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Old 07-17-2008, 04:14 PM
Walther
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Default Crankcase Ventilation

I was going to email the CRB, but prior to I wanted a concensus of opinions.

My "issue" (this time) is that the rules disallow any form of aftermarket crankcase evacuation system. I have given this some thought. Let me expand..

It has become clear the the creativity and ingenuity of AS competitors has created engines whose HP far exceeds what I believe to be the spirit and intent of the originally drafted rules. I am not a professional engine builder but was none-the-less impressed at what my engine developed on the dyno given the limitations of the rules. I am certain that many of you national guys, and a lot of regional guys too, have exceeded that (my) output. All that HP with no form of "induced" crankcase ventilation.

As I am sure most of you are aware, spinning these engines beyond 6000 creates increased crankcase pressure. As the engine wears in, the pressure actually increases. This pressure can have several adverse effects on the engine. Despite the counter-productivity of pistons on the exhaust and power strokes fighting against the internal pressure and fouling plugs, this same pressure can push out gaskets, thereby creating oil leaks.

My first thought was the allowance of vacuum pumps, BUT in doing so it would further open the doors for things like low-tension rings, etc, and broaden the gap between those who have greater racing budgets, and those who don't.

So my solution would be a revision to the rules allowing a pan-evac system similar to the one produced by Moroso "See link". This system is relatively cheap and easy to install. The current rule requiring a catch can for breathers would also be addressed, since the minimal amount of oil (if ANY) that escapes through the top of valve cover would be introduced into the exhaust and burned without any noticable, visual exhaust emission.

Please chime in with your opinions. I would do a poll if I knew how.

Mark Walther

http://store.summitracing.com/partde...5&autoview=sku
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Old 07-17-2008, 04:27 PM
jimwheeler jimwheeler is offline
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You are correct in that the system is not currently legal. Write a short letter to the CRB and they will put it on the agenda. Now would be the time to do it, so it could be discussed for next season.
wheel
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Old 07-17-2008, 04:36 PM
Walther
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Wheel,

Letter or email?

and may I ask for your opinion?
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Old 07-17-2008, 04:46 PM
Dawson Motorsports
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After looking at the instructions I noticed the following problems with the system in question:
1. Drag race put the breathers at the front, all the oil goes to the back under excelleration.
2. Oval, put the breather on the driver side, works great when turning left.

With a good breather system on our current cars you should not have any severe crankcase pressure. If you do it's time to remove the motor. We are currantly running the thin rings and have not had any problems.
Except when the motor tries to vent out the bottom.
Chuck
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Old 07-17-2008, 04:54 PM
jimwheeler jimwheeler is offline
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an email to crb@scca.com will work. I have had engines that have a problem with this. I had to drain the catch tank every race. Current engine doesn't have the problem. Pretty common fix for many race classes. I don't really have a hard opinion, but I do know my engine builder would like to add it.
wheel
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Old 07-17-2008, 04:59 PM
Dawson Motorsports
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The real secret lies in running a PCV, any unburnt or combustible fuel goes back and increases the amount of CFM's. But nobody would do that.
As per the rules, you may remove all the pollution stuff, doesn't say you have to, another gray area.
Chuck
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Old 07-17-2008, 05:03 PM
Walther
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Chuck, not currently having a problem with it other then an unexplanable rear-main "drip", but it is an inherent problem- IMO

PS, I restricted the oil pressure to the top of my motor. the only problem I know of in doing that is the oil actually cools the valve springs, and my set-up will shorten their life.
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Old 07-17-2008, 05:12 PM
Dawson Motorsports
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Mark, you maybe having to much oil pressure at the rear main. We have never run restrictors. Keeping the oil flowing all the time is key and keeping the temp under control.
On Jim's catch can filling up, allow the drain from the catch can to go back to the motor with a valve. You can check it to make sure there is no moisture, you can dump it if it does or recycle it into the crankcase, hint from Smokey Yunick.
Chuck
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Old 07-17-2008, 05:18 PM
Walther
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Always aprreciate the advice Chuck, but I did not restrict it THAT much. These Ford one-piece rear main seals are famous for this, just not this soon. I have maybe 3 hours on the motor. I had NOTHING in the catch can after Homestead/Miami. Could have used one to catch my rear-end brackets though.
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Old 07-17-2008, 05:34 PM
kbsmith1 kbsmith1 is offline
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This effectively allows competitors to put down oil on the
track (via the exhaust system) rather than in the catch can.

I think that is why this system has not been allowed in the past,
and I think I would be opposed to allowing them in the future.
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Kevin Smith
1993 Firebird AS #03 Oregon Region SCCA & ICSCC
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