top end rebuild trouble

[greenshee14]

So im rebuilding the top end and my jugs seem to not fit over the pistons very eaisly they have been bored and honed and the machine shop had the pistons with them when they did it. I got one of them on a little bit and it was still very hard. It almost seems like they dont fit

[captainhowdie]

Are you sure your ring gaps are lined up with the marks on the pistons?

[Duneman101]

there is a small pin looking deal in each ring groove, make sure that the break in the ring pinches this little pin. if not you will never get those pistons on, it can be a little tricky but after you get it on you will wonder why you couldn't have figured that out before.

[GrMeyer]

have you checked the ring gap?

[blowit]

You better stop there and test fit the pistons. I have seen this myself where the shop does not take the time to test fit. I got one back with .005" taper!! Without rings, the pistons should just fall through the hole. If they do not, do NOT run them. Also, as mentioned above, make sure your rings are in their home about the locate pin in the ring lands.

 

IMO, if the ring end gap is way off, there is something wrong with the bore, not the rings. Wiseco has been pretty accurate on rings for some time.

 

Mull Engineering

[greenshee14]

[the rings are in there home lol and they are vitos pistons

[blowit]

[the rings are in there home lol and they are vitos pistons

 

 

Vitos does not roll their own. They have Some wiseco and some other lines. Check the bottom of the wrist pin boss for a "W" or post a pic and I can likely help.

[Koolguyson]

Put the piston in the bore without the rings and check to make sure they are right. Then compress the ring and put it in the bore. If both of them fit fine...put it together.