muzaz Posted February 15, 2008 Share Posted February 15, 2008 Hi all... Thought I'd open a single thread about the subject instead of opening one every time I have a query.... dont know if this is the proper place for it tho! Moderators feel free to move it if its the case... Anyway, last week took the block for honing and now its back...Cant say I'm 100% satisfied with the job as there are still some marks remaining at the top of the bore but the guy at the shop said its fine, he didnt want to take much material off... So now I'm into fitting the pistons, and following the manual to the word I've checked the ring clearance in the bore... the book says top ring 16 to 25 thou, I have 15thou in all 4 bores, mid ring manual says 12 to 19thou, I have 11thou in 3 bores and 12 in one... bottom ring manual says 11 to 23thou I have 12thou on all 4 bores, so thats ok. I bought standard size rings, should I just put them in, end of story or? the difference is only 1 thou should I leave it? Another one, what kind of oil should be used when assembling the parts...pistons, rings crank and shells etc...Is it ok to use engine oil or gear oil? thanks chris Visible marks at the top of the bores Quote Link to comment Share on other sites More sharing options...
western Posted February 15, 2008 Share Posted February 15, 2008 the rings won't come up as far as the marks, I'd leave them, use standard engine oil to lube the bearings. Quote Link to comment Share on other sites More sharing options...
muzaz Posted February 15, 2008 Author Share Posted February 15, 2008 Thanks Ralph... off to fit the rings then... hope they will just fit in easily, had quite a hard time taking the old ones off...slicing my thumbs in the process! Quote Link to comment Share on other sites More sharing options...
muzaz Posted February 15, 2008 Author Share Posted February 15, 2008 how should the rings be orientated before pushing the piston down the bore... the manual mentions something about staggering the rings as illustrated...but theres no illustration! Quote Link to comment Share on other sites More sharing options...
Pete Attryde Posted February 15, 2008 Share Posted February 15, 2008 I think (and I stand to be corrected) you just need to make sure that none of the gaps line up. Setting each one at 120 degrees to the previous one, rings a bell. Pete. Quote Link to comment Share on other sites More sharing options...
Gromit Posted February 15, 2008 Share Posted February 15, 2008 Just looked in my workshop manual and it says nothing about the position of the rings and the diagram show them lined up I'm sure this is wrong. I thought they were installed at 180 degrees. Remember the rings have a top and a bottom. Quote Link to comment Share on other sites More sharing options...
muzaz Posted February 15, 2008 Author Share Posted February 15, 2008 Just looked in my workshop manual and it says nothing about the position of the rings and the diagram show them lined up I'm sure this is wrong. I thought they were installed at 180 degrees. Remember the rings have a top and a bottom. I read it somewhere on this forum that they should be at an angle ...the manual say it at page 59 step 3... but no diagram at all... Will try to find the hanes manual, even tho I dont trust it much... God knows where I hid that book!! chris Quote Link to comment Share on other sites More sharing options...
Gromit Posted February 15, 2008 Share Posted February 15, 2008 From Nige on this thread "NB - the rings have to be positioned with the gaps at 120 degrees to each other with no gaps on the thrust side (recess side IIRC)." Quote Link to comment Share on other sites More sharing options...
muzaz Posted February 15, 2008 Author Share Posted February 15, 2008 Aha! that was the thread I was looking for.. thanks Gromit what about the thrust sides? I take them to be the areas where the gudgeon pin is no? Quote Link to comment Share on other sites More sharing options...
Gromit Posted February 15, 2008 Share Posted February 15, 2008 Will try to find the hanes manual, even tho I dont trust it much... God knows where I hid that book!! From Haynes for 200 and 300tdi. "Position the oil control ring gap to the manifold side of the piston (the left side when viewed with the arrow on the piston crown pointing forward). Arrange the gaps of the middle and upper rings 90 degrees either side of the oil control ring gap, but make sure that no gap is positioned on the thrust side of the piston. See illustration" If you can't find yours, I can post the illustration. I wonder where they got their info from? Quote Link to comment Share on other sites More sharing options...
muzaz Posted February 15, 2008 Author Share Posted February 15, 2008 If you can't find yours, I can post the illustration. I wonder where they got their info from? Yes you'd do me a favour, cant find mine... no hurry mate... calling it a day for now... big boss just called! Quote Link to comment Share on other sites More sharing options...
Gromit Posted February 15, 2008 Share Posted February 15, 2008 This is the pic from the haynes for the spacing on 200 and 300tdi. (According to the Haynes, the 120 degree spacing is for the TD5) Quote Link to comment Share on other sites More sharing options...
muzaz Posted February 15, 2008 Author Share Posted February 15, 2008 thanks for the help gromit, a picture says a thousand words! all understood Quote Link to comment Share on other sites More sharing options...
Gromit Posted February 15, 2008 Share Posted February 15, 2008 thanks for the help gromit, a picture says a thousand words! all understood No problem, good luck with the rebuild, watching with interest Quote Link to comment Share on other sites More sharing options...
Les Henson Posted February 15, 2008 Share Posted February 15, 2008 Thrust side is camshaft side. 1-thou is a bit tight - where you measure on a freshly rebored engine doesn't matter as it should be the same throughout the entire length of the bore at this point. The best way to set the ring in the bore for the gap measurement is to push it in square with an inverted piston - that way it's dead square in the bore and you are not going to get a wrong reading due to the piston being at a slight angle. My 300TDi engine was bored out .020, but they were measured by another engineering company and they are 1/2 thou undersize, which is not very good apparently, as the engine will run too tight for a while. As for the oil - new shells and pistons only usually require care with engine load/high revs, so I just use the recommended oil right from the word go. However - because the pistons are going to be too tight in the bores I will be using a very high/expensive oil initially. My thinking being that cheap is cheap, and this might not be a good idea. A high quality oil will de a better job I think. Personally I would be worried about the measurements you have posted in this thread. From the comments I got from mine being half of what yours are - mine is not good, but not that bad. Turner Engineering read this site fairly frequently and I suggest you contact Frida and point her to this thread and take what she says as being the right answer. Les. Quote Link to comment Share on other sites More sharing options...
cipx2 Posted February 15, 2008 Share Posted February 15, 2008 muzaz, don't worry too much about positioning the ring gaps, the piston rings do rotate when the engine is running anyway. 180 degrees, 120 degrees, even 90 degrees will work as well. I can agree not to place a gap on the thrust side, specially the oil ring, for starters. Other than that, 180 degrees would my choice. Or 120, depending on the weather Quote Link to comment Share on other sites More sharing options...
muzaz Posted February 15, 2008 Author Share Posted February 15, 2008 Hmmm... I cant understand how I came undersize, I mean the bore is standard, I took it only for a hone not rebore... now I'm fitting standard rings and the rings are 1 thou tighter than the minimum limit! I thought that the bore should become slightly larger no? you have the wear and tear of the engine and the honing process which should have shaved some material away. I placed the rings in the bore as you said Les, with an inverted piston, they were nice and square in the bores so the measurements are pretty accurate. MaybeI should get a finer feeler guage which can read 1/2 a thou? Or else I'll file the rings to get the clearance half way between the limits. Quote Link to comment Share on other sites More sharing options...
Les Henson Posted February 15, 2008 Share Posted February 15, 2008 Were you using the 3-bar honing tool (in an electric drill)? These tools are ok for de-glazing, but if your bores are oval, then they will still be that same shape afterwards, but look nice:) When you hone your own bores, you should then measure them at 12 and 6 o-clock, and then at 3 and 9 o-clock to get a true idea of the shape of the bore. Bores always wear more on the thrust side - due to the rotation of the crankshaft and detonation will always push the piston against the camshaft side of the engine. If your bores are oval, then this type of measurement will tell you the ovality of each bore. If there is a big difference, then you are taking a big risk with what you are doing, as the rings will be round and will need to become oval in order to match the bore shape and do their job properly. The worse the oval - the bigger the chance of a ring breaking. It's very important that you know the shape of your bores before doing any other work, as you could be wasting your time and money. Put the ring in the bore and then shine a torch up the bore and see if light seeps through between ring and the bore wall at any point - this will give you some idea of how much the ring will have to deform in order to fit properly. Additionally - it's very difficult to make the cross-hatching in the bores with these tools, which is very important in keeping oil out of the combustion area at the point of ignition. A nice shiny bore is a bad thing - a finished bore should look like this- Les. Quote Link to comment Share on other sites More sharing options...
FridaT Posted February 15, 2008 Share Posted February 15, 2008 Chris No professional engine builder has time to check ring gaps. Providing the pistons and rings are the correct size for the bores they will be there or there abouts. Space the rings out evenly around the piston and fit them. Richard Turner www.turner-engineering.co.uk Quote Link to comment Share on other sites More sharing options...
muzaz Posted February 15, 2008 Author Share Posted February 15, 2008 No didnt do it myself, took it to a machine shop which specialises in this stuff, reboring honing valve grinding etc and had it honed by an appropriate tool...dont know what its called, but it was a big machine pouring oil (smelt more like kerosene!) while doing the process. Tomorrow will check again with the torch and ring... but I saw the guy doing the job using an internal dti measuring the bores every now and then Quote Link to comment Share on other sites More sharing options...
muzaz Posted February 22, 2008 Author Share Posted February 22, 2008 me again... anyone knows of a good online shop I can buy parts like valves, bearings etc from? Parts are quite expensive here! Found a shop with very reasonable prices but dont know if its a trusted one... Can I post its name here or its not allowed? chris Quote Link to comment Share on other sites More sharing options...
Les Henson Posted February 22, 2008 Share Posted February 22, 2008 You can post the link. Some companies in the UK also post abroad. Even with the cost of postage you could save some money. Les. Quote Link to comment Share on other sites More sharing options...
muzaz Posted February 23, 2008 Author Share Posted February 23, 2008 thanks les. After searching the web extensively I found this site David Vincent LTD They have a vast range of spares, and the prices are very reasonable...or at least thats my impression! They ship abroad as well, and combined shipping costs for multiple items is reasonable. What I dont know is the quality of the parts, brands etc... Any advice if I should go on and buy what I need from here? If you know of something better I'm all ears! Quote Link to comment Share on other sites More sharing options...
Les Henson Posted February 23, 2008 Share Posted February 23, 2008 The prices seem very cheap, but I can't find anywhere on that site that says what make the parts are - I would be very cautious of this as some parts manufacturers are very poor quality. The site says that all parts carry a 12-month warranty, but sending something back for a replacement or refund will be a major pain. If you have to buy something from another country, then quality of parts is more important than price in my opinion. You could ask them who makes the parts and then order on that basis - BritPart, white box (unbranded) parts should be avoided at all costs, as these products tend to fail far too soon. Les. Quote Link to comment Share on other sites More sharing options...
muzaz Posted February 23, 2008 Author Share Posted February 23, 2008 took your advice, sent them an email asking what brands they have... I wouldnt want a set of main bearings failing just after a rebuild...that would be a shame! I'm hoping for a pos reply! If anyone knows of a good shop go on, tell me about it Quote Link to comment Share on other sites More sharing options...
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