putting an engine under load and stuck piston ring

hi all,
my lister d has got a stuck oil scraper ring, i asked the previous owner on what to do and he said if the bore is good you can either run it under a good load or run it for ages so it get really hot and the piston expands as much as it can thus freeing the stuck ring.
i have a lister domestic pump and a 1500W dynamo so i could hook it up to the dynamo to give it some load unless there's a better way as i don't know how much load i'll get from the dynamo? i've seen clips where people brace wood against the flywheel or pulley to give it a load.(health and safety would go insane!!)   .
If there is a better way to free piston rings i would be willing to give it a bash as i don't fancy risking the bore even if it looks okay now.
also as a side note, when i was checking the bore through the inspection plate a noticed there was a lot of play in the conrod (side to side) is this normal? it must and been in excess of 3mm. i did have some people saying it sounded a bit knocky.

I was just wondering what you guys thought,
thanks
callum

With the conrod if I'm not mistaking the side float is normal for them, but a d expert might put you right..

Best way to free off rings is to pull pistion out and give a clean up and a soaking in diesel and some heat may help and once free remove rings and clean the grooves up and replace.

Matt

agree with Matt. Head off, get the piston out (it must go up to come out), if you did it his way (the seller), how would you know the ring was intact and not wrecking the bore or even if it had free'd off at all etc. Once piston is out be very gentle with the rings
If you don't have a ring compressor when it comes to putting it back together, you can sometimes get away with using "large" cable ties.

i agrre with the boys above
if a ring is stuck and you cant see if its freed off it can cause grooves/scoring to the bore and result in loss of compression, and load running will not tell you if its freed of as the compression rings hold the pressure and oil scrapper does just that and also is in the coolest part of the piston at all times and also colded by the oil splashed up from the sump

if a ring gets stuck ,there must be some thing for it to bind into the piston grooves with
so remove soak for a while/few days and just keep trying to rotate it by hand ,and a few knocks with a piece of hard wood ,will also aid in loosening it with damage to piston or ring ,once it starts to free up ,just keep working your way around with the knocking wood from the free ring ,and slowly but shorly it will start to all come loose, wonce loosed rotate and soak repeatedly ,and the carbon/rust will start washing out 
then you can carfully remove the ring and get the groove scrapped out clean and ring sides if needed, please remember is a very hard but fragile metal so it can easy break so take your time and go steady ,rings are available of the net if needed for the common 5 ring pistons
kev

thanks guys,
i'll coincide getting the piston out with mounting it on a new trolley, that'll make life easier. you don't need to redo the valve timing after do you? i'll take it out by unbolting the flywheel and bearing assembly. i'll check all bearings ect and maybe give it a de-coke if needs be, anything else i should do while its apart?
thanks again, you've probably saved me from harming my bore!

callum

there is a small spring crirclip on end of crank bearing at the conrod end of shaft to limit the side float of piston connecting rod on bush bearing
easy to see it through the 4 bolt  side door if you know what to look for ,that is all that stops you slidding the crankshaft  out other than the ring of nuts behind the flywheel   
kev