After more thinking, I figured out that the part that is getting pushed away from the block is the top portion of the timing cover, not the front seal of the lifter valley cover. The hole in the front of the block that the blowby needs to get through to pressurize the top end is too small to allow a large pressure buildup in the top end. The pressure is building mainly in the bottom end and the timing cover area.
Lots of blowby
- Thread starter Alky V6
- Start date
Basically thats what I was telling you about needing more(bigger) oil drain back area , so that crankcase air can get to your breathers without impeeding the flow of oil back to the pan through the same holes. Here is what I do to mine to let the crankcase breath without messing with oil flow. Ckeck out the vent tubes in the lifter valley. Mike
BTW your vacuum pump went out Monday!!
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Yes, vent tubes would work nicely. But, the blowby flow would still have to get to the valve cover area. On a Stage II head, there is plenty of open vent area to allow that. On a Stage I style head, it's a different story. If I can keep the flow of blowby from getting to the top end, catch it at the timing cover, then the flow of oil from the heads will have a much easier time flowing down to the lifter valley to be picked up by the drysump pickup at the rear of the valley.
I'll keep an eye out for the pump. Thanks!
Here's something else to think about with my setup. The drysump pickup for the valley and one of the bottom pan pickups are tee'd together to one scavenge stage of the drysump pump. If I was having big pressure in the bottom end and less pressure in the top end, what was the line flow like for that one scavenge stage?
I'll keep an eye out for the pump. Thanks!
Here's something else to think about with my setup. The drysump pickup for the valley and one of the bottom pan pickups are tee'd together to one scavenge stage of the drysump pump. If I was having big pressure in the bottom end and less pressure in the top end, what was the line flow like for that one scavenge stage?
In the run that I have a link to in my signature, that is the run where the rear cam plug blew out. I remember that run vividly. Soon after shifting to 3rd, it felt like someone had lit off a 75 shot of nitrous. It caught me a little by surprise. I wonder if that is when the cam plug blew out, relieving a little bit of the crankcase pressure and allowing an instant boost in power? This dang engine never ceases to amaze me.
I dont know much about stage 1 heads , I assume they are quite similar to factory stock v6 heads and can picture that the pushrod holes are just about the only opening except maybe a drainback slot or two. So I see your point!! That would backup my earlier idea of pulling/venting the oil pan area to keep all that air from needing to travel up through the engine to escape.
Your dry sump sections should never be teed together!! It will simply just pull from the easiest point and not the other. Thats probly why your lifter valley is filling up with oil!! Man you have a lot of things to rethink now!!! Mike
turbobitt
Well-Known Member
- Joined
- Feb 14, 2002
I'm not so sure the tube idea in the lifter area is the way to go. Here is my reasoning,
1 - blow by air will have no mercy, will not pick any specific hole to flow into.
2 - Tubes will only allow oil to exit in remaining holes, although this shouldn't be an issue.
3 - Real solution may be to limit the amount of oil to the rockers since the source for overhead oil is most likely in the rockers..
The above won't eliminate blow-by oil but will reduce the amount of oil exiting the VC breathers.
Allan G.
1 - blow by air will have no mercy, will not pick any specific hole to flow into.
2 - Tubes will only allow oil to exit in remaining holes, although this shouldn't be an issue.
3 - Real solution may be to limit the amount of oil to the rockers since the source for overhead oil is most likely in the rockers..
The above won't eliminate blow-by oil but will reduce the amount of oil exiting the VC breathers.
Allan G.
There's never really been a lot of oil leaving the engine through the breathers or the vacuum pump. That is not a problem. I don't see the need to limit oil to the top end.
I can't really say that the lifter valley is filling with oil. When the cam plug blew out, some oil did spray out the rear due to the breathing hole(s) that are normally found in the last camshaft journal. But, it didn't seem that it was enough oil to say it was emptying a lifter valley that was 'filled' with oil, if you get what I mean.
As I stated above, I don't think the small bit of oil that is collecting on the top of the timing cover is coming from the front seal of the valley cover. It makes more sense that the upper portion of the timing cover is bowing away from the block, and that is where the oil is coming from.
I agree that the tee'd scavenge lines aren't the way to do it. I'll be thinking up a new way to take care of that. Maybe tee the 2 oil pan scavenge lines to one stage and let the valley have its own stage. After thinking about it more, maybe not.
I can't really say that the lifter valley is filling with oil. When the cam plug blew out, some oil did spray out the rear due to the breathing hole(s) that are normally found in the last camshaft journal. But, it didn't seem that it was enough oil to say it was emptying a lifter valley that was 'filled' with oil, if you get what I mean.
As I stated above, I don't think the small bit of oil that is collecting on the top of the timing cover is coming from the front seal of the valley cover. It makes more sense that the upper portion of the timing cover is bowing away from the block, and that is where the oil is coming from.
I agree that the tee'd scavenge lines aren't the way to do it. I'll be thinking up a new way to take care of that. Maybe tee the 2 oil pan scavenge lines to one stage and let the valley have its own stage. After thinking about it more, maybe not.
I assume you must have a 3 stage dry sump pump. By doing a bit of measuring you may be able to determine the size of your pump gears. If your scavange sections are the close to the same size as your pressure section , you probably can eliminate one of the pan lines. If you t the pan lines together then your going to have similar results in that its going to only suck from the easiest point and not the other which will result in not picking up as much oil as it is capable of pumping. Mike
It is a three stage.I assume you must have a 3 stage dry sump pump. By doing a bit of measuring you may be able to determine the size of your pump gears. If your scavange sections are the close to the same size as your pressure section , you probably can eliminate one of the pan lines. If you t the pan lines together then your going to have similar results in that its going to only suck from the easiest point and not the other which will result in not picking up as much oil as it is capable of pumping. Mike
Blocking off one of the pan lines sounds like the ticket. The scavenge sections are a little smaller than the pump section. Not by much.
I just measured the sections and they're one 1.5" pressure and two 1.25" scavenge. I'll be blocking the front pickup in the pan.
I would still restrict oil going to the rockers. Roller rockers do not need alot of oil.
Billy T.
gnxtc2@aol.com
Billy T.
gnxtc2@aol.com
Another interesting clue. The wastegate pipe which is separate from the main exhaust pipe has a very dry, very light grey colored coating to the ID. A sign that when the engine is under load it's not passing any oil. The main oil smoke is occurring on decel, which points again to a pressurized crankcase pushing the oil past the rings until the pressure has lessened in the crankcase.
There is a slight amount of smoke on the top end before getting out of the throttle, but that could be my evac pump pulling some oil out of the valve cover, getting past the separation tank and being drawn into the lower section of the exhaust pipe, where I dump the exhaust from the evac pump. Or, it could just be a slight amount of oil getting past the rings due to the high crankcase pressure. It's definitely pumping more oil into the cylinders during decel.
There is a slight amount of smoke on the top end before getting out of the throttle, but that could be my evac pump pulling some oil out of the valve cover, getting past the separation tank and being drawn into the lower section of the exhaust pipe, where I dump the exhaust from the evac pump. Or, it could just be a slight amount of oil getting past the rings due to the high crankcase pressure. It's definitely pumping more oil into the cylinders during decel.
Noted. I'll look into that on the next PMing of the motor.
I just checked the timing cover over, and the fuel pump mounting area looks like the spot to locate the new breather line. There's plenty of space to snake the new plumbing in.
The problem is, when I was performing the extensive mods to the timing cover, I welded on a block off plate so as to avoid a leaking block off plate gasket. :frown: Would have been pretty slick to just need to unbolt the block off plate and fab a hose adapter to bolt onto the timing cover. Now I'll need to remove the timing cover and weld on a hose adapter. As big a one as I can snake in there.
The problem is, when I was performing the extensive mods to the timing cover, I welded on a block off plate so as to avoid a leaking block off plate gasket. :frown: Would have been pretty slick to just need to unbolt the block off plate and fab a hose adapter to bolt onto the timing cover. Now I'll need to remove the timing cover and weld on a hose adapter. As big a one as I can snake in there.
dr_frankenstein
Mad Scientist
- Joined
- Mar 17, 2008
Don,
I think Kenny uses a Waterman mechanical fuel pump that is attached to the back of the dry sump pump and uses the same drive pulley to move both.
Jeff
The way I have the drysump pump mounted with the engine mounted in a stock frame using the stock engine mounting locations, it puts the drysump pump backed up right against the motor mount. No room to have anything mounted to the back of the drysump pump. If I were using a front engine plate, I could eliminate the stock style engine mounting, and then I'd have the room. Redesigning the engine mounting is something I'd rather avoid at this point.
Browsing the board. Good. I hope that means things are going well with you.
That's fine, Lee. I have enough pics to figure it out.
I would suggest something for others assembling a TA block. If you're going to keep the lifter valley solid with no holes connecting the lifter valley to the bottom end, you should add more holes to the front of the block to allow blowby to travel from the timing gearset area to the lifter valley without restriction to flow. At least in the first gen TA blocks, the one small hole that they came with is not sufficient to keep pressure from building in the bottom end. In my case, I would put the limit at above 1,050 bhp where the problem begins to become acute.
Another area to consider is where the blowby flow needs to get from the bottom end to the timing gearset area. Check the timing cover fit to make sure it doesn't choke off flow at the oil pan mating area.
