Arias Pistons

[BOOSTD]

They quote 3-4thou give +/- .5 on the attached specs

.010 seems huge

[Mik]

They quote 3-4thou give +/- .5 on the attached specs

.010 seems huge

<{POST_SNAPBACK}>

You are mxing up metric and imperial systems

0.10mm is 4 thousandths of an inch.

[B33st]

You are mxing up metric and imperial systems

0.010mm is 4 thousandths of an inch.

<{POST_SNAPBACK}>

Im not sure. Take a look at The Venolia Catalogue why would they use imperial mesurements all the way through then go metric when detailing the Piston clearances.

as far as i can figure 0.010mm is not 4 thousandths of an inch

1 thou...0.001"

1" (25.4mm) / 1000 = 0.0254mm

so

4 thou....0.004"

0.0254mm * 4 = 0.1016mm

and

10 thou...0.010"

0.0254mm * 10 = 0.254mm

is this right or am i confused????

[proengines]

.010mm is 4 ten thousanths of an inch.

.010/25.4=.0003937"

I'd run the pistons with the clearance they have built in to them, maybe .0005" less for a street engine.

Remember that if you finish the bore to smaller than the nominal size, every .001" smaller in bore size will close up your ring gaps by around .003" (using Pi*diameter)

The Venolia's run extra clearance cold as they have a lower silicone content that others and have a greater coefficient of thermal expansion, so when they are hot the clearance will be similar as they expand more and take up the cold clearance.

[CRSRB25DE]

To convert mm to inches-

multiply mm by .03937

To convert inches to mm-

multiply inches by 25.4.

-------------------------------------------------------------------------------------------

Totally agree with you PROENGINES.

But i do not agree with:

Stay away from the ACL / ROSS forgies as they are noisy as and recommend a 6 thou clearance which seemed acceptable maybe 10 years ago.

I hace an RB26 ACL/ROSS piston in front of me.

Reccomended clearence .12mm (.0047")

That is 4thou and 7tenths

[B33st]

.010mm is 4 ten thousanths of an inch.

.010/25.4=.0003937"

I'd run the pistons with the clearance they have built in to them, maybe .0005" less for a street engine.

Remember that if you finish the bore to smaller than the nominal size, every .001" smaller in bore size will close up your ring gaps by around .003" (using Pi*diameter)

The Venolia's run extra clearance cold as they have a lower silicone content that others and have a greater coefficient of thermal expansion, so when they are hot the clearance will be similar as they expand more and take up the cold clearance.

<{POST_SNAPBACK}>

So pro engines what clearance would you / have you run the venolia RB pistons.

[B33st]

Any more updates BOOSTD?

[boostn32]

ive decided to go with arias pistons in my RB20. the engine is being built for drift and should produce around 350 - 400rwhp. what rings should i use, the suplied ones. should i run the recomended clearences.

[Cubes]

400rwhp for drift from an Rb20?

You do realise it won't get going until 6k?

[boostn32]

thats not what i asked

[boostn32]

what was asked is should i use the suplied rings or other rings. and should i run the recomended clearences

[Cubes]

If your engine builder doesn't know what rings to use to suit the application I would go else where, it wouldn't suprise me as aiming for a drifto 400rwhp. lol

[boostn32]

i am the engine builder. thats ok mate, im not loaded to beable to get someone to build my engine, hence why im asking the question. think what you want cubes.

[BOOSTD]

Any more updates BOOSTD?

<{POST_SNAPBACK}>

Yes, The gudgeon pin on number 3 has come out the side of the piston an scored the bore quite badly. Number 6 also has a 1mm line down it. The pistons are still in the bottom end at this stage. It will be interesting to find out if the circlip was installed, failed or forgotten. If the later is the case I will post up the workshops name.

I have taken a stack of pix, just need to find my USB cable.

Matty

PS. I'm most likely going with CP pistons if I can find a cheap supplier. If not ARIAS are my number 2.

Edited August 16, 2005 by BOOSTD

[Bl4cK32]

ive decided to go with arias pistons in my RB20.

<{POST_SNAPBACK}>

why chose that particular brand, than, say a brand that you are comfortable setting up?

Most engine builders stick with what they know works....

Edited August 16, 2005 by Bl4cK32

[Cubes]

Boostn32,

I was going to assemble my motor myself. I was told for $300 the bloke who was doing the machining would assemble it.

The cost isn't in the assemble its in the machining.

Its not about being loaded its about aiming for sensible goals... 350-400rwhp out of an rb20 is simply silly, especially if you don't have heaps of cash to throw at cams and headwork.

For a drifter all you will need is 220-230rwkw, with that sort of power it will be much easier to drift, having a rb20 that comes up on boost from 6k isn't going to be a very nice drifter.

Possibly forget about the rb20 all together, sell your rb20det and buy your self a r32 rb25de, drop a set of forged pistons in that and enjoy your 350-400rwhp, it will be much more reliable as it doesn't need any where near as much boost and as many rev's as the rb20 would.

[B33st]

Find that cable.

[boostn32]

ok, im not giving out details on my engine build at this stage as everyone knows its not easy to get 350 - 400rwhp out of a rb20. its more of a chalenge than other motors and thats what i wanted. lets just say the engine is far from stock. just wanted the finer details to make sure everything is right.

i just want to do it right hence why i was asking about the rings on the arias pistons. we are all here to help each other out i thought.

[BOOSTD]

here r the pics.

There are very light lines on the torque side aswell, not sure if that is normal..

Edited August 16, 2005 by BOOSTD

[B33st]

Not Good!!!

proengines what are your thoughts on this????

Edited August 16, 2005 by B33st