Arias Pistons

[BOOSTD]

Anyone run Arias Pistons at 2.5thou piston to bore clearance?? I've heard it can be done if synthetic oil is used for a quiet engine.

[Guest two.06l]

Anyone run Arias Pistons at 2.5thou piston to bore clearance?? I've heard it can be done if synthetic oil is used for a quiet engine.

We run ours at 2.8 but we had the skirts teflon coated. So quiet.

[BOOSTD]

Great stuff, thank you for that info. Can you give an indication on how much teflon coating is? Does it wear off at all?

[Guest two.06l]

Great stuff, thank you for that info. Can you give an indication on how much teflon coating is? Does it wear off at all?

sorry just checked it was 3.8 thou, teflon coating is $25 per piston and we had ours done at competition coatings at guildford in sydney.

[wrxhoon]

I had mine @4 thou fairly quiet but still noisier than stockers and little more on first start up .

Good pistons but make sure you check the rings if you use theirs .

I used 87 mm in mine and they gave me 8.7 to compression using a stock h/gasket .

Unfortunatly i dont have the car any more to show you so you can hear for yourself , as i have a 34 now .

[BOOSTD]

I had mine @4 thou fairly quiet but still noisier than stockers and little more on first start up .

Good pistons but make sure you check the rings if you use theirs .

I used 87 mm in mine and they gave me 8.7 to compression using a stock h/gasket .

Unfortunatly i dont have the car any more to show you so you can hear for yourself , as i have a 34 now .

Why do you need to check the rings? I also have NOS so will the Cromemolly(spelling) rings supplied be ok?

8.7:1 sounds good. Is that the standard for these pistons or an option?

I'm looking at 3thou with teflon coating atm... going in on sat, still waiting for some pistons tho

do you still have the 33 plates Jerry??

[wrxhoon]

Why do you need to check the rings? I also have NOS so will the Cromemolly(spelling) rings supplied be ok?

8.7:1 sounds good. Is that the standard for these pistons or an option?

I'm looking at 3thou with teflon coating atm... going in on sat, still waiting for some pistons tho

do you still have the 33 plates Jerry??

Sorry mate the plates have been sold , i know you showed some interest but i sold them with the car .

I dont know about 3 thou clearence though , Arias specify 4 Thou , 3 maybe to close and they may pick up on the bore .

You wont have 8.7 : 1 compession unless you use 87 mm pistons , if you go 86.5 you should have 8.6:1 . You may want to use a thiner h/gasket or shave the head a little to achive higher comp . By boring out to 87 you compress a bigger volume to the same comp chamber so you have slightly higher comp .

The chrome ring ( only top one ) is fine but you have to run in a bit harder than normal .

You have to check the rings for size , you put them in the bore and measure the gap to make sure its not to small or to big , measure the the oil scrapers too .

What happen to your engine ? did you do a big end ?

[spandex]

when ordering them from arias u ask for a coating. i sell arias pistons but most ppl dont bother getting them coated from arias.

[FATGTS-R]

Solely for the purpose of topping up my knowledge bank, can somebody explain the positives vs negatives of larger and smaller piston to bore clearances?

[Cubes]

I've got 87mm Wiseco's in my RB30 @ 4thou.

The piston slap can be heard on cold starts but honestly it is only a light thud.

I mistook it for a little bit of top end noise.

Once warm, they are silent.

I've ran running-in mineral oil for the first 1000 (3 oil/filter changes), then Motul 10w40 or 30 (I forget) mineral for the next 9,000 (2 oil/filter changes). Total its done 11,000km's.

I'm now running Motul 8100 5w40 and have noticed that slap when cold is indeed less than mineral oil.

Its not using 1 drop of oil & oil pressure is nice and solid so I'm a happy chappy.

[Cubes]

Solely for the purpose of topping up my knowledge bank, can somebody explain the positives vs negatives of larger and smaller piston to bore clearances?

Wiseco state to run the larger 4" clearance when running 24+psi or for track use.

The pistons expand as they get hotter, track use and 24+psi, I figure that Wiseco figure lol, is around the mark where you should allow just that little bit more room for expansion.

You don't want a piston catching in the bore, if it does you will be able to check out the condition of your crank via a nice little peep hole in the bloke.

Thats my understanding.

[R32-GTS]

Arias state a 4 thou clearance is required and recently i think they've changed it to 4.5 thou.

With the rings , we found the stock arias chrome rings to be a bit iffy with some engines getting quite a bit of blow-by. I used nissan n1 rings in my arias pistons but its not running yet so i can't comment. Was gonna run the engine in on penrite HPR 15 as some people i know have done it with good results. Will post up results in the coming weeks.

[Cubes]

I ran mine in on Penrite Running in oil.

For running in you need an oil that doesn't have non-friction modifiers.

The Penrite HPR gear apparently does.

After a couple hundred km's do an oil/filter change.

Boostd, Wiseco recommend adding 0.001 to the standard bore clearance if running NOS.

[BBQ]

Arias state a 4 thou clearance is required and recently i think they've changed it to 4.5 thou.

With the rings , we found the stock arias chrome rings to be a bit iffy with some engines getting quite a bit of blow-by.  I used nissan n1 rings in my arias pistons but its not running yet so i can't comment. Was gonna run  the engine in on penrite HPR 15 as some people i know have done it with good results. Will post up results in the coming weeks.

I'm running Arias 4 Thou clearance with the supplied rings and no problem with blow by.

Running Castrol Type R synthetic 10w - 60.

They are fairly noise on first stratup but let it warm up for about 5mins and they are fine.

[R32-GTS]

Arias have 3 different types of rings they use. So yeh maybe just one of them not sure.

As for the oil the penrite HPR15 is a 15W-60.

[BOOSTD]

R32-GTS, how much are N1 rings...can they be sourced from nissan or someone else??

Anyone else had issues with Arias rings?

[R32-GTS]

Sourced from nissan. About 300 a set. Expensive but good insurance.

[BOOSTD]

I've ended up buying some Venolia's from CRD. Venolia recommend 3 to 4 thou and .5 variance on top of that depending on engine output. Also purchased some N1 piston ring which apparently cannot be used on Arias. Cost $1550 inc rings. I had a listen to a 34 running 4 thou venolia's and you could ever so slightly here a knock when dead cold. Hopefully 3 thou on mine will not be noticable...will know in a week.

[R32-GTS]

Can use n1 rings on arias rb26 pistons but must use stock nissan second ring.

[BOOSTD]

I've ended up buying some Venolia's from CRD. Venolia recommend 3 to 4 thou and .5 variance on top of that depending on engine output. Also purchased some N1 piston ring which apparently cannot be used on Arias. Cost $1550 inc rings. I had a listen to a 34 running 4 thou venolia's and you could ever so slightly here a knock when dead cold. Hopefully 3 thou on mine will not be noticable...will know in a week.

I've finally finished my rebuild. My Venolia's were installed using 2.5 thou clearance as recommended buy the Venolia Rep. I am very happy to report that they have absolutely no knock at all, cold start and all. I 'll see how they bed in...should be fine with the N1 rings.

chreers

matt