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Splitting the cases

Started by Old Rider, September 18, 2018, 06:53:31 AM

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Old Rider

Quote from: Pat Conlon on November 21, 2018, 12:22:03 PM
I'm not sure, but I don't think so.....the engine experts will advise.

I am a fan of Swain coatings. They have a nice anti-scuff coating they can do on your piston skirts along with a thermal coat they apply to the crown.
http://swaintech.com/advanced-coating-technology/
http://swaintech.com/race-coatings/motorcycle-coatings/motorcycle-coatings-price-sheet/

They have an option for thicker skirt coating to tighten up piston/cylinder wall clearances up if needed.

For a street bike with standard compression, the coatings would be overkill, nice to have, but unnecessary.

I sent my oem collector box to them for their White Lightning thermal coating and I can say that coating really works on keeping things cooler under there.
That is interesting reading , does the coating you got on the collector box have a flat finish ? im thinking of ceramic coating the headers on mine but if it is flat white its hard to clean.I asked a company here in norway that is working with chromeing stuff if they could make a black chrome finish on the headers but they did not do black chrome.

Pat Conlon

The Swain White Lightning coating had a white granular finish which I spray painted (VHT) black.
1) Free Owners Manual download: https://tinyurl.com/fmsz7hk9
2) Don't store your FJ with E10 fuel https://tinyurl.com/3cjrfct5
3) Replace your old stock rubber brake lines.
4) Important items for the '84-87 FJ's:
Safety wire: https://tinyurl.com/99zp8ufh
Fuel line: https://tinyurl.com/bdff9bf3

krusty

Quote from: Old Rider on November 21, 2018, 11:15:21 AM
And now for the big question... have i ruined the pistons im asking because after i had cleaned off the carbon with ovencleaner the piston got a black color.I then tryed many different
metods to get the black stuff off without luck.I then used superfine 2500 grit paper and buffed by hand i got them clean and shiny,but now i started to think that they had a coating that now is gone and mayby they can not be reused ?
Anyone, please correct me if you think this old fart's memory is faulty. I read/saw/heard somewhere in the distant past that the sides of new pistons had a lightly linished finish which assisted in retaining oil on their sides thus promoting reduced wear and longer life. Would "polishing" the pistons counter this. Again, I'm refering to the sides of the piston as polishing the crown would help reduce carbon build up.
91 FJ1200
84 FJ1100 x 2
85 FJ1100
89 GL1500
76 CB750F1
72 CB350F
63 C92 x 2
59 C76
62 C100
63 C100
60 Colleda 250TA x 3
63 Suzuki MD50
77 DT125E
77 DT175E x 2
79 DT250F

ribbert

Quote from: Old Rider on November 21, 2018, 12:07:04 PM

The ringroves i used a piece of the old composite cylindergasket and scraped the carbon deposits out.....

A piston ring groove cleaner is a cheap enough special tool to justify buying even for just a job or two. You could probably buy one for less than $30.



However, in the absence of that, using the gap end of an old piston ring as a scraping tool will do the job, it will give the grooves a nice square profile.



I've always treated ring grooves as a precision part of the piston. They need to be perfectly clean and uniform and I wouldn't put a power tool, such as a dremmel or any other none precision implement in there. Some of the deposits in there can be difficult to dislodge and require something hard metallic and the right shape to get those internal corners perfect, IMO.

I know modern engines are not as bad for deposits but I still think it's something worth doing right.

Noel
"Tell a wise man something he doesn't know and he'll thank you, tell a fool something he doesn't know and he'll abuse you"

ribbert

Quote from: krusty on November 21, 2018, 05:07:14 PM

Anyone, please correct me if you think this old fart's memory is faulty. I read/saw/heard somewhere in the distant past that the sides of new pistons had a lightly linished finish which assisted in retaining oil on their sides thus promoting reduced wear and longer life. Would "polishing" the pistons counter this. Again, I'm refering to the sides of the piston as polishing the crown would help reduce carbon build up.

All things considered, it sounds like a reasonable proposition, but it's not something I've heard of (which doesn't mean a thing). Coatings on the skirts are popular for that reason, some are literally to aid running in, some are meant to be worn away to customize the 'shape' of piston and some are long life friction coatings.

Thinking it through, I'm not sure if the piston having a surface that the oil is more likely to cling to would be a help, there is a lot of oil splashing around there already.

You may well be right, but that's my take on it. We have experts here who will know.


As for Old Rider, by his own words and deeds, he has demonstrated a passion for pulling his FJ apart in pursuit of the 'noise'. If it becomes a problem, well, he'll just have to pull it down and fix it. :biggrin:

Quote from: Old Rider on October 06, 2018, 12:01:45 PM

......I really enjoying this wrenching best recreation ever. Sometimes i swear and shout but i love it anyway......


Good on you OR, that's the spirit that keeps these old girls alive. (...and I salute your enthusiasm)

Noel
"Tell a wise man something he doesn't know and he'll thank you, tell a fool something he doesn't know and he'll abuse you"

ribbert

Quote from: Old Rider on November 21, 2018, 11:15:21 AM
And now for the big question... have i ruined the pistons im asking because after i had cleaned off the carbon with ovencleaner the piston got a black color.I then tryed many different
metods to get the black stuff off without luck
.I then used superfine 2500 grit paper and buffed by hand i got them clean and shiny,but now i started to think that they had a coating that now is gone and mayby they can not be reused ?

The black stuff was never going to come off, it is where the aluminium has dissolved out of the alloy and the colour is that of the remaining metals. It's not something on the surface but rather what is left when the surface is removed. We are talking at a microcopic level here. Keep in mind though it is possible to ruin parts with caustic soda (Sodium Hydroxide being the active ingredient in oven cleaner)

However, I would think with oven cleaner for a short time that you haven't done anything other than change the superficial appearance, I wouldn't worry about it (but don't do it again).

Noel
"Tell a wise man something he doesn't know and he'll thank you, tell a fool something he doesn't know and he'll abuse you"

Old Rider


As for Old Rider, by his own words and deeds, he has demonstrated a passion for pulling his FJ apart in pursuit of the 'noise'. If it becomes a problem, well, he'll just have to pull it down and fix it. :biggrin:

Ribbert: you pretty much nailed it always been a diy man.Interesting pistonringgrove cleaning tool you got there looks  like made in  first world war :biggrin:


Old Rider

Quote from: ribbert on November 22, 2018, 02:32:13 AM
Quote from: Old Rider on November 21, 2018, 11:15:21 AM
And now for the big question... have i ruined the pistons im asking because after i had cleaned off the carbon with ovencleaner the piston got a black color.I then tryed many different
metods to get the black stuff off without luck
.I then used superfine 2500 grit paper and buffed by hand i got them clean and shiny,but now i started to think that they had a coating that now is gone and mayby they can not be reused ?

The black stuff was never going to come off, it is where the aluminium has dissolved out of the alloy and the colour is that of the remaining metals. It's not something on the surface but rather what is left when the surface is removed. We are talking at a microcopic level here. Keep in mind though it is possible to ruin parts with caustic soda (Sodium Hydroxide being the active ingredient in oven cleaner)

However, I would think with oven cleaner for a short time that you haven't done anything other than change the superficial appearance, I wouldn't worry about it (but don't do it again).

Noel

Ribbert:That explanation seems right  and when i used the ovencleaner i did the mistake doing it too long.First i put the pistons in the bags with the ovencleaner mayby 2 hours.The carbondeposits was still a little hard so then i put them a second time and for many hours .I didnt know then that it could react bad with the aliminium i read about that on internet later :dash2:
I have now taken som better pics of the piston ring groves looking at the piston with naked eye they look clean but now on the pics i see the piston ring groves need a little more cleaning

dammag

I wouldn't get too carried away cleaning the ring grooves. The rings should be free to move in the grooves with less than the maximum ring to groove clearance.

ribbert

Quote from: Old Rider on November 22, 2018, 03:44:49 AM

Interesting pistonringgrove cleaning tool you got there looks  like made in  first world war :biggrin:



Interestingly, the design of those has not been changed, tweaked, improved or altered one bit from nearly 50 years ago when I first bought one to the current day.

Noel
"Tell a wise man something he doesn't know and he'll thank you, tell a fool something he doesn't know and he'll abuse you"

ribbert

Quote from: dammag on November 22, 2018, 04:33:39 AM
I wouldn't get too carried away cleaning the ring grooves. The rings should be free to move in the grooves with less than the maximum ring to groove clearance.

For me, the ring needs more clearance than just being free to move, it needs a clean, flat surface to seal on the bottom, and above, the clearance is an engineered gap to allow the right amount of pressure to get behind the ring. Either one of those functions compromised by dirty grooves affects the rings ability to seal properly.

Noel
"Tell a wise man something he doesn't know and he'll thank you, tell a fool something he doesn't know and he'll abuse you"

Old Rider

I have measured and checked the oilpump following the workshop manual and haynes manual instructions with feelerblades everything was in spec ,but when i took a closer look
i found broken splines on the axle.I think i have to replace the hole pump unit .Dont know if this was causing bad noise in engine.Earlier before i dismantled the engine when i replaced the clutch basket and bearings i felt that the oilpump sprocket was very sloppy / wobbly on the axle.I spoke with a mecanick at yamaha he sayd that its normal that the sprocket is loose but not too loose  .I have not had a look at the splines of the sprocket yet.

Old Rider

I have also recieved the valveseat cutter tool from ebay  and started to cut the valveseats.The purpose to cut the seat is because the valveseat width is to wide.The spec of the valveseat shuld be 0.9mm to 1.4 mm if it is wider than 1.4mm it has to be cut acording to workshop manual.I have never done this before so i was a little nervous to mess up.On other hand i only had to cut the top angle the first cut with 30 degree cutter.If i had to cut the 45 degree cut it will be a little more difficult i think.I have finished 12 valves i replaced some of the exhaustvalves because it had a deep dent/pitting in middle of the valveface .It was not leaking vhen i tested them but i the long time it maby will so i replaced some.
There are also 3 inntakevalves with a dent in the valveface so i have ordered some new that will be replaced.One thing i find a little strange was when i started on the intakevalves i notised the angle on the valveseat before i cut it was much different than 30 degree it is more like 90 degree the manual says to use 30 degre cutter so i did.On the exhaust valveseats the angle was more like 30 degre on the cutter i think it was 15 degree. I almost did a stupid thing and install the new valvestemseals before i was finish with the valves
luckily i did not because then they will be worn or ripped when lapping and working on the valves.On the smaller exhaustvalves the cuttertool was to big so i had to cut off a part of the outer end on the cutterblades se pick.I have been very careful to keep things free from metalshavings using a vacum cleaner between the cuts also used paper down in the holes and lubricate the valvestem each time its inserted. this was a long post... and many pics if anyone know if i done something wrong pleas tell me :biggrin:

FJ_Hooligan

I would lean toward the wider side of the valve seat width spec for the exhaust valves.  The valve uses this contact area to transfer heat from the valve to the head
DavidR.

Old Rider

Quote from: FJ_Hooligan on November 23, 2018, 02:21:16 PM
I would lean toward the wider side of the valve seat width spec for the exhaust valves.  The valve uses this contact area to transfer heat from the valve to the head

I read about that somewhere too, one thing i didnt find out is what happens if the valveface widt is too wide but i think the valvesprings then need to be stronger to keep a tight seal
and that it is greater chance of carbon debree getting jammed in the seal.
One correction on my earlier post : the valvefacewidth specs shuld be  0.9mm to 1.1 mm  not 0.9mm to 1.4 mm wich is wrong.The limit is 1.4mm.
Another thing i have not figured out is what material the exhaust valves are made of .They are not magnetic like the inntakevalves.I heard that if the valves are made of titanium they have a coating that can not be lapped.The manual sys to lap them so i guess they not titanium?