I'm purchasing the last parts for my motor and need help deciding which valve cover.
2109 cc 8:1 compression turbo motor
I'm wanting to get some vented valve covers and want to know what everyone thinks.
This one is cast with ridges aluminium in but no idea on hole size or thread type
$99.00
This one is a stock but brazed in AN-8 fitting
$99.00
This one is cast in and looks really nice 1/2 inch NTP thread
$245.00 yikes
If anyone knows of something better please enlighten me!
Which vented valve covers?
- volksbugly
- Posts: 634
- Joined: Thu Sep 16, 2010 5:09 am
Which vented valve covers?
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- turbobaja
- Posts: 2826
- Joined: Fri Sep 14, 2007 4:56 pm
Re: Which vented valve covers?
I've been running the first ones (Cast Bugpack bolt-on covers) for quite a while and have to say I'm very happy with them. They are plenty thick and really hold onto the gaskets thanks to the groove cast into the sealing surfaces. Re-using gaskets after a rocker adjustment is easy, I wipe down the gaskets, covers and head surfaces and the gasket lays right back in the covers where they were last time, bolts back on and seals up perfect every time. I use injector o-rings under flat washers to seal the bolt heads to the valve covers for mounting. Polish the countersunk area and either get some shouldered bolts or file the threads off the mounting bolts just below the head so they don't chew up the o-rings too much. Even so, I like to replace the o-rings once they start getting cut in any way (cheap, easy to find injector o-rings work great). No lock washers or thread locker or sealant of any kind, just a little lube of your choice on the o-ring and snug the cover on good and tight. Go back and check after a couple heat cycles and snug the bolts down again if you installed a new gasket last time, otherwise just drive the thing.
These covers have a 1/4" npt hole on both ends. I opened up one end to 3/8" npt and vented to a breather for quite a while. Found milky water in the breather hose everytime I pulled the valve covers. Now I leave both covers plugged and only vent from the Alt stand. It's working great and one less hassle when removing the valve covers . If you're going to drag race a LOT then vent the valve covers. Otherwise it really is overkill in most cases and only gives the crankcase gases a chance to cool off and condense moisture inside the breather system, rather than getting the moisture OUT of the system ASAP. I use pan-evac valves in my exhaust to suck the vapors right out of the alt sand and its working great. Stuff some SS pot scrubbers down the alt stand above the baffle and delete any kind of external "breather box". Simple usually works better.
These covers have a 1/4" npt hole on both ends. I opened up one end to 3/8" npt and vented to a breather for quite a while. Found milky water in the breather hose everytime I pulled the valve covers. Now I leave both covers plugged and only vent from the Alt stand. It's working great and one less hassle when removing the valve covers . If you're going to drag race a LOT then vent the valve covers. Otherwise it really is overkill in most cases and only gives the crankcase gases a chance to cool off and condense moisture inside the breather system, rather than getting the moisture OUT of the system ASAP. I use pan-evac valves in my exhaust to suck the vapors right out of the alt sand and its working great. Stuff some SS pot scrubbers down the alt stand above the baffle and delete any kind of external "breather box". Simple usually works better.
Karl
DON'T QUIT
DON'T QUIT
- FJCamper
- Moderator
- Posts: 2901
- Joined: Wed Nov 14, 2007 2:19 pm
Re: Which vented valve covers?
Hi Volksbugly, Turbobaja;
Consider drilling and venting the heads rather than the valve covers. This was Porsche's ultimate answer to the problem in the 912 engine, last of the 356 line.
The location for the vent hole on a VW is anywhere along the top edge of the head where you have clearance for the hose. Tap in a 3/8" ID fitting to which you can attach the hose.
Porsche did this because removing valve covers with hoses on them can be awkward and messy.
Oil froth and foam is evidence of moisture. It's the water boiling out of the oil. You'll often see it on the underside of oil caps. But it's not from vent lines that admit atmospheric moisture. It's because for every gallon of gas you burn, you get almost a gallon of water as a combustion byproduct. Most of it goes out as exhaust steam. You've seen water literally pouring or dripping out the exhaust of cars in traffic, right?
The foam will collect wherever it traps into a cooler spot and can condense. By blocking off your valve cover vent lines, you force the vapor to escape though the alternator vent, and its stays hot enough to not condense.
FJC
Consider drilling and venting the heads rather than the valve covers. This was Porsche's ultimate answer to the problem in the 912 engine, last of the 356 line.
The location for the vent hole on a VW is anywhere along the top edge of the head where you have clearance for the hose. Tap in a 3/8" ID fitting to which you can attach the hose.
Porsche did this because removing valve covers with hoses on them can be awkward and messy.
Oil froth and foam is evidence of moisture. It's the water boiling out of the oil. You'll often see it on the underside of oil caps. But it's not from vent lines that admit atmospheric moisture. It's because for every gallon of gas you burn, you get almost a gallon of water as a combustion byproduct. Most of it goes out as exhaust steam. You've seen water literally pouring or dripping out the exhaust of cars in traffic, right?
The foam will collect wherever it traps into a cooler spot and can condense. By blocking off your valve cover vent lines, you force the vapor to escape though the alternator vent, and its stays hot enough to not condense.
FJC
- Chip Birks
- Posts: 4003
- Joined: Wed Mar 12, 2008 5:59 pm
Re: Which vented valve covers?
I just pulled the vented stock covers off of my turbo motor, switched back to bone stock. Gonna do what turbobaja said, just use the alt stand. I have heard others state that the main reason we even do the valve cover venting is just because its a monkey see monkey do kinda thing. V8s do it, why not us..? V8 valve covers are at the highest point of a V8, ours...not so much...
- ONEBADBUG
- Posts: 213
- Joined: Wed Dec 02, 2009 9:25 pm
Re: Which vented valve covers?
Duck Butter!FJCamper wrote:Hi Volksbugly, Turbobaja;
Consider drilling and venting the heads rather than the valve covers. This was Porsche's ultimate answer to the problem in the 912 engine, last of the 356 line.
The location for the vent hole on a VW is anywhere along the top edge of the head where you have clearance for the hose. Tap in a 3/8" ID fitting to which you can attach the hose.
Porsche did this because removing valve covers with hoses on them can be awkward and messy.
Oil froth and foam is evidence of moisture. It's the water boiling out of the oil. You'll often see it on the underside of oil caps. But it's not from vent lines that admit atmospheric moisture. It's because for every gallon of gas you burn, you get almost a gallon of water as a combustion byproduct. Most of it goes out as exhaust steam. You've seen water literally pouring or dripping out the exhaust of cars in traffic, right?
The foam will collect wherever it traps into a cooler spot and can condense. By blocking off your valve cover vent lines, you force the vapor to escape though the alternator vent, and its stays hot enough to not condense.
FJC
- ps2375
- Posts: 397
- Joined: Mon Aug 18, 2014 8:04 am
Re: Which vented valve covers?
This is how mine are, my father built the motor 20+yrs ago, seems he knows a few things, a hole in the cylinder tin at the front for the fitting to go thru and done. He used rubber hose and a push on fitting, but I'll upgrade it to AN fittings and braided lines for longevity first and looks second.FJCamper wrote:Hi Volksbugly, Turbobaja;
Consider drilling and venting the heads rather than the valve covers. This was Porsche's ultimate answer to the problem in the 912 engine, last of the 356 line.
Excuse the dirt, car has been sitting for far too long, in the first pic you can see line from pass side head going up to breather box and also the line from alt stand. The drivers side line is sort of hidden.
And at the head:
- volksbugly
- Posts: 634
- Joined: Thu Sep 16, 2010 5:09 am
Re: Which vented valve covers?
Thanks for all the awesome reply's. Ok so after digesting what everyone said there are a few things I want to think about.
1. For the water in your oil are you running an external cooler with 185 degree thermostat. If so the thermostat needs to be 215 to evaporate the water in the engine. I am running joe gibbs oil and wanted to know what is best operating temperature here was their reply,
http://www.improvedracing.com/thermosta ... p-434.html
2. I'm wondering if there is a reason for evacuating on the valve-train side instead of the crank case side. After looking at the animated gif of the vw engine (for far to long) to me it seems like evacuating both places is needed since the valve cover area doesn't have a way to remove pressure. If I can just e vac at the oil filler area that would be easier but im leaning towards tapping.
http://www.vintagebus.com/gallery/secti ... 101593.GIF
After writing that I just had a thought to look into what a modern boxer engine is doing and Subaru vents both valve covers and crankcase
http://www.youtube.com/watch?v=LU1XzwCmB2s
3. Drilling and tapping seems like a great idea! I've never even considered how much of a pain it would be to deal with the hose when adjusting the valves.
1. For the water in your oil are you running an external cooler with 185 degree thermostat. If so the thermostat needs to be 215 to evaporate the water in the engine. I am running joe gibbs oil and wanted to know what is best operating temperature here was their reply,
So I found this:Thanks for the email. The best temp for the oil is 215F oil temp. That is hot enough to evaporate any moisture from the oil, but still keep the oil in a good operating temperature range.
Thanks,
Lake Speed, Jr.
Certified Lubrication Specialist
Driven Racing Oil - Born From Joe Gibbs Racing, Driven To Win
13201 Reese Blvd, Suite 200
Huntersville, NC 28078
http://www.improvedracing.com/thermosta ... p-434.html
2. I'm wondering if there is a reason for evacuating on the valve-train side instead of the crank case side. After looking at the animated gif of the vw engine (for far to long) to me it seems like evacuating both places is needed since the valve cover area doesn't have a way to remove pressure. If I can just e vac at the oil filler area that would be easier but im leaning towards tapping.
http://www.vintagebus.com/gallery/secti ... 101593.GIF
After writing that I just had a thought to look into what a modern boxer engine is doing and Subaru vents both valve covers and crankcase
http://www.youtube.com/watch?v=LU1XzwCmB2s
3. Drilling and tapping seems like a great idea! I've never even considered how much of a pain it would be to deal with the hose when adjusting the valves.
- Marc
- Moderator
- Posts: 23741
- Joined: Thu May 23, 2002 12:01 am
Re: Which vented valve covers?
Yes. Because of the boxer design, although the total crankcase volume remains fairly constant there's a constant rush of "air" back & forth between the front half of the crankcase & the rear, passing through the windows outboard of the center main bearing and also up and down through the pushrod tubes. When you add crankshaft counterweights to the picture, the "downstairs" passages become partially occluded - effectively a labyrinth seal exists which impedes the flow of vapors. Now the pushrod-tube pathway has to handle much more of the flow, which results in the valvecovers being exposed to pressure pulsations far beyond what the factory engineers ever anticipated and contributes to gasket leakage problems.volksbugly wrote:...to me it seems like evacuating both places is needed since the valve cover area doesn't have a way to remove pressure...
Adding hoses plumbed to an added expansion volume helps to take some of the strain off of the VC gaskets - the larger the hoses and "can" the better. With a dry-sump oiling system the crankcase pressure is being scavenged (and vents to atmosphere out the tank) so a smaller hose like a #8 (~½") is usually more than adequate, but for a wet-sump motor I like to run the largest hoses practical, like ¾", and it's tough to get a fitting that large into the rocker box of the head - I braze tubes into the valvecovers, located where they can come up through the sheetmetal so the hoses can be clamped on topside. On racecars with open engine bays they can go nearly anyplace (and most of the time when the valvecovers need to come off the hoses needn't even be removed) and for a street rig it's more challenging...but the time spent getting them right the first time is rewarded every time you need to work on the engine.
-
- Posts: 101
- Joined: Wed Nov 28, 2012 4:30 am
Re: Which vented valve covers?
Venting the valve covers does help the oil to drain back faster after a long sweeping turn, or if you have improved top end oiling. I run the Bugpack covers, same as the ones in the first picture, and like them. They have a nice groove to hold the gasket, and have never leaked. I do drill the cover bolt heads and safety wire them, as I did drop a bolt once.