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Interference engines

Featured Replies

so I was wondering wich of subaru engines are interfirance

I know that all EJ turbo are but want to know for na engines

heard thet EJ22 from year 1996 are allready interfirance

are you in a foreign location, those might be different than the US which is what most of us are familiar with?

 

wiki-pedia has some information on EJ engines that might help with even some comments about other markets.

 

in the US:

EJ25's are all interference.

EJ22's 1997+ are interference.

EJ18 are not.

The engines are all the same in all countries, not sure about the 2.0. www.cars101.com will tell you about the engines, but it is safe to assume after 1995 they all are (even if they arent) I thikn the 2.2 was starting 1996.

 

I think the early 1995 plus were built in the US using engines and transmissions from Japan. I don't know if they still do, but that is why they are all the same.

small correction:

The phase I EJ22 of early '97 is not interference.

The phase I's have the Subaru logo in valve cover and the spark plugs are just above the VC.

All later are

 

O.

small correction:

The phase I EJ22 of early '97 is not interference.

The phase I's have the Subaru logo in valve cover and the spark plugs are just above the VC.

All later are

 

O.

where did you hear that? EJ22's have spark plugs above the VC up until 1999 so that description doesn't seem to distinguish anything or i'm missing something?
  • Author

do youhave any pics off differences in hose walve covers

If you have please post them

 

 

thanks

do youhave any pics off differences in hose walve covers

 

scroll down this page to see early style EJ22 valve covers:

http://www.vortechonline.com/engines/

 

here's Subaru's website with a valve cover picture that shows the spark plug holes going through the top of the valve cover gaskets of the later PHase II 1999-2001 EJ22's:

 

http://opposedforces.com/parts/impreza/us_g10/type_76/engine/rocker_cover/illustration_2/

 

that's your two different EJ22's and their valve covers.

small correction:

The phase I EJ22 of early '97 is not interference.

The phase I's have the Subaru logo in valve cover and the spark plugs are just above the VC.

All later are

 

O.

 

In 97 the phase1 ej22 changed to a solid valvetrain from the HLA valvetrain. (I have one sitting in my garage.) And yes, it has the old style heads where the plugs don't go through the valve covers.

And I've been told by numerous members on here that it's an interference engine because a piston change or something like that. I'm not sure why, just that I've been told it is.

Right out of the EJ engine Technicians Reference Manual:

 

The 2.2 liter (SOHC) (Phase 1) has been enhanced starting

with 1997 model year. The single overhead camshaft

engines have had internal and external changes that yield

an approximately 10 % increase in power and 3% increase

in fuel economy. Accomplishing this involves many factors,

one of which is engine friction reduction.

The piston, a major source of engine friction has been coated

with a friction reducing agent called Molybendum. This thin

coating not only allows a smoother travel through the

cylinder but also reduces cylinder wall scuffing. This coating

will wear off over time and is not an indication of a problem.

The skirt of the piston has been reshaped and the overall

weight has reduced by approximately 100 grams.

Compression ratio has been increased to 9.7 to 1 by

reshaping the crown of the piston. This eliminates the

clearance that was available between the piston at TDC

and a fully opened valve. Piston pin offset has been

changed to 0.5 mm. Piston to cylinder wall clearance has

been reduced by increasing the piston diameter.

Another source of high engine friction is the valve train.

Hydraulic lash adjusters are always in contact with the

camshaft or valve rockers. The hydraulic pressure of the

lash adjuster must be overcome during operation and the

most critical time of engine start. To overcome this situation

and to contribute to the total reduction of friction loss the

SOHC engines will have solid valve adjusters. The

scheduled service of these valve trains is set at 100,000

miles and is not required during the PDI. The SOHC engine

uses an adjustment screw and locknut.

The intake manifold has been reshaped to increase the air

flow mass and speed, contributing to improved low and

mid engine speed operation. Components located on the

intake manifold have been relocated as compared to the

1996 models. EGR Solenoid, Purge Control Solenoid, etc...

Edited by ferret

so I was wondering wich of subaru engines are interfirance

I know that all EJ turbo are but want to know for na engines

heard thet EJ22 from year 1996 are allready interfirance

 

-NO.

That is not even correct. Turbo ea81, turbo ea82, and for sure the 91-94ej22t turbo were non-interference.

It's very simple - you pull a valve cover and check the rocker assembly. If you have solid lifters it's an interferance engine. If you have hydro it is not.

 

There is only a single questionable year with regard to this - '96 had the hydro valves and single port heads. So a '96 looks identical to a '97/'98 from outward appearance, but will have hydro lifters AND they changed the pistons in '97 resulting in it being interferance. As far as I know there was NEVER an EJ22 made with hydro lifters AND interferance pistons. Those are mutually exclusive from the factory.

 

As far as I know removing a valve cover and checking the rocker assembly style is the only reliable way to tell. If course the solid lifter/roller rocker assembly fits on the older engines (even the dual port heads) so if someone went to the trouble of putting solid lifters on the engine.... you are screwed because there's no way to tell on a single-port engine like the '96.

 

All these parts can be mixed/matched so if the thing has been heavily modified.... there's no rules that apply.

 

GD

There is only a single questionable year with regard to this - '96 had the hydro valves and single port heads. So a '96 looks identical to a '97/'98 from outward appearance, but will have hydro lifters AND they changed the pistons in '97 resulting in it being interferance. As far as I know there was NEVER an EJ22 made with hydro lifters AND interferance pistons. Those are mutually exclusive from the factory.

GD

 

I can confirm this, I have a MY96 that lost it's timing belt cruising 85 on the highway, and it lives to tell the tale.

  • Author

I was not tolking abouth EA81t and EA82t becaus I know they are not interfirance

but nuewer subaru turbo engines we have are all interfirance

we got EJ20g in legacy and early imprezas and so on

I was not tolking abouth EA81t and EA82t becaus I know they are not interfirance

but nuewer subaru turbo engines we have are all interfirance

we got EJ20g in legacy and early imprezas and so on

 

Since you're saying the 20g is an interference engine, the 22t may be the only non-interference ej turbo.

It's very simple - you pull a valve cover and check the rocker assembly. If you have solid lifters it's an interferance engine. If you have hydro it is not.

 

There is only a single questionable year with regard to this - '96 had the hydro valves and single port heads. So a '96 looks identical to a '97/'98 from outward appearance, but will have hydro lifters AND they changed the pistons in '97 resulting in it being interferance. As far as I know there was NEVER an EJ22 made with hydro lifters AND interferance pistons. Those are mutually exclusive from the factory.

 

As far as I know removing a valve cover and checking the rocker assembly style is the only reliable way to tell. If course the solid lifter/roller rocker assembly fits on the older engines (even the dual port heads) so if someone went to the trouble of putting solid lifters on the engine.... you are screwed because there's no way to tell on a single-port engine like the '96.

 

All these parts can be mixed/matched so if the thing has been heavily modified.... there's no rules that apply.

 

GD

This right here. HLA's and interference do not mix. So, check the valvetrain and that will tell you your answer (provided that it's the stock valvetrain).

Just for the note for those that may not be familiar, this is what a solid adjuster valvetrain looks like.

IMG_3506.jpg

 

HLA valvetrain will have flat tops instead of the flathead screw head with lock nuts.

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