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Another boring question. #754404 10/29/18 12:55 am
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Tracey Spear Offline OP
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Well actually two questions.

I got busy on the cylinders with WD40 and scotchbright hoping to clear the rust and get by with honing. No such luck. So next step is a .20 bore. I reviewed several older threads. A few cautioned about going to automotive machine shops for the machine work. Why is that?

Shouldn't any competent machinist be able to bore the cylinders straight, round, parallel, and to spec?
**********
While at it I also reviewed old discussions on pistons and came away more confused than enlightened.


I did read that I should order the pistons first so that the machinist has them available for when boring. And that the clearance should be 0.004. So recommendations will now be accepted for quality pistons/rings.

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Re: Another boring question. [Re: Tracey Spear] #754405 10/29/18 1:02 am
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Ask around and see who the bike shops are using. The critical part is getting the proper clearance. Do not let them tell you what it should be unless they have a lot of experience. Use the piston manufacturer's recommendation. I am lucky and the local auto machine shop is run by a old and very experienced biker/ flat tracker/ machinist.
Jeff

Re: Another boring question. [Re: Tracey Spear] #754456 10/29/18 12:38 pm
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And the bike is? If it’s an A65, bore it to .004-.0045 thou. The later manuals gave this figure, even at .004 it will want to nip up if. It gets too warm before running in. At .0045 I haven’t had this problem. The value is also given for the bottom of the skirt. Could be because most piston rock occurs at the bottom but check the top of skirt clearance also (If one is mentioned) I’ve had auto shops do mine, but they work on other old vehicles too so have a better mechanical sympathy for the old iron.

And yes, get the pistons bought first and bore to suit. Check the clearance before purchasing pistons with the old barrel. Then look at the wear, damage etc. A good shop would give you a good idea before you order anything. As your in the states, Give Ed V at E&V engineering in Howard City, Michigan. He has the best pistons for the job!


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Re: Another boring question. [Re: Tracey Spear] #754459 10/29/18 12:47 pm
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A modern reborer will not be used to cast iron rings and will hone too finely, so the rings do not bed in, as long as they have experience of old bikes and cast iron rings they should be ok. But to be 100% safe then use Ed V or similar.

Re: Another boring question. [Re: Tracey Spear] #754460 10/29/18 12:54 pm
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The first problem is most machine shops index the bore off the head face which is fairly std practice with cars.
However your barrel must be indexed off the underside of the barrel flange
Next most machine shops will ignore what you tell them and bore the cylinder way too close for an old air cooled engine.
Then there is the need for compression plates , some will argue about this
Finally there is the hone, our bikes ilke a really coarse hone 100 to 130 grit where as most shops doing cars with hone it down to 180 grit which will take thousands of miles for the rings to bed in.
Now a machine shop can spend several hours making up plates & jigs to suit a one off job and down here get $ 40 for their troubles or they can set up a 4 or 6 cylinder block in less time and end up with $ 160 to $ 240, so if you had to pay wages , machine leasing and put your kids through school, which one would you choose to do ?
Just about all of the places where I take work to or send others to are run by motorcycle owners who do this work becuse they have a passion for motorcycling


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Re: Another boring question. [Re: Tracey Spear] #758834 12/10/18 11:31 pm
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Tracey Spear Offline OP
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OK, for A65 rebuild I'm putting Emgo+.20 pistons and Hastings +.20 rings. Everything's ready to go to the shop for bore. I need to request .004-.045 piston clearance, and I need to request coarse hone 100-130. Any particulars I'm missing?

Re: Another boring question. [Re: Tracey Spear] #758857 12/11/18 2:07 am
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So far so good. Also, you will need to check the end gaps on the rings and possibly file the rings, unless your machinist does that for you. The last set of Hastings rings I bought had end gaps of .006". According to "the book" they should be .008-.013. There were a couple of long threads on ring gaps a while back. In a nutshell, the consensus of opinion was that the top ring gap should be smaller than the others - also, that too big is definitely better than too small. I filed mine to .010" for the top two rings, and .015" for the oil ring. (I was shooting for .012", but the oil ring files faster than the solid rings.)


Mark Z

'65(lower)/'66(upper, wheels, front end, controls)/'67(seat, exhaust, fuel tank, headlamp)/'70(frame) A65 Bitsa.
Re: Another boring question. [Re: Tracey Spear] #758864 12/11/18 2:49 am
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I beg to differ on the honing. Hastings recommends 220 grit for their cast iron rings. Anything between 180 and 220 will work. I've got several engines that seated the rings during their first start up with Emgo pistons, Hastings rings and 200 grit hone. I would shoot for the upper tolerance on the ring gap. Most of these engines won't see high miles and a little bit extra clearance won't hurt. I use four and half thou clearance on the skirts. Give the new pistons to the machinist so he can measure them and hone to the correct clearance. Be sure and scrub the bores with hot soapy water to remove the stone debris, solvent won't work. If you can put some oil on a white paper towel, rub it around and it comes out white they are clean enough. Otherwise keep at it. That light coat of oil is all they need. Don't drench the pistons and rings in oil. Just a spot of oil on each thrust face of the skirt. Use a dino motorcycle oil that's rated SG for break-in. Don't use anything rated SJ through SN. I use Castrol Go 4T 20w/50. I know you will probably get a lot of contradictory advice, just reporting what worked for me.

Last edited by htown; 12/11/18 3:06 am.

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Re: Another boring question. [Re: Tracey Spear] #758873 12/11/18 3:17 am
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+1 on the 180 grit (sorry, I missed that before).


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Re: Another boring question. [Re: htown] #758906 12/11/18 3:14 pm
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What Htown says, + assembly lube on the pin to the small end bush. Lucas 20/50 breakin oil. at 1st start turn throttle open, closed not one speed till head warm. closed high vacuum to load rings with compression to force rings out to bite the cyl. wall and bed in rings. complete cool down retorque and valve adjust. take it for a spin constantly loading the engine not lugging it. run it hard for a good 10-15 miles

Re: Another boring question. [Re: Tracey Spear] #758908 12/11/18 3:36 pm
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Yeah, on first start up don't let the engine idle, keep opening and closing the throttle 2000-3000 rpm for about 5 minutes or so until nicely warmed up. This is to keep the cam lubed. Then let it cool, retorque and valve adjust. Next start up check timing and adjust carbs and
then ride.

Last edited by htown; 12/11/18 3:37 pm.

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1973 Norton Commando
1974 Norton Commando
2018 Kawasaki Z900RS


Everything will be alright in the end. If its not alright, its not the end.
Re: Another boring question. [Re: bodine031] #758913 12/11/18 4:23 pm
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Originally Posted by bodine031
closed high vacuum to load rings with compression to force rings out to bite the cyl. wall and bed in rings.


Throttle open, making the engine pull is what forces the rings out against the bore.

Start the engine and immediately take off up the road.


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Re: Another boring question. [Re: triton thrasher] #758940 12/11/18 6:31 pm
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Originally Posted by triton thrasher
Originally Posted by bodine031
closed high vacuum to load rings with compression to force rings out to bite the cyl. wall and bed in rings.


Throttle open, making the engine pull is what forces the rings out against the bore.

Start the engine and immediately take off up the road.


As TT says. However once a kin to the belief that thrashing it around will help it bed in... it won’t always with cast iron rings, ride the bike normally, not labour the engine and don’t ride it like you stole it. Build the distance up steadily and let it cool fully between runs, 50 miles is about max for a first proper run out, although I ended up running mine in on a fresh cyclinder going to an international, rode it like I normally would Do and it was fine


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Re: Another boring question. [Re: Allan Gill] #759013 12/12/18 10:59 am
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Originally Posted by Allan Gill
Originally Posted by triton thrasher
Originally Posted by bodine031
closed high vacuum to load rings with compression to force rings out to bite the cyl. wall and bed in rings.


Throttle open, making the engine pull is what forces the rings out against the bore.

Start the engine and immediately take off up the road.


As TT says. However once a kin to the belief that thrashing it around will help it bed in... it won’t always with cast iron rings, ride the bike normally, not labour the engine and don’t ride it like you stole it. Build the distance up steadily and let it cool fully between runs, 50 miles is about max for a first proper run out, although I ended up running mine in on a fresh cyclinder going to an international, rode it like I normally would Do and it was fine



The advice I was given was toss on your riding gear start the bike and off down the road.
As TT said, lots of up & down through the box & wide open throttle to seat or bed in the rings.
500 yards should be enough and in my case it was about 1.5 miles once around the block.
Then back home let it cool down & retorque the head.
Next start, faff around with the carb if you must .
No good playing with tuning till the rings have sealed cause you will have to keep on doing it till the rings have made a proper seal.
Remember this is just for getting the rings to seal against the bore & piston.
It is not running in, a process where brand new bushes & bearings need to run against each other and take up the initial wear.
This is where the gentle riding , o oading the engine, no high revs unloaded or lugging comes in .


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Re: Another boring question. [Re: BSA_WM20] #759066 12/12/18 5:41 pm
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Tracey Spear Offline OP
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Ok....so, have patience with me, I'm a little confused.

Are you really suggesting that I, who have neither rebuilt an engine, nor completely disassembled/reassembled a motorcycle before, fire it up the first time and gently ride down the road running up and down through the gears to full throttle? And on top of that, it's been near twenty years since I last rode my Norton.

I'm having a little trouble getting my head around that. Sounds like asking for a transfer to the RIP forum. Now I'm obsessing about every detail, and will make sure that all systems are go, to the best of my ability. But the image TT painted so blew my mind, I thought he must be joking.

So what is the proper procedure for seating the rings/running in? I would call it break in, that A) Does it proper so it works well and last, and B) gives this old goat a chance to relearn some skills, and not get killed.

Re: Another boring question. [Re: Tracey Spear] #759074 12/12/18 6:29 pm
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There’s a difference of opinion but I had a set of razor sharped burred up rings when I tried to run mine in hard. It would also blow more fuel past the rings and into the oil which is never a good thing either

A decent break in oil will help wonders, ride the bike normally and don’t labour it in too high a gear.


beerchug
Re: Another boring question. [Re: Tracey Spear] #759084 12/12/18 6:57 pm
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Half throttle in bursts of a few seconds is probably enough, if that makes you feel better.

I make sure the oil pump feed side is pumping oil to the crankshaft, but my engine is Triumph. I’m not sure how you do that on an A65. Does it have an oil pressure light?



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Re: Another boring question. [Re: Tracey Spear] #759086 12/12/18 7:08 pm
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Here's what works for me.
Initial start up on the stand, run about 5 minutes or so to get the engine up to operating temps. No idling, keep blipping the throttle between 2000 and 3000 rpm. For breakin, I use Castrol Go 4t 20w/50 which is SG rated. Always use SG rated oil.
Let cool, retighten cylinder base nuts, retorque head bolts, reset valve adjustment
Have timing light ready, start engine up, get it up to operating temps, check timing, rough adjust carbs, don't take time to fine tube carbs.
Now go on first ride. Hopefully a place with little traffic. Run up and down the gears, don't lug it. I never go above 3500 rpm. Don't ride at a steady speed. Close the throttle every so often, this draw oil up into the cylinders.
At 100 miles, change the oil and filter, recheck the base nuts, retorque the head, readjust the valves.
Ride as before, gradually increase the top rpm up to 5000.
At 500 miles, change the oil and filter, recheck the base nuts, retorque the head, readjust the valves. Use whatever oil you plan to run in it.
She should be well broken in at this point.


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1972 Norton Commando
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2018 Kawasaki Z900RS


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Re: Another boring question. [Re: Tracey Spear] #759125 12/13/18 12:56 am
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I didn't notice this until I indexed my throttle, but I found it's normal to bring the throttle to half during even moderate acceleration, and when climbing hills. OTOH, sustained half throttle at speed will bring my A65 over 70 mph.

I think I live on the perfect break-in road - rural and hilly, a safe speed for most of it is around 50 mph, a little slower on the curves and a little faster on the straights. That is, all I have to do is ride that road as I normally would.



Mark Z

'65(lower)/'66(upper, wheels, front end, controls)/'67(seat, exhaust, fuel tank, headlamp)/'70(frame) A65 Bitsa.
Re: Another boring question. [Re: Tracey Spear] #759249 12/14/18 11:37 am
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Originally Posted by Tracey Spear
Ok....so, have patience with me, I'm a little confused.

Are you really suggesting that I, who have neither rebuilt an engine, nor completely disassembled/reassembled a motorcycle before, fire it up the first time and gently ride down the road running up and down through the gears to full throttle? And on top of that, it's been near twenty years since I last rode my Norton.

I'm having a little trouble getting my head around that. Sounds like asking for a transfer to the RIP forum. Now I'm obsessing about every detail, and will make sure that all systems are go, to the best of my ability. But the image TT painted so blew my mind, I thought he must be joking.

So what is the proper procedure for seating the rings/running in? I would call it break in, that A) Does it proper so it works well and last, and B) gives this old goat a chance to relearn some skills, and not get killed.


Go to the piston ring makers web site and read the bumpf about how rings actually work and it will all make sense to you.
You need to get high pressure behind the rings forcing them onto the bore very quickly to bed the rings into the bore.
Light throttle leads to light pressure and light pressure glazes the bore.
Just because you open the throttle wide open, does not mean the engine will be doing 7000 rpm.
So you open the throttle wide thus allowing the piston to gulp in a full charge of fuel, by prefference going up a hill and by the time the engine has got to about 4000 rpm, shut the throttle down.
Slaming the throttle closed pressureizes the rings from the other end.
I like to roll the throttle on fully and off in 3rd gear going up a slight rise.
So you open the throttle wide in first then close it down well before the engine gets much past 1/2 full revs.
A couple of times in 1s then the same in 2nd & 3rd.
If the roads allows do the same in top.
I am not tanking about valve bouncing nor doing 100mph, it is all about working the cylinders hard with a full charge .

What confuses people is the instructions in the owners manuals which tell you to run under light loads for the first 200 to 500 miles.
These instructions are for running in a brand new motorcycle because when brand new the rings had already been bedded in before the motorcycle left the factory and you are running in the bearings & bushes.


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Re: Another boring question. [Re: Tracey Spear] #759270 12/14/18 1:52 pm
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Happy Birthday Trev!

I agree with your statements, but I once told someone to "let the engine rev a bit" as a dumbed down explanation of getting the rings bedded in, not realising that they would hold it at full throttle in each gear until it eventually got a 4 corner siezure and locked the back wheel.


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Re: Another boring question. [Re: Allan Gill] #759370 12/15/18 4:01 am
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Originally Posted by Allan Gill
Happy Birthday Trev!

I agree with your statements, but I once told someone to "let the engine rev a bit" as a dumbed down explanation of getting the rings bedded in, not realising that they would hold it at full throttle in each gear until it eventually got a 4 corner siezure and locked the back wheel.


You been reading the mail ?
Birthdays have not existed for this little black duck from the time he left home.


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Re: Another boring question. [Re: Tracey Spear] #770972 04/14/19 1:58 am
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Update:

My cylinders have come back, bored and painted. I specifically ask for 0.04 to 0.045 piston clearance. I haven't had a chance to measure them yet, but I was told the clearance is 0.035. I was told that the machinist called Emgo, and that was their recommendation. A65, Emgo pistons, Hasting rings.

Is that gonna be too tight?

Re: Another boring question. [Re: Tracey Spear] #770999 04/14/19 12:03 pm
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Rob Hall will run his motors at that or smaller clearances with those pistons. But he likes to see how far he can push whatever boundary is in front of him. For most of us, .045 is safer.
Get everything measured by someone that knows what they're looking at.
I call BS the statement that someone at emgo said to bore at .035 clearance. Going from memory, I thought their instructions called for .04 - .05?

Re: Another boring question. [Re: Mike Baker] #771054 04/14/19 10:47 pm
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Are we missing a 0 after the decimal point, gents?

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