sorr 0 Posted July 31, 2006 I am in the process of rebuilding an Mi engine. Yesterday I deglazed the bores and installed new piston rings. It now takes some considerable pressure to move the piston in the bore, is this normal? By considerable pressure I mean a tap with a large hammer via a block of wood. The bores and rings were well oiled before installation. Share this post Link to post Share on other sites
trickywoo 0 Posted July 31, 2006 I'm no expert but that does not sound right. The only way I would expect what you describe is if you are trying to push the pistons from the bottom with the head (including spark plugs) fitted, ie you have compression. Share this post Link to post Share on other sites
Guest ashnicholls Posted July 31, 2006 what do you mean tap with a hammer and wood? what are you tapping, if you put a long bar/socket on the front pulley, it should turn over just pushing the bar. Share this post Link to post Share on other sites
SweetBadger 94 Posted July 31, 2006 Sounds like somethings not right there, with new liners I found that I could move the pistons fairly easily by hand when I rebuilt mine. Not sure what would cause it, how rough was the finish on the bores after you degalzed them? Share this post Link to post Share on other sites
sorr 0 Posted July 31, 2006 The pistons are not connected at the moment they are free in the bores, so was tapping on top of them. I will connect them to the crank and see how easy it is to them over with the crank. Had a chat with MattSav and he thinks all is well, but suggest checking the gaps whick sounds like a plan. Thanks for the replies. Share this post Link to post Share on other sites
Guest ashnicholls Posted July 31, 2006 My 8v pistons all slid up easily. Did not have to hit them with anything? And i thought my engine was stiff? Share this post Link to post Share on other sites
j_turnell 137 3 Cars Posted July 31, 2006 If they are just pushed in the liners then there should be a fair bit of friction to move them but you should be able to push them up and down the liner by hand, once connected to the crank try turning the bottom end over and see but you may find the liners will move about. Share this post Link to post Share on other sites
Ryan 99 Posted July 31, 2006 Have you put new rings on? Mine was quite tight, but I image it'll loosen up once it's been run in. Share this post Link to post Share on other sites
ALEX 98 1 Cars Posted July 31, 2006 (edited) Mine had brand new pistons and liners and I had to use a breaker bar to turn the crank. Is the engine upside down with the head off? I had a bit of spilt oil on the bench (assembly oil) it was creating a seal and when i cranked the engine over by hand it would jump to let out the compressed air. Cant beat new pistons and liners. If its not locked up before you start it up give it a couple of turns by hand with a breaker bar on the crank pulley. Edit BTW. I thought the same the first time I built my engine, so yes it's normal Edited July 31, 2006 by ALEX Share this post Link to post Share on other sites
James_R 3 Posted August 1, 2006 just check the ring gaps with a feeler gauge and the ring in bore to be safe/peace of mind Share this post Link to post Share on other sites
