mahatma Posted January 18, 2004 Share Posted January 18, 2004 I'm trying to get some new main bearings for my engine re-build but the code that is supposed to be stamped on the bearing ladder is no longer there The code on the crank is fine but how can I go about determining which bearings I need to order ? The engine is still in bits at the moment, so I have the crank, block and bearing ladder all separate. Thanks Andy Link to comment Share on other sites More sharing options...
Roger King Posted January 18, 2004 Share Posted January 18, 2004 Technically incorrect, but pragmatically often acceptable answer is simply to fit mid-grade bearings. The grades are in steps of approximately .0002", but I've seen more than one K-series with the main bearing housings .003" out of round. Worrying about a grade that is fifteen times smaller than an inaccuracy in the system has always struck me as being a little pointless. I should point out that we would correct such a main housing, but it is not uncommon after the engine has run for a bit. Link to comment Share on other sites More sharing options...
Roger King Posted January 18, 2004 Share Posted January 18, 2004 Technically incorrect, but pragmatically often acceptable answer is simply to fit mid-grade bearings. The grades are in steps of approximately .0002", but I've seen more than one K-series with the main bearing housings .003" out of round. Worrying about a grade that is fifteen times smaller than an inaccuracy in the system has always struck me as being a little pointless. I should point out that we would correct such a main housing, but it is not uncommon after the engine has run for a bit. Link to comment Share on other sites More sharing options...
mahatma Posted January 18, 2004 Author Share Posted January 18, 2004 Thanks Roger. I'm not sure if I understand right, but are you saying that; given the overall engineering tolerances in the engine, using the middle grade bearings is unlikely to give me any problems ... or should I take the crank, block and bearing ladder to an engineering shop and get it checked for roundness and then get a new set of bearings ? I'm not even sure where I would take it, if the engineering shop route is an option, can you recommend somewhere ? Regards, Andy Link to comment Share on other sites More sharing options...
Jason Plato Posted January 19, 2004 Share Posted January 19, 2004 To support what Roger states , I understand the uprated bearings - as used in the R500 are / were only available in one size . Link to comment Share on other sites More sharing options...
Roger King Posted January 19, 2004 Share Posted January 19, 2004 It would be a good idea to have your main housings measured, but you must fit the cylinder head too with a K-series before this is done. In the unlikely event that the housings are badly out of round they should be corrected. Scholar can do this, but it is normally unecessary. In most cases, you will probably be OK just to fit mid-grade bearings. I must however point out that this has to be your decison and your responsibility because I haven't seen the engine. Link to comment Share on other sites More sharing options...
mahatma Posted January 19, 2004 Author Share Posted January 19, 2004 Roger, I understand the risks that you are suggesting ... but I absolutely appreciate the advice. I still have the bearings that I removed, separated out in pairs 1 to 5. On closer inspection, I noticed some very small markings on the back side of them - I'd have to get a lens to read them properly but they appear to be numbers. Is there any way that I can collect these markings and use them to specify the new bearings ? or are they just batch number etc ? Also, does anyone know if the bearings are matched pairs; i.e. are the pair for No.1 journal going to be the same size or could they be different top and bottom ? Kind regards Andy Link to comment Share on other sites More sharing options...
CHRIS CLARK Posted January 19, 2004 Share Posted January 19, 2004 I believe the 'new' type main bearings that are fitted to R500's and the high powered ones are a 'one size fits all' anyway. Link to comment Share on other sites More sharing options...
Colin Heseltine Posted January 19, 2004 Share Posted January 19, 2004 The main bearings are not in matched pairs. You have to buy each half as an individual item. The halfs that you require depend on the combination of codes of the crank and block. With the thicker half (where there is a difference) being fitted in the ladder (not the block). The half shells are colour coded (green - thin, blue - inter, red - thick). I have just rebuilt my bottom end and it required red and blue for no. 1 and all blues for the remainder. Also note that you must specify whether the shell half is grooved or plain as well. CHECK CHECK and CHECK again prior to ordering and check again as you fit them. Best of Luck. Colin Link to comment Share on other sites More sharing options...
mav Posted January 19, 2004 Share Posted January 19, 2004 Colin, That is the problem. Some of the codes are missing!!!! Link to comment Share on other sites More sharing options...
Jason Plato Posted January 20, 2004 Share Posted January 20, 2004 well 2 birds with one stone then ........... get the R500 uprated bearings , they are only in one size ( as we all keep saying) so you have no option on size to worry about Link to comment Share on other sites More sharing options...
mahatma Posted January 20, 2004 Author Share Posted January 20, 2004 Thanks guys ... this does sound like the sensible option, but is the manufacturing process the same for the R500 cranks and are the journals the same size ? I guess what I'm asking is, are the manufacturing tolerances much more stringent on the R500 crank, block and bearing ladder enabling Minister to only spec one bearing size Thanks Andy Link to comment Share on other sites More sharing options...
oilyhands Posted January 20, 2004 Share Posted January 20, 2004 I thought the R500 only had uprated rod bearings in VP2 material, I want aware of any uprated mains.... Oily P.S. rogers advice is sound, use the mid rated bearings, a light polish on the crank will minimise the risk of any tight spots. Link to comment Share on other sites More sharing options...
mahatma Posted January 20, 2004 Author Share Posted January 20, 2004 Yet again BlatChat saves the day. Roger, Dave(s), Chris, Colin; your advice and comments are genuinely appreciated. A set of mid-grade bearings it is then. Kind regards Andy Link to comment Share on other sites More sharing options...
Slipper man Posted January 20, 2004 Share Posted January 20, 2004 To confirm what Oily says - the upgraded R500 bearings were big ends - the mains are standard Rover parts. And very cheap Link to comment Share on other sites More sharing options...
mahatma Posted January 20, 2004 Author Share Posted January 20, 2004 OK, could someone just confirm that a full set of mid-grade main bearing means that they are all BLUE - block side and bearing ladder side? I just want to make sure that I get the right ones. With the 3 middle bearing ladder shells being grooved. Thanks Andy Link to comment Share on other sites More sharing options...
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