Welcome to the North American Subaru Impreza Owners Club Thursday March 28, 2024
Home Forums Images WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Go Back   NASIOC > NASIOC Technical > Built Motor Discussion

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.







* As an Amazon Associate I earn from qualifying purchases. 
* Registered users of the site do not see these ads. 
Reply
 
Thread Tools Display Modes
Old 07-03-2019, 10:22 AM   #1
whiterabbitrexy
Scooby Newbie
 
Member#: 379271
Join Date: Jan 2014
Default Gf8 v4 wrx ej20 heads ON a ej205 block stock ecu

Hi everyone i have a 1998 subaru Australian Wrx Gf8.....it has everything from factory stock beshides 3inch Tbe, vf22, fmic, and ecu is standard but soon will be fully tunable by installing a chipset and rom to turn it into a live standalone ecu......

The ej20 block Bottom end craprd it self long story short so i thought about installing a 2002 wrx ej205 for cheap.....i found one cheap for $300 aus, and now thininkg to myself my 1998 ecu parameters might be a bit diffrent fireing order compared to a ej205 block because of crank angle sensor might be off compared to my phase 1 ej20k block being suited to the factory harness and sensors?

Also notice somthing scarry the pistions come out complety FLAT to the top of the deck...my old block only had a ej20 wrx 75mm stroke and stoped a fair bit before the decking of the block.... will this mess with my timing and Valves hiting the pistons????

In all that said.....Block will bolt up perfectly with the ej205 oem gaskets.... i will use a ej205 harmonic balance Not my 1998 ej20k factory harmonic..... i want to play it safe i can run everything from Oil pump to cooling and block matting....so the rest im a little puzzled.

Please give us your advice on what u known i might be missing


* Registered users of the site do not see these ads.

Last edited by whiterabbitrexy; 07-03-2019 at 10:36 AM.
whiterabbitrexy is offline   Reply With Quote
Sponsored Links
* Registered users of the site do not see these ads.
Old 07-18-2019, 11:39 PM   #2
whiterabbitrexy
Scooby Newbie
 
Member#: 379271
Join Date: Jan 2014
Default

Here is a video of what I'm trying to explain and do

https://youtu.be/auiWy5QKM1A
whiterabbitrexy is offline   Reply With Quote
Old 07-19-2019, 08:33 PM   #3
ascendr
Scooby Newbie
 
Member#: 462136
Join Date: Jan 2017
Location: NY Tristate Area
Vehicle:
02 Bugeye

Default

A couple of points of clarification. The crank sensor picks up its signal from the crank pulley not the harmonic balancer. The sensor you are pointing to at 2:20 is the oil pressure sensor not the knock sensor. The knock sensor is the one you correctly identify at 5:35. I noticed that the differences you are pointing out like sensors, PCV, water crossover pipe, etc look similar to those we in the US need to change over to USDM when doing a JDM into USDM swap. There are several posts discussing this here, hopefully that will shed some light on what you will need to do.
ascendr is offline   Reply With Quote
Old 07-25-2019, 07:57 AM   #4
whiterabbitrexy
Scooby Newbie
 
Member#: 379271
Join Date: Jan 2014
Default

Quote:
Originally Posted by ascendr View Post
A couple of points of clarification. The crank sensor picks up its signal from the crank pulley not the harmonic balancer. The sensor you are pointing to at 2:20 is the oil pressure sensor not the knock sensor. The knock sensor is the one you correctly identify at 5:35. I noticed that the differences you are pointing out like sensors, PCV, water crossover pipe, etc look similar to those we in the US need to change over to USDM when doing a JDM into USDM swap. There are several posts discussing this here, hopefully that will shed some light on what you will need to do.
Oh gosh how embarrassing....yeah sorry that is the oil pressure sensor not the crank angle sensor.....i got confirmed by another member that i will need to change over all my sensors and use my Pcv..... anyone know what my compression ratio will be ? I think it will be somthing like 9:98 witch is scary stupid bad for weak wrx pistions
whiterabbitrexy is offline   Reply With Quote
Old 08-05-2019, 08:09 AM   #5
whiterabbitrexy
Scooby Newbie
 
Member#: 379271
Join Date: Jan 2014
Default

Can somone please help me calculate my compression ratio? I cant find any info on volume of air for my v4 wrx cylinder heads.....also anyone know if this combo will work ? From what i know alot of people do add v6 ej207 shortblocks with good success....but this is a wrx ej205.... i think it should work ?
whiterabbitrexy is offline   Reply With Quote
Old 08-05-2019, 12:32 PM   #6
ascendr
Scooby Newbie
 
Member#: 462136
Join Date: Jan 2017
Location: NY Tristate Area
Vehicle:
02 Bugeye

Default

Using Jeff's spreadsheet I entered the following in a custom config:

EJ20G head volume (from Engine 1 on the sheet): 45.2 cc
Piston Dish Volume (EJ205 piston dish): 11 cc
Bore: 92mm
Stroke: 75mm
Gasket Thickness (EJ205 OEM): .8 mm
Piston Compression Height (EJ205): 32.7 mm
Rod Length (EJ205): 130.5 mm

Result: 8.85 Compression Ratio

Hopefully someone more knowledgeable can double-check and chime in but from the looks of it you would be running higher compression. As for the valve to piston clearance concern I was under the impression that the EJ205 piston clearance was more than the ej20g. I've had both blocks recently and the ej20g looked to be about flush with the deck where as the ej205 left some room. Again hoping someone more knowledgeable will chime in.
ascendr is offline   Reply With Quote
Old 11-03-2019, 08:09 AM   #7
whiterabbitrexy
Scooby Newbie
 
Member#: 379271
Join Date: Jan 2014
Default

Quote:
Originally Posted by ascendr View Post
Using Jeff's spreadsheet I entered the following in a custom config:

EJ20G head volume (from Engine 1 on the sheet): 45.2 cc
Piston Dish Volume (EJ205 piston dish): 11 cc
Bore: 92mm
Stroke: 75mm
Gasket Thickness (EJ205 OEM): .8 mm
Piston Compression Height (EJ205): 32.7 mm
Rod Length (EJ205): 130.5 mm

Result: 8.85 Compression Ratio

Hopefully someone more knowledgeable can double-check and chime in but from the looks of it you would be running higher compression. As for the valve to piston clearance concern I was under the impression that the EJ205 piston clearance was more than the ej20g. I've had both blocks recently and the ej20g looked to be about flush with the deck where as the ej205 left some room. Again hoping someone more knowledgeable will chime in.
ascendr thanks heaps for the info..... i think i should be sweet with 8.85 cr, i will be using 98 octane fuel so it should be knock free happy.... as for valve to pistion clearance i should be again sweet and in the clear due to alot of people running ej207 blocks on these heads and they never had an issue with valves hitting pistions.

My only concern now is do i use a ej205 timing chain kit or do i use my ej20 block timing chain kit to help work with the v4 wrx cylinder heads???
whiterabbitrexy is offline   Reply With Quote
Old 12-23-2019, 01:24 AM   #8
whiterabbitrexy
Scooby Newbie
 
Member#: 379271
Join Date: Jan 2014
Default

Quote:
Originally Posted by whiterabbitrexy View Post
ascendr thanks heaps for the info..... i think i should be sweet with 8.85 cr, i will be using 98 octane fuel so it should be knock free happy.... as for valve to pistion clearance i should be again sweet and in the clear due to alot of people running ej207 blocks on these heads and they never had an issue with valves hitting pistions.

My only concern now is do i use a ej205 timing chain kit or do i use my ej20 block timing chain kit to help work with the v4 wrx cylinder heads???
So i guess my real question to eveyone is will this ej205 short block bolt on with no problems? I know alot of people have done the same short block swap with a v7 ej207 short block....and i think case wise they a very similar besides the semi closed deck ???
whiterabbitrexy is offline   Reply With Quote
Old 02-07-2020, 08:22 PM   #9
whiterabbitrexy
Scooby Newbie
 
Member#: 379271
Join Date: Jan 2014
Default

So still trying to find out if anyone has used a ej205 block with v4 wrx cylinder heads?
Anyone ?
whiterabbitrexy is offline   Reply With Quote
Old 02-08-2020, 04:25 AM   #10
can250
Scooby Newbie
 
Member#: 452601
Join Date: Aug 2016
Default

I have used v4 heads on a 96 block 99 block 2013 2.5l block and now a 2018 2.5l block so cant see why they would not work on a ej205
can250 is offline   Reply With Quote
Old 02-08-2020, 04:45 PM   #11
ripman
Scooby Newbie
 
Member#: 305707
Join Date: Jan 2012
Chapter/Region: International
Location: AUS
Vehicle:
1999 WRX
WRC Blue

Default

Quote:
Originally Posted by whiterabbitrexy View Post
So still trying to find out if anyone has used a ej205 block with v4 wrx cylinder heads?
Anyone ?
Are you talking about a non turbo block?
ripman is offline   Reply With Quote
Old 02-09-2020, 10:46 AM   #12
whiterabbitrexy
Scooby Newbie
 
Member#: 379271
Join Date: Jan 2014
Default

Quote:
Originally Posted by ripman View Post
Are you talking about a non turbo block?
Yeah talking about a 2004 wrx ej205 block with V4 wrx ej20g cylinder heads....want to know if i will bump into any problems
whiterabbitrexy is offline   Reply With Quote
Old 02-09-2020, 10:51 AM   #13
whiterabbitrexy
Scooby Newbie
 
Member#: 379271
Join Date: Jan 2014
Default

Quote:
Originally Posted by can250 View Post
I have used v4 heads on a 96 block 99 block 2013 2.5l block and now a 2018 2.5l block so cant see why they would not work on a ej205
LOL now thats impressive......thanks for shearing Can250..... very curious what is the rule of thumb when trying to get the timing belt to work? Like did u keep the V4 timing belt kit or did u have to use the year of the block timing belt kit ? Also was there any major problems u run into?
whiterabbitrexy is offline   Reply With Quote
Old 02-09-2020, 03:17 PM   #14
stu
Scooby Specialist
 
Member#: 25768
Join Date: Oct 2002
Chapter/Region: RMIC
Location: CO springs
Vehicle:
2003 XONA 9569S 40++
2.3 slobaru

Default

It should work no problem. you may have to mix and match some parts between blocks. The sensor in the front is the oil pressure sensor. and yes it should be as close to the top of the deck without going over the top. as far as the sensors I would use everything off the 205 block that you can. Don't look to far into it, they are both pretty much the same.
another thing check the oil pan for any metal flakes before you go to much further on the build. also maybe some ARP 2000 headstuds.
stu is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

All times are GMT -4. The time now is 07:27 PM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2024 Axivo Inc.
Copyright ©1999 - 2019, North American Subaru Impreza Owners Club, Inc.

As an Amazon Associate I earn from qualifying purchases.

When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission
Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.