2 minutes ago, steveo3002 said:

break in procesdures vary depending on who you talk to

 

most say no idling ...get in and drive 

 

some say baby it with low revs , others say drive hard and use lots of revs and overrun 

 

non synthetic oil and change it often  

 

From resources I've read, they say never do infinite idling but do vary the rpm because idling won't produce enough oil pressure for the new parts. They say the best is to perform the rpm variations on a drive instead of a motionless car

you just spin it in  drill?

 

i dont know im told this is best way for a home user and it still uses oil...so i dont know 

I understand what the hone procedure is supposed to do against the scratch in the cylinder. But I'm not quite sure if I'm going to do it depending on the state of my cylinders. This means I'll have to buy this tool and check after honing that it didn't removed too much material for my standard size piston rings.

as far as i know its an absolute must if fitting new rings  

112km i would reuse the engine , thats very little use unless theres signs of  neglect

1 minute ago, steveo3002 said:

as far as i know its an absolute must if fitting new rings  

 

Arf...I suppose I can't do it very gently by hand instead of a drill do I ?

If my drill removed too much material then I would have to buy another set of piston rings if the standard sized can't no longer be used.

 

Yes 112kms is low but I have strong believe the previous owner didn't respect engine maintenance (e.g oil was not changed since long time, engine radiator was leaking...)

needs to be used in a drill....its a light scuffing not removing /resizing the bore 

I see something like this on Amazon (France). Is this the same tool to hone the cylinder ?

https://www.amazon.fr/KS-150-1190-déglaçage-cylindre-Ø32-89mm/dp/B004YZORKQ/

yes that does the same job....the ball style are said to be far better but harder to find 

I didn't find the ball style indeed...

search flex hone 

 

you must scrub the bore after use until youre sure all grit is removed ..i used hot soapy water and a brush in a drill, then wd40 to stop rust

4 minutes ago, steveo3002 said:

search flex hone 

 

you must scrub the bore after use until youre sure all grit is removed ..i used hot soapy water and a brush in a drill, then wd40 to stop rust

 

Yes I've finally found at leat one searching for "flex bone". It is 75-77mm, I believe this is the right size to go since the MH has 75mm bore. But the ones I found are 180 and 120 grid. They're also cheaper than the tool I found on Amazon

Sorry mispelled. I meant 180 and 120 grit only

I didn't find 240 grit or more and the next available size is 81-83mm so I guess that's too big

Edited 20 November, 20214 yr by cedreex

I'll buy one these 75-77mm then. I'll probably choose the 180 grit. I don't know how many of those do I need for the 4 cylinders. Would save money if one is enough for 8 cylinders (my mk2 and mk2f)

yes they last many uses ...you only abrade the bore for say 20 seconds or so 

 

have you checked with the ring seller what grade they suggest ? its important

I'm currently checking the manufacturer website for resources. The piston rings I have ordered are : Kolbenschmidt 800025010000

Their website is https://www.ms-motorservice.com

One must search for "800025010000" on their website if interested because the product link can't be shared (i.e you'll get page not found)

Edited 20 November, 20214 yr by cedreex

What do you mean by "grade" ? do you mean the oil grade ?

Prehoning: grain size 150 (material removal of approx. 0.06 mm based on diameter) • Finish honing: grain size 280 (material removal 0.02 mm based on diameter) • Plateau honing: grain size 400–600 (remove profile peaks in a few strokes applying light contact pressure) • Honing and brushing: use a honing stone of grain size 120, 150 and 180 for honing. For block engines (grey casting) bond 5–7, for cylinder liner (centrifugal casting) bond 5 max. The material removal is between 0.03 and 0.05 mm based on the diameter. Using honing brushes removes peaks that occur on the surface of the cylinder during the final honing procedure. This requires at least ten strokes and the use of honing oil. To achieve optimum results, the direction of rotation of the honing machine should be reversed after half of the processing time. The cylinder diameter is reduced by between 0.001 and max. 0.01 mm as a result of hone-brushing. • Check the diameter of the cylinders at the top, middle and bottom, as well as in a longitudinal and transverse direction (at 90° to each other). Attention: Clean the cylinder bore and cylinder blocks after honing (e.g. ultrasonic cleaning).

1 minute ago, cedreex said:

What do you mean by "grade" ? do you mean the oil grade ?

how rough the stone is ....like how sandpaper has fine and medium grades 

3 minutes ago, steveo3002 said:

how rough the stone is ....like how sandpaper has fine and medium grades 

 

The ones I found are 180 and 120 grit grade only. I can't find grain size 150 or 400. I don't know if that's the stone grade you're asking but the hone seller didn't add other information

I'll check the cylinder diameters of course but I hope one of the 2 bottom end is fine for standard sized rings. Otherwise I would have to buy oversized rings. Obviously I should have checked the cylinder diameter before ordering the rings. But it's too late now, this is gonna be a bet between 2 bottom end.

New rings do really need a honed surface.

There are other hone tools with three stones and a flexible shaft.

 

I used a flex-hone 240 grit (same as stevo3002) and Millers CR0 oil.

https://www.millersoils.fr/en/shop/millers-cro-10w40-competition-running-in-oil/

 

I attached neodymium magnets to the new oil filter .

 

The oil came with running in instructions for five hours on a dyno!

 

Instead I think I held engine at 2000rpm for 15 mins -on axle stands turning the wheels in the air in 2nd gear - when I got it to run properly first time.

(after various carb, pipe and wire faults). 

And took it for a very short trip near home below 3500rpm. Then continued to use that oil for ~400 miles using different gears and engine loads, always working it quite hard uphill, but using engine braking downhill and staying below 4000rpm. Then changed to 10W40 semi synthetic and new oil filter.

 

I did have some exhaust smoke for the first few weeks.

 

That was August 2015 at about 205,000 miles (328,000km).

Done about 21,000 miles since. Compression still high after plenty of abuse on twin carbs. I don't think oil use has increased, but it has since developed a slight oil leak at crank seal that I did not change, so hard to tell.

 

Coolant level had begun dropping recently but now found the heater valve was weeping where attached to heater. Tightened up the two 7mm bolts last weekend.

Edited 20 November, 20214 yr by dvderlm
added 240 grit Flex-hone.

Oversized rings are for oversized pistons after the cylinder has been rebored.

Cylinder would be oval when measured and piston skirts would be very badly scuffed to need rebore. 

'There can be a none worn area at very top of bore where rings don't touch.

 

If you get a rebore the engine shop will hone it too.

Edited 20 November, 20214 yr by dvderlm