25d valve train upgrades

Heads, valves, pistons, rods, crankshaft, etc...

Moderators: Helpinators, Moderators

Post Reply
bmxkelowna
Fourth Gear
Posts: 1047
Joined: Thu Feb 16, 2006 5:00 am
Location: kelowna bc canada
Contact:

25d valve train upgrades

Post by bmxkelowna »

so pulled my motor apart and realized my dead hole wasnt from broken ringlands again but from bent valves

ej22t block
ej25d heads
ej20k cams
ej257 valve springs
ej20g rob tunned ecu
small gt30 turbo running 16psi

by the looks of things im getting valve float around 7000 rpm (while drifting it wont hit the 7500rpm limiter) causing all the exhaust valves to hit the pistons

what options do i have for stiffer valves for these heads? or am i better off trying to find a set of ej205 heads and intake manifold?
bmxkelowna
Fourth Gear
Posts: 1047
Joined: Thu Feb 16, 2006 5:00 am
Location: kelowna bc canada
Contact:

Re: 25d valve train upgrades

Post by bmxkelowna »

Legacy777
Site Admin
Site Admin
Posts: 27884
Joined: Tue Oct 15, 2002 11:37 am
Location: Houston, Tx
Contact:

Re: 25d valve train upgrades

Post by Legacy777 »

I have heard of them, but haven't used them.
Josh

surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT

If you need to get a hold of me please email me rather then pm
PhyrraM
Fourth Gear
Posts: 1980
Joined: Thu Aug 11, 2005 4:34 pm
Location: Lake Elsinore, CA

Re: 25d valve train upgrades

Post by PhyrraM »

I would think that any WRX (not STI) EJ20K upgrade will also work for the EJ25D heads. I would start by researching what it takes to 'upgrade' WRX EK20K heads to STI EK20K spec. (From shim over bucket to shim under bucket)

The other path is to have your machine shop measure everything and find stiffer springs that work with the heads directly. 7500 should be fine for the current lifter buckets and retainers.
'93 Winestone SS Auto, '91 Pearl White SS.
'93 Pure White SS EJ20G slanty intercooled, SIDESWIPED! In stasis.
'94 FWD and '95 AWD Laguna Blue SVXs.
2017 Pure Red BRZ Limited w/Performance pack
bmxkelowna
Fourth Gear
Posts: 1047
Joined: Thu Feb 16, 2006 5:00 am
Location: kelowna bc canada
Contact:

Re: 25d valve train upgrades

Post by bmxkelowna »

my set up that i posted above has been working great until i recently floated the valves for some reason, if it was too much boost you would think the intake valve would have hit the piston but it was the exhaust valves

maybe the 04 sti valve springs i got are a little tired? i think i might order those BC valve springs and see if they help any
PhyrraM
Fourth Gear
Posts: 1980
Joined: Thu Aug 11, 2005 4:34 pm
Location: Lake Elsinore, CA

Re: 25d valve train upgrades

Post by PhyrraM »

How do the EJ257 springs compare dimensionally? I would make sure they are meant for the same installed height and allow at least the same valve opening before coil bind.
'93 Winestone SS Auto, '91 Pearl White SS.
'93 Pure White SS EJ20G slanty intercooled, SIDESWIPED! In stasis.
'94 FWD and '95 AWD Laguna Blue SVXs.
2017 Pure Red BRZ Limited w/Performance pack
bmxkelowna
Fourth Gear
Posts: 1047
Joined: Thu Feb 16, 2006 5:00 am
Location: kelowna bc canada
Contact:

Re: 25d valve train upgrades

Post by bmxkelowna »

they looked almost identical when I compared them side by side while installing them. and from everything I ready online they work. I wouldn't think the lift on the cams would be that much different then then Ej25d cams.
martimus919
First Gear
Posts: 222
Joined: Sat Sep 19, 2009 6:21 am
Location: Reno, NV

Re: 25d valve train upgrades

Post by martimus919 »

I was talking to the guys at Rally Sport Direct here in Utah about running those valve springs in those heads and they said they're all the same really. They also said if I was unsure if they would work I could bring in my stock springs and compare them, talk to Kirill the guy's awesome!
07 Outback XT VF52
94 Legacy Sport, VF23, 550 RobTune, various other things
93 Legacy Touring Wagon EJ205 management and dash swap (in progress)
90 Loyale Turbo, EJ Turbo Swap, 2" lift
82 Brat, EJ22 swap, RX AWD trans w/ LSD rear, 5 lug 4 wheel disc.
bmxkelowna
Fourth Gear
Posts: 1047
Joined: Thu Feb 16, 2006 5:00 am
Location: kelowna bc canada
Contact:

Re: 25d valve train upgrades

Post by bmxkelowna »

well i know they work since both my brother and I have been running this set up for a few months now.

im just trying to figure out why i floated the exhaust valves into the pistons
cj91legss
Fifth Gear
Posts: 6322
Joined: Fri Jun 20, 2008 8:17 am
Location: Lakewood, Wa 98439
Contact:

Re: 25d valve train upgrades

Post by cj91legss »

Did the retaining clips fail?
91 L-TW Wagon with a full Swap -RIP
92 SS Prefaced, GD dash swapped, 22T/205 Hybrid 20 psi - BEAST!
93 SS Bone Stock Gone!
94 TW Bone Stock Gone!
91 SS 4EAT Sold!
98 LGT 4EAT
98 LGT Wagon 4EAT
bmxkelowna
Fourth Gear
Posts: 1047
Joined: Thu Feb 16, 2006 5:00 am
Location: kelowna bc canada
Contact:

Re: 25d valve train upgrades

Post by bmxkelowna »

nope everything is in-tacked

i was told on nasioc "sustaining high rpms the valve springs cant recover fast enough" which there was a lot of before it happened
cj91legss
Fifth Gear
Posts: 6322
Joined: Fri Jun 20, 2008 8:17 am
Location: Lakewood, Wa 98439
Contact:

Re: 25d valve train upgrades

Post by cj91legss »

And what do the usdm sti's redline at?
91 L-TW Wagon with a full Swap -RIP
92 SS Prefaced, GD dash swapped, 22T/205 Hybrid 20 psi - BEAST!
93 SS Bone Stock Gone!
94 TW Bone Stock Gone!
91 SS 4EAT Sold!
98 LGT 4EAT
98 LGT Wagon 4EAT
bmxkelowna
Fourth Gear
Posts: 1047
Joined: Thu Feb 16, 2006 5:00 am
Location: kelowna bc canada
Contact:

Re: 25d valve train upgrades

Post by bmxkelowna »

7200 im pretty sure
dankberries
Second Gear
Posts: 506
Joined: Thu Oct 27, 2011 5:09 am
Location: Dirt Roads, Colorado

Re: 25d valve train upgrades

Post by dankberries »

Reviving an old thread.

I've been trying to figure out if using Sti(04') valve springs in a ej25d(97'+) is an upgrade or a viable option. Aftermarket or OEM, either way. I'm getting mixed readings through different forums on success, I would like to know if anyone on this forum has had success and would care to share.

In a couple different forum posts Jay Storm writes of using them but doesn't say much about it. I would like to know what RPM and cam profile they can handle and most importantly that there won't be valve float or valve to piston contact.

Storm on rs25
more rs25
nasioc talk
more Nabisco crackers

Food for thought: The Sti valves are shorter than 25d, I would think that would mean using Sti springs with 25d valves would add up to a lesser seat pressure, no?
The OP of this thread never detailed the cause of his float, would be nice to know..
In one of the rs25 posts 2Slo4u talks about the spring diameter differences and the correlation to the bucket diameters, i haven't measured myself to see if Sti buckets are compatible to 25d heads but thought that the different sizes of spring/bucket combo could cause bad harmonics possibly.

I.e. if the Sti spring O.D. is smaller than 25d spring O.D. would it sit funny in the bucket?

Any insight is greatly appreciated, thanks!
93 impreza rally muffin
93 legacy ss Tarmac Terminator
89 Nissan 240sx sr20
90 Nissan 240sx 2jz
killajamal wrote:Dank is actually German for "silly term which the kids have come up with to describe exceptionally choice marijuana.''
Legacy777
Site Admin
Site Admin
Posts: 27884
Joined: Tue Oct 15, 2002 11:37 am
Location: Houston, Tx
Contact:

Re: 25d valve train upgrades

Post by Legacy777 »

dankberries wrote:Food for thought: The Sti valves are shorter than 25d, I would think that would mean using Sti springs with 25d valves would add up to a lesser seat pressure, no?

You need to see what the free length of both sets of springs are and how much force is needed to compress them to the "compressed" length. I would guess the different springs would require different forces to compress them to the same "compressed" length, but without checking it'd be hard to confirm.
Josh

surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT

If you need to get a hold of me please email me rather then pm
Mister Anderson
First Gear
Posts: 214
Joined: Sun Aug 28, 2011 7:20 pm
Location: Vancouver, WA/ Spokane, WA

Re: 25d valve train upgrades

Post by Mister Anderson »

-When I built my EJ25D heads I used SuperTech STi fitment double springs. I had to machine the spring seats down in order to drop the seat pressure from 100PSI to 75PSI. Super Tech didn't make any "off the shelf" seats so I bought the thickest ones to mill down at home. SuperTech should be able to make custom spring seats though.
Part numbers for the springs are; SUP-SPRK-TS1015_SU5SPRK-TS1015/SU5 (the seats are thick like I mentioned)

-The valves are also SuperTech. The part numbers for intakes are; SUP-SIVN-1016 SIVN-1016 and the part numbers for exhaust are; SUP-SEVI-1016 SEVI-1016

-For camshafts I'm running Kelford 272's that are for EJ20K heads (They work in 97+ 25D DOHC heads). unfortunately, Kelford no longer makes cams for the EJ20K.



Edit: hopefully that can help with your "food for thought" part of your post. I also have pictures I can post if you want.

Edit again: I just looked at your build thread, so NVM LOL.
91 black SS 5 speed (Canadian).... Closed deck EJ20G, fully built, V5/6 sti ra drivetrain, haltech stand-alone
93 silver TW 5 speed... rebuilt 22T with 20G heads, wrx ra drivetrain, otherwise stock.
73 kazen red VW bus riviera camper
dankberries
Second Gear
Posts: 506
Joined: Thu Oct 27, 2011 5:09 am
Location: Dirt Roads, Colorado

Re: 25d valve train upgrades

Post by dankberries »

MisterAnderson, Did you have issues with the fitment of the Sti springs in the 25d buckets? I've read through your thread sometime ago, but I don't recall at the moment if that was discussed. With that aggressive of a cam I might consider a shim under bucket.

Thanks for sharing, I'm fairly familiar with all the info. When I built my impreza 25d heads I had shipped them out to ferrea where they did R&D and custom made all my parts.

I was hoping for a significantly cheaper alternative to going that route again, and didn't feel it necessary to get that extensive, dual springs maybe a bit over kill for the DD. At most I was considering OEM 20k cams(22° overlap) .
I already made the move and purchased 2004 Sti valve components, based on the minimal info I found , it should be a slight increase over 25d springs.
Hopefully by the end of today/tomorrow I will have collected my own data for comparison.
93 impreza rally muffin
93 legacy ss Tarmac Terminator
89 Nissan 240sx sr20
90 Nissan 240sx 2jz
killajamal wrote:Dank is actually German for "silly term which the kids have come up with to describe exceptionally choice marijuana.''
Post Reply