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Need input on crankcase evacuation remedies
Some basics of my setup first:
Its a 10.1 cr 383 SBC, 0.534/0.537 lift cam that makes 18" vac at idle, Fastburn heads, dual plane intake and a quadrajet, 525 ft lb at 4700 rpm, 467 hp at 5400 rpm. I street drive the car as well as race it on autocross and road course events 15-20 times a year. During it's first season, I noticed significant oil blow by coming out the breather on the pass side valve cover, the driver side VC has a PCV valve plumbed to the carb. I'm investigating cures ranging from a engine driven Vac pump setup to just a catch can with a breather. My main concern is capturing the escaping oil, but I'm trying to figure out if putting a complete crankcase evac setup on the car would be a worthwhile investment. I just started reading about the vacuum pumps yesterday and a few things concern me. It appears that they are mainly used in drag race applications to free up a few horsepower and to help the rings seal to make a little more power. I also read that the pumps need a little bit of oil to go thru them to keep them lubed. I'm not really trying to eek every last little bit of power out of the engine and it gets street driven regularly...will a vacuum pump survive under just regular driving...not getting rung out on ever single run like a drag race application? And is it worth the cost (like $750-1000) and the hassle of mounting one and trying to run a belt to it for my application? Or should I just plumb in a catch can tot he pass side valve cover and call it good? Now onto that part... Is there a way to adapt a -12 type fitting to my existing breather hole in my valve cover or is my only option to have a fitting welded to the valve cover somehow? I'm not opposed to modding them but if I didn't have to it would make this more of a home remedy type job. Here are some engine pics for reference...as you can see there is a lot going on under there so space is at a premium. http://img.photobucket.com/albums/v3...S/P5150012.jpg http://img.photobucket.com/albums/v3...S/P5150011.jpg http://img.photobucket.com/albums/v3...S/P5150008.jpg http://img.photobucket.com/albums/v3...S/P5150009.jpg http://img.photobucket.com/albums/v3...S/P5150010.jpg I welcome any ideas from those with experience in this area. |
I'm not sure if this is a cure or something you've already read about, but I just installed a ME Wagner duel flow pcv valve on basically your same motor. I was noticing blow by and gaskets weeping oil. Once dialed in per their instructions it appears the weeping has quit and oil blow by has been solved too. They suggest an oil catch can to be plumbed inline. I picked up a moroso can but haven't plumbed it because I'm not sure I need it. Time and miles will tell if I do I guess. If you haven't looked into them, maybe see what you think.
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Thanks Matt, that looks interesting... What did you use on the other valve cover, a breather of any sort?
I think my issue is compounded by the type of driving I do on track, mainly on autocross runs. Multiple WOT blasts immediately followed by short closed throttle blades...then WOT once again. I think my current PCV setup just can't catch back up quick enough creating excessive crankcase pressure on the WOT blasts. I don't really care about "pretty" on this engine anymore, I'm more concerned about function. But at the same time I'm more interested in a fix that will work with what I have instead of reinventing the wheel if that makes sense. Some sort of solution that will work with my existing grommets in both valve covers would be ideal for me. |
I have a similar 383 (think 19" vac at idle) and have a similar breather on the passenger and PVC on the driver and haven't experience any problems after installing a Moroso catch can between the PVC valve and the throttle body. The amount of nasty crap at the bottom of the catch can is surprising considering it was going straight in to the engine before. I remember finding a great site that listed out the different breather setups (NA vs. turbo) that I'll try to find and post on this thread.
Here's what I have: Breather - https://www.spectreperformance.com/s...aspx?prod=4919 PVC - https://www.spectreperformance.com/s...aspx?prod=4921 Moroso Catch Can - (got it for $39.99 on Amazon, total screw up on pricing) https://www.amazon.com/Moroso-85474-.../dp/B004K9BIY4 https://lh3.googleusercontent.com/El...w1536-h1152-no |
Catch Can
Hello,
I am running a MightyMouse Solutions Catch Can on my 540 BBC. My set-up includes a -12AN dirty side to catch can, and a 3/8 clean side to throttle body with a turbo car PCV valve. This significantly helped my set-up which originally consisted of one K&N breathers on top of each valve cover. Give Mighty Mouse a call, and he can help you with your application. These are very popular for twin turbo LS cars. www.mmsolutions.com http://i190.photobucket.com/albums/z...pspmdmtvrh.jpg Regards, Larry |
Wow!! Thanks Larry, tons of useful information at MightMouse. Here is the correct link BTW if anyone else goes looking for it...
http://www.mightymousesolutions.com/mm-catch-cans I have contacted them about putting together a custom setup for my application. |
Here is a great article by Arrington Performance. It really explains everything very well and lays out various configurations and their Pros & Cons.
http://www.shophemi.com/images/media..._ccv_bible.pdf Cheers, Brew Oh and Lance your car is very sweet! |
Thanks Brew... And that is an AWESOME illustration that deals with my current issue.
I now understand how that at high load WOT conditions, PCV valves will close instead of staying open causing a foul air condition and ALL blow by gases to exit the engine via the vent which in my current case is just a breather meant only to allow fresh air into the crank case. Considering how much time my engine spends at high load WOT...this is all starting to make a lot more sense. I'm thinking option 3 from the link is a good fix, twin catch cans with no PCV valve. This way air plenum and intake vacuum is pulled from both valve covers at all times under all conditions and all air coming from the crankcase goes thru an oil/air separator first before entering the engine to be consumed in the combustion chamber. Now, to just find a couple affordable catch can separators and ways to plumb them to each valve cover opening. |
A -12 AN bulkhead fits the stock valve cover hole size perfectly I think it's 1.25 IIRC. I am running a single puke tank routed to one valve cover with an oil fill plug to seal the other. The crankcase is common from bank to bank, so I think I should be ok. -12 is huge.
I read that bible too, and it helped make sense of it all. I stalked build photos on DSE's site and saw they consistently used one puke tank, so I figured if it's good enough for them, it's good enough for me. Simplifies plumbing and reduces cost, too. Hopefully it works well. I'm still in the build stage. http://i113.photobucket.com/albums/n...pse1ka8lpd.jpg http://i113.photobucket.com/albums/n...psni5wxmbc.jpg |
Glad you posted this, Lance. I'm wanting to make sure I get mine setup correctly too since my engine is due back soon.
I've got one of Mike Norris's catch cans on order now. It's a nice piece. I'll be hard lining mine since I have room to mount it on the front of the motor near where the factory PVC lines already run. |
Most of you know I'm a visual guy...here is a picture of the setup I'm leaning toward.
https://photos.smugmug.com/Other/i-k...%20setup-L.jpg I took my PCV and breather assemblies apart this morning and I think I can modify and use these for the Valve cover side of the plumbing. https://photos.smugmug.com/Other/i-X...8_091236-L.jpg And here is the hole in my air cleaner housing for the clean air side. https://photos.smugmug.com/Other/i-C...7_144256-L.jpg https://photos.smugmug.com/Other/i-L...6_092823-L.jpg Now I just need to figure out if I can get by with one catch can or two and put the plan into motion. |
So, just had a long conversation with David at Mighty Mouse and I placed an order for some parts. He's a good dude who understands this issue well and helped me decide what I needed without going total overkill for my setup.
We went with his PCV can with both a breather on top, an additional recirculator top for the can which will let me run a line to an additional catch can if needed during long road course sessions, and a brake booster mounting kit. PCV Can Fitting 2: 3/8" Hose Barb Fitting 3: Oil Sight Price: $200.00 http://www.mightymousesolutions.com/.../pcv-tuner-can 'Recirculator' your can Fitting:: 3/8" Hose Barb Order Type:: Old order upgrade Price: $50.00 http://www.mightymousesolutions.com/...lator-your-can MM Can Mounting Kits Mounting Kit: GM Truck Booster Price: $20.00 http://www.mightymousesolutions.com/...-mounting-kits This setup is good for up to 600 HP. The recirculator top is a backup in case for some strange reason I fill the catch can up with oil during a long road course session. With the breather top it would just push the oil out the breather and make a mess and be unsafe. It is very unlikely this will be an issue but I want to have the recirculator top with me the first couple of track days just in case. If I end up not needing it, he'll let me return it as long as it in in resalable condition. The install plan is to gut my current PCV housing and use it to plumb the driver valve cover to the inlet side of catch can. The can has a PCV in it which will be plumbed to the intake vacuum. I'll get another PCV housing just like the one I have, gut it, put it in Pass side Valve cover and run it to the bottom of my air cleaner housing for a fresh air intake to the crankcase. Boom...Should solve any crankcase ventilation and blow by issues, keep oil from spewing down the side of my valve cover and might even help with the garage fumes from time to time. |
FWIW, I have never had any luck with those billet PCV valves, even on cars that don't get driven in anger.
Instead of buying another billet thing to gut and ending up with just a 3/8" line on the clean side to the air cleaner, grab one of these with a 5/8" nipple. http://shop.advanceautoparts.com/wcs...1_pri_larg.jpg The 5/8" will keep your engine will keep your crankcase from going positive pressure in most cases. |
Thanks Donny, a friend has an extra one in his tool box that matches the other so it won't cost anything. David explains that even the 3/8s nipple on these might even be too much air and I may want to slow the air down going in the fresh air side. My logical mind say's it'll only pull in the fresh side the amount of air (minus any blow by) the PVC side pulls out of the can by which will be 3/8s as well.
The big thing to me is the 1" stub that goes in the grommet so that is a tight fit. I'm just happy I don't have to cut on or weld to my valve covers... |
Brake booster bracket
https://photos.smugmug.com/1985-Mont..._163339-XL.jpg Can up to bracket https://photos.smugmug.com/1985-Mont..._163152-XL.jpg It fits well there but I'm not too crazy about it hanging right over the top of a header. I'm going to look around a bit more today to see if I can make the bracket work somewhere up around the core support. I'm less concerned about hiding it and the lines to it and more concerned about ease of checking sight window and draining oil out of the can. The can is a VERY nice piece for sure... Still working on the pass side PCV housing as well, hope to have a remedy there soon too. |
I love the Arrington race catchcan V2. It is simply the best design. The only drawback is cost.
We offer a "good one" from Moroso for about half ... at the bottom of this page HERE. :cheers: |
Alright, 90% of this project is installed and operational. All I'm waiting for is the Pass side breather I ordered to show up so I can plumb it to the bottom of the air cleaner, for now I've just got the old open breather on that side.
Here's the can hanging off the airbox right behind the headlight. https://photos.smugmug.com/1985-Mont..._135235-XL.jpg The 3/8s lines running from the can to the now gutted PCV breather on the valve cover and manifold vacuum port on bottom of carb. https://photos.smugmug.com/1985-Mont..._135246-XL.jpg And I can even see the site glass by looking under the core support by the charcoal canister... https://photos.smugmug.com/1985-Mont..._135314-XL.jpg This setup is pretty sweet, here are a few pictures of the top of the can, inside the breather top and even inside the recirc top for you to see as well. https://photos.smugmug.com/1985-Mont..._092006-XL.jpg https://photos.smugmug.com/1985-Mont..._091803-XL.jpg https://photos.smugmug.com/1985-Mont..._091813-XL.jpg There is a check disc inside both the open breather and the recirc top that lets air flow out if needed but when vacuum is put on the can it seals the top off. https://photos.smugmug.com/1985-Mont..._092012-XL.jpg https://photos.smugmug.com/1985-Mont..._092416-XL.jpg https://photos.smugmug.com/1985-Mont..._092116-XL.jpg https://photos.smugmug.com/1985-Mont..._092128-XL.jpg If any questions just ask away, I think I now have a handle on how all this works and can't wait to try it out under sustained WOT applications... Thanks for all the help with this guys...sure hope it cures a few ills I had last season. |
Interesting thread thanks for sharing. I run two catch cans, with only breathers and no connection back to carb so it just escapes to atmosphere. My car stinks so bad the family won't go in it. I am re-thinkng the set up to get fumes down and family in
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I fixed the pass side breather last night. I thought I'd try another PCV over there gutted and plumbed to the air cleaner but it was too difficult to restrict the flow on...so I looked at the open breather I had there originally and came up with an idea.
https://photos.smugmug.com/1985-Mont..._162906-X2.jpg I cut a piece of rubber gasket material with a piece of copper pipe and poked a small hole in it with a leather punch...and put it in the center of the breather making it just about as hard to suck air through as the Mighty Mouse PCV. https://photos.smugmug.com/1985-Mont..._162921-X2.jpg https://photos.smugmug.com/1985-Mont..._162938-X2.jpg This should give the system the intake restriction it needs to make the MM can setup work as designed. It's all on the car and ready to be tested...I'll update once I get some miles on it. |
I ran -12's from the top of both valve covers to separate catch cans. I ran the snot out of mine everywhere and they worked very well. They would smoke a little until the moisture burned off. I don't recall any messes. I would drain them once in a while. Never more than an ounce or two.
Why suck the vapors back in the engine? I get it on a street car where you want to go 3000 miles between oil changes. |
So, to make sure I have the flow path right.
Fresh air enters the passenger side valve cover through a small hole. Then it flows through the crankcase to the drivers side valve cover where it is connected to the air oil separator with a 3/8" hose and mounted below the height of the valve cover and then connected to the intake or carb baseplate with another 3/8" hose. Right? In theory, the crankcase will have negative pressure at idle and cruise but I just don't see one 3/8" hose being enough ventilation at wfo. Crankcase pressure will go positive and it will try to push through the AOS, taking oil with it, and when that's not enough, gaskets will start to leak. At least that's the way it looks from 500 miles away. I hope it works for you but I think you will want a 5/8" inlet/outlet on the passenger side. |
David (MightyMouse) is a wealth of knowledge on this. I spoke with him at length before setting up my car.
Have his PCV can on mine with: -10 from behind air filter to DS valve cover (clean air) -12 from passenger cover to catch can (dirty air to catch can) -6 from can to intake through a PCV (clean air return) Very happy with the look and so far so good for the performance of it. http://i.imgur.com/ukaBAEm.jpg You can see the -10 on the far side in front of the brake reservoirs, and the -12/can/etc on the passenger side firewall. |
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David at Mighty Mouse says a 3/8s line is good for up to 600 HP generally, but every case is different depending on engine and other variables. The main difference with his setup is his check valve in the can which takes the place of most PCV valves. It will NOT close off under WOT like most PCV do. This lets the manifold vacuum keep sucking on the crank case even under WOT and that keeps the air flowing in the pass side, out the driver side and the excess that doesn't make it out the check valve to the carb goes up out the breather on top of the can. |
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How much oil do you notice that you accumulate in your can? During every day cruising and also during heavy WOT driving? |
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Nature abhors a vacuum. If pressure in the crankcase is negative, blow by will never exit the breather on the passenger side.....physics won't allow it. What will happen at wot, is the negative pressure in the manifold will be lost, consequently the negative pressure in the crankcase will be lost and you _will_ build positive pressure in the crankcase and now it can't breathe out the passenger side. The other issue with restricting the clean air side is when vacuum goes high, like it would in a closed throttle braking zone, it will suck oil into the AOS, far more than if the passenger side breather was open. I've pushed the rear main seal out of an LS motor that had 2 -6 lines, one in each cover, and the OEM style fixed orifice pcv running from valley to the intake. The -6 lines ran uphill to a vent can mounted on the firewall. A Moroso universal AOS was inline with the dirty side. Before we pushed the main out, we could fill the AOS in a track session and we would get oil in the valve cover vent can as well. After we replaced the rear main seal, we upsized the valve cover lines and fittings to the vent can to -10. The AOS gets drained at the end of track _days_ now and is less than half full. All that is in the vent can is water vapor usually. It has been this way for 3 years. Have the tools with you to remove that restrictor. |
I appreciate your concern Donny, I'm learning about all of this from scratch and every bit helps. I know what I had before did not work...and have a pretty good idea why. If I'm correct in that assumption, this should cure my ills.
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He doesn't think I'll have that issue because of the extra height from my tall valve covers, we'll see though. That is why I'll have the recirculator top to put on the can with me along with a line ran to a second can if needed. Quote:
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David said when at warm idle I should just have a bit of vacuum at the breather on the can. With the breather pulled, I can't really feel vacuum with my hand but a piece of tissue confirms there is just a bit of vacuum pulling through the breather. I flushed the cooling system several times today and finished up a few other odds and ends...then beat on the car for a bit after several road tests. I lost 150 RPM at idle... :D Which is fantastic as the car has always idled fast. Now it idles at a rock steady 810-830 RPM instead of the 970-1020 RPM. No sign of oil out the pass side breather yet, big test will be track day Thursday night.
Here's a little video of me testing out my other favorite off season upgrade. Anyone guess what it is...? https://youtu.be/AmerrpIqFDo I'll update how the catch can did after Track Night in America on the newly paved Heartland Park Topeka road course Thursday. |
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Had a blast at the track last night, pics and videos will be posted soon.
Here's what I drained out of the MightyMouse catch can this morning after (3) 20 minute sessions on track at mostly WOT. https://photos.smugmug.com/1985-Mont..._083831-XL.jpg https://photos.smugmug.com/1985-Mont..._083810-XL.jpg Just maybe an ounce or two of gassy smelling water with not even a hint of oil residue on the underside of the breather on the passenger side. Not only that but the engine didn't use or leak a drop of engine oil either. I'm VERY happy with the results of this mod. Not only did it cure a long standing idle problem by blocking a basically wide open vacuum leak but it also fixed the oil mess and usage problems the engine had before. Here's a video of a single lap from session 3, will have the whole session video posted soon with a better update. https://youtu.be/GdXBultZxaY |
Don't drink that.
Seriously though, that's awesome! I'm glad it worked out just the way you had hoped. :thumbsup: |
LOL... It was bad enough sticking my nose in there to smell it. :D
Thanks, I'm very happy as well! Should have done something with this issue a long time ago, especially considering how easy of a fix it is. |
That's great to see, Lance. Thanks for the follow up. I hope my catch can setup works as well.
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I'm running the MightyMouse configuration on my car as well. I have a Scott Shafiroff 540 Ultra Street with Holly HP MPI.
-12AN from passenger VC to dirty side inlet of catch can -6AN clean line to 1/4npt in front of the intake just under the throttle body. This system works very well on my application. http://i190.photobucket.com/albums/z...pspmdmtvrh.jpg |
So I can't remember the last time I drained my catch can...probably after Midwest Musclecar last May. After making 3-4 6,000 RPM blasts per run for about 20 runs at Good Guys couple weeks ago, I figured it would be a good time to check it.
This is what came out... https://photos.smugmug.com/1985-Mont..._115912-XL.jpg It's probably 90-95% condensation water with very little oil in it. Not only that, but the engine has completely quit using or loosing oil as well. It's really nice when a well designed part does exactly what it is supposed to do, fixes an age old issue. So simple too... Thanks Mighty Mouse... |
I bought one for a 427" LS corvette at the shop. If that works out Mighty Mouse will be my go to solution for just about everything.
It still defies conventional theory as I understood it but it obviously works. |
Update us on how it works for you Donnie. I know about 10 guys now running them and they all swear by them. Good luck with it...
Did you tell David who sent you? :D |
I actually did.
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Evac kit
I have run tanks from the valve covers for years
Stop running breathers on the valve covers as they tend to leak if you are spinning things at 7500 rpm I have found that if you keep each side separate they tend to dump things out.. if you tie them together then it balances things out The ones on the Pantera dump into a T and then to a catch tank I empty it usually when I change the oil which is before I go to a track event.. it will smoke slightly if I go hammer it for a while then idle along afterwards The ones on the Bird hit a tank also but I also have a T that goes to the carb with a pvc valve between... never drain that tank or have smoke coming out of the breather That's on a 494 cubic inch engine with a 750 lift cam and 1050 cfm carb so lots of flow going somewhere Bob |
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