Jump to content

High Crankase Pressure


Mix_67
 Share

Recommended Posts

This spring/summer i did a rebuild on my G54b. Basic ring and bearing job reused the stock rods, used a flex hone to clean out the cylinders. Everything went together in spec. minus the ring gap which after discussion seem to be within what everyone else says they should be. I am popping the dipstick about 2" out of the holder. I have just cleaned the oil separator, replaced all the lines and added an auxiliary check valve ontop of the pcv like is common the DSMs. Compression is 132psi on all the cylinders plus or minus 2 (the smallest marked measurment on the gauge). Idles great. Recently replaced the oil pickup tube oring with a new mitsu oring to be sure that this wasn't causing my trouble.

 

Right after I did the rebuild I had big injector trouble and had issues with both the primary and the secondary sticking open. This dosed the cylinders with fuel. Could this be related?

 

discussion on my rings :http://www.starquestclub.com/forum/index.php?showtopic=118574&hl=&fromsearch=1

 

I am hoping to run this this weekend at the DSM shootout, where I won first place in the drag/autox combo event last year.

 

Currently running 8psi on a evo316g

Link to comment
Share on other sites

"added an auxiliary check valve ontop of the pcv like is common the DSMs"

 

Make sure you didn't install that check valve backwards.

BTW, You don't need an aux. check valve in conjuction with a PCV; the PCV is a check valve. OEM PCVs are the best

 

If You're getting 132psi of compression across thats acceptable for stock piston. Look over you're crankcase vent system. Seems like thats the cause...

Link to comment
Share on other sites

The valve is installed the correct direction. The PCV valve is a new OEM unit that is less than 3 years old. It was also cleaned just this week with carb cleaner. The PCV valve that the DSMs use is normally a bandaid for running more boost than the stock PCV valve can take. My PCV valve did not leak up to 12psi when I did my last boost leak test.

 

I have a set of air to sparkplug adapters for changing valve seals with the head on. I am going to try a leakdown test tomorrow night.

Link to comment
Share on other sites

If you think your running too much Crankcase Vacuum....Check it. Get a Vacuum Gauge and a small adapter to hook up to your Dipstick Tube. Start the engine up and read it at Idle. My Crankcase Vacuum reads 6 in.
Link to comment
Share on other sites

You aren't using the stock rubber flex hose going to the compressor inlet are you? How did you connect the hose from the top of the separator up? You can't measure crankcase pressure on the dipstick tube of this motor, the end of it is under the oil level.
Link to comment
Share on other sites

I am not using the stock flex hose. I have a 2.5" mandrel bent tube with a 1/8"npt half coupling about halfway through the radius and a 5/16" hose barb threaded into it. The hose is plumbed between that barb and the top of the separator.
Link to comment
Share on other sites

Well there's the problem. If the hose was just left open to the atmosphere the pressure will blow out and not build very high but it does build up a couple psi at high rpms under boost if the separator system isn't working for that setup. You are trying to let all that blowby go out a tiny hole. You need at least a 1/2" opening there if not larger. We use 1". HIgher boost requires a larger separator system. Stock setups were barely good for stock boost and the separator can isn't that great it still lets oil mist through. DSM engines have no separator at all but I've built EVOs and used separators and had none blow into the intake. The barb in the inlet tube to the compressor housing is where the low pressure from that environment is to act on the crankcase before the pressure accumulates and reaches atmospheric and that can be done. Most have positive pressure in their crankcase but only a little just not enough to pop the dipstick out then some have a fantasy that they have this vaccum all the time and don't even have the hose from the valve cover connected.
Link to comment
Share on other sites

You can get large plastic hose ends and JB weld those to your inlet pipe or get a brass theaded one but the entire system must be completely sealed including the oring where the dipstick tube pokes into the pan. Any leaks and it might not work its sensitive to leaks and you are trying to operate just on the negative side of zero. If you can't find hose large enough, you can use washing machine drain hose its 1" and it will last about a year its not that great and will begin to crack from prolonged heat exposure. Vinyl hose sucks don't try it even reinforced it just gets hard and collapses. If you are out of time and can't get any of that done just stick a piece of hose on that valve cover bard and let it dangle and plug up the line from the oil pan to the separator but that's a nasty way it will blow out mist out of the valve cover but it will get you through the day.
Link to comment
Share on other sites

I can up the size of my threaded port on the intake tube no trouble. I have access to about every type of hose and fitting imaginable as well as a welder. I am going to look at going to a 3/8" bung on the intake tube and at least 1/2" hose between the oil sep and the intake pipe. If that doesn't fix it I can go 1/2 hose from the intake straight to the rear VC port. Thanks for the help. I though it could be a line size issue and bought some 5/16" line on lunch today to try tonight.
Link to comment
Share on other sites

You can't measure crankcase pressure on the dipstick tube of this motor, the end of it is under the oil level.

 

Really? I did it, and the other members can too. Buy a Hand held Vacuum Gauge, Get a adapter to hook on to the hose end of the Vacuum Gauge that will fit tight into your Dipstick tube. Start the car up with the hose attached. Does your Vacuum Gauge have a reading? If it does..... Indy is incorrect. Mine has a reading of 6 inches of Vacuum.Indy, when you start a car up the oil level falls below the bottom of the Dipstick tube. Basic Engine Operation 101 ;)

 

Bill

Edited by Caliber308
Link to comment
Share on other sites

 

Really? I did it, and the other members can too. Buy a Hand held Vacuum Gauge, Get a adapter to hook on to the hose end of the Vacuum Gauge that will fit tight into your Dipstick tube. Start the car up with the hose attached. Does your Vacuum Gauge have a reading? If it does..... Indy is incorrect. Mine has a reading of 6 inches of Vacuum.Indy, when you start a car up the oil level falls below the bottom of the Dipstick tube. Basic Engine Operation 101 ;)

 

Bill

 

 

If it fell below the bottom of the dipstick wouldn't it be dangerously close to also being below the level of the pickup tube? The dipstick tube is like 3/4 inch from the bottom of the pan, right around the height of the pickup baffle. I honestly don't know how low the oil level gets when the engine is running, but it doesn't "seem" like it would get low enough to expose the end of the dipstick tube to air.

Link to comment
Share on other sites

 

 

If it fell below the bottom of the dipstick wouldn't it be dangerously close to also being below the level of the pickup tube? The dipstick tube is like 3/4 inch from the bottom of the pan, right around the height of the pickup baffle. I honestly don't know how low the oil level gets when the engine is running, but it doesn't "seem" like it would get low enough to expose the end of the dipstick tube to air.

 

Well Chip, Buy a Hand held Vacuum Gauge and hook it up the way I posted and see if you have a Vacuum reading. I show 6 inches of Vacuum at Idle. If the Oil Level was too high , I would not show a reading on my Vacuum Gauge at all. This was recommended by Boosted One to set up my Krankvent. You need and I quote: "A reading between 5 to 7 inches of Vacuum at the Dipstick. And before you say anything negative about the K.V. System. I have been running this set up for 6 years now without Blown oil seals, Oil coming out the Rear of the Valve cover or any other problems. With a High Lift Roller camshaft, it was just the ticket to solve my low Vacuum Pressure. P.S. Your dipstick reads BELOW the bottom of the tube itself.

 

Bill

Edited by Caliber308
Link to comment
Share on other sites

 

Well Chip, Buy a Hand held Vacuum Gauge and hook it up the way I posted and see if you have a Vacuum reading. I show 6 inches of Vacuum at Idle. If the Oil Level was too high , I would not show a reading on my Vacuum Gauge at all. This was recommended by Boosted One to set up my Krankvent. You need and I quote: "A reading between 5 to 7 inches of Vacuum at the Dipstick. And before you say anything negative about the K.V. System. I have been running this set up for 6 years now without Blown oil seals, Oil coming out the Rear of the Valve cover or any other problems. With a High Lift Roller camshaft, it was just the ticket to solve my low Vacuum Pressure.

 

Bill

 

 

I've been running KV's for years as well. It just doesn't "seem" like the oil level could get that low. I guess if you measure from the "top" of the opening in the dipstick tube, where it enters the oil pan, you might have a little over an inch there. Still seems lower than I would have expected it to be with the engine running.

Link to comment
Share on other sites

 

 

I've been running KV's for years as well. It just doesn't "seem" like the oil level could get that low. I guess if you measure from the "top" of the opening in the dipstick tube, where it enters the oil pan, you might have a little over an inch there. Still seems lower than I would have expected it to be with the engine running.

 

When you fire your engine up a lot of the Crankcase oil is distributed throughout the motor. Hell, the Cylinder Head alone holds appox. 1 quart of oil in it. I also don't know how much oil remains in the oil pan after start up. Maybe someone here does. That would be interesting to know. Perhaps Shelby???

 

Bill

Edited by Caliber308
Link to comment
Share on other sites

 

When you fire your engine up a lot of the Crankcase oil is distributed throughout the motor. Hell, the Cylinder Head alone holds appox. 1 quart of oil in it. I also don't know how much oil remains in the oil pan after start up. Maybe someone here does. That would be interesting to know. Perhaps Shelby???

 

Bill

 

 

Yeah, I imagine between the filter and the oil passages there is quite a bit circulating when the engine is running. I just wouldn't think it would be enough to drop the level that far down in the pan. I'm looking at a pan on a shelf in my garage, and that's LOW. Seems like it wouldn't take much of a turn or accel to cause the pickup to be exposed to air. Very curious about this as well.

Link to comment
Share on other sites

 

 

Yeah, I imagine between the filter and the oil passages there is quite a bit circulating when the engine is running. I just wouldn't think it would be enough to drop the level that far down in the pan. I'm looking at a pan on a shelf in my garage, and that's LOW. Seems like it wouldn't take much of a turn or accel to cause the pickup to be exposed to air. Very curious about this as well.

 

I started a post in this forum asking that question....Now, let's see if we get a response :D

 

Bill

Link to comment
Share on other sites

what is the actual reason for wanting higher internal vacuum at idle,,you do realize that the engine only sees vacuum at idle and light cruise at no point in the engine or intake is there any vacuum while under boost

the only exception to that would be the air linlet befor the turbo compressor houseing

Link to comment
Share on other sites

what is the actual reason for wanting higher internal vacuum at idle,,you do realize that the engine only sees vacuum at idle and light cruise at no point in the engine or intake is there any vacuum while under boost

the only exception to that would be the air linlet befor the turbo compressor houseing

He wants to get on his Krankvent kick again. He's getting close to time to see someone else and wants to blow smoke up their butt and pass on lies.
Link to comment
Share on other sites

 

Really? I did it, and the other members can too. Buy a Hand held Vacuum Gauge, Get a adapter to hook on to the hose end of the Vacuum Gauge that will fit tight into your Dipstick tube. Start the car up with the hose attached. Does your Vacuum Gauge have a reading? If it does..... Indy is incorrect. Mine has a reading of 6 inches of Vacuum.Indy, when you start a car up the oil level falls below the bottom of the Dipstick tube. Basic Engine Operation 101 ;)

 

Bill

What you did while using check valves does result in what you say but that's as far as it goes and you know it. Again, you CAN NOT measure crankcase pressure there.

 

MikeK WAS WRONG, his assumptions were wrong and what he saw wasn't true. THAT ALL NEEDS TO BE DELETED its spreads a LIE.

Edited by Indiana
  • Like 1
Link to comment
Share on other sites

I know of a member or 2 who also use a catch can attached to the stock oil return fitting on the timing cover. Since a lot of us have put the drain in the pan I think it's a GREAT idea and I will be doing it on the current build.
Link to comment
Share on other sites

I ran a leak down test last night. All the cylinders came out the same. They all showed about a 5psi drop across my compressor regulator. Compression is at 135+/-5 psi as of last night. I am getting a larger bung welded on the intake tube today at work and have uped the hoses to 7/16" from the oil sep to the pan and the oil sep to the intake tube. The VC to the oil sep is at 1/2". I also replaced the dipstick tube oring and the oil fill cap oring. Hopefully this will help. I should get to take it out and run it tonight.

 

I know of a member or 2 who also use a catch can attached to the stock oil return fitting on the timing cover. Since a lot of us have put the drain in the pan I think it's a GREAT idea and I will be doing it on the current build.

 

That's not a bad idea. I may pursue that if the lines don't fix it.

Link to comment
Share on other sites

 

 

MikeK WAS WRONG, his assumptions were wrong and what he saw wasn't true. THAT ALL NEEDS TO BE DELETED its spreads a LIE.

 

 

His advice worked for my set up. Especially if you have a High lift Roller Camshaft. When you see very little vacuum on the start up of a new rebuilt you have to take measures to rectify the situation. I did, thanks to Boosted One.Indy, As i'm sure you well know, Or maybe you don't. High lift Camshafts sometime require more vacuum.Some use Belt-driven pumps, some use Electrical pumps. I chose to use the KrankVent set up recommended by: (as you refer to him) the "Liar" Boosted One. He didn't lie to me about that system creating the Vacuum I needed. This isn't my first trip around the block, I have experienced low Vacuum conditions in Sm. and BB V-8s also,with High-Lift Camshafts. Perhaps the best qualified person to address this low vacuum condition when running a High lift Camshaft in a G54B engine is Tim C ;)

 

Bill

Edited by Caliber308
Link to comment
Share on other sites

MikeK was confused, he didn't understand what happened and he did all this because his vacuum as read on that gauge while he was on the dyno was sealed in that dipstick tube because it was down under the oil level and the oil was sucked up in that tiny vent tube and it was sealing in his false vacuum and I've expained this 100 times. He didn't do that intentionally and I didn't call him a liar.

 

A cam hasn't anything at all to do with crankcase pressure. A cam is about intake manifold pressure. Is your intake open to your crankcase?

 

That ET Performance guy posted Mikes wrong conclusions on his site and had that up for years to sell the valves to non suspecting people because they had a PCV valve that didn't work and he even said that but still implied that at all times you'd have vacuum in the crankcase even under boost with that big valve in the back hanging in the air and blowing crap out all over your engine bay. THAT IS A LIE. All he had to do was just say, hey I got that from someone else and he could play dumb.

 

All you have to do is not measure that off the dipstick. Put your gauge back on like you say you can, let it suck down at idle and you see that vacuum then you shut the engine off, take the oil cap off and guess what, your gauge still shows you have vacuum in the crankcase doesn't it? This is why people have problems just checking their oil level. You have to WAIT until the two levels, the one in the pan and the one in the tube equalize. Pressure can't pass through the oil, it acts upon it causing it to move up and down the tube and that causes the pressure in there to change.

 

 

I've got a vacuum pump, both mechanical and some electric ones. They all need separators between them and the crankcase to keep the oil out of them and they are ones that might not require a connection back to the turbo inlet. There are people that mod smog pumps with rubber flappers so they can see oil but they aren't cheap and they don't last.

 

Moroso makes a pulley that bolts on to that pump and you can use it on this engine mounted where the a/c compressor went. The pump is from Ford Racing.

http://www.b2600turbo.com/images/IM002026.JPG

here's the instruction sheet for it:

http://www.fordracingparts.com/download/instructionsheets/FordInstShtM-9486-A460.pdf

 

and here's adjustable pressure and vacuum relief valves I got to use with it

 

http://www.b2600turbo.com/images/IM001999.JPG

 

Ford and GM also use electric pumps but they can't see any oil meaning there has to be a separator. Ford put these on the Cobras and some other models

 

 

http://info.rockauto.com/Motorcraft/CX1567.jpg

 

 

I have some of these and I took them open to see how they work, here's what is inside

 

http://www.b2600turbo.com/images/IM001984.JPG

 

When all you have to do is hook a separator back up to the turbo inlet where the high volume of low pressure is relative to boost that is free and easier, why not do it?

Link to comment
Share on other sites

MikeK was confused, he didn't understand what happened and he did all this because his vacuum as read on that gauge while he was on the dyno was sealed in that dipstick tube because it was down under the oil level and the oil was sucked up in that tiny vent tube and it was sealing in his false vacuum and I've expained this 100 times. He didn't do that intentionally and I didn't call him a liar.

 

A cam hasn't anything at all to do with crankcase pressure. A cam is about intake manifold pressure. Is your intake open to your crankcase?

 

That ET Performance guy posted Mikes wrong conclusions on his site and had that up for years to sell the valves to non suspecting people because they had a PCV valve that didn't work and he even said that but still implied that at all times you'd have vacuum in the crankcase even under boost with that big valve in the back hanging in the air and blowing crap out all over your engine bay. THAT IS A LIE. All he had to do was just say, hey I got that from someone else and he could play dumb.

 

All you have to do is not measure that off the dipstick. Put your gauge back on like you say you can, let it suck down at idle and you see that vacuum then you shut the engine off, take the oil cap off and guess what, your gauge still shows you have vacuum in the crankcase doesn't it? This is why people have problems just checking their oil level. You have to WAIT until the two levels, the one in the pan and the one in the tube equalize. Pressure can't pass through the oil, it acts upon it causing it to move up and down the tube and that causes the pressure in there to change.

 

 

I've got a vacuum pump, both mechanical and some electric ones. They all need separators between them and the crankcase to keep the oil out of them and they are ones that might not require a connection back to the turbo inlet. There are people that mod smog pumps with rubber flappers so they can see oil but they aren't cheap and they don't last.

 

Moroso makes a pulley that bolts on to that pump and you can use it on this engine mounted where the a/c compressor went. The pump is from Ford Racing.

http://www.b2600turbo.com/images/IM002026.JPG

here's the instruction sheet for it:

http://www.fordracin...M-9486-A460.pdf

 

and here's adjustable pressure and vacuum relief valves I got to use with it

 

http://www.b2600turbo.com/images/IM001999.JPG

 

Ford and GM also use electric pumps but they can't see any oil meaning there has to be a separator. Ford put these on the Cobras and some other models

 

 

http://info.rockauto.com/Motorcraft/CX1567.jpg

 

 

I have some of these and I took them open to see how they work, here's what is inside

 

http://www.b2600turbo.com/images/IM001984.JPG

 

When all you have to do is hook a separator back up to the turbo inlet where the high volume of low pressure is relative to boost that is free and easier, why not do it?

 

You do it your way, and I will continue to do it mine by the suggestions that have worked on my car since 2002. Like I said: Ask Tim C. what he uses for Vacuum. I think Tim is running one of the highest lift Camshafts on this site.P.S. I haven't ran a Oil Separator on my car since 2005. Why? It did not supply the vacuum needed with my Roller Camshaft. You have your way of doing things and I have mine. My way works for me and it will work for other members.And I will continue to tell the members so, Whether you agree with me or not. It seems like every post I respond to...You say i'm wrong. I don't know what your problem is with me or in your personal life...But don't take it out on me here. I give solid personal experience and researched advice. Neither one of us needs to be trying to "One up the other" You stick to your area of expertise, and i'll stick to mine. P.S. Indy, Tell the members how much the Vacuum Pumps cost that you posted pictures of ;) I thought I covered that in a previous post as being too expensive for most members here.Now I see that your saying E.T. Performance says that the K.V. set up does not work? Your killing me...I purchased my KrankVent system from them and still have the original Installation instructions in print form. I see nothing in them that says that they don't work. If you would like a copy of them I will be more than happy to supply them to you.

 

Indy, I have had just about enough of your calling a member a lier.

 

First off, I haven't had my Stock Oil Separator on my car since 2005. Second, I installed the K.V. system at that time. Third, I don't have oil spewing out my Rear Valve cover port nor do I have oil seals that have been sucked into the engine. Forth, I do have Vacuum at Idle (16 inches). Boosted One gave me the correct installation as far as installing a restriction (1/8 inch) in the hose from the Valve cover to the Throttle body. I followed the E.T. Performance installation instructions on the KrankVents to the letter.Yes, my Oil Return Hose to the Oil pan is capped off. You may not like it because you think your always right but, my K.V. set up works as it should. So don't say anyone lied about anything. If the truth is to be told. You didn't have a clue about Boosted Ones advice when it came to installing the K.V.s .And here is one more member you can add to your list of liers that run the KrankVent set up without problems: Chiplee. So, according to the world of Indy there are three liers so far:

 

Boosted One

Caliber 308

Chiplee

 

that say the KrankVent System works for them.Perhaps we that run that set up don't know what we are experiencing, and you know our cars better that we do.

 

Bill

Edited by Caliber308
Link to comment
Share on other sites

 Share

×
×
  • Create New...