Je pistons

[Syed Shah]

I see. I always thought stock were good, but since I only know what sort of power/abuse they can take, that is all I can comment on. Any info on this Chris?

I'll try and find the weight of stock pistons, will allow us to compare with HKS etc.

Have you ever dealt with JUN/Cosworth stuff? Everyone claims they are brilliant, but nobody is using them due to cost. Venom in the US used them, and then switched to Arias IIRC.

[Nathan]

I know the weight of the stock pistons. I know the weight of the HKS pistons. I also know the weight of TODA pistons, the HKS 'H' section rods and the stock rods. All I want to do is find out the weight of the JE pistons.....

Never dealt with Jun. Had LOTS of dealings with Cosworth/Arrow/Farndon in my Burton days. Very good. On par with HKS and (I presume) Jun.

[Martin F]

Good info guys.

Will try to knock up a table over the next couple of days with all this info in.

[Syed Shah]

Ok, the JE pistons (non-PHR spec) weigh in at 338 grams.

Is that more or less than stock?

[Nathan]

lol, OK. So, the JE pistons are lighter than everything except the TODA ones.....glad I said that JE 'tend' to be heavy....obviously on the Mk4 they are relatively 'light'..

HKS piston: 362g
TODA piston: 318g
Standard piston: 376g
Standard rod: 771g
HKS 'H' section rod: 594g

Rods are weighed with bolts and small-end bushes fitted. Pistons are weighed without rings or pins. It's also important to note that the TODA pistons aren't really viable for most Mk4's as the compression with them would be around 7:1. Would love to build a mad 2.5 bar monster with them though. I live in hope.

[Chris Wilson]

Been off the board for a while. back now! JUN pistons are made by Cosworth, here in the UK, but they will not, at all, never, ever sell direct. We buy a lot of stuff from Cosworth, they wouldn't entertain it, I know people who spend hundreds of thousands with them, they too couldn't get them direct. Honourrable comapny! PITA

My limited experience of HKS ones is they work OK, but are very heavy. Skyline 2.6 GTR ones a considerably heavier than stock Nissan ones, and i have never had a definitive answer from HKS as to whether they are forged or cast. they look cast to me... The Skyline ones didn't have the stock oil cooled head galleries either, which added weight, MAYBE added strength, but seriously reduced ring land and piston crown heat transference.

If I end up doing this 1JZ-GTE engine it will have Cossie pistons. Full stop. They are the best, and worth the price hike via JUN, IMO.

[Nathan]

Originally Posted by [b

Quote[/b] (Chris Wilson @ Jan. 14 2004,13:19)]i have never had a definitive answer from HKS as to whether they are forged or cast. they look cast to me...

I am very surprised to hear that Chris. I would lay money down that they were, as are the TODA's. In fact, they look like every other forged piston I have seen, including Cosworth and Accralite. TODA and HKS shown...



As for Cosworth being honourable, yes, they are. Very. Shame more companies don't take the same trading policies

[Nathan]

And no guesses to see where the TODA one gets it's light weight from!

[Martin F]

Interesting pics.

Is that more rings (seats) on the Toda one than the HKS or just the way it appears in the pic ?

[Nathan]

No, they are just extra ridges machined into the piston. Theres a reason for it (supposedly better than not having them) but I can't remember what it is.