2.5 SOHC Block for DOHC Vehicle

[Maverick89]

Hey guys I am wondering if anybody has ran a SOHC Shortblock for a vehicle that takes a DOHC?

 

I have a 98 Forester with a 2.5 DOHC and need a new short block. I have a buddy who has a 2.5 from a SOHC. I know that the compression will be raised slightly but wondering if anybody has had success with swapping blocks?

[86BRATMAN]

Yes, quite a few people have ran this combo. The best part of it is you can use 04-06 sti headgaskets to get rid of the failure prone ej25d headgaskets. One of my friends in PA has just put one together and he is very pleased with the motor, fuel economy is improved slightly by the compression bump when you drive nicely, and the power output is definitely better.

 

I have built one for a local friend with a 97 gt, just waiting for consistent good weather to drop it in. And have a sohc shortblock I'm rebuilding for myself with the same build in mind. And honestly I'll probably build another for my nephew's Impreza he just bought if he proves he can take car of it lol

Edited March 14, 2014 by 86BRATMAN

[Maverick89]

do you have to run the 04-06sti head gaskets?

[86BRATMAN]

No, you don't have to. But they are the safest bet in my opinion. You couldn't pay me to use ej25d gaskets for anything. I'd either run the STi or a cometic gasket.

[thatswhatshesaid]

I've done this. The OEM replacement gaskets are multilayer metal Felpro. They seem to be bulletproof

[Maverick89]

I've done this. The OEM replacement gaskets are multilayer metal Felpro. They seem to be bulletproof

 

what gasket did you use ? and for which application?

[thatswhatshesaid]

what gasket did you use ? and for which application?

Felpro. The Felpros you buy at the parts store are exactly the same as the ones dealerships use under the Subaru name.

I've used them in 96, 97, 99, 00, 01, and 06 EJ25D, EJ251, and EJ253 engines with 100% success

Edited March 14, 2014 by thatswhatshesaid

[johnceggleston]

 

The Felpros you buy at the parts store are exactly the same as the ones dealerships use under the Subaru name.

 

this is probably true, but it was not always true.

back in the late 90s / early 00s when the ej25 head gasket issue first came to light,

the head gasket that felpro was selling was the same as the factory gasket.

when suabru released the updated gasket, felpro followed , some time later.

 

the production lag and the ''old inventory'' on the store shelves created a period of time where felpro gaskets were not as good as the ''newest'' gasket form suabru.

(the old inventory'' was also a problem with some subaru dealers.)

but once felpro caught up, no problem.

 

felpro does not research and develop their own parts.

they either reverse engineer the OEM part and find someone to make it,

or they just go the the OEM part maker and buy it directly from them.

 

there are some companies who do make ''better'' parts for after market use,

but these tend to be specialty companies or performance parts.

felpro is not one of these.

 

and i would buy felpro gaskets if they were lots cheaper,

but in my experience they aren't.

this combined with the ''bad'' gasket they were selling early on

keeps me away from their gaskets.

 

but i buy lots of other felpro parts.

generally they make a quality part for a pretty fair price.

not the cheapest, but not a rip off either.

 

end of rant.

Edited March 15, 2014 by johnceggleston

[thatswhatshesaid]

^ wow. I didn't know that. I've only been rebuilding EJ25s for about 5 years. interesting...