2LikesTekno RC EB48 Thread
05-10-2013 | 10:17 AM
#6331
05-10-2013 | 11:19 AM
#6333
To add to all of the discussion and throw another HUGE variable into the mix - the height of the holes (thickness of the piston) will have drastic affects on damping characteristics. Unless the pistons are identical in thickness, they can't be directly compared. For example, thicker pistons need larger holes for the same effective damping with the same weight oil. The jury is still out as far as whether a thinner or thicker piston is better.
Carry on...
Carry on...
05-10-2013 | 12:44 PM
#6335
Finally the real answer comes out. This makes sense, thanks for the clarification.
05-10-2013 | 01:12 PM
#6336
I mentioned this a few weeks ago. I used a screw 2mm shorter, all good.
05-10-2013 | 02:22 PM
#6337
Overall area that the oil travels through is what is different. The area when combined on a 1.3x8 hole piston is less than 10 holex 1.1mm. The 8 hole will have more pack.
05-10-2013 | 02:34 PM
#6338
05-10-2013 | 02:44 PM
#6339
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From: Norcal
The 5x1.0 + 5x1.3 piston has the same hole area as 8x1.3 piston.
13.45mm^2 v.s. 13.52mm^2.
However, I used to heard about some theory about circumference of holes will also affect the pack. Not sure if true or not.
13.45mm^2 v.s. 13.52mm^2.
However, I used to heard about some theory about circumference of holes will also affect the pack. Not sure if true or not.
05-10-2013 | 03:14 PM
#6340
Not sure on your math on the first part but there is a relation to the size of the hole and pack when maintaining total surface area and oil viscosity. For example, 8x1.3 and 6x1.5 have almost the same surface area, but will not have the same pack when using the same oil.
05-10-2013 | 03:15 PM
#6341
I can't give an accurate way to talk about it, as I only understand that it changes things, rather than fully what each change effects...but that's probably what you're referring to. It was posted about, probably about a month ago, on one of the two Tekno threads here...I think the SCT's.
05-10-2013 | 04:27 PM
#6342
This page is full of conflicting piston info . lol
What is the O.D. of the pistons ?
So I did some math ..
1.2 x 8 hole =9.03mm³
1.1x 10 hole =9.49mm³
1.3 x 8 holes =10.61mm³
1.2 x 10 holes =11.30mm³
The formula is πr² (3.14 x [1/2 of hole x 1/2 of hole ]x # of holes
1.2 mm with 10 holes ::
3.14 x [ .6 x .6] x 10 holes =
3.14 x .36 x 10=
3.14 x .36 x 10 = 11.30
Hope this helps
This will only apply to strait hole pistons
The angles hole pistons when moving slow will act just like (or close enough) to a strait drilled piston but wonce speed of compression increases it will block some of the hole , kind of like crimping a water hose .
Hope it helps
What is the O.D. of the pistons ?
So I did some math ..
1.2 x 8 hole =9.03mm³
1.1x 10 hole =9.49mm³
1.3 x 8 holes =10.61mm³
1.2 x 10 holes =11.30mm³
The formula is πr² (3.14 x [1/2 of hole x 1/2 of hole ]x # of holes
1.2 mm with 10 holes ::
3.14 x [ .6 x .6] x 10 holes =
3.14 x .36 x 10=
3.14 x .36 x 10 = 11.30
Hope this helps
This will only apply to strait hole pistons
The angles hole pistons when moving slow will act just like (or close enough) to a strait drilled piston but wonce speed of compression increases it will block some of the hole , kind of like crimping a water hose .
Hope it helps
05-10-2013 | 04:28 PM
#6343
05-10-2013 | 04:44 PM
#6344
Yes, when dealing with fluid dynamics, your overall feeling of "pack" comes doopenings eral things. One important one that is often not being looked at in this comparison is how the size, shape, and angle of hole affects turbulence at different piston speeds.
I can't give an accurate way to talk about it, as I only understand that it changes things, rather than fully what each change effects...but that's probably what you're referring to. It was posted about, probably about a month ago, on one of the two Tekno threads here...I think the SCT's.
I can't give an accurate way to talk about it, as I only understand that it changes things, rather than fully what each change effects...but that's probably what you're referring to. It was posted about, probably about a month ago, on one of the two Tekno threads here...I think the SCT's.
05-10-2013 | 05:08 PM
#6345
I'm still lost. I'll stick with whatever came in my kit. Seems to work fine. I thought i had a good understanding of pistons/oils, but i guess not. 
What i was always told was thinner oils = less pack, more/bigger holes = less pack, less/smaller holes = more pack, thicker oils, more pack. I have yet to grasp the concept of how 2 pistons with the same surface area, but differ in # holes, can have a different feel. Also, can't you get the desired "pack" by adjusting oils instead of changing out pistons? I understand why you'd change out your pistons if oils starting to get into the high 40's range, but why change them if they have almost identical surface area?
What i was always told was thinner oils = less pack, more/bigger holes = less pack, less/smaller holes = more pack, thicker oils, more pack. I have yet to grasp the concept of how 2 pistons with the same surface area, but differ in # holes, can have a different feel. Also, can't you get the desired "pack" by adjusting oils instead of changing out pistons? I understand why you'd change out your pistons if oils starting to get into the high 40's range, but why change them if they have almost identical surface area?