool much over a 150 HP.

So it would need a bigger radiator.

 

[Welder Dave]

7231 shows as 146 flywheel HP. 7241 shows as 153 flywheel HP. Different transmissions and power trains though. Alt. = altitude.

TEREX EQUIPMENT.pdf (tractorparts.com)

TEREX EQUIPMENT.pdf (tractorparts.com)