NC30 engine rebuild
Posted: Wed Dec 13, 2023 11:03 am
Dear all,
I've just torn down our slightly sick NC30 engine as it was burning far too much oil (smoking on hard acceleration) and following my wife was getting rather smelly It started fine and ran nicely so otherwise was good. Importantly, the bores (standard), cranks and shell bearings are all very good and reusable so I shall rebuild this engine rather than seek out another.
I've not found any major reasons for the oil burning though the front two cylinders were lower on compression and one side had deposits in the combustion chamber. My immediate thought is that I am most likely looking at damaged valve seals and/or worn/stuck pistons rings though I have not yet examined all the parts in detail.
I propose using a pattern gasket sets and seals for the rebuild though I will purchase genuine head gaskets. I see no need to buy genuine Honda valve guide seals but I am torn on what to do about pistons rings. I would like to use genuine Honda but ~£200 for a set seems a tad excessive. Can anyone recommend any good alternatives please?
I'm used to rebuilding engines (albeit mostly 2 strokes) but would certainly appreciate any input on anything in particular to look out for.
Thanks!
Keith
I've just torn down our slightly sick NC30 engine as it was burning far too much oil (smoking on hard acceleration) and following my wife was getting rather smelly It started fine and ran nicely so otherwise was good. Importantly, the bores (standard), cranks and shell bearings are all very good and reusable so I shall rebuild this engine rather than seek out another.
I've not found any major reasons for the oil burning though the front two cylinders were lower on compression and one side had deposits in the combustion chamber. My immediate thought is that I am most likely looking at damaged valve seals and/or worn/stuck pistons rings though I have not yet examined all the parts in detail.
I propose using a pattern gasket sets and seals for the rebuild though I will purchase genuine head gaskets. I see no need to buy genuine Honda valve guide seals but I am torn on what to do about pistons rings. I would like to use genuine Honda but ~£200 for a set seems a tad excessive. Can anyone recommend any good alternatives please?
I'm used to rebuilding engines (albeit mostly 2 strokes) but would certainly appreciate any input on anything in particular to look out for.
Thanks!
Keith