meadowfield 2,545 #1 Posted October 17, 2014 I acquired an M16 from a reel mower as some of you might recall for project bendy. Got a new head gasket today so I can reassemble it after a quick look. Now I knew it was burning, leaking and drinking oil so thought it might be a bit black and oily. It was worse than I thought Looking like a rebuild over the winter, the bore looks good, no scoring, but clearly the oil ring at the very minimum has had it. There's a reasonable amount of piston movement in the bore at tdc. How much is acceptable before I start ordering an overhaul kit? I can fit a 30" feeler in down to the first ring with no effort. Whilst I'm gonna use it hard to test the 4WD it's not going to be a worker. It will probably only do 50 hours a year. Can I get away with a new std piston, rings and overhaul? Thanks Share this post Link to post Share on other sites
Fordiesel69 206 #2 Posted October 17, 2014 How about moving the piston down and shooting some pics of the cyl walls. Often the "quench area" of the piston gets carbon erroded. So yes, .030 would fit right in. Where it matters is the skirt to cylinder wall. And I would bet it is over spec. A carbon erroded piston needs replaced as you will just cook the upper ring. Share this post Link to post Share on other sites
sorekiwi 761 #3 Posted October 17, 2014 Measure it and make your mind up then. I've been bitten before by just looking at the bore and hoping for the best! Share this post Link to post Share on other sites
pacer 3,159 #4 Posted October 17, 2014 I too would strongly recommend getting the cylinder mic'ed - if its as bad as it looks it will just go right back to the same thing - burning oil. Mic 4-6 places around the cyl wall to check for egg shaped. I cant remember off hand what the recommended limits on wear is, somebody will probably come in and know what they are. Need to mic the crankshaft also while this is going on... Share this post Link to post Share on other sites
meadowfield 2,545 #5 Posted October 18, 2014 Thanks for the guidance chaps, it will get a new piston and rings no matter what. Will see if I can borrow micrometer for the bore before I order a piston... If it's oversize I will just look to find another donor engine, rebores in the UK are expensive! Share this post Link to post Share on other sites
Molon_Labe 731 #6 Posted October 18, 2014 See what you have before ordering any parts. Here's what my K-241 standard piston, pulled from a 1976 B-100 engine looked like, but the bore showed less than .001 wear. Share this post Link to post Share on other sites
meadowfield 2,545 #7 Posted October 21, 2014 looking at the top of the piston it still has the bevel from manufacture and certainly hasn't the erosion you show. Once I've proved the 4WD, I'll pull the motor apart and take a proper look - I certainly won't be taking a gamble. With Import duty it's around $150 of parts, then oil, etc. A rebore is over $100 here - so it is easier to look for an engine with less hours on. Will let you know how it goes Share this post Link to post Share on other sites
can whlvr 991 #8 Posted October 22, 2014 100 is reasonable where I live,i paid 150 to have them(machine shop)measure,chemically clean block,grind valve seats and bore Share this post Link to post Share on other sites
Fordiesel69 206 #9 Posted October 22, 2014 You could hone and put rings on it. It would be "good enough" for awhile. Share this post Link to post Share on other sites
