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.

Crank case vent by balance shaft alignment hole on side?

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

eclipsh

20+ Year Contributor
1,608
65
Jun 16, 2005
Durango, Colorado
I'm doing a fresh engine build and eliminating the balance shafts. When aligning the balance shafts you have to pull a bolt on the side and stick a rod through to verify rotation is correct. I'm thinking of using that tapped hole in side of the block as a crank case vent.

The plus side would be lower pressure in the crank case. I'd expect that to let the head drain oil faster among other benefits.

The risk is pulling a lot of oil out into a catch can and potentially running dry. I don't know how much spray/foam might reach that area.

I don't see an obvious way to baffle the interior area but drilling and tapping the block to bolt a baffle in could work.

Has anyone tried this and found good/bad results?
 
I run the vent from that hole into the exhaust. After a moderate pull it'll smoke pretty bad for a little bit. With a catch can and lines heading upward, I don't think it should be an issue. A crank scraper will also help. My lines run straight back into a tee and then downward.
 
I tried using stms fitting they sell for the balanced shaft inspection hole to 6an and with no baffle it would fill the catch can really fast. So I then switched to this http://www.dsmtuners.com/threads/4g63-block-vent.472409/ and it worked extremely well! Barely get any oil in it and dont have any issues with excessive crankcase pressure.
 
Thanks for the info. Are you using this only for drag racing or DD duty as well? Did you have balance shafts in when using the inspection hole?

Edit: I have a 64 block with the capped oil drain holes. I may use a bent stainless tube pressed into one of the rear holes that is exposed under the intake. I'd just need to knock out the freeze plug I have in there now and possibly trim the head gasket to clear it. The head leaves enough room for a tight radius bend.
 
Last edited:
Thanks for the info. Are you using this only for drag racing or DD duty as well? Did you have balance shafts in when using the inspection hole?

Edit: I have a 64 block with the capped oil drain holes. I may use a bent stainless tube pressed into one of the rear holes that is exposed under the intake. I'd just need to knock out the freeze plug I have in there now and possibly trim the head gasket to clear it. The head leaves enough room for a tight radius bend.

Its not dd status but it sees a ton of street time and tons of racing. This is with no balance shafts.
 
Add Value - Be Respectful - No Trolling - No Misinformation - Participate Often!
Support Vendors who Support the DSM Community

Build Thread Updates

Latest Classifieds

  • For sale 4G63 3 inch Magnaflow SS high flow cat
    3 inch Magnaflow stainless cat. High flow. 18.25 inches. Flange holes are 4 1/8 center. Has...
    • Galant665
    • Updated:
  • For sale 4G63 Forge Motorsports BOV
    Original Forge Motorsports bov. Adjustable with over 80 clicks on the dial. Nice to use for...
    • Galant665
    • Updated:
  • Wanted 1g 1991 Black Cherry Eagle Talon
    5-speed
    • bamatalon
    • Updated:
    • Expires
  • For sale Misc Left Over Parts
    Hello, I have a few left over parts for sale, these do not include shipping, please pm me for a...
    • r3dmak
    • Updated:
    • Expires
  • For sale Alpha Injection Clinic 2200cc for 4G63 DSM/EVO
    I have a set of Alpha Injection Clinic 2200cc high z injectors for DSM/EVO. I am stepping up to...
    • spoolinpos
    • Updated:
    • Expires
Back
Top