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Discussion Starter · #1 ·
I am new to subarus so bare with me . Can I put sohc 99-04 heads on an earlier 2.5 dohc block .I want to buy a dohc jdm engine and convert it to sohc .I have to do this this to fit it into a vw bug .
 

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rs2.5-sti hybrid
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subaru engines are like legos man. lol. any head will fit on any block. take a 1.8 and put it on a 2.5 and it will work. the only difference is wiring, and compression. same with all the blocks fitting the trannys. for the exception of the ej22t or k. those have different bolt patterns. but you dont want them anyway. :)
 

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needs more cowbell
95L, 07 2.5i, R6
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You can put the heads on the block, but you'll need to use the sohc intake manifold, and that will open up another can of worms
 

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1998 Forester on Orange 57F
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subaru engines are like legos man. lol. any head will fit on any block. take a 1.8 and put it on a 2.5 and it will work. the only difference is wiring, and compression. same with all the blocks fitting the trannys. for the exception of the ej22t or k. those have different bolt patterns. but you dont want them anyway. :)
This is not true but not far from the truth. If you use blocks that are smaller displacement with large displacement heads you run the risk of valve interference. But most people use large displacement blocks with smaller or equal heads.
 

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I am in a similar situation but I have a SOHC 00 RS that decided to toast the main bearing. Is it possible to use a EJ25D block out of a 97 DOHC Legacy?

I have connections to a good block but want to know if I can swap over my timing belt and tensioners onto that block. Anyone know?
 

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I am in a similar situation but I have a SOHC 00 RS that decided to toast the main bearing. Is it possible to use a EJ25D block out of a 97 DOHC Legacy?

I have connections to a good block but want to know if I can swap over my timing belt and tensioners onto that block. Anyone know?
yes it will work but the compression will be lower and power will be down a bit. all the timing gears will work, may have to use the old sytle tensioner if the 97 block has that type.
make damn sure you use the thick MLS gaskets when you do this. phase I 2.5 pistons go above the deck surface at TDC - i just did this exzct swap and made the mistake of using the thin STI gaskets and the pistons where tapping the heads - seemed fine turning it over by hand but made awful noises when running.
 

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overdeveloped beater
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Qft....I'll add that the loss in power is negligable. You'll never miss it. Also, check the crank timing gear on both blocks just to make sure they have the same number of trigger teeth. Some are 6, some are 8, and some are a whole lot more, like 25 or so....easy to spot when looking at them.

Finally, it's best to use the timing tensioner style that goes with the heads. IE: vertical type for SOHC and horizontal type for DOHC.
yes it will work but the compression will be lower and power will be down a bit. All the timing gears will work, may have to use the old sytle tensioner if the 97 block has that type.
make damn sure you use the thick mls gaskets when you do this. Phase i 2.5 pistons go above the deck surface at tdc - i just did this exzct swap and made the mistake of using the thin sti gaskets and the pistons where tapping the heads - seemed fine turning it over by hand but made awful noises when running.
 

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formerly subidub
'01 Aspen RS & 97 Toyo Tacoma
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Newb question, would a head off a 2009 Impreza 2.5 Sohc be a direct fit on my 01 Impreza RS SOHC? Or is that variable valve timing stuff make stuff difficult?

Sent from Samsung Captivate on AT&T
 
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