How much blow by should an Isuzu Engine have? Are they going to have some blow by like a 60 series Detroit or are they a tighter engine like a Caterpillar? I'm talking in the 5 to 10 thousand hour range.
They will have a bit but generally pretty "tight". Ive never heard that term for an engine before. What machine is it in?
Some Isuzu installations I've seen have single element air cleaners, tend to "dust" prematurely, low compression and excessive blowby. Japanese diesels in general if you do a facelift on them around 6 or 7 thousand hours, rings, gaskets, rod and main bearings, injectors they'll just keep going. Even if you just roll in new bearing inserts it will increase the longevity. The top ends usually stay tight and good power, but eventually they'll spin a bearing it's just physics.
Blow by is another term for crankcase pressure. It can be measured two ways. When I was doing a lot of engine work, Isuzu stated that anything over one inch of water measured through the dipstick tube by a water tube manometer and the crankcase breather open was grounds for a tear down and inspect for repair. Cummins used the same type of test but installed a calibrated orifice in the breather tube and a fitting teed into the up stream side of that orifice. The old L10 Cummins when they came out were good to 7 or 8 but later on the spec was raised to 18 inches of water. That much oil coming out the breather usually coated the engine and everything else in the compartment. Now days I see they use some kind of air flow meter. I'm thinking the new engines with positive crankcase ventilation probably have a vacuum on the crankcase.
It's a Arkansas thing I was looking at 270 and 350 Hitachi excavators. My knowledge of Isuzu engines is pretty weak having only bought one with less than 200 hours until last week. I bought a 270 so now I'm hoping I don't become an "expert" on Isuzu engines anytime soon
We have a few gen sets wih Isuzu 4 and 6 cyl engines some with 25,000 hrs on them with no problems.
In my experience they are good engines. You can always pull up the mic data and see how much idle times on it. That would give you an idea if it was never run hard enough to bed it in.