Ahhh Jim! I am close (a relevant term for me) to finishing my frame mods and I have to remove my hideous engine and prep the frame for powder coating. Right now I am tormented by images of your beautiful engine. Vapour blasting, mmmmm! A total engine strip and pack it off to the UK. It gives me the creeps just thinking about it. Then of course once the engine is apart, may as well do this and that and the other thing. Hell, why not buy the Rotrex supercharger and and and . . . Look now I sabotaged my own thread!
Deglazing Cylinders with a Flex-Hone So I finally deglazed my cylinders, made some videos, and took a photo. I will take another one after I finish the cleaning process so that you can actually see how fine the finish is. The photo that you see here exaggerates the roughness of the finish because of the angle of the shot, and I am shining a light directly onto it. When looking through the sleeve, it is much more apparent how fine it is. The purpose of the video is to demonstrate the speed of the stroke vs drill speed. This is something that gets asked a lot. Of course you could calculate the number of rotations per stroke but you still have to execute it, so a visual demonstration is a good solution. I actually prefer to use a slower drill and stroke motion, but anyway, you adapt to what you have. You can see that I achieved quite an acceptable angle, 45 being optimum, on my cross hatch. Wash with a bottle brush in hot soapy water, solvents are not recommended because they will remove the oil but not the grit. cheers Blair
Hi All, Nice article here on bedding in new rings. https://www.enginebuildermag.com/2018/05/how-to-break-in-your-piston-rings-the-right-way/ My preferred technique is warm engine as described in the article and then take it for a run of about 10 minutes and a few times to redline in on 3rd or 4th. Let it cool completely and repeat. Done.
Great thread.. had another good read of it.. Now I am not sure about other manufacturers but Honda apparently run very tight bore to piston clearances due to the technology in the piston materials and expansion rates etc.. there have been many instances where "Engine builders" thought they knew better and that the data in the factory manual was wrong and bored them with significantly more clearance only to find the rebuilt engine was basically worn out before they even started... now the caveat is that Aftermarket (made in china) may not have the same technology in the materials... so as always.. use the specs from the supplier. the Piston I will be using in the SRX has all the machining details in the box and that will be what I want my machinist to use.. this is a Wiseco 1mm oversize Forged piston..
http://blog.jepistons.com/2618-vs.-4032-material-differences @Andych absolutely correct. It all depends on the alloy. For example, the standard pistons used in the 900cc bevel drive Ducatis were forged 4032 and wait for it . . the recommended clearance for the 86mm bore is 0.02 - 0.04mm. Wrap your head around that. For those of you who like to work in cubits, 0.00078" on the low side.
The Wiseco forged piston's can sometime's be a little noisy till they warm up due to the expansion of the alloy's used. Then there's the Wossener forged piston's, on their site it say's the clearance is already built in to the piston, but they have a recommended bore size written on each piston box too. https://wossnerpistons.com/pages/piston-installation-instructions
I am sure Wiseco use both alloys as I seem to recall the pistons that Brook Henry got them to make for the Ducati also ran tight clearances .
These are the machining specs for my Wiseco Forged Piston.. there is also some good info in the instructions for the rings which I will scan later and post up.. it all ties in with the original post on honing etc. Thee piston to bore clearance isnt quite the same as a Ducati or the SOHC Hond'a but its not far off
Not a baited question Blair, I promise... (everyone probably knows I have strong opinions on this topic and I've shared them elsewhere so I'm not going back there again) but why did you say in your video that "honing" was also "de-glazing"? What's your understanding on those terms - ie in your experience and where did it come from? I'm confused as to why people still use them interchangeably - there's not a lot of specific information on it so am interested to hear your perspective.
As you said many people, including me, use them interchangeably. I get that the terms are not ideal but they have been bandied about since forever.
How do you deglaze if you don't use a honing tool? I use my hone to take off a very tiny amount of metal to remove the polished surface where the rings run. I guess that is where the use of both terms for the same procedure come from.
To "deglaze" is remove shiny or smooth surfaces... most references relate to cooking but by definition the meaning is the same...and to hone... well the below pic is from the Cambridge Dictionary.. So the terminology has been around for a long time and can be used in many different circumstances.. but in this instance they are being used to describe how to take a used (not necessarily worn) cylinder and prepare it for new pistons or rings or even for the original rings, to give them the best possible chance of performing as they were originally designed. The following pics are the Installation instructions from Wiseco who are a well respected manufacturer of not only performance engine products but also OEM products as well..
This was posted on another forum. https://www.highpowermedia.com/blog/3954/rotation-of-piston-rings I still prefer to site them as per the manual, even if they run 'rings' around the piston when the engine is running.
i alwayshave ring gaps at 180 degrees and in line with the gudgeon pin to remove any thrust on the end gap.also have a series of hones ranging from coarse to fine.
Yep, I prefer to use fairly fine grade stones so it doesn’t remove much metal. Use plenty of oil to lubricate and make sure it is a controlled smooth action so you get a good crosshatch. Then afterwards, clean, clean and then clean again in hot soapy water, wipe dry with a lint free white cloth ( you will know it is clean then) and finally oil the surface to stop flash rusting. If I have forgotten anything I am sure @Murdo will add or correct as required. Sent from my iPhone using Tapatalk Pro
I think they do different slightly different tasks. The spring-loaded ones are meant to be used (first) to hone and help keep the bore true/straight before using and the dunny brush ones which are for scoring the bore with crosshatching. The local expert is @Murdo so he can confirm what the correct process is as @Andych said.
The spring loaded will be fine for just busting the glaze before new rings, but if there is any wear of parts of the bore then the stones will glide over the top of the wear areas and not contact. The brush type is better for glaze busting as it will follow the worn areas better. I find WD-40 to be fine for a cutting oil. Wash the bores with Kerosene then with hot strong soapy water and blow dry with air line or hair dryer. Then get a piece of white cotton cloth with some engine oil on it and wipe out the bores. This will stop rust and will show you if there is any grit left in the hone marks by being deposited on the rag, in which case you will need to wash again and wipe with the oily rag until it comes out clean. Remember, the hone is only used to take off the top 1/2 thousands of an inch (whatever that is in metric) not bore the cylinder bigger so only a few passes is all that is usually required.
Thanx y'all. Practicing on a damaged barrel to get pressure on stones right. FYI Yamaha Aust can get me a head gasket in ~6wks due ship backup, extra ordered a Chinese one. "Sorry, pls cancel. I'm in lockdown". OK mate, I'll leave the order anyway. So he snuck out and sent it for me. Hungry for biz, or just hungry?