What new pistons avail for EA82T ?

discopotato03 · Post by **discopotato03** » Sun Apr 15, 2007 8:11 am

Hi all , I'm curious to know what is available piston wise for the EA82-T engine . I'd prefer a higher than 7.7:1 CR because our higher octanne ULP is far better now than it was in 1985-7 .

Any help appreciated , thanks Adrian .

Outback bloke · Post by **Outback bloke** » Sun Apr 15, 2007 2:19 pm

I don't know if they do them as a standard thing but I would try Arias pistons. Or ACL.

steptoe · Post by **steptoe** » Tue Apr 17, 2007 10:01 am

If you are brave - normal non turbo pistons ?

Suby Wan Kenobi · Post by **Suby Wan Kenobi** » Tue Apr 17, 2007 10:31 am

As far as standard replacement pistons go there are all oversizes but no standard bore sizes available off the shelf. If you where keen i would contact a piston maker and find out what they can do for you but more than likely you would get forged pistons and with that around $1200 a set with rings. I dont think it would be worth the cost for minimal gains. Other alternative would be a shave of the heads or block although a big raise in static aint going to happen

julian · Post by **julian** » Tue Apr 17, 2007 6:15 pm

jono wrote:If you are brave - normal non turbo pistons ?

Just thinking about that makes me smell burning coolant.

schultzie · Post by **schultzie** » Tue Apr 17, 2007 7:22 pm

a good combination i have heard off is a na carby block and then turbo heads.... good for 12psi every day... now im not too keen on trying it but none the less it sounds good

steptoe · Post by **steptoe** » Wed Apr 18, 2007 9:15 am

using the n/a block raises some questions re the different pcv castings between the two. I have some bits earmarked to try later one day - n/a pistons in turbo block

discopotato03 · Post by **discopotato03** » Sat Apr 21, 2007 8:59 am

Guys this thread was all about trying to find something to rebuild the EA82-T with and have it end up being a little better than Subaru had it .
Its a catch 22 wanting to have better performance from an 85 era engine , the CR is always low and the engine management/injectors the limiting factor . I guess I'm in denial about the propper path which is to fit an EJ20 turbo engine and dual range gearbox . In the past I've been down the road of aftermarket engine management systems and trust me wiring them up and getting the thing running is only half the fight , tuning them properly is a big issue .

Back to EA82 factory pistons , I have a picture of the turbo and N/A next to each other and it looks like only the crown/dish is different though the skirt on the turbo ones is a bit longer . My main concern was where on the sides the rings were located as many turbo production pistons have wider ring lands than the N/A equivalent to cope with the higher piston temperatures (piston rings conduct heat from the piston to the block) . It seems obvious that Subaru was intending to run the EA82-T is a pretty light state of tune so their pistons were not designed to live in a higher state of tunes environment . If anyone has access to an EA81 piston I'd really like to see it measured up agains an EA 82 piston to see if they are dimensionally the same . If the EA81's 8.7 CR could be had with all EA82 mechanicals then this would be the low cost option with the EA82-T engine . Other than that I guess we are stuck with std EA82-T pistons because most would not spend the money on custom forged pistons for these engines . By the way I've heard that there was some late variation of EA82 with "The Spider Type" inlet manifold but not sure if is Subaru or aftermarket .

The simple truth is that the EJ20 is a far more modern engine with more sophisticated engine control and ingition systems so a big leap beyond the EA's .
Shoot me because I'm a wuzz who fears the electrical side of things and for me hell on earth is 100,000 wires and a dash all pulled apart . I did see somewhere on this boad that someone was offering to strip and tag EJ looms to more or less plug into an L series so this would be of huge benefit to me .

Cheers Adrian .

PS . Anyone with an EJ powered RX Turbo please feel free to bombard me with the pitfalls and fixes for doing the conversion from an electrical point of view . There are many EJ20 turbo variations so another issue is which one ?

steptoe · Post by **steptoe** » Sat Apr 21, 2007 9:52 am

funny how threads lose focus in some way at times...

join the club for sticking with same. i did very same with my Brumby - worked EA81 coz it fits, looks sorta factory and no computer to deal with. if you check out Brumberty's gear, he went LPG with a points dizzy conversion to run an EJ without a factory fuel and spark management computer - i have been very pleased with the gains i made and have had five years and 180,000 reliable kms with my EA81.

I am going down same path with my GLTA at present - just wanna run it as factory for that turbo thrill - first.

Now. the piston suggestion i made above has been done by someone (s) on USMB website apparently- dunno engine management changes if any but you'd think it'd lose turbo 'lag' . and no wires to play with

an efficient intercooler is said to add 15%

the spider manifold musta been turbo vortex maybe imported only but is factory. with the tps being wired in reverse it no straight swap from what i read here some time ago. can send you a photo to email addy

when i see people buy crashed EJ22 libs for a coupla hundred bucks i start to see financial advantage (paid $400 for reco welded heads for EA82T) and challenge i am not ready for so i am essentially same sort of scaredy cat as you !

brumbyrunner · Post by **brumbyrunner** » Sat Apr 21, 2007 10:38 am

spider manifold is from turbo Vortex.
Said to increase throttle response and inprove driveability. I guess that's why Subaru did it.

Discopotato03 - has it occured to you that perhaps you've bought the wrong car?
You want to change the front hubs to run Liberty struts, change the rear suspension to Liberty 5-link, increase the power to WRX levels without playing with engine management, make it handle and stop but probably don't want to spend any more than 10 grand?
Do you think maybe a WRX or RS Lib would suit you better? Do all of the above stock standard and cheaper?
Just a thought.

discopotato03 · Post by **discopotato03** » Sun Apr 22, 2007 3:48 pm

Brunbyrunner no not the case . The Subaru theme was all new to me and as as I've said the learning curve is steep .

I had been hoping that there was an easy solution to the EA82-T's low CR problem but the propper solutions don't justify the cost .

I was def after an RX-T because they have a lot of potential particularly if you get a clean example for the right sort of price . A Leone parked in the street or rolling down the road will never have the attention grabbing abilities of a Rex and thats just the way I like it . The spec sheet looked good - factory EFI (means the right tank and pump) , closer ratio box , rear LSD , all independant susp , four wheel discs (inc larger front CV's/drive shafts) , power steer and A/C which is going over the shoulder as soon as I find a factory non A/C type alternator mounting bracket . Loads I mean HEAPS of spares available cheaply . Heaps of transmission options available .

My problem with electricals is that I can't do them myself meaning the things off the road for a week during the conversion process . Not always easy when this car was ment to be the daily driver .

Anyhow first things first , probably going with Lib/Imp front struts and better dampers/springs and possibly Bilstein coil overs on the back because I doubt there's anything that I'd call decent available for it . That also takes into account different brakes wheels and tyres so shoulkd keep me busy for a while . Time to research the EJ20 turbo family and pic the one that suits me best . Then explore the wiring fiasco and try to sort it before it goes in .

Should end up with the ultimate sleeper thats quiet and user friendly , nice daily driver and interesting project .

Cheers .

steptoe · Post by **steptoe** » Sun Apr 22, 2007 7:24 pm

someone in victoria had one for sale in here for 2000 no rego , sounds good buy.

sublime · Post by **sublime** » Mon Apr 23, 2007 12:37 am

jono wrote:someone in victoria had one for sale in here for 2000 no rego , sounds good by.

Hmmm... jono I think you will find that is the one discopotato03 has!

discopotato03 · Post by **discopotato03** » Mon Apr 23, 2007 7:28 am

....

sublime · Post by **sublime** » Mon Apr 23, 2007 9:04 pm

If I'm not mistaken you brought the RX Turbo on Wednesday, while I was planning on being in Melbourne on Friday! Damn you discopotato03!:p

discopotato03 · Post by **discopotato03** » Tue Apr 24, 2007 4:48 pm

I had days off and didn't miss the chance . I did not want to be on the Hume in the double demerit period either .

Cheers .

bpm · Post by **bpm** » Mon May 07, 2007 8:11 am

i broke a couple of std ea82t pistons on different occasions, i was just buying replacement from subaru, not cheap, and then they ran out. the last time i pulled the engine i fitted a set of ea82 aspirated pistons made by acl. they are flat tops with valve reliefs. part no is 4kry7000-std. they are to fit a 92mm bore. box says they fit ea71 and 81s too! i cc'd the chambers to work out the CR, but i cant remember what it came in at. i think it was around 9.2-9.5. i fitted a tdo4 and run 15psi all day every day. that was twelve months and 30,000km ago and i havent broken one yet. much stronger piston.

discopotato03 · Post by **discopotato03** » Mon May 07, 2007 8:59 am

Hey thanks for that Bpm . Can I take it that you're using the std computer and gate/vane type AFM - three plug system I think people call it ?

The EJ may be a bit much to chew on ATM , not sure . I figure that a bit of chamber work could possibly get it down to 9:1 and I'm a bit of a fan of slightly lower coolant temps and low/med viscosity synthetic oils . Keeping the deck and head temp down is more important to me than longer oil life .

I haven't looked but are your pistons oversize or std bore .

Thanks for the tip , cheers Adrian .

bpm · Post by **bpm** » Mon May 07, 2007 11:23 am

im running a microtech computer, they are 1000 buks but its the only way you can get the engine tuned properly. it can be swapped onto an ej down the track too. no airflow meter, it runs a map sensor. yes the pistons are standard size.

steptoe · Post by **steptoe** » Mon May 07, 2007 12:01 pm

bpm,

sounds good what you got with the na pistons

a few ???'s

whose head gaskets do you use ?

microtech ? are they the ones that give model numbers like MT4, MT8 ?

what model do you have ?
did you fit it and tune it ?
did it get wired into std wiring harness in place of old computer ?

or old ecu still there ?