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Discussion Starter #1 (Edited)
These engines need vacuum all of the time...

For proper oil control and ring seal these engines need vacuum all of the time, manifold vacuum and boosted conditions. When the engine is under manifold vacuum the pcv (positive crank case ventilation) valve pulls vacuum on the crankcase via intake manifold connection. When the turbo produces boost the pcv valve is forced shut (closed) and crankase is to be vacuumed via air intake connection. Despite rumors and claims there is a nice amount of vacuum and up to 10whp worth.The air intake while the turbo is producing boost has a strong vacuum signal and needs to hooked up to do so. The problem we see over over and over is the drivers side of valve cover is left open simply venting to atmosphere from some one just adding a breather or filter. This is when oil because the lack of vacuum starts to work its way by the rings and valve seals from the lack of vacuum under boosted conditions. The valves start to gunk up and the oil working past the rings can cause detonation from its low specific octane rating and also building up on the pistons tops, combustion chambers and valve faces. We all know without a catch can installed and a good catch can at that what happens. Oil gets pulled from the pcv thru the intake and into the engine. So installing one catch can fixes just that issue. Without the connection from the driver side valve cover to the air intake you have the severe issue mentioned above but also the problem of this side pulling oil thru the air intake. This oil ends up making its way thru the piping, intercooler, intake manifold and also back into the engine as well.From tearing down stock to building engines and knowing oil control, ring seal, crankcase pressures and there effects there is a correct way to address the issue.

The cure is running both connections for vacuum to occur under both conditions (manifold vauum+boosted) and installing not just one but two catch cans. The problem with this is making additional room for both catch cans in everyones engine bay. We are making DCR Compact Catch Cans to accomodate this. Our catch cans have media inside to catch oil from passing thru and particularly the humidified oil from the crankcase. Keeping vacuum under boost can provide an additional 3-20whp depending the size of turbo and boost pressure. The bigger the turbo and the more the boost the better the vacuum. Its one thing to assume what works its another to prove it and know.

Check these out.
Pricing is $100 each and comes with hoses, fittings and clamps.
For powder coating add $20 each and colors are red, black, or silver. Custom colors can be done on special order.
 

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"The problem we see over over and over is the drivers side of valve cover is left open simply venting to atmosphere from some one just adding a breather or filter."

But that's basically how it is with the stock airbox which uses a makeup line between the driver side of the valve cover and the stock airbox with the sponge filter beyond that. There is no constant vacuum with the stock setup. It's still just a simple breather filter. And it seems to work just fine (83K miles here) with the stock design implementation.
 

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Discussion Starter #4
Have you looked at the valves, pistons and chambers with or without? we have and see the difference. Some may not want the additional benefits of the constant vacuum. Stock is not for performance and longevity DCR standards. The higher the output the more it is needed unless you run special rings for all out racing. Chrysler put the lowest tension rings possible for fuel economy and the after market pistons come this way as well. The problem with this is it increases oil seepage as well as blow by over our standard. To take advantage of additional ring seal, reduced oil seepage by the rings, valves seals, oil passing thru vacuum connections and a few extra hp, we do it this way.
 

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"Without the connection from the driver side valve cover to the air intake you have the severe issue mentioned above but also the problem of this side pulling oil thru the air intake. This oil ends up making its way thru the piping, intercooler, intake manifold and also back into the engine as well."

I think this was a much better point in the original post. Connecting the valve cover on the drivers side to the intake tube (i.e. typically on the AEM instake) would provide more of a vacuum due to the bernoulli effect than is possible with just a plain breather filter or the stock makeup/breather that I mentioned previously. Problem is, as you indicated, that doing it that way would allow oil vapors from the valve cover to enter the intake tube, so a catch can in between would solve that problem. That right there leads us into the benefit of making this change to add a second catch can (i.e. and not just to replace the breather filter, stock or otherwise, which was described originally). Of course, this second catch can (on the drivers side) should definitely be of the lowest resistance possible otherwise the whole PCV system may not work as well as it should. Like many motors, these A853's definitely run their best when there is a small amount of vacuum under the pistons. A properly functioning PCV is more critical than most people realize. :thumbsup:
 

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Discussion Starter #6
^^^^^^Yup:thumbsup:
 

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One issue I see is the pcv valve. Darrel mentions when under boost the pcv shuts so boost doesn't shoot out though the drivers side VC breather. I have yet to see a pcv that shuts off any more that the smallest amount of boost. Most I have messed with are basically useless & dont shut at all. U can blow though most of them just as easy through either direction.
 

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Discussion Starter #8
You are right. We find a few that will actually shut as intended. Always use a check valve for back up. Most already have them if not we can add them in for few bucks.
 

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One issue I see is the pcv valve. Darrel mentions when under boost the pcv shuts so boost doesn't shoot out though the drivers side VC breather. I have yet to see a pcv that shuts off any more that the smallest amount of boost. Most I have messed with are basically useless & dont shut at all. U can blow though most of them just as easy through either direction.
Not to hijack this thready more than it already has been, but a couple of things I've found over the years with the PCV valve and the check valve:
1. The 04 and up PCV valve is definitely superior to the original 03 version. Yeah, I can blow though it ever so slightly...when it's new. When it gets old and I can blow though it easily, I get a new one from the dealer. I'm on my 3rd now. Don't rely on the "PCV rattle test". Blow through it to check it.
2. The check valve seems like a good idea, if only to backup the PCV valve. But again, like anything else, it may become defective over time. The one I had (McMaster Carr p/n 7775K63 with viton seal and a cracking pressure of 0.3PSI) was totally plugged when I checked it last winter after a couple of years use. I was re-doing my PCV system. Evidently the "good for 1000PSI at 400*F" was not good enough for day-in, day-out use. I didn't replace it with another check valve. And the S3R still boosts as well as it always has (totally stock, 20PSI spike, 17PSI redline). If anything made a difference, it was the proper PCV hose that I used instead of the sorft fuel line that I and everyone else uses. The PCV hose is so stout, I found it best to use a hacksaw to cut it. The fuel line hose was easily cut with one snip using basic wire cutters.

Again, the PCV system is quite important, more so than most people realize. Using the proper pieces definitely helps, but you have to check up on them from time to time to make sure everything is working correctly. Keeping it simple stupid sometimes works out best. My car currently has just the catch can on the PCV valve side, proper PCV hose, a PCV valve in good working order and a filter on the driver side that will need replacing soon due to oil.

HTH
 

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I think



i have the same check valve as u stark. I checked mine recently & it still worked well. I did recently change intakes from the AEM to the JMB. No nipple for that VC hose. I just left the hose open to the air. It leaks a tad bit of oil, but only when I'm at Wot drive on the track. In fact I never saw even moisture on it til I spent the day at Laguna Seca.
 

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Holly fuck is that a iceman Intake I spy? I had one of those... Probably the ONLY intake for the SRT-4 that actually made power...

To Bad Iceman Joined the ranks of some of our "pride and joy" vedors lol
 

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I think



i have the same check valve as u stark. I checked mine recently & it still worked well. I did recently change intakes from the AEM to the JMB. No nipple for that VC hose. I just left the hose open to the air. It leaks a tad bit of oil, but only when I'm at Wot drive on the track. In fact I never saw even moisture on it til I spent the day at Laguna Seca.
OK, my last hijack...honest...
Yeah, I've been beating the snot out of my car lately.
It just seems to drive better when I lay the wood on it's arse.
And with 83K on the original motor I'm not suprised to see a little blowby on the breather filter, especially boosting so much!
Stupid man in a BMW 745 tried to race on Dalton the other morning.
My car easily won and 145MPH on those skinny 2-lane rods is insanity so I'd better stop.
Hopefully the Caliber will arrive on Tues/Wed and will be ALOT slower.
These damn Neon's are just too fast for me :rofl:
 

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Well That sux!!! I have a AGP CAI and it doesn't have a port for the Valve cover.
Stock air box does:rofl:
Good info:thumbsup:
 

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No shit??? Crap I already powder coated mine. Ill be making a call tomorrow to ask why this is not standard option.
 
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