| JD 9400 - 7/19/2016 05:40
You mentioned having a 466 cu. In. In your 8430. You also mentioned using a head from a 4630 which would originally have had a 404 cu. In. engine. Or had someone put a 466 in the 4630?
I've seen JD 466 engines "burn" water because of heat cracks in the head. Sounds like your problem to me. But you will want to take a close look at the head gasket, etc., when you pull it apart. As far as vacumm testing a head, I'm thinking that is to ensure the valves/seats don't leak after being redone. I could be wrong on that.
From my limited personal experience with cracked 466 heads, they are pretty much toast when that happens, unfortunately. A used head is OK, but you will want to make sure it has no heat cracks. What you pay for a used head would be dictated by the condition of the valves/seats, valve guides, how true (flat) it is, and how much surfacing has already been done to it. You don't want to buy a head with the max (or nearly the max) amount of machining already done on it, or you will have no recourse but another head if you happen to warp it. If a lot of surfacing has already been done on a used head, it makes you wonder how many times the head has been overheated already, which could lead to future heat stress cracking.
Good luck on whatever you decide!
The heads are the same on a 466 and 404 which is why I switched them. The part numbers are the same depending on serial number breaks.
Im pretty sure they said thats why they vacuumed tested it to check the valves, but i wasn't sure if it would detect head cracks or not.
And this head had major heat cracking, but they said it "shouldn't hurt anything." Yea, right! I cant remember what it cost, but it was a pretty thorough rebuild and wasn't cheap. New valve guides, a couple new seats, resurfaced, proper valve protrusion, lapped, all new hardware, the whole 9 yards. Its expensive, but sometimes learning is painful. |
Water in oil on 466 john deere
