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?

http://www.dsmtuners.com/threads/rear-bs-delete-only-and-pcv-idea.480368/

Like this?

Thanks. Didn't find that in my search. Pretty mixed opinions in there but I don't see any harm in going forward.

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.

eclipsh said:

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.

Click to expand...

Its not dd status but it sees a ton of street time and tons of racing. This is with no balance shafts.