2.5 DOHC plus 1.8 rotating assembly

PRIOR · 07-25-2003, 03:12 AM

ok, i have no idea if this would remotely even work... but hey, whats to lose by posting it up here....

first off, im looking at putting a 98 DOHC motor into my 95 L....

the motor is out of a forster, and i have no idea if it's one of those special "magic bullet" engines with the phase II block and DOHC.... but anyways...

i was wondering if you could pull the rotating assembly or just the rods out of an EJ18, and put them into the 2.5.... now just incase your wondering ' why the heck would he want to do that?'..... listen to this quote from mike at spd....( taken from spd's site...)

"It is interesting to note that the RA motors still share connecting rods with the N/A 1800cc motor. The quality is in the N/A motors, it is just put to different use. The 2.0, closed deck, 1995 WRX-RA short block is still the drug of choice in Japan for the "Big Power" motor."

i find this idea intresting, and since i have access to a ton of 1.8's and the 2.5 thats going into my car is gonna be on an engine stand for a while.... i was wondering if it could be done....

thanks,
andy

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8Complex · 07-25-2003, 04:10 AM

I don't think so, but don't quote me... I have never checked personally, but I'd question the wrist pin to piston face height differences. Then again, I don't think anyone has ever checked... Mike is in a world of his own, at times.

PRIOR · 07-25-2003, 05:55 PM

yeah, i was thinking that some custom pistons would be needed...

on another note, i just remebered that the good combo for high revs is a short stroke and a big bore... just like the rb26....

if the 1.8 rotating assembly gave the engine a shorter stroke... could it maybe rev better? also, something about the 1.8's being non-interference motors, and the 2.5's being interference motors....? would this change the 2.5's into non interference motors?

im not sure what non interference means, but im thinking that it means that the pistons cant come in contact with the valves.... no matter what..... i could be wrong though

could someone please clear this up for me....?

thanks,
andy

PRIOR · 07-27-2003, 01:49 AM

im guessing that no one has even done this, let alone thought about it....

maybe once i get my hands on the motors, i'll tear them both down and see....im kinda reluctant to tear down the 2.5 though, as it'll be going into my car afterwards...

im def. going to tear down a 1.8 though, and then maybe i could post pics and dimensions...

i guess only time will tell.

~andy~

ShadowIMg · 07-27-2003, 07:29 AM

Quote:

Originally posted by PRIOR
im guessing that no one has even done this, let alone thought about it....

maybe once i get my hands on the motors, i'll tear them both down and see....im kinda reluctant to tear down the 2.5 though, as it'll be going into my car afterwards...

im def. going to tear down a 1.8 though, and then maybe i could post pics and dimensions...

i guess only time will tell.

~andy~

Find a salvaged 2.5 and get an engine, shouldn't be too expensive. That way you can test all you want.

PRIOR · 07-27-2003, 11:34 AM

i wish i could... but money is tight (as im only 17), and im getting this 2.5 engine and wrx brakes for a great price.....

the guy is also gonna sell me a 1.8 w/ a blown headgasket for 25 bucks, so i can experiment with that one....

07-25-2003, 03:12 AM	#1
PRIOR Scooby Newbie Member#: 27524 Join Date: Oct 2002 Location: Las Vegas, NV Vehicle: 95 Impreza L awd 2.5 swap & only 2400lbs	2.5 DOHC plus 1.8 rotating assembly ok, i have no idea if this would remotely even work... but hey, whats to lose by posting it up here.... first off, im looking at putting a 98 DOHC motor into my 95 L.... the motor is out of a forster, and i have no idea if it's one of those special "magic bullet" engines with the phase II block and DOHC.... but anyways... i was wondering if you could pull the rotating assembly or just the rods out of an EJ18, and put them into the 2.5.... now just incase your wondering ' why the heck would he want to do that?'..... listen to this quote from mike at spd....( taken from spd's site...) "It is interesting to note that the RA motors still share connecting rods with the N/A 1800cc motor. The quality is in the N/A motors, it is just put to different use. The 2.0, closed deck, 1995 WRX-RA short block is still the drug of choice in Japan for the "Big Power" motor." i find this idea intresting, and since i have access to a ton of 1.8's and the 2.5 thats going into my car is gonna be on an engine stand for a while.... i was wondering if it could be done.... thanks, andy * Registered users of the site do not see these ads. Last edited by PRIOR; 07-25-2003 at 07:09 PM.

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07-25-2003, 04:10 AM	#2
8Complex Moderator Member#: 922 Join Date: Feb 2000 Chapter/Region: MWSOC Location: Schaumburg, IL Vehicle: 04 FXT Red	I don't think so, but don't quote me... I have never checked personally, but I'd question the wrist pin to piston face height differences. Then again, I don't think anyone has ever checked... Mike is in a world of his own, at times.

07-25-2003, 05:55 PM	#3
PRIOR Scooby Newbie Member#: 27524 Join Date: Oct 2002 Location: Las Vegas, NV Vehicle: 95 Impreza L awd 2.5 swap & only 2400lbs	yeah, i was thinking that some custom pistons would be needed... on another note, i just remebered that the good combo for high revs is a short stroke and a big bore... just like the rb26.... if the 1.8 rotating assembly gave the engine a shorter stroke... could it maybe rev better? also, something about the 1.8's being non-interference motors, and the 2.5's being interference motors....? would this change the 2.5's into non interference motors? im not sure what non interference means, but im thinking that it means that the pistons cant come in contact with the valves.... no matter what..... i could be wrong though could someone please clear this up for me....? thanks, andy

07-27-2003, 01:49 AM	#4
PRIOR Scooby Newbie Member#: 27524 Join Date: Oct 2002 Location: Las Vegas, NV Vehicle: 95 Impreza L awd 2.5 swap & only 2400lbs	im guessing that no one has even done this, let alone thought about it.... maybe once i get my hands on the motors, i'll tear them both down and see....im kinda reluctant to tear down the 2.5 though, as it'll be going into my car afterwards... im def. going to tear down a 1.8 though, and then maybe i could post pics and dimensions... i guess only time will tell. ~andy~

07-27-2003, 11:34 AM	#6
PRIOR Scooby Newbie Member#: 27524 Join Date: Oct 2002 Location: Las Vegas, NV Vehicle: 95 Impreza L awd 2.5 swap & only 2400lbs	i wish i could... but money is tight (as im only 17), and im getting this 2.5 engine and wrx brakes for a great price..... the guy is also gonna sell me a 1.8 w/ a blown headgasket for 25 bucks, so i can experiment with that one....