Arias Pistons

[Cubes]

Let us know how they sound on a cold start after ~1000km's.

At first mine were perfectly quiet, after ~1000km's they began slapping slightly on a cold start first thing in the morning, I thought it was a noisy cam or something, its only ever so slight.

EDIT: I used Wiseco pistons, I can't remember the clearance set but it was the larger side that was recommended for 24+psi or race.

Silly doing that now but all appears to be well, there isn't any more slap than there was at 1000km's, its now done ~16,000km's.

[BOOSTD]

will do, I've done 28km's so far =)

[OMY-08S]

i got a set of then for my race car,to be honest i dont like them,they seem cheap to me but the mechanic said the top fueler cars use arias and im like woop de-doo id still rather use to ross forgies cause in 5 years of use they never let me down.

[Blitz]

I hope those Venolias last BOOSTD, most of the GTR's I have seen with these have had to be rebuilt due to the piston cracking around the skirt.

[lwells]

i got a set of then for my race car,to be honest i dont like them,they seem cheap to me but the mechanic said the top fueler cars use arias and im like woop de-doo id still rather use to ross forgies cause in 5 years of use they never let me down.

Are you talking about Arias or Venolias?

Lucien.

[OMY-08S]

arias

[NickR33]

I have 20 thou oversize Arias pistons with the supplied rings installed with the recommended clearance... piston slap can be heard on cold starts but was much worse when running the engine in, its pretty quiet now...

I have since been told by a reputable engine builder (not the one who did mine) that they run the Arias pistons with less clearence than recommended so as to eliminate some of the piston slap... but he didn't say by how much...

[R32-GTS]

My arias pistons are very quiet even from a cold start. I think alot is to do with the machining also

[Cubes]

I've actually grown quite fond of the slight slap noise.

[boostn32]

ok so are Arias pistons worth the money i was going to use them in my rb20.

[R32-GTS]

seem good so far

[BOOSTD]

I think I can here them now, or maybe that cams just don't like the monograde 30 oil.

How long should I run them in with crappy oil??

[Cubes]

I didn't run monograde but rather the Penrite Run-In oil for the first 1500km's. I did quite a few oil/filter changes within this period.

I then ran a std mineral oil until 10,000km's just to be sure, I figured there was nothing to loose by doing so.

Changing too early depending on rings and bore hone type can be a bugger.

Showing pics to RIPS he said by the look of my bore hone I would want to make sure i get plenty of load in to it. So I drove around with a flat foot (wastegate wired open) up until ~3500rpm and there is zero oil in the inlet pipes.

[r33GTS-t-200kw]

im going to be running in my engine on some sort of 'run in' oil for the first 1500 as cubes has done, and run mineral for another 3000k's then start it on better oil. Im not sure whether to go semi-syn or fully-syn :confused: but i guess its been done before, oh and my arias were installed with 4 thou clearence. Seems to be pretty good

[Fitzpatrick Speed Works]

There is nothing wrong with Arias pistons, especially as the last few sets I have had have been full forged ie the older set where forged then machined down.... on not only the outside as all pistons are, but also the inside, only slightly ( far less than say wiseco) as they where probably used for a few different models.... The newer versions the inside is left cast (Like a JE, or CP) which tells me that the piston is forged specifically for its application which is a very good thing in terms of strength... Personally Ross isnt fantastic, they are by far the best for FOrds, no arguements, its all we use in clevo's but their sports compact range (as yanks call it, meaning rb series, sr's ,Fj's etc)) stuff is all machined and has sharpe edges on the inside and just stuff you dont like to see on a piston as when something is really thick (around the gudgeon and skirts) then it steps down to thinner in a sudden drop it is far weaker then a graduated difference as on a non machined piston.... I think most of the pistons now available the difference is nothing (they are all made really well to good standards) the failures and problems people run into is to do with how the engine is put together.... theres is so many factors that can work against you when running clearances and also how the rings are set up (many trick old engine builders use to get good ring seal and vacuum)... Chromium rings as provided by Arias are really good, as are Sealed power ones...The N1 rings feel exactly the same when filing as the Arias ones so I would think they might be a chromium ring also.... Hope this helps...

Daniel

[R32-GTS]

Good information there s13drifter

[boostn32]

so it looks like its a thumbs up for buying Arias Pistons. do u need to do anything to the piston or leave them as they come. what about the rings do u need to file the ends or leave them, what sort of gap should there be between the ends of the rings?

[wrxhoon]

so it looks like its a thumbs up for buying Arias Pistons. do u need to do anything to the piston or leave them as they come. what about the rings do u need to file the ends or leave them, what sort of gap should there be between the ends of the rings?

I have used Arias pistons before with good resaults but i know someone that used them and when he checked the rings ( the gap ) it was far to big .

Make sure you check the gap on the rings , as a rule for every inch diameter you need 4 thou gap , in the rb25-26 case 86mm =3.4 inches so about 14 thou gap is about right .

Second ring usualy a little bigger gap ( 2-3 thou ) and oil scrapers can be bigger still even double 7 thou per inch .

[Cubes]

I'm curious as to why people decide not to use Wiseco's?

[Fitzpatrick Speed Works]

Wiseco are quite good as they have nice long skirts to keep them really square in the bore, and the ring lands and incisions are really good in terms of squarness to the bore and are made pretty exact... the only thing I personally dont like is on the edge of the piston top is perfectly square ie they dont have a slight chamfure like every other piston on the market and I have seen wisecos in the past suffer failures that other pistons might not have experienced due to the edges cracking and flacking due to slight pinging... not saying they are bad just what I have seen, plus I really like Arias as they have heaps of meat around the wrist pin area which is good for high hp....

Ring gap depends on rings, but generally on Arias I run 16-18thou for an engine under 400kw or 22psi, and upto 20thou for full on high hp engines.... and also I run the second ring at the same gap, and always make sure the second ring is 180 degree to the first so the piston ring gap is on opposite sides so they cant line up which can cause blow by problems!!!!

Cheers