gt6878e Posted May 11, 2012 Share Posted May 11, 2012 Hi all, i took the gt out today after fitting new rack mounts. All good with the steering but the engine started to make a hell of a racket.Took the head off after checking the plugs and seeing one was badly damaged and one of the pistons has blown.Can i remove the pistons out without taking the engine out the car? and what is required to take the piston off the con rod? Many thanks in advanceDarren Link to comment Share on other sites More sharing options...
Gt6s Posted May 11, 2012 Share Posted May 11, 2012 gt6878e wrote:Hi all, i took the gt out today after fitting new rack mounts. All good with the steering but the engine started to make a hell of a racket.Took the head off after checking the plugs and seeing one was badly damaged and one of the pistons has blown.Can i remove the pistons out without taking the engine out the car? and what is required to take the piston off the con rod? Many thanks in advanceDarrenYes you can remove the pistons and rods with block in car, but it is LOTS OF FUN !!Gudgon pin is held in with circlips then just push's out. Link to comment Share on other sites More sharing options...
ferny Posted May 11, 2012 Share Posted May 11, 2012 gt6878e wrote:Can i remove the pistons out without taking the engine out the car? and what is required to take the piston off the con rod? Many thanks in advanceDarrenDead easy in a 4-pot but not sure how much room you get with the 6. Sump off, bolts undone, slide up through the block (might want a tap with a bit of wood and a mallet). Getting them back in can be fun as you try and get clear purchase on each bolt. Also helps a lot if you can get the car up high. You've done it the slightly awkward way now you can't get it on ramps. Link to comment Share on other sites More sharing options...
Nick Jones Posted May 11, 2012 Share Posted May 11, 2012 Possible, but not a lot of fun or perhaps the way to get the best result. You'll need to raise the engine quite a bit and/or remove the rack to gain access to the front end.You may need to dunk the piston in hot water before you can push the gudgeon pin out (even after removing the circlips!).One other thing that would bother me is you will need to hone that cylinder before refitting piston (good used?) and new rings and just how you'll get the honing dust out of the engine.....Also - how has the piston damage occurred? Standard engine? Was it pinking horribly? Matching valve damage?Nick Link to comment Share on other sites More sharing options...
gt6878e Posted May 12, 2012 Author Share Posted May 12, 2012 Thanks for the advice, just sounded a bit scary when i was reading the manual ( take to a triumph specialist etc)Nick, it's a standard set up, no pinking or anything, just pulled up at a junction and heard a god awful tapping sound. there's been no damage to the bore at all, the piston has a big hole down the edge of it though. I'll post a pic later.CheersDarren Link to comment Share on other sites More sharing options...
Richard B Posted May 12, 2012 Share Posted May 12, 2012 When in doubt, whip it out ::) Link to comment Share on other sites More sharing options...
Nick Jones Posted May 12, 2012 Share Posted May 12, 2012 Richard_B wrote:When in doubt, whip it out ::)I agree.... it is so damn heavy though. They seem to be breeding in my garage and they stay right where they are if you bump into them......Nick Link to comment Share on other sites More sharing options...
Gt6s Posted May 12, 2012 Share Posted May 12, 2012 Nick_Jones wrote:Possible, but not a lot of fun or perhaps the way to get the best result. You'll need to raise the engine quite a bit and/or remove the rack to gain access to the front end.You may need to dunk the piston in hot water before you can push the gudgeon pin out.Yeah I should have noted (sarcasm) when I posted LOTS OF FUN !!And yes gudgeon pin takes a bit more than a push. Link to comment Share on other sites More sharing options...
gt6878e Posted May 13, 2012 Author Share Posted May 13, 2012 Well I tried like hell to get the sump out without removing the engine but as I'm not David blane I gave up, bit the bullet and now I have an engine laid on my garage floor!!!!Where's the best/ cheapest place to buy a rebuild kit, whilst it's out I may as well do a proper job on it. Link to comment Share on other sites More sharing options...
Richard B Posted May 13, 2012 Share Posted May 13, 2012 Chris Witor, Canley Classics, James Paddock,Try and get the heavy duty bearings if you can they are the County equivalent of the tri-metal.Does your block have the breather on the side by the petrol pump? If so it will have the smaller main bearing, 2" rather than 2.3". Means it revs nicer, less drag. :)Only fitted to MkI's upto KC5000 I believe. :-/ Link to comment Share on other sites More sharing options...
Clive Posted May 13, 2012 Share Posted May 13, 2012 What do you want to do during the rebuild?I would be inclined to fit new big ends and mains, plus thrusts (you may be able to squeeze an extra 5 or 10 thou in too, worth a try)Hone the bores, new rings.Use a payen gasket set if possible. Check the oil pump, it may respond well to a little work to remove scoring and so on. And a good clean inside :) Link to comment Share on other sites More sharing options...
gt6878e Posted May 13, 2012 Author Share Posted May 13, 2012 Richard b, breather next to the fuel pump??? it has a blanked off plate next to the fuel pump.cliftyhanger, i was thinking of a basic rebuild, pistons rings, bearings, oil pump. I havent got that much to spend as i've just been made redundant Link to comment Share on other sites More sharing options...
Clive Posted May 13, 2012 Share Posted May 13, 2012 Buy the best parts you can, it will be a much better bet and less grief long term. I reckon about £150ish in parts, and if the oil pump was OK, I would just fettle it a little. I have never replaced an oil pump.You never know, bargains do turn up, there were a few sets of bearings and rings (I suspect mainly 4 cylinder) at the TSSC show in Leatherhead today, and worth looking at ebay. Otherwise try the various suppliers. Link to comment Share on other sites More sharing options...
Richard B Posted May 13, 2012 Share Posted May 13, 2012 gt6878e wrote:...it has a blanked off plate next to the fuel pump.Sounds like it. Oh yes see piccy, on the early saloons thats a breather, probably no space on a GT6.Thats the early crank version of the MkI. Link to comment Share on other sites More sharing options...
gt6878e Posted May 14, 2012 Author Share Posted May 14, 2012 It says in the manual there should be some lock tab washers on the con rod bolts..........mine hasn't............. Link to comment Share on other sites More sharing options...
Richard B Posted May 14, 2012 Share Posted May 14, 2012 Think those were dropped from production. The only ones normally I see in the engine are on the cam wheel bolts. Link to comment Share on other sites More sharing options...
gt6878e Posted May 21, 2012 Author Share Posted May 21, 2012 Been and picked up my nice and new shiny pistons tonight.....now to start the rebuild.Will i need to set the gap in the new rings or will they be just to put in and away i go? Link to comment Share on other sites More sharing options...
Nick Jones Posted May 21, 2012 Share Posted May 21, 2012 You should check the ring gaps on all compression rings by pushing them down the bore about half way with a ringless piston and then measuring the gap with feeler gauges. There will probably be a bit of paper with your pistons telling you what the gap should be. The one from my County brand ones says 0.003 - 0.004" per inch of piston diameter...... so 0.009 - 0.012" gap. Too small is the bigger risk as if the gaps close right up when the engine is hot the rings will break. If you get a huge gap it suggests the rings are the wrong size for the bore (std rings in +0.020 bore say)Did you ever determine what caused the original failure? Any pics of the wreckage?CheersNick Link to comment Share on other sites More sharing options...
gt6878e Posted May 22, 2012 Author Share Posted May 22, 2012 I'm going to check the gaps as you've said nick....don't want any more harm done.I've no idea what caused it but looks like the ring has failed and cracked. I'm lucky as when i heard it go i stopped the engine and coasted home, was only 200 yrds away.Another question, do i "wellseal" the head gasket or just put on dry?.....proper copper oneDarren Link to comment Share on other sites More sharing options...
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