With the state of the top end you should definitely strip the bottom end, it could be bodged as well, I’m just trying to get you to do more videos because I find them very entertaining, thanks keep up the good work
As it was running well, I’d leave the bottom-end and ride it for now, and possibly strip it in the winter if you think it needs it. Too much riding time can be wasted in the garage (ask me how I know!). Les
Adrian, one solution is to look back to the past before helicoils when engineers turned up an internal/external threaded bronze insert. This method was used by BLR engineering at Surbiton, Surrey having done a few for me.
Trevor Barnes was the leading light at BLR engineering, known for Triumph twin exhaust stub repairs, valve seats, bronze thread inserts, oversize valve guides etc etc. He has made an entire gear cluster for his vintage 500cc moto guzzi race bike, he fell off at Goodwood, both him and machine sliding across the grass some years ago. Going there entailed a 50 mile round trip motorcycle ride, happy days. 😊
Interesting videos Adrian! A 90 year old friend who is an accomplished vintage m/cycle engineer said in reference to your engine that someone may have fitted an alloy piston made in Italy or Australia! The alloy is a bit 'leady' and he did say that you need 6 or 7 thou clearance. Interestingly, he said that there are no pistons made in the UK anymore.
Don't strip the bottom end, as if it gets noisy, it will give you a winter project. A man of your calibre can deal with that. Plus it will give you the opertunity to see how the JB weld fairs under the summer riding. You can take measurements of the position of the centre of the JB weld threaded hole with respect to the other three bolt hole centres if you need to rework it.
I've used JB weld for years on speedway bikes, forever breaking and stripping things on them. Biggest issue I find is the metal breaks, the jb weld doesn't. Wouldn't use it on a head stud but on anything else like tappet covers, exhaust studs, inlet studs etc, perfect
I would never have thought of using a Helicoil in JB Weld! I HAVE used JB Weld on my truck to fix the Differential (where someone had not shimmed it properly and caused a side bearing to fail), and it's held for 15 years now! I expect that your fix will be as good as permanent!
It's a very good product that can rectify a whole host of issues. Not the 'best' engineering fix by a long chalk, but it works - as you've definitely found! 😁
Thanks for the video. I have a 1937 VH with the later enclosed valve cylinder head so pretty much the same as yours. Looking forward to the bottom end strip.
With the amount of booger on the top end I would crack the bottom open and have a look. I still say some hack started to rebuild that thing and found out they were over their head. Slapped it back together to get rid of it quick. You might get lucky and the jackwagon stopped at the topend and the bottom is fine. Good luck on whatever you pick. For the rocker covers JB weld works great. I had a chevy v8 that had 2 out of the four bolts on the valve covers strip and I jb welded studs in place. Never leaked a drop after my roadside fix.
I would flush the crankcases and look for glitter. If there was nothing untoward, I'd go ahead and put some more miles on the bike. A winter strip-down will tell you how well the top end rebuild has succeeded as well as revealing the health of the bottom end.
26TPI is cycle thread, I used to get taps and dies from place down on south coast (Tracey Tools in Devon) Never found JB Weld to work well on things that get hot but it is one of the highter heat epoxies. I would strip it, even if you want to get out there on it, failed big end, main bearings or timing side will ruin your day. You can check crank for proper alignment, make sure magneto base isn't worn strange shape and needing shims, (either mag or crankcase) and check the oil pump isn't too filthy or worn out
My W/NG nipped up after a rebore. The bloke who bored the barrel gave only 4 thou clearance. I honed the barrel out an extra thou or two, cleaned up the piston and she's running as sweet as a nut! Lesson learnt, always check the piston to wall clearance.
So many rebore companies don't understand that older engines need bigger clearances. A friend got so fed up with poor rebores that he refuses to give them the piston any more. He tells them the bore size that he wants, and when they ask for the piston, he refuses!
Given how relatively simple and easy this engine is to strip, I'd finish the head work, get it back on the road for Summer, then do a complete strip over next Winter. Even though the bottom end sounds fine, you may well find something that "isn't quite right" or not not quite in spec and then your looking at possibly more machining work and/or sourcing and waiting for new parts, all of which = more time off the road. If the bottom end felt or sounded bad then it's a no brainer, strip the whole thing. JMO
@@phils2180 I'd considered it, but in the end stripped it. Good job I did - loads wrong inside. I made video parts 3 and 4 to show how bad it was, and the finished bike after rebuilding. They are both on my TH-cam channel 😊
I would definitely strip the bottom end, given what you have found so far. That is good news about the head bolt threads as they are the most critical ones on the whole bike.
you dont need to strip the bottom end but you need to pull it out of the frame , inspect it thurerly ,conrod play , distribution , oil pump , if its all ok just fit it back and go for the races . cheers!
@@williamnethercott4364 ARIEL kh 500 twin 1948 model ,,, rebuilt it and rode it but had to sell it years back ,still regret it . some day i will have another one .cheers!!
I have just read down the other comments and see someone already made the same suggestion as me . Also those look like stainless bolts on the rocker covers , and where used in cast iron can pick up threads after time .
I would leave until after the summer as it was running fine. Enjoy the summer then investigate, after the horror of the top-end you can't risk leaving it too long.
Bye the bye , my dad had an Ariel Square Four block to hold the shed door open when I was a lad 65 years ogo, could buy a shed for the price of one today hahaha. Good luck.
I can see why you are torn regarding whether or not to strip the whole thing. If it was mine I’d check the big end for play in both directions. If no wear then reassemble and enjoy.
Hello Adrian, 1 On ringed piston engines the bores should be substiantially parallel. If tapered as your trusty Arial was the rings will expand and contract with each stroke, which could well lead to fatigue cracking of the rings but will certainly wear out the piston ring grooves. 2. I don't like helicoils as it is possibe to ping out the end of the coil whilst screwing in the bolt or stud , especially if working blind and the bolt goes in at an angle. Also the top end of the helicoil has to be a turn or so below the surface or again the bolt or stud can lft out the insert end. 3. What I have done is do a bit of research and find a thread bigger than the bolt which has its minor dia. a bit bigger than the original thread major dia. Then tap the housing out that size and make an insert of the same material as the housing or maybe a stronger grade, leave the threaded end on the bar and screw that in tight into the housing. Saw it off above flush then in the Mill, mill it back to almost flush then diamond file down to flush. Next fit the mating part and spot through with a drill that is a close fit in the mating part's hole. Remove the mating part and next drill a small hole down at the intersection of the insert and the housing and turn up a slightly tapered pin to be a press fit into the hole. Press in, cut off excess and finish flush. This axial pin then stops the screwed in insert from ever turning. Set for centre of the spotted through hole and drill and tap for the original size. Smallest insert I have done is 10BA on a 1947 model aero engine crankcase, so should be a lot easier on motor bike sizes! For cast iron parts the inserts could be made from mild steel though cast iron could be used. Best to use mild steel for the axial pin. On my 500 DB Gold Star the big ends as fitted by others never seemed to last. 2 years at best. So when the timing side crankshaft broke I fitted the new shaft myself after getting it nickel plated to bring it up to be a press fit in the steel flywheel and also fitted the new roller big end myself, corrected original BSA manufacturing faults as I went (conrod big end bore had a false start so was tapered) and that assembly went for many years and did not fail..
Thanks for that detailed response - very informative. I might well repair the head threads like that - particularly so if my JB weld 'cure' fails. It would be very satisfying to fix it 'properly' 😊
Hi Adrian, I well recall my late Dad, a very experienced mechanical engineer, explaining to me that coarse threads were used to secure studs in cast iron blocks and fine threads were used on them to secure the head for the reasons you explained. So, how were the original factory fitted heads secured? With fine threaded bolts? If so assuming the barrel is cast iron my Dad would have said they were wrong. The lass or glad who fitted the larger bolts coarser threaded bolts may well have been worrying about the old fine threaded ones stripping out of the barrel under load. Since the threads cleaned up easily they must have been formed well, somehow muck has got down them over the years. And, while I'm at, what was with that hole in the top of the carb? I'm amazed that no cylinder gasket was used, but who am I to argue?
Thank you for your very information comments. Good news that the cylinder's head bolt threads cleaned up, so a course thread is what I have to use - as I have no choice. Should work OK. 🤞 The ground head 'gasketless' seal surprised me, but looking at friends bikes in the Ariel Owners Club - it works fine. Probably because both head & barrel are the same material, which helps.
Change your gear case oil and inspect. If you want you can have a sample tested. Unless you have crankshaft seal issues put the top end back together and Ride!
Gearbox on my MZ ts150 is a bit noisy, but the gears go in fine, so I changed the oil and left it, still going strong. So don't beat yourself up, get out and ride it. If it starts to feel iffy it will keep you occupied in the winter😂
Doubt it applies to four strokes (maybe it does?) but I have a Fireblade but recently got back into two stroke scootering again (Vespa PX200E). Learning this time around, I realised most of our seizures on Lambretta's/Vespa's back in the 80's were because we tuned them but did not understand two stroke mixed fuel is: 1 Fuel. 2 Lubrication and most importantly 3 COOLANT!!!! We ran them lean for "power" but never understood this critical knowledge about fuel being a coolant! Immediately they began to nip up we'd do the worst possible thing and close the throttle, depriving an already overheated engine of its coolant!
Two strokes are a very different thing - and tuning them is a black art! My 1967 Classic Racing air cooled Suzuki T20 was tuned to stupid amounts, and as you say, they become more and more fragile... Once I won a really good race at Brands Hatch, beating a quick rival by about a wheels width... As I crossed the line I raised my right hand in a victory gesture - hence closing the throttle - and the engine seized almost instantaneously due to the lack of cooling & lube! One piston had nipped up very badly indeed... The highs and lows of racing huh? 😂
As already stated by someone else, coarse threads for cast iron aluminium etc ie soft metals. Don't use bolts. Turn the bolts into studs. UNC on one end for the cast iron and UNF on the other for head nuts. JB Weld bad idea. I use JB Weld and am a fan - but not in this instance. Do the job correctly. Plug the old hole first with a threaded plug of cast iron - whatever size fills the hole. Use high temperature Loctite. Then same routine as before - drill tapping size through rocker box bolt hole and tap thread. If it were me I would also convert the rocker box bolts to studs. Less wear on the threads in the head.
I agree with much of what you say, but the trouble with studs, on THIS engine, is that you can't then get the rocker covers or head off without removing the whole engine first.
JB Weld has a quoted tensile strength of 5,020 psi. That's less than a third of aluminium and anything between about a half and a twentieth of cast iron. Just don't over tighten the rocker cover bolts to avoid pulling the helicoil insert out. The insert will be fine with the wear on the threads but will not be as firm as one screwed directly in, if there was a decent hole to screw it into!
If this were for something taking a significant load, then JB Weld would be a big failure. As it only for a rocker cover, worth a try. BTW, all epoxy products, JB included, tend to soften with heat. So that may be a factor here. What about filling in the hole with brazing rod and drilling/tapping that?
@@TornadoCAN99 I'll see if my quick & simple fix works (as it has in the past), but if not, I'll probably go for a timesert insert. They are brilliant, but not available in the original size that I'd prefer
Hi I know it's a bit li g winded but now the barrel is tapped 7/16 × 18tpi unc I think I would make custom studs with that thread form for the barrel with a 7/16 × 26 this at the other end This would give the same clamping force per unit torque as was originally required if you continue with a corse bolt the clamping g force will be reduced for the same torque applied, just a thought it's what I would do coarse in castings fine with a nut
It's just a couple of hours work to remove and strip the bottom end. And if it's all good another couple to reassemble it. Any issues and you'll be glad you did it. At least you'll ride confidently. On the other hand if you don't do it you'll be second guessing yourself every time you kick it over.
Hadn't been used since the last owner rebuilt the top end with a new piston. The piston was too tight in the bore, but it hadn't been run until I bought it and got it to run.
Excuse the Aussie ignorance… but what is ‘firefly’? Regards Robert PS Given the bodgey-ness of the top end, I’d go for the bottom end rather than risk it.
@@RobertBrown-lf8yq Oh, that makes sense. Draganfly is a fantastic Brit bike spares dealer in Bungay, Suffolk. They have huge stocks of Ariel (and BSA) spares - it's THE place to go. So helpful too.
Many did, but this engine dint have one originally. Friends bikes in the Ariel Owners Club don't have them either and they seal as they should. Hopefully mine will too
The honing has hopefully sorted it out. The cylinder is already oversize, and a new piston would cost not far short of £200, so I'm keen to try it as it now is. Hopefully it'll be OK. 😊
Trouble is if you don’t strip the bottom end you will always be listening for something, and hearing noises that are not there , if it was the winter you wouldn’t think twice
Still sick I'm afraid. I will strip it totally now, but, I have been very busy with other projects (and life!) and will leave it for the fast approaching autumn & winter months
@@t20racerman Don't blame you ! - I retired thinking I'd be able to devote my every waking minute to tinkering and fettling my bikes but somehow 'other stuff' just keeps on getting in the way !..
You know the score Adrian, if it were me and I didn't investigate the bottom end it would forever be preying on my mind !.. While you've got the engine apart anyway you may as well go the whole hog and make sure it's all sound rather than have it fail later and have to repeat the process.. But of course, that's just what I'd do, and it's not my bike or my riding time I'd be sacrificing !..
@@t20racerman I wish you the very best of luck with it Adrian - I'll be looking forward to seeing your findings but I have to admit that it's with a little trepidation due to the state of the top end ! - It really needs checking because the poor state of the top end proves (with your Ariel at least..) that just because a bike SEEMS to be running perfectly well it doesn't necessarily follow that all IS well !.. With a bit of luck the 'Artful Bodger' who butchered the top end may not have bothered to delve any deeper !..👍🤞
It's on my bench at the moment. I've been inundated with other things, but I'll have the casings apart and crank out tomorrow if all goes well. I was reluctant to split it, as I knew it would be ages until I could finish the job, but it's definitely the right thing to have done. 😊
Tempting! I'll be inspecting the bottom end closely in a few days time (I'm so busy with other stuff) and decide when I've done that. Hopefully no more horrors...
I cant believe you used JB weld to hold a bolt, not once in history has glorified epoxy body filler ever done the job. The hole needed to be cleaned out properly and welded up before retapping to the correct size.
Used it before several times. With the helicoil it should hold. Welding a big cast iron head would be expensive, JB weld cost a few pounds. I'll use an insert if it doesn't work.
You gotta open and clean the bottom..you will have debris from the seizure .... you just had a new piston and cylinder work..which you can destroy if you don't do it properly....
I am doing, don't worry! 😁 Gearbox is leaking oil too, so loads to do. I've been far too busy over the summer but hope to get it all sorted in the next couple of months. Watch this space for Part 3...
Strip it down and check it out. It won't take that long and you eill have peace of mind instead of sitting on the bike every time you go to ride it saying to yourself I should have done the rite thing when I had it down that far.
You have no choice really. Horrible place to be. You need to strip it down. If you don't strip it down, ride it and then something catastrophic occurs, that you could have avoided by stripping it down now............how will you feel then?
With the state of the top end you should definitely strip the bottom end, it could be bodged as well, I’m just trying to get you to do more videos because I find them very entertaining, thanks keep up the good work
That's very kind, thank you. Watch this space... 😉
As it was running well, I’d leave the bottom-end and ride it for now, and possibly strip it in the winter if you think it needs it. Too much riding time can be wasted in the garage (ask me how I know!). Les
That's the dilemma - and I really want it back running asap. Nothing worse than finishing a rebuild as winter sets in. 😕
I love it when a plan comes together. Bang the top end on and see how it runs. Then strip it all down in the autumn if you have too.
I'm tempted, but I'm moving towards a full strip down. Hopefully won't take too long
Adrian, one solution is to look back to the past before helicoils when engineers turned up an internal/external threaded bronze insert. This method was used by BLR engineering at Surbiton, Surrey having done a few for me.
It's definitely a very good solution and something to look into 😊
Surbiton Engineering - those guys used to do all the rebores for Roy Smith Motors, where I worked in the stores. That was 50 years ago.
It was used by me as well in the 1970's 😁
Trevor Barnes was the leading light at BLR engineering, known for Triumph twin exhaust stub repairs, valve seats, bronze thread inserts, oversize valve guides etc etc. He has made an entire gear cluster for his vintage 500cc moto guzzi race bike, he fell off at Goodwood, both him and machine sliding across the grass some years ago.
Going there entailed a 50 mile round trip motorcycle ride, happy days. 😊
Helicoil and other thread repair inserts are well over half a century old and very reliable.
Thanks for taking us along with your rebuild. I love Arel motors. We fix everything with J-B Weld here in Texas. Cheers
Thank you 😊 J-B Weld is really good stuff isn't it? I'm sure it'll work on my Ariel
Interesting videos Adrian! A 90 year old friend who is an accomplished vintage m/cycle engineer said in reference to your engine that someone may have fitted an alloy piston made in Italy or Australia! The alloy is a bit 'leady' and he did say that you need 6 or 7 thou clearance. Interestingly, he said that there are no pistons made in the UK anymore.
6 or 7 thou sounds about right. Interesting comments about piston availability 😕
It's a shame that someone before you did such sloppy work on such a beautiful machine. Well done sir.
Thank you. It will be sorted out and looked after MUCH better from now on 🙂
Don't strip the bottom end, as if it gets noisy, it will give you a winter project. A man of your calibre can deal with that. Plus it will give you the opertunity to see how the JB weld fairs under the summer riding. You can take measurements of the position of the centre of the JB weld threaded hole with respect to the other three bolt hole centres if you need to rework it.
That was my plan originally, but I'm torn now about whether to strip it or not as I'm 1/2 way there...
@@t20racerman then your winter project could just be to redo the JB weld bodge. All good fun regardless. Enjoy.
@@ianhames2465 I have faith in J-B Weld 🙏 😉
@@t20racerman 😁I'm on the fence.
I've used JB weld for years on speedway bikes, forever breaking and stripping things on them. Biggest issue I find is the metal breaks, the jb weld doesn't. Wouldn't use it on a head stud but on anything else like tappet covers, exhaust studs, inlet studs etc, perfect
I would never have thought of using a Helicoil in JB Weld! I HAVE used JB Weld on my truck to fix the Differential (where someone had not shimmed it properly and caused a side bearing to fail), and it's held for 15 years now! I expect that your fix will be as good as permanent!
It's a very good product that can rectify a whole host of issues. Not the 'best' engineering fix by a long chalk, but it works - as you've definitely found! 😁
love to see old iron kept running
And me! 😁 So nice to ride too
Thanks for the video. I have a 1937 VH with the later enclosed valve cylinder head so pretty much the same as yours. Looking forward to the bottom end strip.
I'm struggling to find the time to do it! Hopefully not too long... 😊
With the amount of booger on the top end I would crack the bottom open and have a look. I still say some hack started to rebuild that thing and found out they were over their head. Slapped it back together to get rid of it quick. You might get lucky and the jackwagon stopped at the topend and the bottom is fine. Good luck on whatever you pick.
For the rocker covers JB weld works great. I had a chevy v8 that had 2 out of the four bolts on the valve covers strip and I jb welded studs in place. Never leaked a drop after my roadside fix.
Good to hear that the JB weld worked well. 👍
I'm probably going to strip the bottom end - I really need to know what it's like inside 🤔
I would flush the crankcases and look for glitter. If there was nothing untoward, I'd go ahead and put some more miles on the bike. A winter strip-down will tell you how well the top end rebuild has succeeded as well as revealing the health of the bottom end.
Will do. I've not had time to touch it since recording the last video, but will be giving it a close inspection shortly
OOOhhhh a Lister DK, very nice, I had one once, it had a radiator as well, right now though I just have a standard D.
Well spotted! 😁
Yup, a totally original DK.
Get out there and strip it down in the winter :)
Very tempting.... 😁
26TPI is cycle thread, I used to get taps and dies from place down on south coast (Tracey Tools in Devon)
Never found JB Weld to work well on things that get hot but it is one of the highter heat epoxies.
I would strip it, even if you want to get out there on it, failed big end, main bearings or timing side will ruin your day.
You can check crank for proper alignment, make sure magneto base isn't worn strange shape and needing shims, (either mag or crankcase) and check the oil pump isn't too filthy or worn out
I'll be inspecting the bottom end closely next week. Anything untoward and I'll pull it apart.
Great job. If bottom end not broke don't fix it, wait until winter if needed. Mike.
Thanks. One way or another, can't wait to get it running again. It's so nice to ride
Assemble and enjoy the rest off summer, then strip the bottom as a winter project!!!!
It's tempting...
My W/NG nipped up after a rebore. The bloke who bored the barrel gave only 4 thou clearance. I honed the barrel out an extra thou or two, cleaned up the piston and she's running as sweet as a nut! Lesson learnt, always check the piston to wall clearance.
Also... I didn't take the bottom end to bits, I just checked the metal gause in the sump plate and the strainers in the oil tank.
So many rebore companies don't understand that older engines need bigger clearances. A friend got so fed up with poor rebores that he refuses to give them the piston any more. He tells them the bore size that he wants, and when they ask for the piston, he refuses!
Good work! Do the job once and for all!
Thanks. I think I'll have to..
Adrian I'm sure you are aware but ACCU is a great place for all types of fixings and ancillaries including Imperial nuts & bolts
I wasn't aware! Just checked out their site and they have a great range of stuff. Thank you for the tip 👍
Given how relatively simple and easy this engine is to strip, I'd finish the head work, get it back on the road for Summer, then do a complete strip over next Winter. Even though the bottom end sounds fine, you may well find something that "isn't quite right" or not not quite in spec and then your looking at possibly more machining work and/or sourcing and waiting for new parts, all of which = more time off the road. If the bottom end felt or sounded bad then it's a no brainer, strip the whole thing. JMO
@@phils2180 I'd considered it, but in the end stripped it. Good job I did - loads wrong inside. I made video parts 3 and 4 to show how bad it was, and the finished bike after rebuilding. They are both on my TH-cam channel 😊
I would definitely strip the bottom end, given what you have found so far. That is good news about the head bolt threads as they are the most critical ones on the whole bike.
I think I will - it makes sense. 😊
Couldn't agree more about stripping it down,wise move,will rule out any hidden horrors that maybe lurking there..
@@stuartandrews4344 I can't disagree with you. It needs doing
you dont need to strip the bottom end but you need to pull it out of the frame , inspect it thurerly ,conrod play , distribution , oil pump , if its all ok just fit it back and go for the races . cheers!
That's definitely a good suggestion. Will do that first, then decide
Exactly what I would do and have done in the past (but with Triumph rather than Ariel because, sadly, I've never owned an Ariel).
@@williamnethercott4364 ARIEL kh 500 twin 1948 model ,,, rebuilt it and rode it but had to sell it years back ,still regret it . some day i will have another one .cheers!!
@@luisantolafrancis519 That must have been a fantastic bike!
@@williamnethercott4364 they are, if you ever cross path with one dont think twice .
I have just read down the other comments and see someone already made the same suggestion as me . Also those look like stainless bolts on the rocker covers , and where used in cast iron can pick up threads after time .
Stainless isn't ideal. I bought a new set from Draganfly and they only had the two longer ones in stainless. I'll use plenty of copper slip..
my enfield 350, I use the same head barrel sealing lapped in ,,,18000 miles no probs !
It seems to be a tried and tested design feature. I presume it can only be used though if both the head and barrel are made from the same material
I would leave until after the summer as it was running fine. Enjoy the summer then investigate, after the horror of the top-end you can't risk leaving it too long.
I've got so much else to do that it might be the end of summer before it's running either way... 😕
Hi strip the bottom , who knows what you will find , like the top end? Many thanks enjoyed the video. From Nr Chester
Thanks, glad you enjoyed it. Will be looking at the bottom end when I get time - next week hopefully
@@t20racerman Peace of mind, if nothing else and be comfortable when you go out and about.
Bye the bye , my dad had an Ariel Square Four block to hold the shed door open when I was a lad 65 years ogo, could buy a shed for the price of one today hahaha. Good luck.
@@chrissmith7655 That would definitely stop a shed door from moving! 😁
I can see why you are torn regarding whether or not to strip the whole thing.
If it was mine I’d check the big end for play in both directions.
If no wear then reassemble and enjoy.
I'll pull the bottom end out of the frame and give it a good inspection, then decide
Hello Adrian,
1 On ringed piston engines the bores should be substiantially parallel. If tapered as your trusty Arial was the rings will expand and contract with each stroke, which could well lead to fatigue cracking of the rings but will certainly wear out the piston ring grooves.
2. I don't like helicoils as it is possibe to ping out the end of the coil whilst screwing in the bolt or stud , especially if working blind and the bolt goes in at an angle. Also the top end of the helicoil has to be a turn or so below the surface or again the bolt or stud can lft out the insert end.
3. What I have done is do a bit of research and find a thread bigger than the bolt which has its minor dia. a bit bigger than the original thread major dia. Then tap the housing out that size and make an insert of the same material as the housing or maybe a stronger grade, leave the threaded end on the bar and screw that in tight into the housing. Saw it off above flush then in the Mill, mill it back to almost flush then diamond file down to flush. Next fit the mating part and spot through with a drill that is a close fit in the mating part's hole. Remove the mating part and next drill a small hole down at the intersection of the insert and the housing and turn up a slightly tapered pin to be a press fit into the hole. Press in, cut off excess and finish flush. This axial pin then stops the screwed in insert from ever turning. Set for centre of the spotted through hole and drill and tap for the original size. Smallest insert I have done is 10BA on a 1947 model aero engine crankcase, so should be a lot easier on motor bike sizes! For cast iron parts the inserts could be made from mild steel though cast iron could be used. Best to use mild steel for the axial pin.
On my 500 DB Gold Star the big ends as fitted by others never seemed to last. 2 years at best. So when the timing side crankshaft broke I fitted the new shaft myself after getting it nickel plated to bring it up to be a press fit in the steel flywheel and also fitted the new roller big end myself, corrected original BSA manufacturing faults as I went (conrod big end bore had a false start so was tapered) and that assembly went for many years and did not fail..
Thanks for that detailed response - very informative. I might well repair the head threads like that - particularly so if my JB weld 'cure' fails. It would be very satisfying to fix it 'properly' 😊
The mixture looks fine to me.
A tad weak on the main jet I think. Not weak enough to cause any problems, but I'm going up a size on the main jet when I rebuild it.
Hi Adrian, I well recall my late Dad, a very experienced mechanical engineer, explaining to me that coarse threads were used to secure studs in cast iron blocks and fine threads were used on them to secure the head for the reasons you explained. So, how were the original factory fitted heads secured? With fine threaded bolts? If so assuming the barrel is cast iron my Dad would have said they were wrong. The lass or glad who fitted the larger bolts coarser threaded bolts may well have been worrying about the old fine threaded ones stripping out of the barrel under load. Since the threads cleaned up easily they must have been formed well, somehow muck has got down them over the years. And, while I'm at, what was with that hole in the top of the carb? I'm amazed that no cylinder gasket was used, but who am I to argue?
Thank you for your very information comments. Good news that the cylinder's head bolt threads cleaned up, so a course thread is what I have to use - as I have no choice. Should work OK. 🤞
The ground head 'gasketless' seal surprised me, but looking at friends bikes in the Ariel Owners Club - it works fine. Probably because both head & barrel are the same material, which helps.
@@retiredbore378 very informative, thank you for posting 👍
Change your gear case oil and inspect. If you want you can have a sample tested. Unless you have crankshaft seal issues put the top end back together and Ride!
Clutch is off now anyway as I decided to treat it to a new primary chain, having found the one fitted had lots of loose & tight spots.
Gearbox on my MZ ts150 is a bit noisy, but the gears go in fine, so I changed the oil and left it, still going strong. So don't beat yourself up, get out and ride it. If it starts to feel iffy it will keep you occupied in the winter😂
Trouble is, I've already got loads of projects to keep me busy in winter!
Unless the casing is a leaky basket, I would check slack on the crank bearing, and if ok assemble top end.
I'll be examining the bottom end shortly and strip right down if necessary. If not, I'll leave it :-)
Doubt it applies to four strokes (maybe it does?) but I have a Fireblade but recently got back into two stroke scootering again (Vespa PX200E). Learning this time around, I realised most of our seizures on Lambretta's/Vespa's back in the 80's were because we tuned them but did not understand two stroke mixed fuel is: 1 Fuel. 2 Lubrication and most importantly 3 COOLANT!!!! We ran them lean for "power" but never understood this critical knowledge about fuel being a coolant! Immediately they began to nip up we'd do the worst possible thing and close the throttle, depriving an already overheated engine of its coolant!
Two strokes are a very different thing - and tuning them is a black art! My 1967 Classic Racing air cooled Suzuki T20 was tuned to stupid amounts, and as you say, they become more and more fragile...
Once I won a really good race at Brands Hatch, beating a quick rival by about a wheels width... As I crossed the line I raised my right hand in a victory gesture - hence closing the throttle - and the engine seized almost instantaneously due to the lack of cooling & lube! One piston had nipped up very badly indeed... The highs and lows of racing huh? 😂
@@t20racerman It seems very clear to me I have nothing of value to offer a man of your experience but thanks for the discussion! 👍👍
@@kevinchamberlain7928 Nope, you made an excellent point. 😊
Always enjoy a chat about 2-strokes
if you change the tread pitch don't you get different clamping force for a given torq number ?? Keep up the good work
Good point. Yes you do 👍
great job lad keep it going
Thank you! Bottom end inspection and/or strip time next week...
As already stated by someone else, coarse threads for cast iron aluminium etc ie soft metals. Don't use bolts. Turn the bolts into studs. UNC on one end for the cast iron and UNF on the other for head nuts.
JB Weld bad idea. I use JB Weld and am a fan - but not in this instance. Do the job correctly. Plug the old hole first with a threaded plug of cast iron - whatever size fills the hole. Use high temperature Loctite. Then same routine as before - drill tapping size through rocker box bolt hole and tap thread. If it were me I would also convert the rocker box bolts to studs. Less wear on the threads in the head.
I agree with much of what you say, but the trouble with studs, on THIS engine, is that you can't then get the rocker covers or head off without removing the whole engine first.
leave it for now and enjoy it as you say it was running well so🤞
Tempting, but I'm beginning to think I'd be worried all the time, thinking "what's wrong with the bottom end, what's that noise..." all the time 😕
JB Weld has a quoted tensile strength of 5,020 psi. That's less than a third of aluminium and anything between about a half and a twentieth of cast iron. Just don't over tighten the rocker cover bolts to avoid pulling the helicoil insert out. The insert will be fine with the wear on the threads but will not be as firm as one screwed directly in, if there was a decent hole to screw it into!
It should hold if I don't go crazy torquing it down, but if not, I'll fit a M8 timesert insert - that'll fix it for good.
Helicoil inserts are actually stronger and can withstand more tension than the surrounding material.
@@onecookieboyAgreed. That's why I put a helicoil in the JB weld to make it as strong as possible 😊
If this were for something taking a significant load, then JB Weld would be a big failure. As it only for a rocker cover, worth a try. BTW, all epoxy products, JB included, tend to soften with heat. So that may be a factor here. What about filling in the hole with brazing rod and drilling/tapping that?
@@TornadoCAN99 I'll see if my quick & simple fix works (as it has in the past), but if not, I'll probably go for a timesert insert. They are brilliant, but not available in the original size that I'd prefer
Is it just me, but does that Ariel head look sort like a cross between a HD Ironhead and a Knucklehead from the top?
A little! It's a horrible thing, but was on it when I bought it. I'll replace it with something more suitable eventually
Hi
I know it's a bit li g winded but now the barrel is tapped 7/16 × 18tpi unc I think I would make custom studs with that thread form for the barrel with a 7/16 × 26 this at the other end
This would give the same clamping force per unit torque as was originally required if you continue with a corse bolt the clamping g force will be reduced for the same torque applied, just a thought it's what I would do coarse in castings fine with a nut
It's not a bad idea, but I'd then need to remove the whole engine to take off or refit the head due to the lack of room above the head.
@@t20racerman what if after removing g the head nuts you then removed the studs ?
@@TheBlibo A possibility, but I'll see if it seals ok as-is first
It's just a couple of hours work to remove and strip the bottom end. And if it's all good another couple to reassemble it. Any issues and you'll be glad you did it. At least you'll ride confidently. On the other hand if you don't do it you'll be second guessing yourself every time you kick it over.
Yup, have to agree with you. 👍
why would the tight barrel decide to cause trouble after all these years of not?
Hadn't been used since the last owner rebuilt the top end with a new piston. The piston was too tight in the bore, but it hadn't been run until I bought it and got it to run.
Have a good look at bottom end too…just to satisfy yourself all is OK. You’d hate to have to pull the motor apart again later.
Agreed. 👍
Excuse the Aussie ignorance… but what is ‘firefly’?
Regards
Robert
PS Given the bodgey-ness of the top end, I’d go for the bottom end rather than risk it.
Not sure. When do I say that?
No my bad….… it was ‘Dragonfly’… at about the 13 minute + mark
@@RobertBrown-lf8yq Oh, that makes sense. Draganfly is a fantastic Brit bike spares dealer in Bungay, Suffolk. They have huge stocks of Ariel (and BSA) spares - it's THE place to go. So helpful too.
As other say “ Leave it alone ! “
Tempting... I'll have a good look at the bottom end next week and decide fully then, although as its stripped down this far already...
Definitely strip the bottom end. The previous owner was obviously a criminal. You cannot possibly rely upon any aspects of that engine. Good luck.
Be nice if we could prosecute people who do that to an engine! :-)
@@t20racerman I agree. And define the punishment.
some of the bikes had a thin copper ring as a gasket I dont know Ariel it was like shim stock
anneal then tighten down, run the bike and check
Many did, but this engine dint have one originally. Friends bikes in the Ariel Owners Club don't have them either and they seal as they should. Hopefully mine will too
Perhaps it could use a rebore?
The honing has hopefully sorted it out. The cylinder is already oversize, and a new piston would cost not far short of £200, so I'm keen to try it as it now is. Hopefully it'll be OK. 😊
Did you gap the piston rings?
The gaps are about 5 thou above the recommended size, but that should be fine.
Trouble is if you don’t strip the bottom end you will always be listening for something, and hearing noises that are not there , if it was the winter you wouldn’t think twice
Summed up perfectly. I'll have to strip it won't I?
Any news on the sick Ariel Adrian ?..
Still sick I'm afraid. I will strip it totally now, but, I have been very busy with other projects (and life!) and will leave it for the fast approaching autumn & winter months
@@t20racerman Don't blame you ! - I retired thinking I'd be able to devote my every waking minute to tinkering and fettling my bikes but somehow 'other stuff' just keeps on getting in the way !..
You know the score Adrian, if it were me and I didn't investigate the bottom end it would forever be preying on my mind !.. While you've got the engine apart anyway you may as well go the whole hog and make sure it's all sound rather than have it fail later and have to repeat the process.. But of course, that's just what I'd do, and it's not my bike or my riding time I'd be sacrificing !..
That's definitely the concensus view. I'm pretty certain now that that is what I'll do. 😊
@@t20racerman I wish you the very best of luck with it Adrian - I'll be looking forward to seeing your findings but I have to admit that it's with a little trepidation due to the state of the top end ! - It really needs checking because the poor state of the top end proves (with your Ariel at least..) that just because a bike SEEMS to be running perfectly well it doesn't necessarily follow that all IS well !.. With a bit of luck the 'Artful Bodger' who butchered the top end may not have bothered to delve any deeper !..👍🤞
@@jjrider6758 Definitely going to check it out.
Off subject but do I spy a set of Suzuki T250 barrels behind you right ear ol ? 🤔
Nearly right - They are the earlier T20 Suzuki cylinders.
"Do it once - Do it right"
Of course, do the bottom end. You won't regret it 😊
It's on my bench at the moment. I've been inundated with other things, but I'll have the casings apart and crank out tomorrow if all goes well. I was reluctant to split it, as I knew it would be ages until I could finish the job, but it's definitely the right thing to have done. 😊
Enjoy it but strip over winter
Tempting! I'll be inspecting the bottom end closely in a few days time (I'm so busy with other stuff) and decide when I've done that. Hopefully no more horrors...
If someone told me Adrian was the first cousin of both Sean Lock and Cristopher Lloyd, I might believe them.
Harsh (but true...)! 🤣🤣🤣
@@t20racerman that's amazing, I was just thinking "ooh, I should rephrase that a little" and you'd already replied 🙃
@@LongPeterMade my family smile - and they all agreed with you 😁
I cant believe you used JB weld to hold a bolt, not once in history has glorified epoxy body filler ever done the job. The hole needed to be cleaned out properly and welded up before retapping to the correct size.
Used it before several times. With the helicoil it should hold. Welding a big cast iron head would be expensive, JB weld cost a few pounds.
I'll use an insert if it doesn't work.
You gotta open and clean the bottom..you will have debris from the seizure .... you just had a new piston and cylinder work..which you can destroy if you don't do it properly....
Agreed. I'll have to have a look.
Don’t take a chance having got this far, strip and check that bottom end now.
I will do. I'm inundated with other stuff at the moment, so the Ariel will have to wait until the autumn now. Shame, but best to do it properly
Split the crankcase, split the crankcase, split the crankcase....... Pleeeeeeeaase!!😢
I am doing, don't worry! 😁 Gearbox is leaking oil too, so loads to do. I've been far too busy over the summer but hope to get it all sorted in the next couple of months. Watch this space for Part 3...
Go on, strip the bottom end! If nothing else for peace of mind....
I know it makes sense... Probably will do
Next job - fix VM30 😎
Ha ha - it's a tad noisy isn't it?
I would........
I probably will have to...
Strip it down and check it out. It won't take that long and you eill have peace of mind instead of sitting on the bike every time you go to ride it saying to yourself I should have done the rite thing when I had it down that far.
I know! I'll definitely give it a close inspection
Whilst you have it stripped so far……
I know it makes sense, but... 😊
Just think of how chuffed you will be when you KNOW it’s ALL perfect. Plus you will have us enjoying the videos 😎.
Ride safe mate 👍
@@stephenhewitt5835 Yup.
Glad you're enjoying my videos 😊
Naaaah! Ride it till it breaks then you'll know where the problems lie.
😂😂
If you really love the machine do it properly, and once.
Yup, agreed. It'll be pulled down in September.
You have no choice really. Horrible place to be. You need to strip it down. If you don't strip it down, ride it and then something catastrophic occurs, that you could have avoided by stripping it down now............how will you feel then?
I'd feel very pissed off indeed! 😕
Just run it the rest of the season, if something major was wrong with the bottom end you would have ventilated cases by now anyway!
That's true!