Yes the pistons came first once I checked it was a standard bore, I found them locally [+ 030 presumably as stamped] . The engine been bored & honed to suit the pistons. I purchased the rings when I made a complete order up of stuff from the USA , I cant get rings here [ I had to take the chance].
To replace the original set the machinist wanted me to try and get a set of gapless rings , he wanted to set the gap himself [he didn't want me to do it] . Anyway after me inquiring with my normal U.S. supplier he could not find any sort of thing and... yes this is where we assumed that the original rings were in the wrong box and just ordered another set.
Its a bit of a crap situation because parts aren't readily available here I have to source all of it, I know he tried to get rings locally but, no one has these sizes and it gets thrown back to me to sort it out and half the time it like Chinese whispers..
All I can tell you is that when I was in there I checked it with the head engine builder [ he normally doesn't look at my engine its the owner of the business that's had it under his wing ] We put a ring in the bore [we knew straight away it wasn't right] measured it and yup.030 gap , he simply said your pistons are marked incorrectly get a set of .040 rings.. I said are you sure that'll do it ? "yup absolutely" .
So this is where Im at and needed to double check with you guys if a set of .040 will close up that gap @ .030
Aghh I cant begin to tell you how much of a cluster f *%$k this has been .. Its coming on 12 months and Im still not ready to button it up ...
Quote:
Originally Posted by JSeery
Something sounds very strange about this whole issue. The normal procedure is first you acquire the pistons you are wanting to use. Then bore/hone the cylinders to match the pistons. I see no way possible a machinist would not know the size of the pistons and the size of the cylinders. These two factors are needed before you purchase rings! Almost sounds like there is some guessing going on somewhere, am I not understanding the situation?
At the very least, you need to back up at this point and measure things so you know where you are. There should be no "guessing" as to what piston size you have, or what cylinder size you are working with! After establishing sizing, put the pistons in the cylinders and measure the clearance between the piston and cylinder wall. Order the correct rings based on the correct piston size.
Engine rebuild manuals will show how to measure piston/cylinder clearance. But still a little difficult to believe a machinist doesn't understand all of this.
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