Shock pistons????

[Lee]

What is the difference in "feel" of a drilled piston compared to a factory piston?

Will it pack more because of the sharper edges around the hole??

i am after personal experinces here, not what you think it might do, ash

[Southwell]

Well if you drill out two holes to the 'standard' holes and leave one smaller you will get more pack than a std piston. I quite like my drilled ones, the car feels quicker overall, but slightly less stable over bumps imo. Im going to try some standard ones to do a back to back test as i have been running them since southport nat.

[Lee]

Yeah i understand that if you leave one hole smaller it will give more pack, but i have heard people say that a drilled piston feels different to a std piston with the equivelant holes

[RogerM]

If they are talking about a square edged entry like the AE pistons they are talking out of their behinds ....... on this planet we call Earth the laws of fluid dynamics are clearly defined .....

If your talking about comparing a bell mouthed entry to that of a square edged entry then there will be a difference, and what is more that difference will change as piston speeds change. The square edge piston will feel like it's gaining "pack" at lower piston speeds, this is to do with the transission between turbulent and laminar flow as the fluid goes through the holes.

[Chrislong]

I have wonderred this too.

Roger I think you are talking about the edge of the piston, i.e. the Losi is rounded edge vs the AE is square edge, and its an interesting & relevant arguement. But what Lee asked about is regarding the profile of the hole.

I have heard a drilled piston feels nicer than its equivalent moulded piston... the question is... why?

[Northy]

The holes on a moulded piston are tapered (have some draft angle on them) to make it possible to remove from the mould.

G

[Southwell]

Originally Posted by Lee

Yeah i understand that if you leave one hole smaller it will give more pack, but i have heard people say that a drilled piston feels different to a std piston with the equivelant holes

Drilled ones should be more accurate size than std ones, if you drill them straight....

[RogerM]

The piston holes don't need to be drafted as the material shrinkage would open the holes out. Certainly don't darft IDs on our mouldings at work.

[Wraggy]

Originally Posted by RogerM

If they are talking about a square edged entry like the AE pistons they are talking out of their behinds ....... on this planet we call Earth the laws of fluid dynamics are clearly defined .....

If your talking about comparing a bell mouthed entry to that of a square edged entry then there will be a difference, and what is more that difference will change as piston speeds change. The square edge piston will feel like it's gaining "pack" at lower piston speeds, this is to do with the transission between turbulent and laminar flow as the fluid goes through the holes.

de ja vu !!!!!

[RLGfx]

i run white pistons.....

[Wraggy]

Originally Posted by RogerM

. double post

lol Roger they were an hour apart from each other !!!!
and said word for word ...
what book was that out of ???

[RogerM]

Originally Posted by Wraggy

lol Roger they were an hour apart from each other !!!!
and said word for word ...
what book was that out of ???

The book of the "hung Win 2K PC"

[Lee]

Ok, so i am struggling to source some imperial drills to drill out some pistons, but the #54 drill that i am after is equivelant to 1.40mm the equivelant to a black hole is 1.09mm, but the nearest drill i can get is 1,10mm, am i really going to notice 0.01mm??? afterall im going to be using a dremel anyway

[elvo]

Originally Posted by Lee

Ok, so i am struggling to source some imperial drills to drill out some pistons,
afterall im going to be using a dremel anyway

No! Do it by hand!

[Lee]

Originally Posted by elvo

No! Do it by hand!

Cheers elvo, i didnt know how easy it would be

I didnt think i would feel it but you never know

[Chris Doughty]

I would definately buy the correct imperial drill bits, they are called #56 #57 and so on.

don't buy the metric equiv if you plan to 'copy' peoples setups and referance other companies pistons like Losi.

[Northy]

Lee, I'll get you some today

[Alfonzo]

Originally Posted by Lee

Ok, so i am struggling to source some imperial drills to drill out some pistons, but the #54 drill that i am after is equivelant to 1.40mm the equivelant to a black hole is 1.09mm, but the nearest drill i can get is 1,10mm, am i really going to notice 0.01mm??? afterall im going to be using a dremel anyway

No!