Pistons on Mi16

kaiser

kaiser

Active member
Fellow Frogger
Joined
Sep 3, 2003
Messages
356
Location
Canberra ACT
Hi guys

I have just removed my head after snapping my timing belt and have noticed that there are indentations on the crown of the pistons where they have hit the valves.The marks are quite deep, about 1-2mm. Is this normal? I have also noticed that the pistons "wobble" a fraction. Again is this a normal thing or am I being paranoid? Any feedback would be great.

Thanks
 
We've just done one of these motors up & actually had the indentations touched to allow for the O/S valves so I wouldn't lose too much sleep if that's all it is, but wobble in the pistons sounds a worry eek! eek!

I do hope you realise that on wet sleeve motors that the sleeves have to be retained in position & under NO circumstances should the engine be turned over without the liners being held, otherwise chances are the liner seals will have been dislodged and will probably leak. In this case, the job just got a whole lot bigger. mallet
I'm just hoping the wobble wasn't the liners moving & not just the pistons. How many klms has it done?

Alan S
 
Hi Alan

Thanks for your reply. I didn't turn the engine over so it's all good. The car has done about 215 000 kms and has been using a bit of oil over the last 12 months or so so I'm hoping that the "wobble" is just worn rings. The liners don't move but if I try to move the 2 pistons on the top they move side to side just a fraction... 0.5mm I guess, but within the liners. I'm glad the dents on the pistons are not too worry about, someone told me that I'd have to replace as there maybe a small hole it them as a result of the impact and of course that would be bad cry
 
How much lip is at the upper end of the liner?

I can't quote the acceptable tolerance, perhaps Peter T may know, but if it's burning oil & needs rings, now is the time to do them as the major part of that operation is the head removal & refit.
FWIW, if that's the way you decide to go, my son has a complete set of rings for one of these motors which we bought for ours prior to deciding to go the full monty with the pistons, liners etc so if you decide on that, I'd say he'd sell them at his cost.
With a re-ring job, the liners would need to have the lip honed off prior to refitting of course and the sump has to come off.

Alan S
 
There is virtually no lip, the liners appear to be in good shape, you can even still see the origianl hone marks on them.
I'll definitely be doing the rings so I might buy those rings off your son. Do you know how much he'd want for them?
 
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