Arias Pistons

[Blitz]

B33st can you take a photo of the underside please - you can already see how thin the skirts are in that photo compared with for example an ACL piston below:

[B33st]

Can't get any more photos the pistons are at the engine builders already, that is the only photo i took before i dropped them off.

[someonestolecc]

Good luck. Watching this thread with interest.

[blk180]

My engine builder said i am using mahl pistons but they came in a ACL race box so not sure

[BOOSTD]

2.5thou clearance. My thoughts are similar Mik

[Tektrader69]

If you read my earlier post I brought this up as well.

Mahle actually own ACL. I have ACL pistons and always thought they where made by Mahle.

But a few people have said they are ROSS pistons. Now I am really unsure.

We need this clarified I think.

My engine builder said i am using mahl pistons but they came in a ACL race box so not sure

[Mik]

2.5thou clearance. My thoughts are similar Mik

What clearance to Vernolia suggest? That seems pretty small.

[fatz]

i have aris and she is apples on start up

havent got a clue but was machined by dominator performance and fit like a dream

pete

[OFENSV]

apples meaning quite? i have arias pistons with 4thou clearance as specified but there is noticable piston slap when cold

[fatz]

apples = quiet

[BOOSTD]

What clearance to Vernolia suggest? That seems pretty small.

They quote 3-4thou give +/- .5

[proengines]

The ACL piston in the photo above is made by Ross. The milled spots under the head of the piston is where they normally have the Ross brand. They also use spirolox where mahle pistons use round wire clips. All the mahle performance pistons are a dark grey colour rather than shiny alloy. ACL don't really try to hide the fact, they also supply Ross with the piston rings they supply with their kits.

The ACL pistons for the RB26 are a little too thick in the skirts in my opinion, you could lose a fair bit of weight without losing strength. Compare them to a Wiseco or JE and you'll see the difference.

[B33st]

Any more news on what's happened BOOSTD

[Tektrader69]

I quick question for those that know.

In the Z32 there are squirters below the bore that direct oil up into special holes in the piston crown to keep the piston cool.

Do the stock GTR and GTST pistons have that as well?

I notice on the ACL forged pistons I have they are missing. I wonder if it makes any difference?

[BOOSTD]

GTR pistons have cooling oil channels under the piston crown, GTST do Not.

B33st- No. 3 is 100psi the rest are 155psi. A teaspoon of oil brings No. 3 up to 155psi.....so looks like definate piston/bore or ring issue unfortunately. The head is coming off this weekendish.

[hungry6]

Remember to takes lots of photos

[BOOSTD]

Can u guys tell me much about the N1 blocks, just jap have one for $3500. Do the normally come with pistons etc?

Also any info on N1 pistons regarding strengh, price etc?

[knore]

Can u guys tell me much about the N1 blocks, just jap have one for $3500. Do the normally come with pistons etc?

Also any info on N1 pistons regarding strengh, price etc?

Nah you only get a bare block

You can order brand new N1 GTR engines from nissan and various other companies for about $12,000 but this doesnt include any of the ancillaries.. wiring.. etc

[BOOSTD]

Just had a good chat to the guys At ADVAN. They said 2.5thou clearence was fine.

Venolia were crap,

Arias are good with the iron rings as the bed quicker.

Don't use the 1.5mm restrictor in the block as it causes the cams to sieze unless the N1 oil pump is used,

Use a semi syn for run-in and half throttle to 4000rpm over 500KM.

Compression is best around 8.5-8.7

The head is coming off on Sunday, pix to come.

[B33st]

I just had a look at the Venolia web site and in their 2005 catalogue it recomends clearances of between .006 & .010. I think that the .0025 clearance that you ended up going with was a big part of your problem.