3TNV70 Questions

[MikeL]

I have a 3TNV70 Yanmar engine that was salvaged from a utility vehicle. The PO ran gasoline thru it and wanted a new engine. So we replaced it with a new engine. No core on the old one and it was being scrapped. It got scrapped into the back of my pickup! I took it home, changed oil and fuel filters, disassembled and inspected injectors and glowplugs. All looked good. I removed the cylinder head and inspected the pistons and bores. All looked good. There was only 135 hr on the clock when removed.  I temp mounted it to some wooden skid material for a test run. I gave it some fresh fuel and fired it up. My plan is to belt drive a 7k gen head for temp power. Eventually this will all be mounted in an enclosed trailer.
One concern I have is that this is a variable speed unit. My funding says I will have to go with a 2 bearing, 2 pole, 3600 rpm gen head. If I match the drive pulleys so that the engine turns at 2200 to 2400 rpm, will the engine, being a variable speed unit, pick up the load without dipping too low?

[unimog_jason]

I think this is the same engine that my John Deere tractor uses.  One thing I've noticed about this engine (at least in a tractor application) is that the govenor has a lot of drift and will not hold a set speed when load levels change significantly.

It would be nice if I could run a PTO generator off my tractor, but given the less then ideal speed control of the engine I don't think it would work well.

If I was in your shoes, I would mock something up so that I could do load testing to determine if the drift is going to be an issue.  If everything tests OK, then proceed with the full scale build.

Jason

[Tom Reed]

Lots of governors have sensitivity adjustments. Perhaps that would resolve the problem.