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Post by tzsteve on Jul 25, 2018 14:25:44 GMT
A few jobs to be done while i wait for the new crank to arrive ( thanks for the link gav ) first; is to repair the head. this is what happened when the big end bearing cage fell apart it took me by surprise as its not even a particularly fast engine and only puts out about 15 BHP. i have used this type of mandrel for about 35 years. its basic but it works. this requires the stud holes to be tapped deep enough for the bolts to hold the head inplace during machining. the lathe set up i prefer to use a rotary table and a single point tool to do this work, but the radius on this piston crown is about 196mm so a very long cutting tool would be needed ( this would bring a lot of problems ) so for this job i used a form ground tool having the same profile as the piston crown. the squish band was re-cut, i only needed to cut back into it by about 0.4 mm. then the gasket face was re-cut, this needs to be set back 0.6 mm to keep the original quatrinni specs. there are a few little marks left on the squish band but these are only a couple of thou` deep so are not a problem .......................................................... second little job ( the carb ) ive been using a 34 mm amal for the last couple of years its a nice carb but too big for this engine. due to a lot of luck and someones generosity i now have a 30mm PHBH. i dont want to change the manifold as it is well blended and does the job well. so i needed to alter the back of the carb to suit the rubbers that i have ( yes i know that stepped rubbers are available but standard 34mm rubbers are easier to find ). so a little aluminium from the scrap bin was machined down, with a groove in the right place to match a 34mm dellorto rubber. fitting this was straight forward chill the carb and put some loctite on the back of the carb then heat the ring and place it onto a bench and with one quick movement push the carb into the ring ........................................................... the crank has a welded pin so splitting it can be a little difficult. its only an ETS crank and quite cheap. they are actually cheaper than the "DRT" rod kit that i fitted to it. so while the new crank is coming from the dealer i am looking for a much better big-end bearing,
still a few more jobs to do yet
any suggestions on the bearing gents?
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Post by henri on Jul 25, 2018 19:14:45 GMT
am always jealous of your play-pen an skills . as for bearing , when looking into changing rod on a crank for the t5 barrel experiment ,solved by getting a ready made crank from a gent on here . i discovered worb5 us machined early p200 rods to fit onto smally pins . not sure what bearing there using but its same inner dimension as smalls crank . if its same outer dimension as the rod you use ,a bit of investigation , or use a early p200 rod ,slimmed at big end ,packer below barrel (there 110mm long) an the heavy duty 16 to 15 little end conversion bearing .just a thought . H
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Post by gav on Jul 25, 2018 19:47:09 GMT
Nice job Steve it's looking good 👍
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Post by tzsteve on Jul 25, 2018 21:07:44 GMT
the standard big end bearing is 20 x 26 x 11.8 INA do a very nice bearing 20x26x12 i`ve used them in the past but at £10 each and only in packs of 10 plus P+P they are a little expensive when only using one i think maz do a silver plated version for about £14 or £15 passably the INA bearing in their wrapper
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Post by tzsteve on Aug 3, 2018 14:32:35 GMT
On the last build i used a DRT 105mm rod kit with a silver plated big end cage very nice but it needs an 8mm packing piece also the rod needs a chamfer machining on one side so that the rod can fit into a primmie/ETS crank ( a bit too much work for now ). for this repair i plan to use a standard length rod, so the packing piece goes ( anybody want an 8mm packing piece for a quatrinni M1 for the cost of postage ?) this means a little fresh blending is required at the transfers. ................................ so out with the toys a few burrs and stones for the rough work a few rubberized stones these are nice for getting close to the final finish prior to a quick rub with 200 grit emery cloth these are the die grinders, if you are on a tight budget get the rotozip. if you are considering the Fordom flexidrive system get the reversable motor sometime and a few cups of coffee later this is close enough the plan is to raise the exhaust port by another 1 to 1.5mm. one problem when grinding plated barrels is the risk of lifting flakes of plating from the port edge when grinding i hope to see pugwash for this as he has a nice collection of diamond burrs and a lot more experience of grinding ceramic coated barrels than i have. .................................. a quick look at the cluster to see if there are any signs of the welded cog moving or the weld cracking. and all looks good. also, still waiting for the crank to come from the dealer and still looking for a stronger than standard big end bearing. any tips gents?
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Post by tzsteve on Aug 3, 2018 14:36:01 GMT
a little time to spare so i decided to make a simple mesh filter for the carb. just an old flour sieve found at work, a 60mm jubilee clip. a little super glue, and some bicarb soda. once the mesh was fitted and trimmed to size i ran some glue over the sharp wire spikes then dipped the bellmouth into some bicarb soda. then a quick rub down with a file and some emery cloth. job done.
................................................................
i posted something like this a while ago but photophucket messed all my photos up so account closed and deleted. so here it is again
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Post by trackten on Aug 5, 2018 7:54:43 GMT
Great thread this one - envious of your lathe skills
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Post by pugwash on Aug 5, 2018 10:19:24 GMT
If you can wait a couple of weeks I’ll do some porting for you under your supervision as I know you’ve already worked out your required port timings. Am I welding the pin on the new crank ?
You’ve done a great job of resurfacing that cylinderhead.
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Post by tzsteve on Aug 5, 2018 11:58:48 GMT
see you after your little holiday,
re the port timings, my experiance is based on old scool expansion chambers so its suck it and see, then do some more. i know the newer kits have more hype than power but lots of potential
thanks the welding offer
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Post by tzsteve on Aug 8, 2018 14:34:01 GMT
another day and the crank has arrived, the task today is just to check the crank so a quick check to see if it is true. total run out is about 0.015mm or 0.75 thou in old money which is pretty good. as i have not been able to find a big end bearing that is significantly better than the standard item i am not going to split the crank. if the crank was being split the cutting and grinding for the bigger inlet timing would be a lot easier and considerably quicker as most of the work could be done with a bench grinder. so its going to be done by covering the big end with rags and tape ( i dont like doing it this way ), then out with the die grinders and other whizzers. cutting the inlet to the points marked by the yellow tape ( only used for clarity in the photos ) will give an inlet of about 195-200 deg at best guess. i`ve seen cranks from race engines with the inlet time being considerably bigger than this when the cutting is finished i will drill a hole in one of the crank webs to try and get the balance a bit closer to symetrical again. this is how it was when it left the factory i guess this crank suffered a little hammer rash in the factory as there are a couple of small dings in one crank web, and signs that the thread has been in conflict with a metal object at some time, but nothing too serious. thats the checking finished and work stops for today as i have some lathe work that needs doing. ......................................... another day with the crank. and a couple of hours with the wizzers and cutters then a quick rub down with some 80 grit emery cloth, also a little de-buring with a smooth file, if this is not done the crank can catch on the inlet pad as the crank turns. a good dunk in the bucket of paraffin / diesel. then drill a small amount of the crank away. the crank was 20 grams lighter when i had finished the grinding. the theory is that by removing some metal from the opposite side of the web i can reduce the out of balance effect to some extent. and then another couple of good dunks in the paraffin / diesel. the work stops now as pugwash who is welding the pin for me has other commitments at the moment.
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Post by tzsteve on Sept 12, 2018 14:43:25 GMT
so continuing with the rebuild, its all quite simple and straight forward remove the old bearing from the case. i used a simple slide hammer type of puller after heating the case a little the bearing came out nice and easy.
my case uses a larger bearing than the standard type its a 205 type similar to a lambretta mag bearing. i had a drift and mallet ready but after heating the case a little the bearing simply dropped in. i always find the bearing a little difficult to remove from the crank, so i have exaggerated the chamfer that is already ground on the inner track this should make it easier to remove in the future.
the two sides go together, tighten the bolts around the crank first then continue to the other case bolts. oil the two con-rod bearings. fit the piston. lower the barrel into the case, place some solder on top of the piston crown, fit the head. give the crank one turn to squash the solder. remove the head and measure what the solder has been compressed to 1.00 mm is the target, then decide how much you need to lift the cylinder by ( this is done by using the correct thickness gasket paper). my head clearance of 0.94mm is ok. so no gaskets will be used just some gasket goo. now the piston ring is fitted to the piston, some gasket goo is put on the barrel gasket face and a little suitable goo to the head. the barrel and head are now fitted and torqued to about 14 NM. at this point i realised i had lost the nut for the small gear cog. bugger job stops for a couple of days while i wait for some M12x1.5 A4 nuts to arrive
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Post by tzsteve on Sept 19, 2018 15:12:05 GMT
so a few more hours and a little more work
again its all pretty simple stuff
i got to this stage and decided to replace a few cables when i realised i had;
9 clutch cables. only 1 gear cable. no throttle cables. and would need to make a new choke cable. also no hose clips to fit my fuel pipe.
so job nearly done.
i used a jubilly clip as a temp item to test the engine, engine fires up but carb needs some work as its new to this engine.
i have power to the battery which is always handy.
now the job is on hold for a few days while the few bits arrive in the post.
i know this sort of stuff is all simple and has been posted many times. but these are my ways of doing things and a lot of my old photos had been screwed up by photofucket.
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Post by pugwash on Sept 19, 2018 17:03:55 GMT
Hi Steve, Engines looking good... I’ve got a set of needles/needle jets, pilot jets and a range of main jets you can use to set your carb up, just call in over the weekend if you get the chance and I’ll dig them out for you.
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Post by tzsteve on Sept 19, 2018 17:24:06 GMT
thanks cap`n. i`ll drag the lady along as well
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Post by artidaz on Sept 19, 2018 22:10:05 GMT
Steve, attention to detail is great mate, photos with detail txt are helpful
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Post by tzsteve on Sept 20, 2018 15:28:59 GMT
thanks artidazsome of my ways are not "correct" but they work for me
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Post by vinrouge on Sept 20, 2018 16:24:20 GMT
Amazing work as usual, technical skills above and beyond my limited abilities, very envious.
Inspired me to get my a$$ in gear and sort out my knackered engine
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Post by nickj on Sept 20, 2018 23:29:33 GMT
Nice stuff and always interesting to see how others work. I use a similar set up for the clutch build on the motor but welded an old bearing on top of the spacer. I found that stopped the tendency for the spacer to try and twist off centre as you tighten up the spring, particularly with higher rated springs. Pinched the idea off a tool sip sell...
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Post by gugne on Sept 21, 2018 10:25:29 GMT
Great thread. I'm restoring an ET3 now. Always looking for tips. Why did you build the clutch in the basket rather than building it then dropping it into the basket after?
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Post by tzsteve on Sept 21, 2018 14:44:10 GMT
its much, much easier this way some times i just cant "flip" the built clutch in more so with some of the aftermarket clutches thats why sip and beedies sell a "special" tool to do it this way
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