I saw this post is active now. What does the oil port mod actually do? If you port it wouldn't it drop your oil pressure? Like what's a good oil pressute for our evos? I know mine was at like 60-70 psi while cruising and that and would settle to anout 30psi at idle when warm. Just curious since it seems coue people have done it in this thread.

Glad to see things are still coming along Erik, Still waiting on my motor to be built as well. To late now for Swaintech stuff with only 5 weeks to the shootout I am wondering if I am even going to get the car back in time.

Post is active. It's just that things can take time. Maybe other people have figured out how to do this super quick, but I haven't lol.

There are a two different mods you can do. I did the oil galley mod.


There is also a mod you can do to the head on the oil port.



So, there you go

Yeah, things take awhile. Life, work and funds can all get in the way. Building an engine ain't cheap, ESPECIALLY the way I'm doing it lol.

But assembly is getting closer. I just have to discuss a few things with Aby and then we should be good to go.

If you do either of these won't they drop the overall oil pressure? What's the lowest oil pressure a evo could have at wot that wouldn't starve lifters, turbo, and or bearings and stuff

Did you watch the vids? He explains in the head port mod one how it can save things like turbos, etc.


I would assume the oil galley mod would help oil pressure, or at least make it more consistent. You're getting rid of the flash, which obstructs flow, and also radiusing the entrance to the block, so oil doesn't get held up. As long as you don't port too much and stay true to the galley's original shape, you should be fine. It's just detail work. Many people don't do it. Then again, my build is all about the details so I am trying to leave no stone unturned.

There are plenty of threads on the subject on dsm tuners and other sites.

Yeah i watched the video I'm just wondering what'sthe lowest safe oil pressure you should have while romping on it, because less material will decrease pressure which overall would slow oil down i would think. It's like water coming out a water hose compared to you putting your finger over it. Just overall curious

I think you are confusing pressure with volume. Putting your thumb over a hose increases pressure coming out but drops the volume of water coming out. By radiusing and removing flashing, you are actually increasing the volume of oil being moved without significantly changing the pressure. Smooth, laminar flow is what you want rather than the turbulent flow induced by sharp edges during exit and excess material in the channel.

Great vid on how to enlarge the oil ports!

- Renato

I get the volume pressure thing, but we did this oil port mod on my evo head and removed 25 thousandths overall total just like the vide which he went futher than we did. Put the car together and now i noticed my oil pressure while cruising has dropped 20 psi. That's the oil thing done besides oem lifters instead of gsc one. Car used to run 70psi on the gause while cruising now it sits at like 40 to 55 psi at times. I'm worried i won't build enough pressure when I'm romping on it or what's the minimum pressure we should see while romping on it?

Dude, you should have mentioned this with your first post lol.

I think the rule of thumb is 10 psi of pressure per 1,000 rpms.

Is your engine built? What weight oil are you running. I know some guys go to a 20w-50 on built engines if they run into low oil pressure. I plan on running at least 10w-40, unless Aby has specific recommendations for the clearances on the engine.

Currently running 10-40 with a built motor no balance shafts. After doing the head oil port i noticed drop in oil pressure. I was going to bump to 20-50 but the engine builder said run 10-40. Could running 20-50 be to think for the bearing cleances since he said 10-40

40-55psi is fine if you're cruising at 3k-4K rpm's..

when building a "race/street motor most remove the balance shafts. and thus turning the bearings so the oil ports are blocked. this will increase oil pressure, the above mods help bring things back in check when "romping on it"

love me some jafromobile youtube vids. wish he did evo notors