Pete Lewis Posted December 12, 2020 Report Share Posted December 12, 2020 if the bores are std then std size rings there are other snags like has the piston ring groove worn so the rings are a slack fit if not reboring i would still fit a ' Stepped ' top ring ,as any small wear ridge will soon break a normal ring when it comes into contact at the top of its stroke yes must get in the bore and dull it down as its worn nice and shiney your new rings will not run in and bed down making the whole exercise a waste , with smoke and oil burning for ever called glaze busting can be done by hand or using an expanding hone pads in a drill as shown earlier very easy DIY but time consuming needs a sort of figure of eight action not upsy downsy why do you feel the crank needs a polish ??? the shells so far look fine as example .........some would put them back in Pete Link to comment Share on other sites More sharing options...
NonMember Posted December 12, 2020 Report Share Posted December 12, 2020 I agree with Pete - that looks like a hone (don't need to be too determined, it's only to bust the glaze, not to remove any metal) and new rings should give good life. Link to comment Share on other sites More sharing options...
AidanT Posted December 12, 2020 Author Report Share Posted December 12, 2020 1 hour ago, Pete Lewis said: there are other snags like has the piston ring groove worn so the rings are a slack fit Once I have pulled all the pistons, would you be able to tell from a video with me moving about? 1 hour ago, Pete Lewis said: why do you feel the crank needs a polish ?? Only reason for this is what looks like a ring of rust under one of the shells - one of the early pics 1 hour ago, Pete Lewis said: if the bores are std then std size rings Chicken and egg situation, how would I know if the bores are std? Stepped top rings sound like a good idea!! 😁 The top of the pistons are stamped with a number / letters. Is this of any use or interest? Btw, one has a different letter code! Aidan Link to comment Share on other sites More sharing options...
Iain T Posted December 12, 2020 Report Share Posted December 12, 2020 Aidan, I know the avid diy'ers will shoot me down but if you can get the block to an engine company the price of getting bores honed is really cheap, a few tens of pounds. They can also measure the bores, prior to honing and advise of size and condition. Unless you are going to make engine building a hobby the cost of buying a hone and bore gauge plus knowing how to use them and interpret results isn't in my opinion worth it. They can also advise on ring groove wear. Iain 1 Link to comment Share on other sites More sharing options...
AidanT Posted December 12, 2020 Author Report Share Posted December 12, 2020 I will at least have a chat with the machine shop. I will need the flywheel skimmed in any case as it has a coat of rust on it, so a visit is inevitable Btw, what's that coating you have to clean off things like replacement brake discs? Aidan Link to comment Share on other sites More sharing options...
Pete Lewis Posted December 12, 2020 Report Share Posted December 12, 2020 18 minutes ago, Iain T said: Aidan, I know the avid diy'ers will shoot me down thats sound advice from Iain if you are delving into the unsure world as for pistons the crown will be stamped with + something if its oversized due to being bored no marking would seem std. the is normally a sort of triangle arrow head to mark front/forwards any letter is the factory mark for grading ie the best fit of piston to bore on orig assemble so as original there were graded piston diameters cant get at it right now but grade size and letter codes are in the workshop data im sure the presevative on bare machine surfaces can be a variety of products generally brake cleaner removes most of these on production we had a product that didnt need clean off it disappeared on first use , cant remember what it was called almost a dry wax type of stuff and it stopped clutch discs sticking to flywheels with trucks in storeage Pete Link to comment Share on other sites More sharing options...
NonMember Posted December 12, 2020 Report Share Posted December 12, 2020 1 hour ago, AidanT said: Only reason for this is what looks like a ring of rust under one of the shells - one of the early pics The ring of rust was in the gap where the oil way in the shell means nothing was in contact. If there's anything flaky there you will probably have to get it reground, but if it's just surface discolouration then I'd leave well alone. The working surface looks good. As to Iain's invitation to shoot him down... While it may only be "a few tens of pounds" to get a machine shop to hone your bores, this three-prong honing tool is only 16. Link to comment Share on other sites More sharing options...
Iain T Posted December 12, 2020 Report Share Posted December 12, 2020 2 hours ago, NonMember said: While it may only be "a few tens of pounds" to get a machine shop to hone your bores, this three-prong honing tool is only 16. However as with all manual operations and even cnc machines it's much easier if you have been shown how to do it by an experienced person. The 'black art' comes hugely into play with all manual ops and can make the difference between a good job and cocking it up. It's really down to each individuals choice but I can't help feeling Aidan has a greater chance of getting a nice cross hatch by the machine shop. Iain Link to comment Share on other sites More sharing options...
AidanT Posted December 17, 2020 Author Report Share Posted December 17, 2020 Other questions for the weekend. In continuing to strip, do I need to remove the crank to check the main bearings and shells? Will I need to re- time from scratch when I replace the timing chain? Finally is there a real issue regarding tensioners? If so, are there sources for good ones? Thanks Aidan Link to comment Share on other sites More sharing options...
Nigel Clark Posted December 17, 2020 Report Share Posted December 17, 2020 You will need to undo the main bearing caps to look at the state of the shells, and lift out the crankshaft to see the opposing shells that are fitted in the block. Removing the timing chain will require re-timing from scratch unless you put the chain back without anything moving - but you need to remove the cam to check it for wear and the crankshaft as above. Timing tensioner and chain replacement... Unless it's badly worn with groves from the chain, keep the original tensioner. When replacing the tensioner and/or the timing chain, go to a reputable supplier. Pay for a top quality replacement e.g. chain from Germany, not further east! I've seen chains from India where the sides of the links were so rough it would quickly cut into the tensioner blade. If you don't mind me saying, I feel you need to really get your head around how far you're going with this engine rebuild. Half measures when rebuilding a tired engine usually end in disappointment. Doing the job thoroughly, everything needs to be stripped, cleaned, inspected and measured before deciding what machining is needed. Then you're ready to rebuild, with clinical cleanliness and precision. The result will be an engine that's strong and trouble free for years. Please keep asking any questions, we're all here to help and to learn. Nigel Link to comment Share on other sites More sharing options...
Pete Lewis Posted December 17, 2020 Report Share Posted December 17, 2020 removing the split pin that holds the tension blade pin in place is an interesting escapade you need to read up cam timing and sprocket timing carefully you can set the cam lobe tdc with the rockers or make a piston stop and use a dial indicator more on this later Pete pete Link to comment Share on other sites More sharing options...
Peter Truman Posted December 18, 2020 Report Share Posted December 18, 2020 In recent times I’ve left the pin and split pin in place and pulled the old tensioner spring out intact by rotating it around and opening the two blades of the spring a little similarly I put the new spring in by opening the two leaves a little to enable the sleeve part of the spring to push past the locating pin. I haven’t had any subsequent issues as before fitting the timing chain cover the two leaves of the tensioner spring are slightly sprung apart, I assume the pressure exerted by the spring closes the two leaves of the spring up! Time will tell but it’s relatively easy to remove the timing cover and fix! I have a new set of duplex cam and crank sprockets plus timing chain (origin unknown) do I need a special timing chain spring tensioner? Is it wider Link to comment Share on other sites More sharing options...
thescrapman Posted December 18, 2020 Report Share Posted December 18, 2020 That trick with the tensions only works for simplex tensioner, duplex tensioner are too wide for the gap. THAT is when it gets interesting doing the split pin. Link to comment Share on other sites More sharing options...
Anglefire Posted December 18, 2020 Report Share Posted December 18, 2020 When I fitted my duplex chain (Canley Classics from memory) I don't recall any particular issues with the tensioner. I do know the timing is every so slightly out- as it happens to the good as it effectively brought the torque down which is no bad thing on a 1500. Link to comment Share on other sites More sharing options...
AidanT Posted December 18, 2020 Author Report Share Posted December 18, 2020 I've seen a full kit on Paddocks for a duplex system with German Chains, but its around the £100 mark - Is it worth the investment? The car however will not be a daily whilst I own it so it will never do a massive mileage I will buy the chain etc, once I have added pictures on here and got your opinions on both it and the sprockets; I will check the chain as per the manual before I remove it 10 hours ago, Nigel Clark said: If you don't mind me saying, I feel you need to really get your head around how far you're going with this engine rebuild. Half measures when rebuilding a tired engine usually end in disappointment. Doing the job thoroughly, everything needs to be stripped, cleaned, inspected and measured before deciding what machining is needed Nigel I want to do this properly, but don't own any of the kit to measure anything apart from a micrometer and feeler gauges. The head is being done professionally, so I may end up taking it to a machine shop in any case, but if that's the case I want to have the knowledge to be specific on what I want them to do, That's where your opinions are important here. Once all is sorted, I will obviously need help putting it all back together again !!! Aidan Link to comment Share on other sites More sharing options...
NonMember Posted December 18, 2020 Report Share Posted December 18, 2020 13 minutes ago, AidanT said: I've seen a full kit on Paddocks for a duplex system with German Chains, but its around the £100 mark - Is it worth the investment? I would say not unless you're intending to seriously tune it up. The duplex gives no real benefit other than being stronger. You don't need it any stronger unless you rev to silly revs (8000+). The reason the 2500 engines had a duplex chain was purely that the first incarnation of that engine was the PI, with all the extra load of the metering unit hanging off the cam. Incidentally, a "fast road" cam with long period actually puts less load on the timing chain than a short period cam. It's down to the slope of the valve lift, which has to be quick if the period is short but can be more gentle if you've got plenty of period and overlap. Long period with a fast lift causes loss of torque at low revs, so it's more of a race cam than a fast road. Link to comment Share on other sites More sharing options...
AidanT Posted December 18, 2020 Author Report Share Posted December 18, 2020 Should have said - any recommendations on chain manufacturer? i see there are quite a few Rolon's in the market place - no idea if these are German or even if its like Lucas - a name and not a real manufacturer (Shopping list growing ! 😁) thanks Aidan Link to comment Share on other sites More sharing options...
rogerguzzi Posted December 18, 2020 Report Share Posted December 18, 2020 Hello Aiden Rolon is Indian and rough Irwis is the good one there may be others? I have a Rolon you can have for free! Roger Link to comment Share on other sites More sharing options...
Nigel Clark Posted December 18, 2020 Report Share Posted December 18, 2020 47 minutes ago, AidanT said: I've seen a full kit on Paddocks for a duplex system with German Chains, but its around the £100 mark - Is it worth the investment? The car however will not be a daily whilst I own it so it will never do a massive mileage I will buy the chain etc, once I have added pictures on here and got your opinions on both it and the sprockets; I will check the chain as per the manual before I remove it Nigel I want to do this properly, but don't own any of the kit to measure anything apart from a micrometer and feeler gauges. The head is being done professionally, so I may end up taking it to a machine shop in any case, but if that's the case I want to have the knowledge to be specific on what I want them to do, That's where your opinions are important here. Once all is sorted, I will obviously need help putting it all back together again !!! Aidan Hi Aidan, A good machine shop will measure bores, pistons, crankshaft etc and advise on what needs doing, e.g. reuse old pistons with new rings and bores honed or rebore and new pistons, refit crankshaft with new standard bearing shells or regrind and fit with undersize shells. Don't worry about having to do all the measurements yourself. As for a source for the timing chain, my advice is to go to a reputable supplier (not necessarily the cheapest) for all your parts, including the chain. We're talking of the kind of supplier that would only sells parts he's happy to fit to his own Triumphs, for example Chris Witor or Canley Classics. As a further check of the new timing chain, run your finger round the edges of the links. If there's any feeling of roughness, reject it and find another. One more suggestion... Practical Classics magazine is running a seven part series on the complete strip down and rebuild of a Spitfire engine at TRGB. It covers pretty much every step of overhauling a small Triumph engine with colour photos (unlike a Haynes manual), and words explaining each step. Part 5 is out now in the January issue, no doubt the earlier parts can still be purchased as back numbers. I have to admit a connection, as I photographed and wrote this series for Practical Classics! Nigel 1 Link to comment Share on other sites More sharing options...
johny Posted December 18, 2020 Report Share Posted December 18, 2020 Does it really need new timing chain and sprockets if youre not going to do huge mileage? Remember you could be replacing original items with poorer or at least unknown quality ones.... 1 Link to comment Share on other sites More sharing options...
AidanT Posted December 18, 2020 Author Report Share Posted December 18, 2020 16 minutes ago, rogerguzzi said: Hello Aiden Rolon is Indian and rough Irwis is the good one there may be others? I have a Rolon you can have for free! Roger Hmm just got mailed back from Canleys and they swear by them - I get most of my kit from them. Maybe you got a fake ???? We have only ever sold the Rolon branded 105131 timing chains (thirty plus years), never had an issue with quality. Tensioners come from the same supplier, and the same sort of timescale. Canleys Regards 5 minutes ago, johny said: Does it really need new timing chain and sprockets if youre not going to do huge mileage? Remember you could be replacing original items with poorer or at least unknown quality ones.... This is provisional Johny! I've not even taken the cover off yet - As said I will be adding more pics over the weekend to get everybody's view Aidan Link to comment Share on other sites More sharing options...
rogerguzzi Posted December 18, 2020 Report Share Posted December 18, 2020 Hello Aiden Fair enough but the edges are rough and wear tensioner butthen it depends on mileage to be done! Plus just remembered the one I have is a Duplex one Roger Link to comment Share on other sites More sharing options...
Sparky_Spit Posted December 18, 2020 Report Share Posted December 18, 2020 Hi Aiden - one tip before removing the timing chain and sprockets..... Set the engine at top dead centre with piston no1 on the firing stroke. The timing marks that are scribed on the engine's front plate and sprockets should all line up. There may also be some centre punch marks. Mark all these with a tiny blob of paint. Then take some pictures for reference when you put it all back together again.. See below for what I mean. 3 Link to comment Share on other sites More sharing options...
AidanT Posted December 18, 2020 Author Report Share Posted December 18, 2020 Thanks Great advice will do this Sunday Cheers Btw, is County a good chain manufacturer??? Link to comment Share on other sites More sharing options...
ludwig113 Posted December 18, 2020 Report Share Posted December 18, 2020 whatever you do, take LOTS of pictures before and during the dis-assembly , building an engine isn't difficult but you have to be methodical, make notes and take pictures. unfortunately you will probably have to buy some semi specialist tools especially if you're doing timing/top dead centre etc. paul Link to comment Share on other sites More sharing options...
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