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Old 02-09-2008, 03:05 PM   #41
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Some thread on electric vacuum pumps:

http://www.corral.net/forums/showthread.php?t=356004

and from that thread one guy's setup:

http://www.cardomain.com/ride/479951/3
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Old 02-09-2008, 03:19 PM   #42
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I won't argue the effectiveness of a vacuum pump- there's a reason they exist and are used. And for having two vent ports, well, I doubt it's going to cause problems, and if it did, nothing a 3/8" npt plug couldn't fix. Don't forget, this is a scrap cam cover.
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Old 02-09-2008, 03:34 PM   #43
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Here is some more info - the pros and cons of vacuum pumps:

http://www.dragstuff.com/techarticles/vacuum-pumps.html

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Old 02-09-2008, 03:35 PM   #44
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I was going to ask if you had pics of the whole thing, but i flicked back a page and found them. notice the lengths they go to on the pcv one? the thing you call the entry is i think an oil drain and there is an open port on the side above it. in that way any oil that came in from the side would fall straight out the bottom and any oil that found its way in the bottom would find its way back out again fairly quickly. If you consider the rotation direction of the cams, the exhaust side of each chamber is the side to put the slot/holes i think as it would be flung past them rather than into them. just like the pcv side.

Now instead you have those two flaps almost catching oil.

I guess my only concern would be that now the entry is right above the cam getting oil fired at it at high speed whereas before it was in that dead area between the cams and with IIRC a little cover stamped/spotted in.

I'm still wondering just how restrictive that chamber was in its full form and if there was a way of opening up the inlet end and maybe shortening all of the "walls" without cutting it down so much and leaving the open end in the between cam dead area.

I was expecting that you would just free up the chambers but leave the walls partially there. and open out the end in that middle area. Having seen yours and your nice pics i think i'll cut some notches into the edges off the ally at the pulley end and on the exhaust side at that end. that way you still get all the filtering of the long chamber and walls but less restriction.

after you pulled the fitting out, did you do a blow/suck ghetto flow test through the chamber to see if it was already free enough or not?

Either way, the worst that can happen is that your catch can gets more work to do. If it was plumbed to the turbo or intake like stock it would matter, but not how you have it setup.

Fred.
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Old 02-09-2008, 03:59 PM   #45
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Bending up was an effort to shield oil as the oe finds on the plate do. Keeping the OE channel at the center V and V on the edges was for drain back. As is the OE hole in the rear at the "well". I figured that when the oil gets to the actual port, it still has to make a right angle and go up to get to the hose. And this is w/o the aid of pressure as before.
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Old 02-09-2008, 04:56 PM   #46
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thanks for the pumps info
the bolt pattern of their pulleys might match the miata water pump pulley
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Old 02-10-2008, 10:31 AM   #47
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Re: exhaust venturis to create vacuum, by using the O2 bung. With a street exhaust this point will show positive backpressure due to muffler and cat restriction. You will end up blowing exhaust into the crankcase.

Re: measuring effectiveness: Measure the crankcase pressure at the dipstick by fitting a rubber hose over the dipstick tube, and using a reducer to a 3/16" vacuum hose going to a boost gauge. BTDT; I found that the breather hole on the exhaust side is indeed restrictive - was getting 2 psi! I simply tee'd a hose from the dipstick tube to the vent line from the cam cover that goes to my "y8s hardware store special" PVC catch can. This greatly reduced oil weeping from my cam cover, and my turbo bearings too.
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Old 02-10-2008, 10:51 AM   #48
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Quote:
Originally Posted by JasonC SBB View Post
BTDT; I found that the breather hole on the exhaust side is indeed restrictive - was getting 2 psi!
One the fe3 or the bp?
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Old 02-10-2008, 11:04 AM   #49
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for the B - good info Jason, thanks. I can't remember exactly what the B cam cover and vent system is composed of. I remember finding a restricter inline somewhere...
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Old 02-10-2008, 11:16 AM   #50
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From memory, pretty much exactly the same fitting as on the fe3. Interesting figures. How much boost, how many rpm and how much power with that 2psi?
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Old 02-10-2008, 02:34 PM   #51
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This is on my '00 miata, at around 240hp, 10 psi, 6000ish RPM.
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Old 06-27-2011, 11:27 AM   #52
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Hi, I have a major problem with either blow by or crankcase pressure. I'm not sure how many of you are familiar with "rappadan" old drift miata. But I have it now. I got it with a blown head gasket and the pistons smacked the head. I put in a 1.6 long nose, it was a short nose. At first oil was pooring out the exhaust mani (turbo off) I had the head rebuilt and also the turbo, put a mls head gasket on it. It's no where near as bad as it was but a very little oil in the exhaust still. It's not bad at cruising speed, just under a load. It's blowing the dip stick out also. I've tried catch cans. new pcv. I'm lost, the car runs great, no problem. Just smokes any ideas? Is there a vent port on the block? There isn't any oil coming out any where else, just the exhaust mani, And blowing out the dip stick.

Matt
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Old 06-27-2011, 11:33 AM   #53
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Hi, I have a major problem with either blow by or crankcase pressure. I'm not sure how many of you are familiar with "rappadan" old drift miata. But I have it now. I got it with a blown head gasket and the pistons smacked the head. I put in a 1.6 long nose, it was a short nose. At first oil was pooring out the exhaust mani (turbo off) I had the head rebuilt and also the turbo, put a mls head gasket on it. It's no where near as bad as it was but a very little oil in the exhaust still. It's not bad at cruising speed, just under a load. It's blowing the dip stick out also. I've tried catch cans. new pcv.I'm lost, the car runs great, no problem. Just smokes any ideas? Is there a vent port on the block? There isn't any oil coming out any where else, just the exhaust mani, And blowing out the dip stick.
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Old 06-27-2011, 04:15 PM   #54
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Did you use a PCV valve from a turbo car like a 323gtx or a Mazdaspeed Miata?

Have you done a compression test? What numbers did you get?

EDIT: Thank you for searching related topics. I don't mind the resurrection.
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Old 06-27-2011, 04:26 PM   #55
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No I have been using the stock pcv. I didn't know I needed a turbo pcv, but ill do that. I drive a rig so I won't be home for another two weeks or so. Is there a particular pcv valve I should use? No I haven't done a compression test. I'll do that also.
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