Burro
Full member
Had my engine (Daihatsu HD-E 1.6) rebuilt about 10,000km ago including cylinders bored and trued for o/s low comp pistons. Right from the onset there was a nasty vibration that ran through the whole car with even the slightest excelleration fromaround 1,800 to 2,000rpm. 1st gear was fine but the vibration was present through all the rest especially 2nd and 3rd. Might also be worth noting that I run 31" mud tyres which are about 15% bigger than stock.
Did a bit of research and think I narrowed it down to piston slap
. I changed the oil to a thicker one which made a difference but the vibration is still evident. As long as I don't change gears under 3,000rpm it's not an issue but that's not always practical with a 4x4 that's soon to have a blower strapped to it as I'm looking for low down torque.
From what I can gather there's not much else I can do about it other than throw the block at the engine builder and get them to sleeve the cylinders (not my preferred option) or telling them to buy me some larger pistons and try again (again not a great option as the work was done about 12 months ago, it just took me a while to get it on the road. It was also a cash job so I could save a few quid so there's nothing to stop them from telling me to take a hike).
So my questions are, is it likely to be piston slap or could there be another reason and, if it is piston slap, does anyone have any other solutions that I haven't considered yet?
Did a bit of research and think I narrowed it down to piston slap
. I changed the oil to a thicker one which made a difference but the vibration is still evident. As long as I don't change gears under 3,000rpm it's not an issue but that's not always practical with a 4x4 that's soon to have a blower strapped to it as I'm looking for low down torque. From what I can gather there's not much else I can do about it other than throw the block at the engine builder and get them to sleeve the cylinders (not my preferred option) or telling them to buy me some larger pistons and try again (again not a great option as the work was done about 12 months ago, it just took me a while to get it on the road. It was also a cash job so I could save a few quid so there's nothing to stop them from telling me to take a hike).
So my questions are, is it likely to be piston slap or could there be another reason and, if it is piston slap, does anyone have any other solutions that I haven't considered yet?
