Hit and miss versus hand picked.
11-24-2013, 02:41 PM
#46
11-24-2013, 07:01 PM
#47
Nicacil is used in the past but without succes. Yes, on larger engines it is succesfull but the main difference is that large enginges have piston rings so no pinch is needed. The high pressure of the pinch of our enginges (for sure when it is new) is capable of tearing away the nicacil layer. I believe the old HPI Nitrostar 12FE was such an engine and I know Picco has tryed it.
11-25-2013, 04:52 AM
#48
http://i107.photobucket.com/albums/m...ps74c59bdd.jpg
That is indeed also an hone tool.
Here a movie about that brush:
http://www.youtube.com/watch?v=_Bj81...layer_embedded
The guy on rcuniverse is talking about finding a piston that will fit. I had barely succes with using pistons in a different sleeve. The expansion rate could be different with the result of a bad running engine or a fast worn piston.
Regarding a new chrome layer.... Ofcourse that is possible but if it is worth the money and efford, I doubt that. after the new chrome layer you have to give it a perfect honing or grinding.
I know some companies who are doing a DLC layer on the chrome surface. It will bring back a worn out fit and it will give a low friction for the piston.
11-25-2013, 06:53 PM
#49
Nice find!
http://i107.photobucket.com/albums/m...ps74c59bdd.jpg
That is indeed also an hone tool.
Here a movie about that brush:
http://www.youtube.com/watch?v=_Bj81...layer_embedded
The guy on rcuniverse is talking about finding a piston that will fit. I had barely succes with using pistons in a different sleeve. The expansion rate could be different with the result of a bad running engine or a fast worn piston.
Regarding a new chrome layer.... Ofcourse that is possible but if it is worth the money and efford, I doubt that. after the new chrome layer you have to give it a perfect honing or grinding.
I know some companies who are doing a DLC layer on the chrome surface. It will bring back a worn out fit and it will give a low friction for the piston.
http://i107.photobucket.com/albums/m...ps74c59bdd.jpg
That is indeed also an hone tool.
Here a movie about that brush:
http://www.youtube.com/watch?v=_Bj81...layer_embedded
The guy on rcuniverse is talking about finding a piston that will fit. I had barely succes with using pistons in a different sleeve. The expansion rate could be different with the result of a bad running engine or a fast worn piston.
Regarding a new chrome layer.... Ofcourse that is possible but if it is worth the money and efford, I doubt that. after the new chrome layer you have to give it a perfect honing or grinding.
I know some companies who are doing a DLC layer on the chrome surface. It will bring back a worn out fit and it will give a low friction for the piston.
11-25-2013, 10:53 PM
#50
No, not really needed and not adviseable. The DLC layer is thin and as mentioned very low friction.
11-30-2013, 04:57 PM
#51
08-07-2014, 12:54 PM
#52
Tech Regular
But do you think they measure this on a machine for handpicked motors, how could they otherwise know they have a good casing.
What is your opinion on building a new engine in a proven good used casing.
We drive stock motors and i have a motor with over 10km/h topspeed then average,
should i use the casing when i buy a new motor and put all the new stuff in there..?
08-08-2014, 01:11 AM
#53
The keyword is tolerances. Tolerances are also set with the speed of the machines making the parts. Speed is needed for production but bad for low tolerances. Aslo the calibration and freshness of the toolbits and machines can also make a difference.
I can imagine with new toolbits, a fresh calibration, some extra care mounting the bare crankcase and slow speed milling a more perfect crankcase is produced.
Regarding your motor it can be anything like a perfect car, a perfect balanced clutch and not to mention all positive tolerances in your engine up to the used glowplug and headclearance. And do not forget there are timing differences to find between production series of the stock motors as I have seen a lot with the N21-5T.
I can imagine with new toolbits, a fresh calibration, some extra care mounting the bare crankcase and slow speed milling a more perfect crankcase is produced.
Regarding your motor it can be anything like a perfect car, a perfect balanced clutch and not to mention all positive tolerances in your engine up to the used glowplug and headclearance. And do not forget there are timing differences to find between production series of the stock motors as I have seen a lot with the N21-5T.
08-08-2014, 03:40 AM
#54
Tech Regular
Indeed, think they take extra care or fresh bits for the A-spec`s,
we could only alter the fit of the cranck and the bearings and sleave in casing.
Check if the bearing are pressed in the casing.
Next time i`m trying the old case with new internals, just to try.
we could only alter the fit of the cranck and the bearings and sleave in casing.
Check if the bearing are pressed in the casing.
Next time i`m trying the old case with new internals, just to try.
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
