Aircon from Inverter from Batter Charger

[Dockhead]

Originally Posted by OceanPlanet

To be honest, we leave the "signing off" to the builder and their engine suppliers. And I'm pretty sure that some of these are technically outside of warranty.

However, many many engines, old & new, have added high power alts and I have not heard confirmation of any actual failed bearing.

I personally raced twice around the world with an added 130A x 24V alt on a Yanmar 3GM. Never had a problem, and AFAIK, it has never had an issue since

B

I humbly would suggest paying attention to this issue.

Yanmar publish tables of acceptable HP vs RPM vs pulley centerline distance. If you exceed this you can ruin the engine (blow the front crank bearing and blow up the engine) and it won't be in warranty.

Fingers would be pointed to anyone doing the work contrary to Yanmar specifications.

There are ways to get beyond the limits using serpentine belts, and your system with more wrap around the pulley might be alleviating the loads, but this is a job for a serious engineering calculation, not just "I've done it before and never had any problems with it" kind of shadetree mechanic guess.

[OceanPlanet]

Originally Posted by Dockhead

I humbly would suggest paying attention to this issue.

Yanmar publish tables of acceptable HP vs RPM vs pulley centerline distance. If you exceed this you can ruin the engine (blow the front crank bearing and blow up the engine) and it won't be in warranty.

Fingers would be pointed to anyone doing the work contrary to Yanmar specifications.

There are ways to get beyond the limits using serpentine belts, and your system with more wrap around the pulley might be alleviating the loads, but this is a job for a serious engineering calculation, not just "I've done it before and never had any problems with it" kind of shadetree mechanic guess.

ALL of these are serpentine, would be pointless to try with V-belts.

No one has to buy these kits if they don't want to. Use at your own (engine) risk.

How many failed crank bearings have you seen, or blown engines, from large alt installations? Think of the load the bearing takes from pistons driving down on the crankshaft.

[transmitterdan]

Originally Posted by OceanPlanet

How many failed crank bearings have you seen, or blown engines, from large alt installations? Think of the load the bearing takes from pistons driving down on the crankshaft.

I know of one broken crank where Yanmar would not replace or repair under warranty. Sorry, I can't give out the personal details. It was not a job your company did.

[Dockhead]

Originally Posted by OceanPlanet

. . .
How many failed crank bearings have you seen, or blown engines, from large alt installations? Think of the load the bearing takes from pistons driving down on the crankshaft.

Why would you risk it, if you could do just a little bit of engineering work, instead of eyeballing it like a shadetree mechanic?

Side loads certainly do kill engines. They are different from the loads from the work of the pistons, which are intermittent, and which are distributed over the whole crankshaft. And those loads also are worked out by engineers, and not just eyeballed. Side loads from PTO's are constant, and can squeeze the oil film out and cause the bearing to fail. This is not a joke!

Some information: Side Load on Pump or Motor Shaft Equation Calculation - Engineers Edge

"A front power takeoff is often used to drive a refrigeration compressor, water-maker compressor, additional alternators, a hydraulic winch pump, etc. As excessive side loads may break the crankshaft, the Yanmar recommended MAXIMUM FRONT PTO at various rpm for individual engine models can be calculated HERE.

"The way the accessory is mounted is critical. The two mounting systems dealt with here are referred to as 'A' type and 'D' type drives.
The 'A' type is side loaded with no support for the crankshaft.

"Excessive load or excessive belt tightening can break the crankshaft, I've seen it happen where the 'fridgie' used a bar to tighten his ' V ' belts."

ENGINE INSTALLATION

[OceanPlanet]

Originally Posted by Dockhead

Why would you risk it, if you could do just a little bit of engineering work, instead of eyeballing it like a shadetree mechanic?

Side loads certainly do kill engines. They are different from the loads from the work of the pistons, which are intermittent, and which are distributed over the whole crankshaft. And those loads also are worked out by engineers, and not just eyeballed. Side loads from PTO's are constant, and can squeeze the oil film out and cause the bearing to fail. This is not a joke!

Some information: Side Load on Pump or Motor Shaft Equation Calculation - Engineers Edge

"A front power takeoff is often used to drive a refrigeration compressor, water-maker compressor, additional alternators, a hydraulic winch pump, etc. As excessive side loads may break the crankshaft, the Yanmar recommended MAXIMUM FRONT PTO at various rpm for individual engine models can be calculated HERE.

"The way the accessory is mounted is critical. The two mounting systems dealt with here are referred to as 'A' type and 'D' type drives.
The 'A' type is side loaded with no support for the crankshaft.

"Excessive load or excessive belt tightening can break the crankshaft, I've seen it happen where the 'fridgie' used a bar to tighten his ' V ' belts."

ENGINE INSTALLATION

Great info. Our custom alt/pulley guy probably has all this, however I will fwd, just in case.

[Journeyman]

Originally Posted by transmitterdan

I know of one broken crank where Yanmar would not replace or repair under warranty. Sorry, I can't give out the personal details. It was not a job your company did.

Dan, no "personal" details needed. But to be fair you need to provide a few specifics for this to be a helpful annecdote. Was the person putting an 800A alt on his own jury rigged bracket? Or something reasonably close to Yanmar sideload calcs using best practices bracketing. There's a world of difference.

Jman

[Journeyman]

Originally Posted by Dockhead

Why would you risk it, if you could do just a little bit of engineering work, instead of eyeballing it like a shadetree mechanic?

Side loads certainly do kill engines. They are different from the loads from the work of the pistons, which are intermittent, and which are distributed over the whole crankshaft. And those loads also are worked out by engineers, and not just eyeballed. Side loads from PTO's are constant, and can squeeze the oil film out and cause the bearing to fail. This is not a joke!

Some information: Side Load on Pump or Motor Shaft Equation Calculation - Engineers Edge

"A front power takeoff is often used to drive a refrigeration compressor, water-maker compressor, additional alternators, a hydraulic winch pump, etc. As excessive side loads may break the crankshaft, the Yanmar recommended MAXIMUM FRONT PTO at various rpm for individual engine models can be calculated HERE.

"The way the accessory is mounted is critical. The two mounting systems dealt with here are referred to as 'A' type and 'D' type drives.
The 'A' type is side loaded with no support for the crankshaft.

"Excessive load or excessive belt tightening can break the crankshaft, I've seen it happen where the 'fridgie' used a bar to tighten his ' V ' belts."

ENGINE INSTALLATION

Dockhead,
As a reality check, Yanmar itself offers twin 130A alts. So this isn't shade tree stuff, if done right.
Jmam

[Dockhead]

Originally Posted by Journeyman

Dockhead,
As a reality check, Yanmar itself offers twin 130A alts. So this isn't shade tree stuff, if done right.
Jmam

Absolutely. The key phrase here being "if done right". With a wee bit of engineering work.

[transmitterdan]

Originally Posted by Journeyman

Dan, no "personal" details needed. But to be fair you need to provide a few specifics for this to be a helpful annecdote. Was the person putting an 800A alt on his own jury rigged bracket? Or something reasonably close to Yanmar sideload calcs using best practices bracketing. There's a world of difference.



Jman

The owner did not tell enough to make a definitive diagnosis thus the paucity of details. But the hours were <100 as I recall. From listening to the story it appeared pretty clear that Yanmar believed something about the install was the root cause. There was a "big" albeit nonspecific size alt.

Beyond that what I was responding to was whether there had been any broken Yanmar cranks (there have been) and I know from this story that Yanmar held to the position it was not a warrantable failure. More details I don't have. Make of it what you will. But Dockhead is right. There is not a 4:1 safety factor on these small engine cranks like maybe there was "back in the day".

[s/v Jedi]

I would recommend to check out how Steve Dashew engineered this in his designs.

For example: we have a 4-cyl Yanmar with it's stock alternator, plus two Lestec Brute 210A alternators, plus a power take-off for a big crash pump. This is done with custom brackets and by balancing side-loads.

The stock alternator charges the starting batteries and the two big boys can put 420A into the house bank at the same time. On his Beowulf design he put in even bigger alternators.

[OceanPlanet]

Dashew has also used some very cool alts by Electrodyne (Maine), that put out AC to external rectifiers. This moves off roughly 1/2 the heat so works very well for charging Li or big Pb banks. Mark Grasser (also in Maine) has recently started doing small-case alts with external rectifiers as well. We have a backlog of orders for them already...