BritBike Forum logo
BritBike SponsorBritBike SponsorBritBike SponsorBritBike SponsorBritBike SponsorBritBike SponsorBritBike SponsorThe Bonneville ShopBritBike Sponsor
Upgrade to: Premium Membership | Premium Life Membership | Vendor Membership | Site Sponsor Membership
ShoutChat Box
Comment Guidelines: Do post respectful and insightful comments.
Buy BritBike staff a coffee
Buy BritBike's staff a coffeeStill here since 1996 serving BritBike enthusiasts..
Search eBay for motorcycle parts in following countries
Australia, Canada, France, Holland, Italy, United Kingdom, USA
Random Gallery photo
Member Spotlight
fil
fil
Austin TX
Posts: 150
Joined: November 2004
Show All Member Profiles 
Newest Members
Bryan Holmes, TODD CHILD, Devon Dave, Jpanis, IRONSMILEY
10819 Registered Users
Top Posters(30 Days)
franko 152
NickL 79
DavidP 72
reverb 51
Popular Topics(Views)
971,855 mail-order LSR
a word from..
Forum Statistics
Forums34
Topics67,347
Posts677,016
Members10,819
Most Online14,755
May 5th, 2019
Who's Online Now
59 registered members (Al Eckstadt), 391 guests, and 803 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Page 9 of 83 1 2 7 8 9 10 11 82 83
Re: 1928 Ariel Model C [Re: Magnetoman] #703810 08/03/17 2:59 pm
Joined: Nov 2011
Posts: 5,346
Magnetoman Offline OP
BritBike Forum member
OP Offline
BritBike Forum member
Joined: Nov 2011
Posts: 5,346
Guys,

All your piston, clearance, circlip, etc. suggestions duly noted and will be factored into my final decision on how to proceed once I've explored all options that I can think of. Thanks.

The latest news is JP can supply the rings for my old piston but say that at the stock depth of 0.112" they won't have much tension and ask if I can deepen the grooves to take 0.140" rings. I don't yet know what material they're made with, but the low tension seems counter to the experience kommando described from several years ago.

Update: I somehow overlooked it before, but I learned this morning that a few years ago the Ariel Owners Motor Cycle Club (AOMCC), of which I'm a member, had commissioned Omega to make pistons. I emailed the person handling these spares, got a quick response, and just now ordered a complete 7.5:1 piston. So, I now have two different aftermarket pistons on their way to me from England. I may hold off on ordering rings for my current, worn Hepolite. Unless I'm running short of time, in the interests of science I'll toss all three in the oven to accurately measure their thermal expansion since unverified statements/speculations on the subject are to be found.

There's more to a healthy piston and cylinder than being gluten-free and having the correct bore and clearance. I cleaned the base of the cylinder and set it on a surface plate using Brown & Sharpe Ultra-Precision Parallels (accurate to 0.0002") to support it on its base rather than the protruding spigot. Since the base bolts to the crankcase this ensures the bore is perfectly perpendicular to the base and hence to the crankshaft. Or, so it should be. In the case of the Ariel the first problem was the base rocked on the parallels indicating it isn't perfectly flat. A 0.011" feeler gauge at the low corner stopped the rocking.

Next I set my Brown & Sharpe cylindrical square (accurate to 0.0001") inside and pushed it against the cylinder in different locations. In the worst location the cylindrical square made contact with the cylinder at the bottom but I could slip a 0.013" feeler gauge between it and the cylinder at the top, which means the cylinder bore is not perpendicular to the base (if it were perpendicular, the cylindrical square would be in full contact with the cylinder wall no matter the location). Although the tilt is all or mostly in the fore-aft direction rather than side-to-side, even if entirely fore-aft this it still would be an issue since I'm trying to rebuild the engine as well as is possible.

I then thoroughly cleaned the protruding top flange (that seals to the head, the same way as with a Gold Star) of carbon and set the cylinder upside-down on the surface plate and found 0.005" tilt in the fore-aft direction. Since this is likely how it would have been held if bored on a table-type machine (in which case the tilt would have been 0 with respect to that flange; unless the spindle of the machine wasn't perpendicular to the table -- there are so many places where things can go slightly wrong if assumptions, rather than careful calibrations, are made...) it indicates to me that a separate boring bar probably had been used. I then mounted an indicator on a height gauge and ran it around the very rough mounting surface of the base to look at the warping in different locations. However, I didn't do this carefully since, no matter what, I already knew I would have to skim that face to make it flat and perpendicular to the bore.

Note that these measurements don't indicate how far the cylinder currently is from perpendicular to the crankshaft axis since to know that also requires determining the relationship of the top face of the crankcase to the axis of the crankshaft, which I can't measure until after disassembling the bottom end. However, I do know there is a ~0.005" step between the two case halves, which is another related problem to address as part of "blueprinting" this engine.

I can deal with rectifying the cylinder independent of the bottom end. I'll (somehow) accurately mount the cylinder upside down on the mill with the cylinder itself perfectly (or as close to it as my instruments can make it) parallel to the spindle axis. Or, if my final solution will be to overbore it for a +40 piston, and since it's already close, I'll just mount it directly on the top flange and then skim the bottom so both are parallel to each other and will be perpendicular to the cylinder after boring. At that point it will be ready for boring using either the top or bottom flange for mounting. Even if I reuse the current piston, having the bore precisely perpendicular to the crankshaft is better than not.

I didn't want the engine tottering on the bench any longer so I made a stand from an 11" piece of 2"x2" Al 'U' channel with vertical Al arms and bolted to a 7" piece of 2"x6" lumber to give it a wider base. It's a lot more stable now, as well as easy to move around on the work bench.

I also finished hogging out the ~3" hole in the steel for the to-be torque plate. In all ~6 cu.in. of steel had to be machined away to create this hole so it took some time. I still have to finish the ID to size and drill the four holes for the mounting bolts.

As I wrote in a previous post, when done I'll measure the distortion near the top of the cylinder to 0.0001" before and after clamping down with the torque plate and report my findings so people will know whether they should do this themselves, or if I foolishly just wasted several hours of my life machining something that makes little or no difference. The four head bolts are 3/8"-20 and a BSA A65 manual lists 30 ft.lbs. for head bolts of this size so that's what I'll use.

2nd Update: I've now finished the torque plate and used it through four torque/untorque cycles, each time measuring the bore along the bolt-to-bolt axis as well as the axis midway between bolts using a Mitutoyo bore gauge with 0.0001" indicator. I made the measurements at the estimated distance to the top ring when at TDC. Before reporting the results (which might or might not be 0), here's your chance to go on record predicting whether or not I wasted my time making this torque plate. My steel plate is 6" dia. x 3/4" thick with a 3.6" ID hole in it. I torque the bolts to 30 ft. lbs., approaching that value in steps on each bolt. It mounts to the top surface of the muff, not against the top of the protruding cylinder liner. Whoever comes closest to predicting the correct result to the nearest 0.0001" without going over (and 0 certainly is a possible prediction) will win a prize of something to be determined later. In the case of ties for the correct answer, whoever posts first wins. (The one person who've I've already told the result is disqualified, as are all other dodgy Aussies who might have learned it from him).

Attached Files IMG_5580.JPGIMG_5579.JPG
Last edited by Magnetoman; 02/15/18 3:06 am. Reason: added photos
Support Your #1 BritBike Forum!

Check out British motorcycles for sale:
British Motorcycles on e-Bay UK
British motorcycles on e-Bay North America
Re: 1928 Ariel Model C [Re: Magnetoman] #703954 08/04/17 7:02 pm
Joined: Nov 2011
Posts: 5,346
Magnetoman Offline OP
BritBike Forum member
OP Offline
BritBike Forum member
Joined: Nov 2011
Posts: 5,346
Since some of you might not have seen the "2nd Update" I added to my previous post, and since none of you have yet responded to it despite ~100 views of this thread since it was posted, I'll repeat it here and then add some new information:
Originally Posted by Magnetoman
2nd Update: I've now finished the torque plate and used it through four torque/untorque cycles, each time measuring the bore along the bolt-to-bolt axis as well as the axis midway between bolts using a Mitutoyo bore gauge with 0.0001" indicator. I made the measurements at the estimated distance to the top ring when at TDC. Before reporting the results (which might or might not be 0), here's your chance to go on record predicting whether or not I wasted my time making this torque plate. My steel plate is 6" dia. x 3/4" thick with a 3.6" ID hole in it. I torque the bolts to 30 ft. lbs., approaching that value in steps on each bolt. It mounts to the top surface of the muff, not against the top of the protruding cylinder liner. Whoever comes closest to predicting the correct result to the nearest 0.0001" without going over (and 0 certainly is a possible prediction) will win a prize of something to be determined later. In the case of ties for the correct answer, whoever posts first wins. (The one person who've I've already told the result is disqualified, as are all other dodgy Aussies who might have learned it from him).

To test if clamping down directly on the protruding sleeve might have a different effect than clamping on the muff I used a 4-1/2" blank of 5/8" steel. Since the DRO was still turned on, and the hole coordinates noted, I put a piece of that steel in the mill and cut the four slots in the edges needed to clear the bolts. I then used my torque plate to clamp this new one to the protruding flange of the cylinder itself, simulating even closer what happens when the head is attached, and measured the possible distortion from the other end of the cylinder to see if it was the same (which might have been 0) or different than the torque plate alone.

Some of you are going to have to be brave enough to answer the question posed in my "2nd Update" if you want me to post the results. Otherwise, they'll be my secret. So, does a torque plate make a difference, or not, with this cylinder? By extension, whether or not it has an effect with this cylinder has implications for Gold Star and other similar cylinders.

Re: 1928 Ariel Model C [Re: Magnetoman] #704015 08/05/17 3:53 am
Joined: Mar 2013
Posts: 365
robcurrie Offline
BritBike Forum member
Offline
BritBike Forum member
Joined: Mar 2013
Posts: 365
I predict that the bore will be smaller by .001" on the axis through the bolts. I also predict that when riding the 'bike across America, you would not notice it laughing

When I got my '62 AJS, I tore down the engine and took it to a friend that used to build our racing and rally car engines (he was also and old Brit biker in his youth). The engine had its original pistons that had the grooves enlarged to take metric rings, and the barrels had corrosion patches. We decided to go with a hone and I managed to find rings to fit from a BMW. I thought I might have to put up with a bit of piston slap and some smoking, but after five years of hard riding it doesn't smoke at all. A riding buddy has a Matchless with the same engine and fitted new pistons and had it nipping up until he took an extra 2 thou' more than the reccomended clearance, now it smokes.
Moral of the story is worn original beats modern wrong spec.

Rob C

Re: 1928 Ariel Model C [Re: Magnetoman] #704043 08/05/17 3:41 pm
Joined: Nov 2011
Posts: 5,346
Magnetoman Offline OP
BritBike Forum member
OP Offline
BritBike Forum member
Joined: Nov 2011
Posts: 5,346
I finished the torque plate by countersinking with a 15/16" drill so the bolt heads would sit below the surface and there would be clearance for a 3/8BS socket to tighten them with a torque wrench.

The front and rear brake assemblies are nearly identical in design and each weighs 3.2 lbs.

I know I'm not alone in hating to backtrack, but yesterday I bit the bullet, disassembled the rear wheel axle and bearings, thoroughly cleaned all the "High Temp" grease from it (450 oF drop point), replaced it with Mobil 1 synthetic grease (550 oF), and reassembled. But, this time with the freshly refurbished brake backing plate. Also, I wasn't happy with the press fit of the oil seals so this time I carefully degreased the surfaces and used Yamabond as an additional aid to keep them in place. I snugged the bearings but then lightly tapped one end of the axle with a soft mallet, which resulted in some clearance developing that I removed by slightly tightening the nut. I repeated this process several times, alternating ends of the axle, until no further clearance appeared, at which point the bearings were fully seated.

There aren't all that many nuts, washers and spacers in the assembly, but more than enough to have been a nightmare had I not photographed it as I disassembled it. I pulled the photos for the wheel disassembly into Word for printing and they're now in the 'shop manual'.

p.s. Four months after this thread was started it now has the most views in this forum, passing a thread that started eight years ago. Who knew so many people were interested in reading about an old Ariel?...


Last edited by Magnetoman; 08/05/17 4:54 pm. Reason: added p.s. and sentence about Yamabond
Re: 1928 Ariel Model C [Re: Magnetoman] #704058 08/05/17 5:27 pm
Joined: Aug 2001
Posts: 4,609
gavin eisler Online Content
BritBike Forum member
Online Content
BritBike Forum member
Joined: Aug 2001
Posts: 4,609
i am up for a guess, going for the torque plate closing the bore 2 tenths.


71 Devimead A65 750
56 Norbsa 68 Longstroke A65
Cagiva Raptor 650
MZ TS 250
The poster formerly known as Pod
Re: 1928 Ariel Model C [Re: Magnetoman] #704062 08/05/17 6:05 pm
Joined: Nov 2011
Posts: 5,346
Magnetoman Offline OP
BritBike Forum member
OP Offline
BritBike Forum member
Joined: Nov 2011
Posts: 5,346
Originally Posted by robcurrie
I predict that the bore will be smaller by .001" on the axis through the bolts.
Originally Posted by gavin eisler
i am up for a guess, going for the torque plate closing the bore 2 tenths.
Well, after a few hundred views of the question, it looks like I'm going to have to count the above as an overwhelming response. Rob is closer, but Gavin wins according to the rules of the competition.

The answer to whether or not a torque plate has any effect, when it is bolted to the top surface of the muff with 30 ft.lbs it squishes the cylinder in by 0.0007" on the bolt-to-bolt axis and squishes it out by 0.0001" on the axis midway between the bolts. Applying the pressure directly to the protruding cylinder with a modified version of the pressure plate increases these two figures to 0.0009" and 0.0002" respectively. However, although the resolution of the bore gauge is +/-0.0001" I can't distinguish between these results within experimental resolution and repeatability. So, the effect is ~0.0008".

As Rob wrote, it's an old engine design and probably would work OK even with huge clearances, large amounts of wear, significant out-of-round, etc. However, since the piston clearance is ~0.005" this distortion is a ~15-20% effect, and it occurs near TDC where the combustion pressure is highest. Since I have the torque plate I'll certainly use it when doing the final honing to size. Also, based on these results, if I ever find myself needing to bore another Gold Star cylinder I'll definitely fabricate a torque plate for it as well.

What motivated me to make this plate in the first place was that for some years I've wondered if torque plates actually had a significant effect, or if they were mostly smoke and mirrors "knowingly" repeated by people without ever having actually checked. This was the first time since I started wondering about this that I was at a point where a cylinder would be bored.

Note that if anyone wants to question the results they'll have to make their own torque plate repeat the measurements on a 1928 Ariel cylinder. As for the winning prize... hmm, I hadn't thought that far ahead.

Re: 1928 Ariel Model C [Re: Magnetoman] #704064 08/05/17 6:40 pm
Joined: Aug 2001
Posts: 4,609
gavin eisler Online Content
BritBike Forum member
Online Content
BritBike Forum member
Joined: Aug 2001
Posts: 4,609
No prize required, good game. Glad it was worthwhile. Great thread. Maybe recheck the measurements at running temps next.!


71 Devimead A65 750
56 Norbsa 68 Longstroke A65
Cagiva Raptor 650
MZ TS 250
The poster formerly known as Pod
Re: 1928 Ariel Model C [Re: Magnetoman] #704068 08/05/17 7:52 pm
Joined: Mar 2013
Posts: 365
robcurrie Offline
BritBike Forum member
Offline
BritBike Forum member
Joined: Mar 2013
Posts: 365
Well done Gavin. The only time we have ever used a torque plate was for reboring a 4 cylinder VW Golf (Rabbit in USA) engine for racing. The 'head is held down by stretch bolts torqued to 40nm then 60nm then 90 degree finally another 90 degree, so there is some serious force applied to the cylinder block over a non uniform area compared to a single cylinder with symmetrical bolts.

Rob C

Oh.... and the plate was 2 inches thick

Last edited by robcurrie; 08/05/17 7:58 pm. Reason: Added Oh...
Re: 1928 Ariel Model C [Re: Magnetoman] #704091 08/06/17 3:37 am
Joined: Nov 2011
Posts: 5,346
Magnetoman Offline OP
BritBike Forum member
OP Offline
BritBike Forum member
Joined: Nov 2011
Posts: 5,346
Originally Posted by gavin eisler
Great thread.
Thanks very much. I'm applying everything I know, or think I know, about engines, bearings, machining, crack testing, etc. to this rebuild and not cutting corners even where it might not have any significant consequence. At the same time as dealing with a myriad of details, some at the level of 0.0001", I'm trying not to overlook the big items as well.

Originally Posted by gavin eisler
Maybe recheck the measurements at running temps next.!
Your '!' may mean you weren't serious, but I am. It happens that the cylinder will nicely fit in the oven I have in the garage that I will use for thermal expansion measurements on the pistons.

Frustratingly, today was a two steps forward, one step back day.

I put the cylinder aside until the pistons arrive and returned to the wheels. I'd already dealt with replacing the grease in the rear wheel with Mobil 1 Synthetic Grease so the only thing remaining to do with it was to put the complete assembly back on the bike. For the record, the total weight with tire, tube, and brake plate with new shoes is 36.2 lbs. Lifting the rear end quite high with the engine hoist I somehow managed to get the tire under the mudguard and back on the bike. Jeez, I sure hope I don't get a flat on this ride. But, it was progress.

I then raised the front of the bike, inserted some wood blocks under the frame to hold it at that height, and removed the front wheel. I had installed it, minus the brake, simply to support the front end (the rear was held up by the bike's stand). One it was off I thoroughly degreased the bearings and inside of the hub with MEK and acetone and repacked it with Mobil 1 grease. Everything went back together without issue, this time with the brake plate and again with Yamabond to help the seals stay in place, and I got the assembly back on the bike without extraordinary effort. Unfortunately, only at that point did I notice what I should have seen before, that the bead wasn't seated fully on the rim over ~20% of its circumference. After a number of attempts with a tire spoon, tire lube, ratcheting tie-down strap, and overpressure I could see no improvement and called it a day. Maybe it will fix itself overnight...

Since the bead has had a month to fix itself I'm not betting anything will change overnight. Trying to see the bright side, tomorrow I'll try a hot air gun to soften the rubber and if/when that doesn't work I'll wrestle the wheel off the bike again and get valuable practice using my tire changing tools in the hopes removing and replacing it -- without puncturing the tube, s'il vous plait! -- magically results in the bead seating all the way around. But, I don't want to practice with my tire changing tools(!), I just want the tire to be seated so I can be done with the wheels. Sigh...


Re: 1928 Ariel Model C [Re: Magnetoman] #704104 08/06/17 11:43 am
Joined: Aug 2001
Posts: 4,609
gavin eisler Online Content
BritBike Forum member
Online Content
BritBike Forum member
Joined: Aug 2001
Posts: 4,609
Getting beads seated can be a PIA, I find the smoother the rim seat and the more lubed the rubber is then the better it goes, tyre fitters soap is best , at a push I have used Vaseline/ petroleum jelly in the past. Last time i re fitted rubber on my deep flange Borranis i spent an extra hour cleaning the rim / bead seat with scotchbrite back to shiny Alloy, the rubber seated with no real grief. It was much easier to refit .The old trick of deflating the tyre and bouncing it around sometimes works, re-inflate / deflate bounce, re-inflate, repeat till happy ( or disappointed).

I was semi joking about the up to temp measurements, a tricky job, made even trickier by the thermal gradient along the barrel when in service, the top end being bolted to a very hot thing and the bottom being bolted to a fairly warm thing when its running. My BSA has case temps around 55 c and head temps around 230 C when measured after a run.


71 Devimead A65 750
56 Norbsa 68 Longstroke A65
Cagiva Raptor 650
MZ TS 250
The poster formerly known as Pod
Re: 1928 Ariel Model C [Re: gavin eisler] #704136 08/06/17 4:23 pm
Joined: Nov 2011
Posts: 5,346
Magnetoman Offline OP
BritBike Forum member
OP Offline
BritBike Forum member
Joined: Nov 2011
Posts: 5,346
Originally Posted by gavin eisler
Getting beads seated can be a PIA, ... repeat till happy ( or disappointed).
Indeed. I hate tires. Plan A this morning (once I steel myself for the task) will be to mark the "bad" section of tire and rim with tape in case I need the information for developing Plans B, C, ..., and try to lever it off the edge of the rim all the way around the wheel while it's still mounted on the bike. If I succeed in doing that I'll then squish it with the ratcheting tie down strap, slather it with plenty of tire soap, and hit it with a blast of air. Should that not work... well, let's not contemplate that just yet.

Originally Posted by gavin eisler
I was semi joking about the up to temp measurements, a tricky job, made even trickier by the thermal gradient along the barrel when in service,
I don't know how to predict what to expect, but the fact the torque plate only distorts the top inch or so of the cylinder is why uniform heating seems like a reasonable approach to seeing how it behaves. That is, my premise for trying this is if the top of the cylinder "doesn't care" what is going on more than an inch away then whether there is a gradient and the base is at 200 oC rather than 20 oC won't matter. Again, this indifference to temperature gradient is an operating premise, not a demonstrated fact.

Since I can't predict the result I can't tell you what I'll do with the information until I see it. It's easy enough to make the measurement, not even requiring me to remove the cylinder from the oven if I locate it with the top facing the door. At 100 oC the bore should increase by ~0.003" which is well within the range of the dial gauge. I'll set it to 0 at room temperature, let the cylinder cook for a few hours to get up to temperature, then open the oven and quickly measure the bore along the two axes before the tip of the bore gauge knows what hit it. That temperature should be high enough to tell me what might be happening under operating conditions, but not so high my bore gauge will be at risk.

Re: 1928 Ariel Model C [Re: Magnetoman] #704157 08/06/17 9:28 pm
Joined: Nov 2011
Posts: 5,346
Magnetoman Offline OP
BritBike Forum member
OP Offline
BritBike Forum member
Joined: Nov 2011
Posts: 5,346
The bead didn't seat itself overnight, and Plan A didn't work either. So, I got more practice with my expanded tire changing tool kit. I still hate changing tires but it's now significantly faster and easier.

I had marked the problem region of the rim and tire with tape and when I examined the rim I found what I had previously ignored as irrelevant. That is, the previous restorer had applied a heavy coat of paint to the rim while it was hanging from something and some of it ran to the low point and dried into fairly large "glops." There were glops elsewhere as well but, whether it's coincidental or not remains to be seen, the low point with the largest collection of large glops was where the tire refused to seat.

I mounted the rim on the mill with a steel brush in the chuck and, supplemented by another in a hand drill, I spent a half-hour smoothing the sides that the bead has to ride up as well as the flat surfaces where it is to sit. I then cleaned the inside of the rim surface, took it outside, mounted it in a drill press chuck, and hit it with a thin coat of etching primer as I spun it. I applied just enough primer to make the patches of bare metal disappear. Following directions I waited 30 min. and then hit it with a thin coat of gloss black enamel.

I won't know if this makes any difference at all until tomorrow because the directions say it takes 24 hours for the enamel to fully dry. I want to be sure there's a smooth low friction surface without any residual stickiness before re-mounting the tire so I'm not going to rush this. Fingers crossed that this was the problem and it is now fixed.

Re: 1928 Ariel Model C [Re: Magnetoman] #704168 08/07/17 12:00 am
Joined: Dec 2013
Posts: 4,713
kevin roberts Offline
DOPE
Offline
DOPE
Joined: Dec 2013
Posts: 4,713
i use P80 and overpressure to seat the beads on my stuff. it's not failed me yet, but yours may be a unique enough situation to merit special attention.

this stuff is incredibly expensive-- usually twenty TEN bucks for 10ml. but i was looking for a picture to illustrate this post and found an entire quart of the stuff for sale on eBay for US$19.99. i bought it immediately.

so it sometimes comes up as a bargain.

Last edited by kevin roberts; 08/09/17 10:04 pm. Reason: ten, not twenty

every day you do not take a chance is a day of your life that you will never get back.
Re: 1928 Ariel Model C [Re: kevin roberts] #704194 08/07/17 4:05 am
Joined: Nov 2011
Posts: 5,346
Magnetoman Offline OP
BritBike Forum member
OP Offline
BritBike Forum member
Joined: Nov 2011
Posts: 5,346
Originally Posted by kevin roberts
i use P80 ...
I'd never heard of the stuff before but it sounds quite useful. It comes in varieties with drying time from 20 min. to 2 hrs. Any of them sound like they'd be fine in the garage, but the 20 min. version seems best for the road. Which variety do you use?

Re: 1928 Ariel Model C [Re: Magnetoman] #704196 08/07/17 5:05 am
Joined: Apr 2006
Posts: 1,390
J
johnm Offline
BritBike Forum member
Offline
BritBike Forum member
J
Joined: Apr 2006
Posts: 1,390
The 90/90 Avon race tyres are incredible difficult to get the bead to sit. I use over 50 psi. The Speedmaster style race tyre on the front of the KTT is also damn near impossible. I wont say what pressure my friends used but it was considerable more than 50 psi. Personally I'd find a way to sit behind a concrete wall while I did it !!!

Re: 1928 Ariel Model C [Re: Magnetoman] #704214 08/07/17 12:09 pm
Joined: Aug 2006
Posts: 523
RPM Offline
BritBike Forum member
Offline
BritBike Forum member
Joined: Aug 2006
Posts: 523
Heating the cylinder in an oven will allow it to heat up evenly and expand accordingly. Going down the road at full operating temperature the cylinder will be hotter in some parts and cooler in others making the bore not so round in more than one place. It is the nature of the beast. I still say torque plate was a waste of time.

P80 is a great tool. I buy it from Coventry Spares and did not know they had different drying time formulas. The one I have seems to work every time I use it . I will see if it has a part number on bottle.

Avon race tires can be hell getting to bead up. We use the 130/650/18 rears and put well over 75 PSI ( or more ) in to get them to bead up. In the summer we would put the tire outside in the sun for a few hours before installing. I also remove the valve stem core when airing up stubborn tires to let the air in more quickly.

I got three big boxes back from Buchanan's on Friday so now I can figure out the wheel bearings to use. I am looking at some tapered roller bearing kits that are made for older flat tank bikes to replace the loose balls or just getting sealed ball bearings. The sealed bearings will need some spacers made and would be a little cheaper. The spokes are a little bigger than the old ones. I have to carefully drill out the special bolts that mount the brake pulley to each rear wheel.

Hope to get the 1915 back on the lift this week and rebuild gearbox. We want to take it to Davenport Swap meet at the end of the month.

Re: 1928 Ariel Model C [Re: Magnetoman] #704243 08/07/17 5:58 pm
Joined: Nov 2011
Posts: 5,346
Magnetoman Offline OP
BritBike Forum member
OP Offline
BritBike Forum member
Joined: Nov 2011
Posts: 5,346
Guys, guys, why didn't someone mention the problem of seating Avon tires when I was discussing the possible choices for this trip and before I bought them? Although I can quickly and easily fill tires to high pressure with my compressor in the garage, it will be a different story on the side of the road with a bicycle pump.

However, leaving tires and torque plates aside for the moment, let's turn to compression plates. At least two people have suggested this possibility for reducing the CR of a 7.5:1 piston to something more iron-engine friendly. I realized I may have been too quick to dismiss the suggestion because of its effect on rocker geometry since the adjusters are at the pushrod end of the rockers not at the valve end as they are on BSA and Triumph twin and triple heads.

I haven't yet measured the volume of the combustion chamber, but if I take 7.5:1 at face value as being accurate for the stock piston it means the volume of the head is 66.57 cc. Although 0.060" doesn't sound like much it increases the swept volume to 518 cc, in turn increasing the compression ratio to 7.78:1.

To decrease the compression of my 518 cc engine with a +60 nominal "7.5:1" piston to, say, 6.5:1 would require increasing the combustion chamber by 13.12 cc. This could be achieved with a compression plate of thickness 0.095" (2.41 mm).

After re-examining the rocker box it may be possible there is this much adjustment in the screws, in which case the geometry at the tip of the valves would remain unchanged. So, I shouldn't have been so quick to dismiss the suggestions of a compression plate. However, I'll have to do a test re-fitting of the cylinder, head, and rocker to see if there actually is that much available adjustment. If there isn't sufficient adjustment neither longer pushrods nor longer screws is an easy alternative because of their construction with mating hardened balls and cups.

Re: 1928 Ariel Model C [Re: Magnetoman] #704252 08/07/17 8:52 pm
Joined: Aug 2001
Posts: 1,987
Alan_nc Online Content
BritBike Forum member
Online Content
BritBike Forum member
Joined: Aug 2001
Posts: 1,987
Tires/Wheels:

Coming in from way in left field here. Any chance of a second set of wheels with tires already mounted? And....following the left field thoughts....I know you are trying to be 'period' but Metzeler & Michelin both make tube type road tires in the size you need.


Alan
Cleared m out....left only
59 BSA Bantam (Trials)
78 Triumph Bonny (UPS)
02 Suzuki GS500
Re: 1928 Ariel Model C [Re: Magnetoman] #704278 08/08/17 2:52 am
Joined: Feb 2008
Posts: 4,423
Tridentman Online Content
BritBike Forum member
Online Content
BritBike Forum member
Joined: Feb 2008
Posts: 4,423
Getting the tire bead to be Concentric with the rim-----
I always use talcum powder on both the inside of the rim and the tire bead.
Pump up to about 70 psig and in 90% of the cases they are Concentric.
The other 10%?--deflate, bump the tire on the ground several times rotating the wheel as you do it and then try again.
I have never had to bump the wheel more than once.
Number of tires fitted to wheels over 55 years of riding?
Hundreds---particularly when young and couldn't afford new tubes-- so had punctures 3 or 4 times a week.
HTH

Re: 1928 Ariel Model C [Re: Magnetoman] #704297 08/08/17 9:25 am
Joined: Apr 2006
Posts: 1,390
J
johnm Offline
BritBike Forum member
Offline
BritBike Forum member
J
Joined: Apr 2006
Posts: 1,390
" Guys, guys, why didn't someone mention the problem of seating Avon tires when I was discussing the possible choices for this trip and before I bought them? Although I can quickly and easily fill tires to high pressure with my compressor in the garage, it will be a different story on the side of the road with a bicycle pump. "

I think you will be fine. Once they have gone on once things are much easier. And you would be pretty unlucky to get a puncture anyway unless the roads in the US have gone down hill a long way since I was last there.

And its the Avon race tyres that were the issue. Street tyres have never been a problem for me.

Last edited by johnm; 08/08/17 10:38 am.
Re: 1928 Ariel Model C [Re: Magnetoman] #704309 08/08/17 12:32 pm
Joined: Aug 2006
Posts: 523
RPM Offline
BritBike Forum member
Offline
BritBike Forum member
Joined: Aug 2006
Posts: 523
Yes Avon race tires can be tough to bead up. The street tires you are using do not seem to be very much trouble around here.

I would not run a compression plate just yet. If you check the compression ratio with fluid I think it will be lower than 7.78-1 or even 7.5-1. It seems to always be lower than what the piston manufacturers state.

Re: 1928 Ariel Model C [Re: Magnetoman] #704340 08/08/17 5:58 pm
Joined: Nov 2011
Posts: 5,346
Magnetoman Offline OP
BritBike Forum member
OP Offline
BritBike Forum member
Joined: Nov 2011
Posts: 5,346
Originally Posted by Alan_nc
Any chance of a second set of wheels with tires already mounted?
Even if it were possible to find a second set of wheels for a 1928 Ariel, having them wouldn't address the issue that worries me, of fixing a flat on the side of the road. Once back to the motel each day I can try to dragoon other people into helping me with the current wheels using all the tools they have at their disposal. On the road, I'm on my own.

Originally Posted by Tridentman
Getting the tire bead to be concentric with the rim...
I lubed, I strapped, I bumped, I overpressured, I seriously overpressured, I swore. Nothing worked. But, the last thing I did was to remove the tire and smooth the very rough surfaces that could have been the cause of too much sliding resistance for the bead.

Originally Posted by johnm
I think you will be fine. Once they have gone on once things are much easier.
Originally Posted by RPM
The street tires you are using do not seem to be very much trouble around here.
I hope you're right, but it will be a few days before I'll have a chance to check if that worked.

I should say that I am very happy with the upgraded tire changing tool set I've assembled (and practiced with). The fact the bead is being such a PITA is unrelated to the tools.

Originally Posted by johnm
And you would be pretty unlucky to get a puncture anyway unless the roads in the US have gone down hill a long way since I was last there.
Unfortunately, the roads have gone downhill over the past two decades. It used to be that, on average, roads in all industrialized nations I visited were pretty much comparable to ours. Some were a bit better (Sweden, quite a bit better), some a bit worse (although, not worse than Chicago). But now, again on average, our roads definitely have slipped to the condition in the next tier of countries.

Originally Posted by RPM
I would not run a compression plate just yet. If you check the compression ratio with fluid I think it will be lower than 7.78-1 or even 7.5-1. It seems to always be lower than what the piston manufacturers state.
I won't make that decision until after the piston arrives and I've measured the volume of its crown as well as that of the combustion chamber. My previous post was to show that it would be possible if needed, depending on the free length of the adjusting screws.

In that previous post I calculated that if I take the specifications at face value I would need a 0.095" compression plate to reduce a +60 "7.5:1" piston to 6.5:1. It turns out that [email protected] has the pattern for later Red Hunter engines cylinder bases, which are identical to mine, and he has on hand 0.094" (3/32") copper material. He custom makes these by CNC within a day so I should have it by the end of the week. Whether or not I use it will depend on the measurements I haven't made yet, but one thing gets crossed off the list knowing the option to take that path will be on the shelf waiting.

Even if I don't use it, it (and the JP piston) will be along for the ride in case they're needed on the ride. On the subject of JP pistons, they've confirmed that the rings they supply are cast iron.

Re: 1928 Ariel Model C [Re: Magnetoman] #704399 08/09/17 6:56 am
Joined: Apr 2006
Posts: 1,390
J
johnm Offline
BritBike Forum member
Offline
BritBike Forum member
J
Joined: Apr 2006
Posts: 1,390
"Unfortunately, the roads have gone downhill over the past two decades"

Mmm. that's a surprise. The last roads in the US I tried were L.A. to San Francisco. Very nice trip.

For the past 4 years I have been in Eastern Europe and have destroyed two tyres on potholes. The worst - which has not happened to me - is when someone steals a manhole cover for scrap metal value. Imagine hitting that at 100 km/h.

My car is a Scoda Octavia 4WD station wagon. Basically a Czech Volkswagon. Really solid car and good in snow with snow tyres. Even though I destroyed two tyres hitting big holes the steering has never been misaligned.

49 years of driving and only ruined two tyres - both here - so perhaps even worse than Chicago !

Last edited by johnm; 08/09/17 7:09 am.
Re: 1928 Ariel Model C [Re: Magnetoman] #704471 08/09/17 10:10 pm
Joined: Dec 2013
Posts: 4,713
kevin roberts Offline
DOPE
Offline
DOPE
Joined: Dec 2013
Posts: 4,713
Originally Posted by Magnetoman
Originally Posted by kevin roberts
i use P80 ...
I'd never heard of the stuff before but it sounds quite useful. It comes in varieties with drying time from 20 min. to 2 hrs. Any of them sound like they'd be fine in the garage, but the 20 min. version seems best for the road. Which variety do you use?



i looked it up again-- the stuff sells on eBay for ten US dollars for a 10-ml squeeze tube:

[Linked Image]

this is what i use:

[Linked Image]

no specifications on the container, but the manufacturer is international products corp. the only two types i can find there are standard and food-contact formulations.

https://www.ipcol.com/assembly-lubricants/p80-emulsion

it's expensive, but like i said, search on it occasionally in eBay. i bought a quart there for US$19.99, and saved over 900 bucks.

better not be fake.

Last edited by kevin roberts; 08/09/17 10:17 pm.

every day you do not take a chance is a day of your life that you will never get back.
Re: 1928 Ariel Model C [Re: Magnetoman] #704494 08/10/17 4:22 am
Joined: Nov 2011
Posts: 5,346
Magnetoman Offline OP
BritBike Forum member
OP Offline
BritBike Forum member
Joined: Nov 2011
Posts: 5,346
Originally Posted by johnm
For the past 4 years I have been in Eastern Europe and have destroyed two tyres on potholes.
I just returned from a short trip to Los Angeles. Earlier today I drove to a house in the Hollywood hills on a very twisty series of streets where my speed in many places was limited by the condition of the streets, not by the twists and curves. I rounded one corner and hit a "ripple" in the concrete so high and deep that the car bottomed out.

After my visit Waze gave me the option of a longer, but faster route back to LAX with all but 3 miles of the 17 on city streets. Some stretches were fully "up" to Eastern European standards, and even the best stretches were no better than any of the streets I drove on in Russia in June (where the harsh winters have to be harder on the roads than the mild So. Calif. weather).

Originally Posted by kevin roberts
the only two types i can find there are standard and food-contact formulations.
The manufacturer's web site has a table showing six types, with drying times ranging from 20 min. to 2 hours:

https://www.ipcol.com/products/assembly-lubricants/

Originally Posted by kevin roberts
The stuff sells on eBay for ten US dollars for a 10-ml squeeze tube
It's always worth looking on Amazon.com because often products are less expensive there than on eBay. I just found it for $9.29 including shipping (although that isn't much of a savings in this case, it's still 70 cents).

There have been two new twists in the piston saga. When I arrived home the piston was waiting that I already had ordered from Draganfly before "discovering" the existence of the Omegas. Although Draganfly is clear that they supply several different brands, I assumed it would be a JP. It's a Gandini. So, now I have to research its reputation.

The other twist is offline someone said there have been reports of problems of partial seizures with Omegas when used in Ariels. I've asked for additional specific details. I note that when I ordered the Omega I was sent a scanned page from an old Ariel manual showing clearances, rather than anything issued by Omega itself. No matter what piston I use I'll need to know the proper clearance to keep it from seizing.

Meanwhile, "piston" moves from the 'problem solved' list back to the 'needs research' list. That's not progress. Sigh...

Page 9 of 83 1 2 7 8 9 10 11 82 83

Home | Sponsors | Newsletter | Regalia | Calendar | Bike Project | BritBike Museum | Spiders Cartoons | DVD- Manuals & Parts books
Upgrade to: Premium Membership | Premium Life Membership | Vendor Membership | Site Sponsor Membership
BritBike Sponsor
Powered by UBB.threads™ PHP Forum Software 7.7.3