Skip to content
View in the app

A better way to browse. Learn more.

Ultimate Subaru Message Board

A full-screen app on your home screen with push notifications, badges and more.

To install this app on iOS and iPadOS
  1. Tap the Share icon in Safari
  2. Scroll the menu and tap Add to Home Screen.
  3. Tap Add in the top-right corner.
To install this app on Android
  1. Tap the 3-dot menu (⋮) in the top-right corner of the browser.
  2. Tap Add to Home screen or Install app.
  3. Confirm by tapping Install.

3.0

Featured Replies

I whant to put 6 wrx pistons in my 3.0 six has anyone done thiss ? very close in size and stroke and way way stronger have 2 3.0 sixs and like the engine but pistons were weak any ideas ? oh and i have my own boring bar and block bench setup for boring subaru engines

'Close' in bore and stroke?

 

So you'd have to bore your engine?

 

What about the piston compression height, deck height and chamber clearance/squish?

Edited by CNY_Dave

What is wrong with the pistons? Are they really the weakest component in the rotating assembly? Just asking.

Edited by avk

Wat is wrong with the pistons? Are they really the weakest component in the rotating assembly? Just asking.

 

yeah - first I heard of this, plus, aren't some newer pistons having cracked land problems? Dunno that WRX would be an upgrade.

They have cracked land issues because the tune is run on the bleeding edge of detonation to meet EPA specs and fuel economy targets. It's likely they're also moving the top ring groove up closer to the crown to reduce the quenched area around the side of the piston where unburned HC's can lurk.

 

I would spend the money on the right size forged pistons before boring it out. You are talking a big jump in bore size which will probably require a re-sleeve. That money and effort is better spent on real pistons.

 

Get the tune right and keep dumping water/meth in there and the stock pistons should last a while.

  • Author

the stock pistons are realy weak worse than 1600 pistons same dementions as the wrx one just slightly smaller the wrx ones are at least 50-70 % stronger by design and have a ceramic coating and a slight dish to drop comp ratios. I broke 2 pistons on thiss six runing on propane so was not detanating but the pistons just couldent take boost they are flat tops with realy thin sides and very little space between ring lands. Is there even any forged pistons avalible for a 3.0 six ?

pistons same dimensions as the wrx one just slightly smaller the wrx ones. Is there even any forged pistons avalible for a 3.0 six ?

http://www.ebay.com/itm/SUPERTECH-SUBARU-H6-EZ30-PISTONS-P6-SU8920-N18-/330455563045

 

That's the first result I pulled up. Wouldn't hurt to call wiseco or any of the other big piston manufacturers and ask what they have.

 

A 2.8mm bore is big. The stock steel sleeves would probably be weakened enough by that to split under boost. So you're looking at re-sleeving the engine with these:

http://www.ebay.com/itm/Darton-300-028-Performance-Flanged-Sleeves-Subaru-EZ30-Outback-Legacy-Tribeca-/180882450033

 

You'd want to use forged WRX pistons too, so add that cost on top of the sleeves and the machine work.

That still leaves you with the stock rods. I found a few references to forged ones made by Pauter, but that's another $1400.

http://www.pauter.com/subaru.htm

  • Author

nice parts bitt pricey trying to keep low budget wonder if i could bore it for sleaves myself ?

Why don't you take one Piston from the 6 and another one from the WRX and place 'em together for Visual comparison; that could be a start point: could you post some Pictures of both together, and their measurements?

 

Sometimes other people see what we couldn't see...

 

Kind Regards.

  • Author

I have both out on ground right now the wrx ones are bigger so it might not work i have six wrx pistons here waiting i would like to use what i have because the buggy is based of low budget raceing that what makes it competative and interesting raceing high budget guys with low budget platforms my engine is way cheaper than the big block guys i race and it bugs the crap outa them realy how mutch do's a 517 dart engine with alcholol injection and nitros injection realy cost so whos winning

The WRX pistons are 2.8mm bigger diameter than the 3.0l ones.

 

... the wrx ones are bigger so it might not work ...

 

...unless you send the Block to a Machine shop to change the Cylinders (Walls) on the 6 with the WRX ones, but that should be very expensive, isn't it?

  • Author

i have my own boring bench setup for subaru engines was going to bore it myself but may not be enuff materail there also thiss is a dragrace block so could cement it posibly to hold liners together is a long term project and have two 3.0 engines to work with one has cracked block so would be a good candadate to try things with

  • 1 month later...
  • Author

hmm or bolt two 3.0 back to back and make a 6.0 48 valve flat 12 oh it even sounds good might be a tadd heavy but whould sound sweet. And use one monster turbo for both engines

  • Author

man do i whant thiss engine !! bad ! looks like a mud dragster engine to me

  • Author

well two 3.0 = 6.0 L close but need more have two svx 3.3 that whould make 6.6 L closer butt still not enuff. To catch a blown acohall hemi think he was 2700 hp last time i checked did 200 ft mud pitt in 2.1 seconds take me a while to get there.

  • Author

was thinking two bolted back to back with two speed power glide behind it with ford 9 inch in rear and subaru in front

a long time ago, I think Johnson brothers??? had a Honda Civic with an engine/transaxle in the rear too.

 

maybe I heard of a Smart car or some other tiny car recently built-up with a second engine?

  • Author

thiss whould be a rail type car long and high hp wonder if could get a mega squirt that could run 12 cly at same time ?

Please sign in to comment

You will be able to leave a comment after signing in

Sign In Now

Account

Navigation

Search

Search

Configure browser push notifications

Chrome (Android)
  1. Tap the lock icon next to the address bar.
  2. Tap Permissions → Notifications.
  3. Adjust your preference.
Chrome (Desktop)
  1. Click the padlock icon in the address bar.
  2. Select Site settings.
  3. Find Notifications and adjust your preference.