The Central Hub for DSM Community and Information

For 1990-1999 Mitsubishi Eclipse, Eagle Talon, Plymouth Laser, and Galant VR-4 Owners. This is where the DSM platform history is documented and archived. Log in to help us in our mission, and to remove most ads from the browsing experience.

Oil Pressure Relief Valve Porting Pictures

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Saturdee

10+ Year Contributor
405
0
Nov 9, 2010
Duncannon, Pennsylvania
I'm curious as to how much I can port before I cross the line of too much, if anyone could let me know where it's safe to stop, or better yet post some pictures of your own, that'd be great. Thanks in advance
 
I'm curious as to how much I can port before I cross the line of too much, if anyone could let me know where it's safe to stop, or better yet post some pictures of your own, that'd be great. Thanks in advance



Every Port is different, If you have too much pressure then you need to crazy But if you are not building much pressure then you can do a light port.

What's your Oil Pressure?
 
Every Port is different, If you have too much pressure then you need to crazy But if you are not building much pressure then you can do a light port.

What's your Oil Pressure?

I don't know, my engine is apart right now and I am going to be eliminating my balance shafts, and I read that doing so makes your oil pressure run high which is why I was just going to port it before I put it all back together.
 
Here is a pic of the one I did.
You have to make a straight line at the top side and (DO NOT GO TO CRAZY).
After the porting job, If you are able to see the little hole on the Piston, Then you Housing is (TRASH).

How would it be trash??? You can see the little hole on a stock, non ported one! Its more then likely trash when you port past the top of the piston, so if you can see the top of the piston, then its trash!
 
so it is almost a "requirement" to port your OFH when eliminating balance shafts?

No not necessarily, It only depends on your oil pressure, when you eliminate them! Some people has seen no oil pressure difference after doing so!
 
so it is almost a "requirement" to port your OFH when eliminating balance shafts?

Almost. There are also many little factors that affect oil pressure. Feeding oil from the head, the oil filter housing, squirters or not, bb or journal bearing turbo (restrictor), oil weight being used and of course clearances. A loosely built motor will generally let more oil through the bearings. This will slightly lower oil pressure.

There are so many factors that can play into the oil pressure field, that its just best to port slightly then heat cycle the engine to see where you stand. You can do this with the timing cover off, but with your pulleys and water pump belt on. Then, pull the oil filter housing and have at it again.
 
Almost. There are also many little factors that affect oil pressure. Feeding oil from the head, the oil filter housing, squirters or not, bb or journal bearing turbo (restrictor), oil weight being used and of course clearances. A loosely built motor will generally let more oil through the bearings. This will slightly lower oil pressure.

There are so many factors that can play into the oil pressure field, that its just best to port slightly then heat cycle the engine to see where you stand. You can do this with the timing cover off, but with your pulleys and water pump belt on. Then, pull the oil filter housing and have at it again.




:thumb:

Can't be better explained then that.

I took off three times and port three times my housing to hit my target.
 
Last edited:
Sounds good, I'll do some slight porting, then just go from there when I get my engine put back together and in.
 
Ive been reading all about this problem on other dsm/evo sites, but i havnt seen anything about the actual relief valve piston itself

I have a theory on the 4G63 dsm/evo/gvr4 ect.. oil relief valve piston, theres a gallery and 2 ports for oil to flow under the piston, maybe if this gallery/ports are removed, oil pressure will only be at the top of the valve, giving 100% flow out of the valve

You must be logged in to view this image or video.


ive found a pic of the pressure relief valve from the mitsubishi 4g9* series engine (dosnt have the gallery/ports like the dsm/evo/gvr4 in the picture above (the 4g9* series engines dont have balance shafts/ hla reg's/ oil pump runs around the crank shaft like 6g7*'s, the turbo 4g93t versions have water/oil coolers and oil piston squirter/jets like the 6g72tt's

You must be logged in to view this image or video.


anyway just a theory, not claiming anything here, just looking at this problem at a new angle

would like to hear what people think!
 

Attachments

You must be registered for see attachments list
I always thought those holes were just a drain so that oil couldn't build up behind the piston in the "spring" area causing a hydro-lock situation which wouldn't allow the valve to open at all. I don't think they do anything to effect the flow of the oil or the pressure at which the valve opens.
 
So if I'm experiencing higher than normal oil pressure on a newly rebuilt engine, also just had BSE done, is it worth worrying that something is wrong, given how many things are factored in for causing the pressure increase? I haven't ported the OFH since I didn't know about this before. I don't remember what weight oil I put in, I'd have to look at the jug when I get home. Just trying to get a concept in mind of what all is involved in determining the need for the port job. What actually makes it required to do the port job?
 
Not to be a necromancer, but this thread was recommended before I made another, so here are my pictures.

You must be logged in to view this image or video.


You must be logged in to view this image or video.


How would it be trash??? You can see the little hole on a stock, non ported one! Its more then likely trash when you port past the top of the piston, so if you can see the top of the piston, then its trash!

Sorry, why would seeing the top of the piston through the relief port render the unit inoperable?
 

Attachments

You must be registered for see attachments list
Last edited:
Didn't want to make a new thread, just curious if this is old.

You must be logged in to view this image or video.


Looks like it seals. Just curious to see if I didn't go over
 

Attachments

You must be registered for see attachments list
Didn't want to make a new thread, just curious if this is old.

You must be logged in to view this image or video.


Looks like it seals. Just curious to see if I didn't go over

As long as the surface area that the oil sees to lift the valve is not changed, you didn't go over.
 

Attachments

You must be registered for see attachments list
Add Value - Be Respectful - No Trolling - No Misinformation - Participate Often!
Support Vendors who Support the DSM Community

Latest Classifieds

  • For sale VIRGIN 4G63 6-BOLT TURBO HEAD
    Came off a virgin stock AWD Auto 1G DMS (91), also have matching block and crank which are also...
    • The_Partout_Spot
    • Updated:
    • Expires
  • For sale 1G DSM 4G63 6-BOLT TIMING COVER
    Used, see condition in photos. Buyer covers shipping / fees.
    • The_Partout_Spot
    • Updated:
    • Expires
  • For sale Garage clean out
    Changing setups on the car and getting rid of some stuff as well that's been laying around. Will...
    • 92GSXtacy
    • Updated:
    • Expires
  • For sale 4G63 Griffin intercooler cores
    Griffin intercooler cores. Top to bottom flow. High cfm and heat transfer. 24x8x2.75 and...
    • Galant665
    • Updated:
  • Wanted wtb black 2g dashboard
    Looking to buy a 2g black dashboard. Located in southern california but willing to travel.
    • randizzle420
    • Updated:
    • Expires
Back
Top