Oil return into EJ25 SOHC heads

[sammydafish]

I've seen a photo before of someone who just tapped the valve cover for the oil return. I'm wondering how this worked out. Did the oil drain out fast enough? I'm putting together a new engine for my new leggy wagon and it's getting EJ25 SOHC heads and a manifold. The simplest way to do the oil return would be to tap into the valve cover, but I'm a little concerned that the oil might back up in the line and not drain out fast enough. So who was it that I saw did that and how were the results?

[Legacy777]

The stock drain goes into the heads, which is pretty much the same area that the valve cover drains into.

Technically, you have twice the area if you go into the valve cover.

See pic
http://www.main.experiencetherave.com:8 ... P_4718.JPG

[206er]

matts valve cover for his S/C motor has a 90* elbow into the valve cover, the line looked like 3/8. pretty sure it was the kind of fitting you can buy at the hardware store, maybe NPT or compression I cant recall. however, it had a bung welded in; I wouldnt trust the thin material of the valve cover alone for some threads. *maybe* ok with a stop nut on either side but I think I would want to somehow permanently attach the inner nut if you know what I mean.
why not just go into your oil pan, youve already got that with a fitting eh?
I am unsure wether to weld a fiting to the cover or the oil pan, I am leaning to the oil pan though.

BTW sammy, do you have a SOHC ej25 sprocket and an ej22e sprocket side by side? if so it would be awesome if you could reply to my thread. it seems we are building the same engine (ej22e/ej25 SOHC) for the same car(blue prefacelift wagon)

[sammydafish]

Yup, we're building the same engine combo... on my old engine I had the return going to the oil pan, but now I'm goign to be running a header for a WRX so I need a new oil pan. welding the return onto the oil pan is a PIA and a really tight fit so I'm looking for a cleaner/easier way to do it. The old way I cut about a third off the motor mount (welded solid) and the lines going to the rack were still in the way and had to be bent a lot to clear. If stock turbos drain to the head, I don't see why I shouldn't, especialy since the new turbo will be in the stock WRX location, with a little personal touch by me of course

I'll grab the cam sprocket and take a peak tomorow for you.

[Project_Legacy]

OT: sorry for goin a lil off topic, you guys are making turbo motors with an N/A ej22e block and ej25 sohc heads? how is the compression ratio on that?

[206er]

8.3:1

[Project_Legacy]

thats not bad at all! i thought it would be higher, but i guess it doesnt really matter too much between sohc and dohc on the 2.5 heads does it?

[sammydafish]

8.3:1

huh? more like 8.9:1

edit, 8.9:1 using the SOHC 0.75mm thick head gasket. The EJ22 gasket doesn't line up right. and would give you a 8.34:1 ratio if you could use it. I'm more a fan of the metal gasket anyway for a boosted application Plus I'll be milling 0.5mm off the head to get me to 9.25:1 compression

[Matt Monson]

Seems like I showed up after all the questions were answered, with the exception of the cam gear question...

[206er]

the thick DOHC gasket will work with that combo though wont it? currently have a DOHC gasket running with ej22e heads so it is likely that it will work with an open deck block ej22. that gasket will give 8.3:1.
also what is going to be the weak link with the ej22e bottom end once the CR is lowered and is tuned well? piston or HG, got to be one of those 2.
also I did some more messing around and I could run my phase 1 2.5 bottom end with a thick gasket and SOHC heads and have around 9:1. even with metal HG's, youve got to wonder about the potential to pop one...

[sammydafish]

ahh... didn't think of the DOHC gasket..... just matched up the DOHC and SOHC gaskets and they are interchangeable. If you ran the DOHC 1.5mm gasket then you would end up with 8.3:1 compression.

As far as weak links go, the pistons are no doubt the weak link on the NA engine. I've torn the ringlands off them in 2 engines so far. This one will be of much better tune though, so we'll see how long they hold up. I'd have run forged slugs in mine but I would have had to have them custom made since anything for a turbo car would have yielded way to low compression for my needs.

[206er]

at $5 a piston, I may have mine cryo treated.

[Matt Monson]

I concur with Junior, the pistons are the weak link. I am also planning on using the phase I DOHC Ej25 HG's on my Ej22T bottom end.

206er,
If you are interested in them, I will give you my Ej22T stock pistons. Don't know if you want to run a CR that low, but you could try them in your Ej22E...

[sammydafish]

if you were to run EJ22 turbo pistons, even with the thin SOHC 0.75mm gasket your compression would only be 7.6:1 (provided the EJ22T piston dish is 28cc, I don't have one here to measure) that's really low, off boost there would be no power and you might even have trouble getting it to start.

[Matt Monson]

if you were to run EJ22 turbo pistons, even with the thin SOHC 0.75mm gasket your compression would only be 7.6:1 (provided the EJ22T piston dish is 28cc, I don't have one here to measure) that's really low, off boost there would be no power and you might even have trouble getting it to start.

I know 5 different guys here in Colorado that used to run stock EJ22t's with Ej25 heads and that low mid 7's CR. Trouble getting it to start? Never. And off boost is not as dead as everyone seems to think it is.

Hell, mid to late 70's Porsche 911 turbos run 6.5:1 and the start fine. I made my suggestion to Jeremy because I know what kind of a beast of a turbo he's going to run. That lower compression offers more of a margin of safety with regards to detonation if the tune isn't perfect...