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xbeerd
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99 block will be an 8 bolt bell-housing. It's the only 8 bolt dual cam N/A out there.... Well till you get into the H6's and newer FB/FA engines, etc.

 

It's really a 251 case/crank/rods with 25D pistons. A little trick on Subaru's part.

 

GD

 

so does the EJ251 have a shorter stroke then the ej25d, and thats why the lower compression in the frankenstien setup with the 99 block vs the earlier ej25d blocks? (piston doesnt come out of the block as far on extension)

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so does the EJ251 have a shorter stroke then the ej25d, and thats why the lower compression in the frankenstien setup with the 99 block vs the earlier ej25d blocks? (piston doesnt come out of the block as far on extension)

 

No it's the same stroke. Different piston height. And yes they crest above the block. But the 25D pistons are dished like a turbo piston in the center to lower the compression. 251's don't crest above the block but they have flat-top pistons AND use a much thinner HG resulting in higher CR. You can always get a Cometic gasket to lower it back down some. The '96 25D has flat-top pistons AND they crest above the block so even with a thick HG (required) they are still over 12:1.

 

GD

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Sorry for this highjack but maybe this could be useful for others....

 

I have a 99 Lego OB EJ25 short block here with an "X" as the tenth digit. It was a DOHC & is 8 bolt bell-housing pattern. Don't know the mileage as the donor odometer was missing when I pulled it. Guess I'll find out the rod journal size when torn down for brgs/rings.

 

Were there any other variations to this tenth digit "W" designation?

 

Edit: xbeerd posted his "X" just as this post was being typed.:cool:

 

Typo on my part. Should be X. W is 1998. I edited the previous post with the right letter.

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anybody on here have a carfax? my frankenmoter block has this engine vin:

4S3BG6856W7655075

 

I would like to know what the carfax says cause I pulled it out of 97 obw but the block would be a 1998. So something doesn't add up. the obw had 158k on the odometer so I thought I was doing pretty good.

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i couldnt find the vin at first on the block, had to get out the degreaser and a brush i found it, its a X, which per the decoder shows its a 99 motor, (plus the vin matches)

 

Thanks guys, im absorbing all these little notes about the differences. :headbang:

 

hey what are these markings on the block (mine are different but this was the only pic i could find showing them, i couldnt find any answer on the web or here

 

the 73 3 followed by a symbol. is that a piston designation?

SnipImage-1.jpg

Looked at my 99 ej25d block & saw similar numbers. Having been a maintenance mechanic for a die casting shop, these appear to me to be the plates they insert into the die molds to ID the production run & mold used.

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So i got my headgaskets today, they are thinner than the ones that were on the block. I just got FelPro's p/n 26415PT.

 

there is a note on the pkg saying if my previous gasket measures .026" thick i can use it, if its .053" thick i should order a different part, P/n 26167PT

 

(i know there is difference of opinions on head gaskets, so i really dont want to hear that. would just like an answer for my question)

 

can i use this thinner gasket with the ej22 heads? or will there be contact from the valves to the piston?

 

im hoping it will work since the pistons are shorter on the 99 vs say like the flat 96 piston, mainly hoping it will work since its gonna be damn near 50 degrees this weekend and i wont freeze my sack off

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Can't use em. The pistons will hit the HEAD and you will cause severe and irreparable damage . They crest above the deck of the block. What you have are the 251 gaskets. You need 25D gaskets or Cometic's.

 

As I have said the pistons are NOT any shorter on the 99. They are the same piston as 97/98. They crest above the block and are dished with a squarish pattern in the center. The raised portion around the dish is just exactly as high as the '96 pistons. The gasket thickness is to prevent piston/head chamber interference.

 

And yeah - Fel-Pro or any aftermarket non-performance head gasket with the 25D block is a super bad idea. It will not end well.

 

GD

Edited by GeneralDisorder
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k, well. i guess thats not totally bad then, my loyale has a ej251, (a a real 251, not the goofy 25d with the 251 block as talked about above), so all is not lost then, plus i have a slow coolant leak in that motor. either that or the locals are siphoning it out while i sleep. LOL

 

guess i'll just suck it up and buy the cometic gaskets. i dont know what thickness i need tho. guess i'd get the .051" they list? or best just to call them and tell them what im doin?

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i wasnt trying to imply that the pistons didnt come out of the head any less or more, i just couldnt tell from pictures of the ej22e head had enough clearance for the piston to protrude into it with out contacting valves or the head itself, thats all.

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yeah i definately dont wanna to go to hi, not tryin to blow it up, haha. just a fun DD project. might grab stock from dealer since the guy said they keep them in stock all the time. yet he had to order head bolts for me lol.

Edited by xbeerd
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You don't need to replace head bolts. But you do need to use 2.2 bolts. They are longer than 2.5's.

 

GD

 

i picked up some 2.2 bolts, i figured they should be matching the heads vs the block. ;) thats one thing i did taht went well so far. haha!

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Thought I should chime in here as I have worked with GD on this before.

 

The motor we built for my car has a 96 EJ25D block, ACL Main and Rod Bearings, 220 Delta cams in 90-95 Dual port heads and new rings.

 

The ECU hates it at times. I have to do an ECU reset every few days in order to keep the motor running happily. I also have to mix E85 with Premium so it doesn't ignition knock.

 

Also likes to think its misfiring all the time when it's not.

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Thought I should chime in here as I have worked with GD on this before.

 

The motor we built for my car has a 96 EJ25D block, ACL Main and Rod Bearings, 220 Delta cams in 90-95 Dual port heads and new rings.

 

The ECU hates it at times. I have to do an ECU reset every few days in order to keep the motor running happily. I also have to mix E85 with Premium so it doesn't ignition knock.

 

Also likes to think its misfiring all the time when it's not.

 

Sounds like you need some re-mapping of the ECU like Presslab did. Does the '96 short block raise the CR even higher than the 97-99 block? Do you have an idea of what the CR is?

Thanks,

paul

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Sounds like you need some re-mapping of the ECU like Presslab did. Does the '96 short block raise the CR even higher than the 97-99 block? Do you have an idea of what the CR is?

Thanks,

paul

 

Yes it does. We figured around 12:1 compression with Flat top pistons, OEM Head gaskets and the Dual port 2.2 heads.

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  • 2 weeks later...

Has anyone run the higher flowing pink top (370 cc?) 22T Injectors on their frankenmotor? I was wondering if those would help with the lean idle mixture and all the other fuel mapping and timing corrections that Presslab corrected with his daughterboard.

 

I believe all red top injectors whether from a 2.2 or 2.5 flow the same (up to '99) is that correct?

 

Thanks,

Paul

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