My Poor Inter AR162 has had a heart attack

I don't know how they can quote maximum hp at 3600rpm when they quote the maximum rpm at 3400!

There can be a few reasons for this- one is that a bare, stock engine on a test stand will dyno 108hp/3600rpm, but when it is installed in a vehicle, with a fan and generator, and having its rpm limited by the top speed/gear ratio, it will only dyno at 93HP/3400rpm.

Another reason, which usually applies to industrial and agricultural engines, is the manufacturer will quote 2 power ratings, one for continuous use and one for intermittent higher power use. This means the engine will run happily all day making 93HP at 3400 rpm, but if you need extra power for a minute or two, you can ramp it up to 3600rpm for the full 108HP.

Just keep in mind that International was primarily an agricultural equipment company, and the engines they built were designed for agricultural use, but were also used in many other applications such as trucks.

thanks for the information people. I had sort of guessed the water pump, fan and generator stopped the engine making as many revs as with no load

Some good news is it is the reconditioned water pump was delivered today so if the mechanic's week stays quietish it could be getting driven home this week!

Well the Inter hasn't come home as there were a couple of setbacks.

If we use the mounts that came with the motor then we need to play with the cross member. If we use the original 240 mounts then the mounts are in the way of the belts. With a little bit of measuring we found that if we swapped the harmonic balancers over and used the generator (which has been rebuilt) off the 240 all it needs is a spacer on the water pump and all is fine.
So we got a spacer and had it mailed up. All that arrived was a ripped package with an apology denying all liability from Australia Post.

We then found out that the grubby mark on the harmonic balancer was in fact a crack from the keyway to the edge.

The good news is replacement parts have been located.

Sounds like what I did to get the 281 in the ASW120, and the benefit is it looks more original. I didn't have any good water pumps, so I got a new one (for a diesel - was all I could get) and pressed the old 281 hub on it to the right height.
Sad to hear you've had more troubles, but sounds like it's on its way home soon.

Best of luck, Jarrod.

Bruce, Some one said, life wasn't ment to be easy, and that goes double for changing engine from some other model > > >
Colin

Hey Bruce I was just wondering if you have weighed those harmonic balancers? If you fit another balancer of a different weight or balance then you could very well upset the harmonics of the crank and end up breaking it.

Hi Diesel dog.

As far as I am aware the new parts have not arrived. A couple of old timers (including one that managed a spare parts division for an ih dealer back in the day tell me that they definitely didn't change from the AGD through to the later 281s and the later motors were often dropped in with the balancer changed to the older style to save rewiring the truck as they could then use the generator.

I will take some scales to the mechanics to check though

The harmonic balancer is also known as a vibration damper, and that is what it does.
Harmonic sound like a big fancy word but the weight of said article varies by specification on all engines so as long as it damps vibration its all good.
More likely to cause damage with a faulty balancer / damper .
I have just bought a 281 to perform the same swap into an AR and the engine I bought was fitted with air con (pretty big in 1970) so had an additional pulley bolted to the damper.
Did you keep the original Flywheel housing or change to the later Bruce ?
Rags

When I picked up the 281 it had the same bell housing as the 240 so it will bolt straight onto the gearbox and cross member. The idea is to make as few changes to the truck as possible to keep things easier and keep the budget under some sort of control.
That doesn't mean things are not being done properly as it needs to be reliable just trying to not let a remotoring turn into a complete truck rebuild and use standard rather than custom parts so it's easier to maintain and repair in the future.

The harmonic balancer is also known as a vibration damper, and that is what it does.
Harmonic sound like a big fancy word but the weight of said article varies by specification on all engines so as long as it damps vibration its all good.
More likely to cause damage with a faulty balancer / damper.

Everything has a natural vibration- a fence, a building or a crankshaft. Have you ever seen videos of bridges or buildings swaying in the wind? That is the natural frequency. The problem occurs when the structure has additional vibrations forced into it and these combine with the natural frequency to move at the resonant frequency, which can be highly destructive.

To explain how harmonics play a role with your engine, go out to your vehicle and start the engine. Now slowly increase the throttle while feeling the vibrations. Do you notice that at some speeds, the engine vibrates more? This is happening because the crankshaft is passing through critical speed ranges where the resonant frequency is at its highest. However, the engine will be designed so that these frequencies cannot reach the point of being destructive.

So what is happening? As the crankshaft spins, it has its own natural vibration, but as cylinders come up on compression, that part of the crank slows down. On the power stroke the crank speeds up. So when you have the various cylinders on compression and power stroke, there will be a forced twist in the crank, and from end to end, the crank could twist up to several degrees. The crankshaft will essentially wobble and vibrate as it spins and it is this forced vibration that adds to the natural vibration to reach the resonant frequency of the crank, at which point the crank is now set up to fail.

How can we control the vibration? By adding a harmonic balancer, which essentially a shock absorbing flywheel at the nose of the crank. The weighted portion act as a flywheel by keeping the crankshaft at the same speed at both ends. The rubber insert allows for a little bit of twist or vibration but absorbs most of it. If one is to fit a balancer of a different specification, less weight might not be enough to control the vibration and too much weight may cause the rubber insert to be destroyed. So if the weight is not within the designed specifications, you will be changing the harmonics that the parts have been engineered for and possibly setting your engine up to fail.

A short story of my own. Many moons ago when I worked for a tractor dealership, we had a 10 year old tractor come in with a completely destroyed transmission. In the transmission there is a large compound planetary gearbox that has the four powershift gear ratios all in the one planetary. All four sets spin at the same time but only the one that has the clutch engaged will transmit the power. The whole planetary unit was held together with a large circlip, maybe 12 inches wide. What happed was that the circlip had came out and allowed the planetary to walk apart and gears to break.

The question is how does a circlip just come out? I contacted the manufacturer and asked the question. It turns out that some of the carriers, of which the ring gear and circlip groove are one piece, were of a different weight and balance, and at certain engine speeds and gear ratios, they would vibrate at a resonant frequency which would cause the circlip to just jump out of its groove and the transmission to self destruct.

It turns out that a major complaint of all the failed tractors was that the outside mirrors on the cab would vibrate so bad a certain speed, you couldn't see the reflection. The manufacture even provided warranty on the parts for a ten year old tractor with 5000hrs.

Sorry to hijack your thread Bruce, carry on....