Hi,
My '68 Thunderbolt has covered a possible 130,000 miles without a full rebuild. I bought it with perhaps 25,000 already covered and I have done the rest along side my wife's 51' Flash which shows about 115,000 miles so corroborating my mileage. Even allowing for some inaccuracy in the mileage recorded by the speedos it is still quite a bit. Both have needle roller timing side conversions and have been run on 20/50 oil with inline filter.
So the dilemma is, do I strip it down and overhaul the bottom end or wait a bit longer?
Until recently even when the engine was very hot the oil light would stay off at tick over so indicating enough oil pressure. During our return from Belgium whilst enduring up to 42ºC the oil light had started to flicker and a tad of throttle was needed to turn it off. Similarly, after a very spirited run locally on a hot day, the oil pressure light behaved the same way. I will have to do a sedate run as a comparison but I suspect that the time has come for a bottom end overhaul.
Dave.
If it was me, I think I would try to measure the oil pressure to quantify whether there is a problem with it or not. That said, you've probably had your money's worth out of the current set of big-end bearings and it may well be time for a new set?
if in doubt .
Hi,
I think I will strip it down. It would be a shame to push my luck and end up with damage rather than wear.
It will be interesting to see if there is any wear in the main bearings and if the it is just new shells needed or a regrind as well. With having been run a full detergent 20/50 with a filter it will be interesting to see how much sludge, if any, has built up in the crank.
Dave.
:) :) :) :)
Dave. This is an interesting dilemma. Your decision to do it has to be the right one. As stated "if in doubt, theres no doubt". I would be very interested in the amount of crankshaft wear so would appreciate it if you could keep us in the loop.
Mike 8) 8) 8) 8)
Dave, a dilemma Im looking into, The A10, I rode a few weeks ago for 3 miles. thats the first time Ive ridden it for 11 years! Ive started it a few times over the years but it wet sumps. As you know, this means a total strip of the motor.
Do I want to do it??? The T100 was running, I thought a tidy up, so £2500 later its rebuilt.
Didnt need it but hey ho.
The recent import A50 has been stripped, the cases are still away 20 months later along with crank so if I take A10 apart how long will that be off the road AND with finances being hit by energy prices etc, will I be able to afford it?
The B40 has just been finished but has to be sold to recoup the £2500 spent on it and son needs his money out of it for his investment in it.
I suppose, as you ride it a lot, its worth it to you to check and rebuild, once the A50 is finished, Im not doing any more. Availability and quality of parts being the main hang up, machining services the next. In the past I would have machined myself, had works contacts for paint and chrome. As previous discussion quality of parts has been talked about, I liked to do my own but you just have to put up with what you can get and put that right.
Hi Chaz,
As your A10 stands for long periods some wet sumping is almost inevitable. There is a trick to avoid stripping the engine to replace the spring and ball.
Remove the pump and carefully drill out the hole that contains the ball and spring to release them outwards. Ensure that all bits of aluminium are removed and the drilling is smooth. Use some suction if possible. Seat the new ball on the back of the pump ensuring good contact all around and refit.
Dave.
thanks Dave, will look into it, but as mentioned... 3 miles in 11 years, probably needs a decoke at the least, the Triumph started that way!!
:) :) :) :)
The expensive words--"while I'm at it I'll just check"
Mike 8) 8) 8) 8)
My Question is the loss of oil pressure, i have never had a Engine end fed (Genuine bushes are fine) so how would rebuilding cure that as on the old engine worn bush loss of pressure on a end fed what controls the pressure
Wear or other damage to the end feed oil seal will reduce pressure.
Hi Paul,
Yes, with the bush the oil flow to the big ends is dependant on a good fit on the bush. This obviously helps to keep the oil pressure up. The big end shells also contribute to the oil pressure. Shells within tolerance offer resistance to the oil hence pressure is created. Worn shells offer less resistance so oil pressure drops.
No matter how good your pump is, it is the resistance to the oil flow that causes the pressure, so lower resistance results in lower pressure the pressure. A good pump will certainly ensure a good flow which is as important as pressure. At tick over the pump is proving very little pressure and very little flow so this is the danger zone. Less oil is also bad for cylinders and at tick over there almost no 'splash' up the bores.
Although it is nice to have slow and steady tick over it is probably not good idea to leave and engine ticking over for any longer than necessary.
As part of my pre strip down I will see what rpm I have at tick over and what increase is needed to keep the oil light off when the engine is very hot.
Just to throw another variable in, is the oil pressure switch working at the right pressure and, as Julian said, is the seal in good order?
Dave.
Hi,
A bit of an update. After good ride to warm things up I had a reliable tick over at 700rpm and the oil light was on. Increased the rpm to 1000 and light went out. Previously the light would not come on at all with the engine running at 700 rpm. So I have a base line to work from so next I will try a different oil switch. Although that one may not be perfect either. Is there a way of testing them?
Dave.
Hi Dave,
The switch could be tested by connecting it to a tyre inflator and calibrated gauge.
Best wishes...
Hi,
I decided that I should as even if the oil pressure switch was iffy I have put a doubt in my mind. Also, considering the mileage the bottom end has done I thought better to do it now than wait until a disaster.
So with the with the primary and timing sides stripped it was time to start having a look.
The crank pinion was quite happy to stay where it had been last 30+ years and well over 100,000 miles but with persistence and a much modified two leg puller I managed to get it off. I suspect a bit of a Loctite product had been used. I had to be very careful as the quill of the end feed had to be protected at all costs.
So once the pinion was off the inspection could begin with the outer race of the ball race being first. For those of you not familiar with the bearing used in the end feed conversion there is a radial ball race that locates the crank to the timing side. A couple of photos show what I have found so far.
You can see that the bearing surface is visibly rough but is not that rough as to be very noticeable to the touch but never the less, as I now know about it, replacement is necessary. The other image is perhaps a bit dark but look closely and the wear (arrow) to the cage for the balls can be seen. Again, once known about it has to be replaced.
I will post a few more images as I progress with the strip down.
Dave.
hi dave,
interesting insight into the relability of the srm conversion.
looking at the failing bearing in the photo i would suspect an oil lubrication issue when the engine gets hot. i understand that the bearing relies on splash lubrication and oil there will probably linger rather than travel. therefore i think srm might have a point regarding running straight oils under the running conditions you mention in belgium . but 100,000 plus miles is a big achievement.
Hi Eddie,
Just above the bearing is a drilling in the case to take more oil to the needle roller which is more than likely to exit past the ball race so oil type is probably not the problem. I have previously mentioned that this bottom end could have done up to 130,000 miles so the 100,000 is conservative to allow for inaccuracies in the speedo.
I think that the bearing that can be fitted without major alterations is probably a tad on the small side, even smaller on A10s. Ideally, as with Triumphs and some BSA singles a decent size ball or roller bearing, would have been better. Having said that, the bearing has done quite well especially when considering that these small ball bearings are holding the crank hard to the timing side. Once I split the cases I will be able to see how the needle roller part has done and it will be interesting to see how the drive side roller has fared when I get to it.
Dave.
I found similar wear in the thrust bearing on my SRM'd A10.
Converted in early 1985 and bearing changed in 2007, many miles done in that period. No significant wear found in the needle roller part.
I was very pleased with how it lasted and, of course, no bush to wear and reduce oil pressure.
Hi,
An update on the strip down.
I have the widely used and to some degree recommended sump plate with magnetic drain plug fitted on 3 bikes. With this comes the convenience of a magnet to trap ferrous bits and a drain plug to make oil draining/changing easier. There is also the gauze filter/trap for bigger bits that could block the scavenge pipe. So a belt and braces approach is a good thing is it not?
Although this should have been one of the first things to do, I removed the sump plate today and was quite pleased but also dismayed with what I found. It confirmed my suspicions that the big end shells are in fact past it but also highlighted that some 'improvements' can cause a bit of laziness that could have disastrous consequences.
As can be seen from the photo there is quite a bit of material sitting on the gauze and it is not ferrous as checked with a magnet. The plus side is that none of it got through to cause a problem with scavenging. The negative is that had I not had a functioning oil pressure light then I may have continued riding until irreparable damage was caused.
Now to get the bottom end out and split the cases. I am hopeful that the crank will be in tolerance so just new big end shells and bolts and nuts will be needed.
Dave.
Hi,
The next instalment.
Firstly if you have a stuck bolt/stud and either can't be bothered waiting for penetrating oil to work or you simply haven't got any then try a bit of heat and a candle. It does help as the melted wax finds its way down the stud and helps to ease any corrosion etc.
I now know for definite that I made the right decision as can be seen from the photos of the big end shells and true to form the drive side is what has suffered. Bearing in mind the mileage that this engine has done I would say they have done very well. You can see that rather than worn through to the backing metal the bearing surface has suffered fatigue and started to break up. Interestingly, the crank looks fine but yet to be measured so new shells may be enough. Despite this there was no discernible vertical movement in the con rods. Just in time I think.
Although the drive side main bearing is fine, it will be replaced as will all the gearbox gearings - better safe today than sorry tomorrow. Obviously the timing side combined needle roller and ball will be replaced but I discovered today that the cage for balls is in fact some type of plastic. Is this good or bad? It has taken quite a while for the cage to wear and any microscopic bits or plastic would probably be a lot less harmful than bits of metal. I will see what is available.
Tomorrow's job is to remove the sludge trap. It will be interesting to what is there after all those miles but on full detergent oil and a filter.
Dave.
Hi,
After a lot of effort with an impact screwdriver I got the sludge trap plug out. The plug is obviously not reusable and the impact driver bit did not do much better.
So after trying various ways to take a photo down a hole this is the best I can do. Very little sludge. Just some accumulated in the recess behind the plug and a coating along the inside of the tube. It will be interesting to see how much is behind the tube.
Make your own judgement but a full detergent oil and a filter definitely keeps the engine cleaner over extended mileage.
Dave.
Hi,
I forgot to mention that the needle roller part of the timing side bearing looks perfect as does the drive side roller.
Dave.
Good morning,
I have just managed to get the sludge trap tube out. Inevitably the tube suffered terminal mutilation to get it out.
This regardless of the small amount of sludge behind it - compared to a £1 coin in the photo.
I am questioning the need for this tube when running a filter and detergent oil. The question being that if the tube was not there would all of this sludge have been carried with the rest of it to filter to be taken out of the oil?
My next challenge is to remove the inner sleeve of the needle roller bearing from the crank. The fit against the crank is such that even a Stanley knife blade will not go in so, any ideas on this one would be appreciated.
Dave.
:) :) :)
Just a vague thought. Would not using the sludge trap affect the balance of the crank to any serious degree.
Mike 8) 8) 8) 8)
Hi,
I suppose it will to some extent as there being no tube will make the big ends lighter but consider how the build up of sludge over time could also affect the balance. As the crank has been balanced perhaps I should fit another tube.
Dave.
As you are replacing bearings I would use a dremel or something similar to cut the inner race and then break it off!
Kev
Hi Kev,
Yes, replacing the bearings so the Dremel idea is an option. The bearing is very hard so will take a bit of time but that could be the only way.
Dave.
if you have a welder just weld a piece of steel to the inner race and use as a slide hammer shaft , just make sure not to weld the race to the crank !!!!
Hi Bob,
I may give that a try.
Dave.
Hi,
The inner race is off. I made couple of flats with a small cutting disc in a Dremel. A bit if heat and few whacks on a small chisel had it moving.
It look like I have 0.002" clearance on the big end journals so a regrind is probably required.
Dave.
Hi,
The big end journals still have quite a mirror affect but the 0.002" wear means a regrind is probably the best option. If it had been a max of 0.0015 I would have got away with new shells.
So does anyone know of a good place to take my crank in North Lincs.?
I used to use a place in North Norfolk but that is perhaps a bit far to go.
Dave.
Hi,
It is raining so I have been indoors thinking. I know it can be dangerous but it just happens.
I have always loved the fact that my A65 would tick over very reliably at about 700rpm. To some extent I saw this as testimony to me getting the settings right. So a bit of kudos perhaps.
Thinking back to some previous posts were oil pressure was discussed it was suggested/stated that 10psi per 1000rpm was a good benchmark. So taking this idea a bit further and linking it to my slow tick over, it would imply that at 700rpm the oil pressure would be 7psi. This would fit in with the oil pressure switch being set to activate the warning light at 7psi as BSA seems to have intended it. I would assume that the 7psi is to considered an absolute minimum for the oil pressure. Also, at such low rpm, has the ability of the big ends to create an 'oil wedge' been compromised as the revs are slow and the pump is also performing at a minimum.
Could it be that over the years my slow steady tick over has contributed to some of the wear of the big end shells.
I think that I will use 900/1000 rpm and not worry about the extra fuel it will use. Also, the engine will pick up better on opening the throttle and I will be reassured in the knowledge that the is a bit more oil and bit more pressure there to protect the bearing surfaces.
Dave.
The oil pump would certainly work better at higher revs.
hi dave, the breakdown in oil viscosity at low speed and hot engine days was a reason for the oil cooler on tridents and rocket 3s. its stated in the t160 factory manual somewhere from memory i m sure. i dont know if the a65 oil pump is up to an oil cooler . of course cover it up in the winter.
years ago i owned a norton 650ss with one fitted by previous owner who swore by it for long distance motoring.
another direction is to have the crank nitrided. i had my t160 crank nitrided at p&m who said the standard crank journals are too soft. the process distorts the crank and the trident crank has to be staightened on a press afterwards. not sure if a twin would distort.
the oil cooler option would be a lot cheaper.
Hi Eddie,
The pump can cope with an oil cooler as it does not present any restriction to the oil flow.
I know that Norman Hyde produced a thermostat for the 3s so it mist have been considered that they could be running too cool. I know of a T160 rider who fitted one and the only time it opened was after riding up and down the Pyrenees on a very hot day.
The cooler will only cool the oil when the bike is moving and the hotter the air the higher the speed needed to have an affect and it is when stationary that I find that things get hot. Perhaps an oil cooler with a thermostatic fan would work as on the cooling systems of modern bikes as even on summer days it could be possible to over cool the oil at higher speeds. One advantage is that a bit more oil will be in the system.
I suspect that the high mileage is mostly responsible for the need to replace the shells and it is interesting to note that the one that has suffered the most is the upper drive side. The upper shells must take more hammer as they take the combustion pressure and if there is an issue with oil delivery and or pressure it is the drive side that suffers most.
Although on the limit of clearance tolerance, the crank journals look good so I am leaning heavily towards the mileage of the bike and the resulting fatigue in the shells causing the issue and the weakest shell went first.
Dave.
hi dave, yes i also have a hyde thermostat somewhere in the back garden where i chucked it.
i think your partly wrong about the oil cooler not working at tick over as oil is still cooling off as its pumped round. i once fitted an oil pressure guage to my t160 as the red light used to flicker on in traffic and what i noticed is that oil pressure was greatly boosted when the airflow hits the oil cooler so will help maintaining viscosity in stop start traffic conditions. speaking to srm who have a test rig recommend straight oils due to thinning oil when hot.
Hi Eddie,
The increased oil capacity and surface area of the cooler and associated pipes will help but one with a fan would be even better. Once moving the cooling will better/quicker with an oil cooler than without.
I have always used 20/50 and never had a problem over a very high mileage. I suspect that the fatigue/wear on the big ends is down to high mileage rather than the oil.
Dave.
Hi,
I am always unsure about how to compare mono grade vs multi grade. My understanding is that at a 20/50 is thinner than a straight 50 when cold so equivalent to a 20 and so circulates easier at startup getting the oil around the engine easier. At working temperatures the 20/50 and the 50 have the same properties and viscosity and so circulate with the same thickness.
If this is so then why use a straight grade oil?
Dave.
hi dave,
i also use 20/50 on my bsa s with the commando oil filter but i have 2 bsa s without filters and use straight oils in those engines. i must say the b31 seems to like the mono oil and no leaks. my only worry with multigrades is the low viscosity at tick over when really hot. i m not convinced you get 50w then although it says it on the tin. just my view.
as you managed over 100,000 miles your oil and filter did its job. which oil make did you use / recommend dave?
Hi Eddie,
When it was available in Asda I used Duckhams. At the time it was always on offer but Asda stopped stocking it. I ended up speaking to a chap who used to supply tractor oil for work and he recommended a commercial car fleet oil called Batoyle by Freedom Oils which was taken over by Fuchs, 20/50 full detergent oil. As we were doing a lot of miles I bought a 200l drum and it lasted for quite a while and worked out quite a good deal. I am now on the last 40l of a second one which has lasted longer due to doing less mileage and Covid restriction.
When I need some more oil I will have to see what is out there but perhaps not 200l this time. Fuchs still do a range of 20w/50 oils.
I think the thing is to probably avoid supermarket oils, change the oil regularly and use a filter. Generally, I did an oil change before and after a long trip.
Dave.
Hi Dave,
Multigrade oils can be fine depending on their shear stability. They can shear down below the 20W/50 stated on the can in service, which could be below the original monograde requirement of SAE40 (summer). After the oil has sheared and its viscosity has lowered you might find you have flow but less pressure, usually seeing less pressure at tick over. If your oil pump is worn damaged oil will flow back from the discharge to the suction side of the pump at low revs.
When using multigrade and experience low pressure try SAE40 first. If the oil pressure is fine go back to multigrade, change the oil more frequently and use a better standard of multigrade. If the pressure is still low check the pump. PRV, engine etc.
I wouldn't use multigrade on worn engines, the polymers and additives will increase carbon deposits.
I wouldn't use multigrade on engines with roller bearings such as the B31 as the rollers speed up the sheer.
Best wishes...
Hi Bess,
Thanks for the reply. I agree re roller big ends. As I have mentioned I do think that the drop in pressure was most certainly due to wear and fatigue with the heat of our ride back from Belgium being the final straw that dropped tick over pressure to below the 7psi that triggers the warning light. In the image of the shells it can be seen how the fatigue had caused 'worm' channels and distorted the bearing surface. It has also been suggested to me that this could be caused by acidity in the oil but why now and why predominantly one shell?
Dave.
Just done a bit research about engine oil shelf life. Most suggest about 5 years for an unopened container. I am now thinking that as I have had my oil for a few more years than 5 that, not withstanding the mileage covered, that this may have been a contributory factor.
Hi Dave,
I had a look at your shell images. To me it looks like surface fatigue, from the mileage you had from them its expected. I would say you did well, you have the PPM and fluids about right.
Best wishes...
all interesting information from bess.
duckhams oil was a lovely blue colour so looked like real oil. i havn t seen it about so much any more.
the old , long deleted esso 20/50 oil was a lovely colour and texture as well. i believe the green colour upset the greenies so it was banned in holland.
the fan cooling oil via an oil cooler is not such a bad idea as those fans are widespread and cheap and used for cooling electrics on trains, forklifts etc. only a live and neutral and could use a handlebar switch for hot days stuck in traffic.
not all roller bearing cranks need mono oil though. jap 4 s such as suzi 750s use 10/40 multigrade and will cruise at 70mph all day long. food for thought.
Hi,
I have ordered the parts and arranged for the regrind so all is going to plan. If any one is interested I may start a new post when I have every thing ready to go.
Dave
Personally, I wouldn't bother regrinding a crank with just 0.002" wear on the journals, only just over the wear limit.
I'd purchase another crank that was more badly worn and have that reground instead, the finished result should be just as good, and you'd still have the slightly worn crank as a spare.
Of course this could be a recipe for disaster if you buy a worn crank that is stress fatigued, or cracked by someone butchering the sludge trap plug, you have to exercise some common sense and caution.
Hi,
I know it is just out of tolerance but I need to use this crank as it has had the end feed conversion and has been balanced. To get another crank done would just add to the cost. If it been right on the wear limit I would have gone just for new good quality shells and new big end bolts and nuts.
I am unlikely to do another 100,000 miles on it but when the time comes I want to pass on a good engine.
Dave.
Yes you're right, I wasn't aware of the end feed or balence job.
And of course you know the history of your crank for the last 100,000 miles or so.
A worn crank from an autojumble could have suffered massive abuse in a previous life
Hi,
I should be getting my crank back this week so work can commence. I opted for Cotterel Engineering in then end and it was interesting to chat to the youngish chap and see some Sunbeam S8 bits in for some work. I have everything else plus some new sprockets, PRV and oil light switch. It is surprising how small a box is needed to send over nearly £600 worth of bits.
Dave.
Hi,
A minor issue I have to overcome is that one of the small ends is a bit worn. New bush you may say but on these late rods there isn't a bush. The gudgeon pin goes directly in to the small end. I have a spare rod that is not worn but it is quite a bit heavier than the one from the engine. In order to use it I would have to get the total weight the same as well as ensure that the small end weight and big end weight are the same as on the original rod. Within a gram is probably OK to ensure that the balance of the crank is maintained.
Rather than do this I bought some small end bushes as the rods can be opened up to take them. I considered farming it out but that would mean finding a good engineer and then waiting for the work to be done and it would incur a cost. Instead I have ordered two adjustable reamers for less than the probable cost of the work. It will be a two stage job with the smaller reamer taking out the bulk of material and the other one finishing the job leaving a good fit for the bush in a warmed up small end. Although I have fixed reamer of the right size, I could use one of the new ones to do the final ream for the gudgeon pin. I will also have two reamers for the future jobs.
Dave.
Hi,
A more accurate tot up takes the figure to nearer £700 and it does not look like a lot. Just the bottom end!
Dave.
Dave
I know your pain, The Triumph was running when I decided to decoke it, top off, barrels off, cases out, stripped, ended up powder coating the frame etc as well. £2500 later and that didnt include my time!!
Hi,
Crank collected today so just waiting on a reamer and it can all kick off.
Dave.
:) :) :) :)
As I said a while back. The final cost always involves the "while I'm at it I'll just do this-----and maybe that" its only a few my squids.
Mike 8) 8) 8) 8) 8)
Hi,
The reamers eventually arrived and I plucked up the courage to get the job done. Adjustable reamers have a limited range so two were needed to open up the small end and a final one to finish off the bush once pressed in.
Wanting to keep everything square I put the reamer in the chuck of my pillar drill and with the con rod on the bed everything looked square. The idea was to disconnect the drive belt and turn the chuck by hand and slowly feed the reamer through the small end, gradually opening it out from 19mm to 21mm and then from 21mm to just under the OD of the bush to give an push fit with the rod heated.
These are relatively cheap hand reamers and look OK but once in the chuck it was evident that whilst the reamer part fine the rest was not that straight resulting in a bit of eccentricity. B...er, I thought, but an idea soon formulated. Using the chuck in the pillar drill was not an option.
These adjustable reamers were to open up the small end to take the bush and I already had a reamer of the correct size to ream the bush out for the gudgeon pin. With lot of slow and careful work I got the small end opened up enough for the bush and and it looked nice and square.
With a nice warm rod I pressed in the bush using a vice and it lookled perfect. Once the oil hole was drilled I now had to finish it off to take the pin. I was not too fussed about the oil hole lining up with the 'scroll' in the bush as no other small end bush I have fitted has had one.
This was the part that had to be spot on so I fastened a good rod to the one to be reamed. The reamer would go through this first and it would ensure that the reamer was straight as it took out the last bit of the bush to get the correct size.
With the bush reamed out the gudgeon pin slides nicely through both small ends with the rods held together.
So job done but with hind sight I think that it would have been worth taking it somewhere to get done as it took quite lot of time.
Hi,
A bit more progress but not without a bit of fiddling about.
As the crank had been balanced with a sludge trap tube fitted I thought it best to replace the one I had to butcher to get out. So line it up with the hole through the flywheel and tap it in to place. It took a bit of tapping somehow in the process it had turned slightly so now the fly wheel bolt would not goo in fully as it was fouling the tube. B....r!
An easy solution would be to open up the hole a bit. File it or drill it perhaps but what about the bits of metal from filing or drilling? How would I know if I had got them all out?
So the answer was to remove it and re-clean the internals of the crank.
Would this mean destruction and the need for another new one? Despite seasonal brain fog I managed to recall something about tapping a thread and using a bolt like a puller. So a 3/8 BSW tap was press ganged into cutting a thread. It was a snug fit and took a bit effort to start the thread cutting process.
After few turns I though it was slipping and not actually cutting a thread at all but it had bitten in to the tube and with the turn in force the tube had started to rotate. The hole in the fly wheel now lined up easily so job done. Not quite as there still be some metallic bits in the crank so the tube was pulled quite easily and the crank cleaned out again. Tube refitted, plug inserted with some thread lock so now for rode to be fitted.
Making sure they went back the same way as they had been fitted. Plenty of clean oil applied to the journals and a smear of oil was applied to the big end bolts but not the threads. This ensured that the bolts pulled the cap to the rods without any resistance whilst the dry threads ensured the correct torque was applied.
With the cam and breather bits carefully put in place and the drive side case sitting securely on the B&D workmate the next job is to put the crank in the case and then fit the timing side.
Isn't it a sod of a job to tighten up the gearbox sprocket nut when it is all assembled so why not do it before assembling the cases. Straight forward - it should be.
More about that next time.
Dave.
Hi,
It is far easier to get a spanner on the sprocket nut with the cases still split but how do you hold the sprocket.
After a bit head scratching I cut about 18" off an old chain and put it around the sprocket and clamped the two tails together with mole grips. With suitable piece of steel through the chain I was able to hold the sprocket still whilst pulling on the spanner. As in effect I had two levers to use against each other I was able to get it really tight.
I think I would say tighter than trying to use a box spanner over the main shaft whist attempting to keep the rear wheel locked with the brake.
With some oil smeared on the bearings I put the crank into the cases and just nipped up a few bolts to check the rotation. Nice and smooth so the next job will be a thin smear of Hylomar on the joint, some oil on the cam bushes and together thewy will go.
Dave.
Hi,
I bolted the cases together today but just as an extra check on the new hand reamed small end bush I carefully put the reamer through both small ends ensuring that the parallel part was through both small ends and rotated the rods around the crank. Everything was nice and smooth.
Next job is to touch up the frame and then put the cases in the frame. This is lightest the engine will ever be and it is quite easy to built everything on to cases rather than try and lift the whole engine.
Luckily I have a bike lift so it is a simple (now there's tempting fate) matter of picking up the bottom end, turning through 180º and putting it in the frame. I will get my wife to help so that if it goes wrong I can blame her.
Dave.
hi dave,
i m surprised you dont build up the engine on the bench and block up the engine on the ground then lay the rolling chassis over. once you have the front and bottom bolts in you can lift the whole lot onto the sidestand. with the top end rebuild method i m always banging my head on the handlebars.
Hi Eddie,
I have seen this method described before but not tried it. I don't really have room to do this and apart from the handle bars occasionally getting in the way it easier when tightening things up as the engine is stable in the frame. Also, the complete engine is a heavy lump to pick up off the bench and then put it down on the floor. Being tall, I have a higher than usual bench to avoid stooping and the height difference between the bench and the frame on the lift is minimal so I am not actually lifting or lowering the engine that much.
Dave.
Ive got a big envelope of broken glasses from hitting bars, which is why I dont buy expensive ones.
Ive still got to try the lay down method but due to current lack of room its easier with the frame on the ramp
Late to the party here Dave as I rarely come on here.
I would have stripped it too. It's a lot of miles. At this point major things like big ends are most likely still A1, but cleaning the sludge trap and replacing the shells will be a much better investment than waiting until the big end shells did eventually start to fail then either need a regrind or another crank. Cleaning the trap in addition will ensure that you hopefully get another 130k out of the motor. New drive side bearing and TS NKIB bearing (if that's what you used before) will almost guarantee that.
Hi Allan,
Better late than never.
All bearings replaced with INA timing side bearing and RHP drive side. If you look back through the thread there is phot of the shell that had started to break up due to fatigue as much as anything. The photo of the total amount of sludge removed is also quite illuminating considering the mileage. A regrind was needed as the crank was 1/2 thou out of wear limits but with American made shells I fully expect the bottom end now has more mileage in it than I have.
I am interested in doing some work on a cylinder head so may in touch.
Dave.
Hi,
This is probably the last post for this topic as the bottom end is now back together. Just fitting in the frame, gearbox, primary and top end left to do.
One last thing I have bought is a gear plunger with a ball bearing rather than just a pointy bit. I fitted one in another A65 and it does make the box a bit easier to get through and it less 'notchy'.
It cannot be fitted to the A65 unless the cases are split as there is very little room because of the sprocket or the gear box cassette removed giving easy access from inside.
Dave.