Rear BS delete only and PCV idea

[boost97gst]

Ive just begun my long long long.... build. Got the motor stripped down to the block with rotating assembly still in.
Thats as far as im going. The machinist can take over from there. To be perfectly honest, ive never had a 4g down this far with my own hands. Its intimidating but i bag n tag like crazy and take tons of pics.

On to my question: I would like to leave the front bs in and only delete the rear. Why? To not have any oil pressure "issues". No porting OFH, no possiblities of screwing something up or blowing turbo seals. I would just need the stubby shaft (MD098626), correct? I can leave the front bs completely alone. No belt attached of course.

Second: I have an idea thats been done before, not really MY idea. Use the rear bs inspection hole for a cc vent.
This seems far more effective than venting from the head due to oil being blocked by gasses rushing up. This would bypass that and most cc gasses would simply go out the bs hole. With the rear bs deleted i will have plenty of room for a plug or AN fitting if i want to get fancy. Has anyone done this and how did you baffle it. Gravity is a baffle in its own right and oil will not want to travel 2 feet up easily. So a screen or something shrouding the opening would work?

Thanks


PS: Throwing it out there again wherever I can: If you live in st louis area or Illinois side, need some money and want to help PM me!!!!

 

[c2ypt1c]

Yup all you need is the stub shaft, nothing else. This is exactly how I deleted mine.

Not sure about the vent idea, but my gut tells me it won't work. I'm interested in what others have to say about it.

 

[97gsxIA]

Yes, you can vent from the balance inspection hole on the block. It is probably the best way to ventilate crank case pressure.

I would recommend going larger to a -10AN fitting instead of one like this which is only -6AN :

They even have a nice picture of it on the block too!

http://www.streettunedmotorsports.com/parts/stm_balance_shaft_inspection_hole_breather_fitting.htm

And you do not need a screen for it.

 

[c2ypt1c]

http://www.streettunedmotorsports.com/parts/stm_balance_shaft_inspection_hole_breather_fitting.htm

And you do not need a screen for it.

NICE! Now I have to look into this...

 

[boost97gst]

Yes, you can vent from the balance inspection hole on the block. It is probably the best way to ventilate crank case pressure.

I would recommend going larger to a -10AN fitting instead of one like this which is only -6AN :

They even have a nice picture of it on the block too!

http://www.streettunedmotorsports.com/parts/stm_balance_shaft_inspection_hole_breather_fitting.htm

And you do not need a screen for it.

Thats what im talkin about. I didnt think it would need much baffling if any tbh. Good.
The hole itself would be the bottleneck. if its ~ 6an diameter then 10an would not provide additional flow. It would decrease velocity though.......actually that would be a good thing in the hose leading to the catch can. Less oil would make it up the hose the larger the diameter it is.

cryptic: your oil pressure stayed the same didnt it? Thats what im shooting for

 

[c2ypt1c]

Yeah it sounds like this, combined with the valve cover ports being vented, will provide some very nice pressure relief. Anyone know the thread size of the balance shaft inspection bolt?

cryptic: your oil pressure stayed the same didnt it? Thats what im shooting for

Yes sir, I observed little-to-no difference in oil pressure.

 

[darknezz7]

Nice another thing to add to our project. Seems like a great place to vent from along with upgraded vc breathing.

 

[MIdsm]

You may be better off using the large square pad next to the inspection bolt as a vent. I would say to put as large a fitting as possible on there - weld or drill/tap or drill/epoxy. The reduced air velocity with a larger hose ought to minimize oil flow. The baffle may be something as simple as a flat metal plate welded or bolted in on the inside of the block. The idea is that the oil doesn't like to make sharp turns. Good luck.

 

[boost97gst]

You may be better off using the large square pad next to the inspection bolt as a vent. I would say to put as large a fitting as possible on there - weld or drill/tap or drill/epoxy. The reduced air velocity with a larger hose ought to minimize oil flow. The baffle may be something as simple as a flat metal plate welded or bolted in on the inside of the block. The idea is that the oil doesn't like to make sharp turns. Good luck.

Ive seen it done professionally with 2 an bungs welded on the hump to the left of the inspection hole. Inside, just like you said, they welded a small piece of steel over the holes. Very simple baffle but it would seem to work. A "hood" over it on the inside would work as well. I think ill vent from the vc as well as the Bs inspection hole. Both in conjunction should do very very well for me.

 

[2slow4now]

I would probably drill and tap instead of weld. Cast iron doesn't like to be welded but some people can and have had good luck at doing it.

In the shop I used to work at they built alot of performance engines with custom oiling/pcv systems and if they did a cast iron block they always drilled and tapped for an fittings attached to the block/head. The only time I saw them weld on a block was to repair a hole from a thrown rod (and jb welded it) as a back up engine only for a guy that was running in the busch series. His situation was a little different because it was almost the end of the season and he planned to swap to a different engine platform the next year.

 

[boost97gst]

^^^^
Absolutely agree. A drill/tap would be ideal. I might see about having the shop do that. 2 separate 6 -an s coming off the block would be more than enough venting. my current setup with one line coming off the vc was enough. Hadnt even installed a catch can. Turbo inlet very clean, intake pipe was very clean as well.
This would be a mod that may pay off down the road and regardless, venting from a lower spot is better no matter what. If i actually get ahold of the machinist before i leave town ill have a chance to discuss this with them.

 

[darknezz7]

Ive seen it done professionally with 2 an bungs welded on the hump to the left of the inspection hole. Inside, just like you said, they welded a small piece of steel over the holes. Very simple baffle but it would seem to work. A "hood" over it on the inside would work as well. I think ill vent from the vc as well as the Bs inspection hole. Both in conjunction should do very very well for me.

any pics of this somewhere?

I want this done to the block we are building.

 

[LandSpeed-DSM]

Don't bother with drilling and tapping the block of you have room on the front of the engine to stick at least -10AN (ideally -12AN or -16AN) on the BS Delete.

You had the right idea to begin with. This has been on my to do list for a while as part of an oil control scheme.

I wasn't planning on a baffle for the block vent and neither of the -10ANs on my valve cover are baffled at the moment. Not that you shouldn't baffle these, but I never got around to it.

 

[94allwheeldsm]

Landspeed, where are you talking about placing the CC vent on the front?

 

[boost97gst]

Theres another BS hump up front that sits higher. WOuld make sense to vent from the highest place you can in the bottom end. All the benefits, less oil to spray up in the hose. Thats the idea i think he was implying. Im sticking to the rear just cause its cleaner and can get the job done for my application

 

[JacksonAuto]

I understand wanting to ventilate the pressure, but how do you plan to pull a vacuum on the crankcase? A passive system of just venting to atmosphere is not a good idea.

 

[GRAVEDIGGER]

I understand wanting to ventilate the pressure, but how do you plan to pull a vacuum on the crankcase? A passive system of just venting to atmosphere is not a good idea.

YES! This ^^^ You need to pull a vacuum in order to properly vent the crankcase.

 

[edged1g]

I understand wanting to ventilate the pressure, but how do you plan to pull a vacuum on the crankcase? A passive system of just venting to atmosphere is not a good idea.

Pulling from the intake tube should provide some vacuum to help pull the pressure form the case. If you run a metal intake you could weld a male AN bung on the intake and run AN line from block to catch can then catch can to intake pipe.

 

[JacksonAuto]

I know how it's done. I just wanted to make sure that the OP knew that a simple vent to atmo wouldn't be sufficient I see a lot of bad information relating to PCV and catch can systems which gets people into trouble.

 

[lasthope05]

There are exhaust scavenging systems to help pull vacuum under load with check valves to prevent back flow.

 

[athlete3344]

Using the exhaust as a source of vacuum may not be the best idea, since you are venting a flammable substance. From a safety point of view, using the intake as a source is probably the best option (with filter if youre worried about recirculating oil).

This is an interesting thread, and I will be following it since I have my engine completely dismantled.

 

[1qkfwd]

Haven't you seen the back of Honda engines?? They have a good sized hole with a baffled box plugged into. At the top of the box there is a fitting that goes to the intake.

In our case creating just a crankcase pressure relief will help. But you need to look at the design of the head in the rear section because its more or less designed just for crankcase to travel up. Creating pressure reliefs in the block area allows you to modify the head for another oil drain back.

 

[JacksonAuto]

There are exhaust scavenging systems to help pull vacuum under load with check valves to prevent back flow.

Only work at high RPM and will absolutely destroy your hopes at passing emissions.

 

[JacksonAuto]

Creating pressure reliefs in the block area allows you to modify the head for another oil drain back.

Oil drainback will be impeded by any pressure, even atmospheric. For proper windage and drainage a crankcase must be under vacuum. Otherwise the oil wont drain properly no matter how many drains you add.

The oil drain holes in the head provide plenty of area for the vacuum to draw on the entire crankcase. Take a V8 for example which has two, small drains around 1/2-9/16". Using a standard PCV system we can draw 2-4 in/Hg vacuum. Add a vacuum pump and we can easily draw 10-12 in/Hg. The 4G has more drains and they're larger diameter so to say they're insufficient to pull enough vacuum on the crankcase is not an accurate statement.

If you cannot draw at least a couple inches of vacuum on an engine using a conventional PCV system then there is a problem. I'd be looking for cracked or leaking PCV lines and fittings. Additionally, any gasket or seal on the engine that is leaking will allow air to flow in and reduce vacuum. The rear main seal, oil pan and valve cover are the most common areas for this to happen.

 

[boost97gst]

I understand wanting to ventilate the pressure, but how do you plan to pull a vacuum on the crankcase? A passive system of just venting to atmosphere is not a good idea.

Whoa whoa, , yes its going in to a catch can and from there to the intake tube. I've warned people about those little filters and no vac on teh cc for a very long time. Im not one of those guys

EDIT: I hope i didnt imply in any of the posts i would just vent that to atmo! That would be pretty dumb.....

Anyway, block and head going to machinist tomorrow. My entire future in DSMs hinges on the measurements taken tomorrow, thats another story. I may have a huge part out coming