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Originally Posted by Jack
So please tell me.... when making a high speed right hander, such as the down hiil at Lime rock, this system prevents oil from climbing up the oil necK?
https://www.rx7club.com/forum/showth...&page=13&pp=15 A tee in a turbo oil return line may have problems with venting the sump while flowing allegedly frothy oil from the turbo. A BB turbo (as for a 2nd gen) with very restricted oil flow to the turbo, would have the best chance of a tee vent in the drain line. |
Here's a stumper. At one particular track running counter-clockwise I would lose through my stock PCV system about a quart of oil per hour of running. Yesterday I ran the track clockwise and lost no oil at all (at least none that I can identify from the dipstick). I assumed oil loss would be much worse with all the hard right turns but it wasn't. How could that be?
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Let's the track layout, including any elevation changes . . .
:-) neil |
Could be the quality of the right hander, not the quantity. I suspect worst case is a long right under high load and high rpm. At same track, I noticed a significant difference in oil flow if I'm at 8 tenths vs 9 tenths on corners, or if I push near redline more.
Did you start at same oil level both times? Both dry days ... any g-meter logs for both tracks? |
I've noticed that if I am on the wrong line, which means I am placing more strain on the suspension, and usually pushing over 1G in cornering, I'll get more oil sloshed around.
Stay on the most efficient line, which means you don't need to pull lots of G's, and you'll have less oil. . . Of course, I'm only driving at 7 or 8/10ths on the track since I'm not competing . . . :-) neil |
Originally Posted by KevinK2
Did you start at same oil level both times? Both dry days ... any g-meter logs for both tracks?
Originally Posted by KevinK2
Could be the quality of the right hander, not the quantity. I suspect worst case is a long right under high load and high rpm.
Originally Posted by KevinK2
At same track, I noticed a significant difference in oil flow if I'm at 8 tenths vs 9 tenths on corners, or if I push near redline more.
I logged one 25 minute session on Geez but haven't gone through it yet. I was on race tires every time and am certain cornering will be well over 1g. |
Damon, et al.,
It's all about lateral G's and the direction of the corner. You guys are correct it's the sustained high G right handers under engine load that do it. All the oil is on the left side of the pan right at the base of the oil filler neck with the oil pan pressure building from engine load. Run that same corner inthe otehr direction (making it a left hander) and you will not have any issues. Crispy |
Originally Posted by CrispyRX7
Run that same corner inthe otehr direction (making it a left hander) and you will not have any issues.
Crispy |
I forgot if the turbine oil seals are the usual piston ring type seals, or carbon face seals. Under sustained high G lefts, the oil will tend to back up in the return pipes. With high enough G's it could get to the seals, and burn through the exhaust path. But I think this would make a mess of the seals and create a smoker.
I still think/hope going counter-clockwise had some nasty rights to cause the oil flow. |
Originally Posted by KevinK2
I still think/hope going counter-clockwise had some nasty rights to cause the oil flow.
http://www.motorsportranch.com/images/misc/TrackMap.jpg |
Originally Posted by DamonB
What perplexes me is my results were just the opposite of your statement. On the track with mostly left handers I was losing a quart of oil. The same track but run in the opposite direction is now mostly right handers and I lost nothing. That doesn't add up unless the slight RPM difference KevinK2 mentioned accounts for it.
Crispy |
Originally Posted by DamonB
The track I'm speaking of is marked "existing track". The pic doesn't show the elevation changes but there are many. In many places it drives completely differently then you would guess from just looking at the map.
http://www.motorsportranch.com/images/misc/TrackMap.jpg |
FWIW, in a stock FD with only race tires on 16x9 wheels, Koni "yellow" sport shocks, and a Tri-Point front swaybar, I will get oil into the intake system and thus a white smokescreen in the following turns at Roebling Road, going clockwise, and they are NOT all right-hand sweepers:
T1 T2 T3 T9 :-) neil Summit $29 catch-can coming soon. http://www.silcom.com/~neilv/rx7/RRTrack.jpg |
Neil,
Roebling looks like a catch can filler for sure :) Lots of big sweeping right handers.
Originally Posted by M104-AMG
FWIW, in a stock FD with only race tires on 16x9 wheels, Koni "yellow" sport shocks, and a Tri-Point front swaybar, I will get oil into the intake system and thus a white smokescreen in the following turns at Roebling Road, going clockwise, and they are NOT all right-hand sweepers:
T1 T2 T3 T9 :-) neil Summit $29 catch-can coming soon. http://www.silcom.com/~neilv/rx7/RRTrack.jpg |
Originally Posted by Fritz Flynn
Neil,
Roebling looks like a catch can filler for sure :) Lots of big sweeping right handers. Yep, I only wish I had a catch-can installed, and the PVC plugged! :-) neil |
1 Attachment(s)
So I found a Summit quart catch-can that has two inlets up-high, a filtered breather on the top, and a drain-valve below.
Please tell me if I'm hooking up this correctly. I read about 15 different threads, and am completely confused. 1) remove PCV valve, and plug PCV inlet at UIM; 2) run a new line from the old PCV source (top nipple of oil-filler tube) to inlet of catch can; 3) disconnect 2nd line from oil-filler tube and extend it to 2nd inlet of catch can; 4) plug the now open nipple on the oil-filler tube. Attached is the proposed setup. BTW: Can the catch-can be mounted below the intake elbow (near the dipstick) as long as the lines run UP first and then down into the catch-can ? Is there any harm in having the PCV valve in between the oil-filer line and the catch-can inlet ? |
Originally Posted by RX-Heven
Here you can see it all installed. There is also a -8an line coming out the top of the oil filler cap that goes to the oil catch can that I had previously installed.
https://www.rx7club.com/attachment.p...d=141916&stc=1 https://www.rx7club.com/attachment.p...d=141917&stc=1 I thought of teeing into the turbo oil return line as some others have suggested but decided against it. The reurn line is obviously used for returning oil so in turn the line will contain oil...duh. These lines are not under any pressure, or should not be in any case, otherwise you will be pushing oil past the seals in the turbo. Because the line is not supposed to be under pressure, it might work but I wanted something I can be sure of. The return line sees the same pressure as the inside of the oil pan. I figured the necessary venting would just push some of the oil that is always present in the return line into the oil catch can since it's role would become dual purpose if t'eed into. T'eeing into the drain line may also hinder the lines abilty to properly drain oil from the turbo as the vented air is pushing in the opposite direction the oil needs to be draining in. In the end, it would probably help, i cannot see how it wouldn't. However, I want to eliminate the problem of pushing oil into the catch can, not just reduce it. I will report on the results in late January after Laguna Seca Well, What happened? Based on what I read, this is only a big problem for road racers. If you just a street car that goes down the 1320 once in a while, you can just vent the lines to atmosphere or to catch can if you want correct? NZConvertible....... One line's on the center plate at the base of the filler neck and the other's actually on the filler neck at the cap end. Both essentially go to the same place, so you should either run both under the car or run both to a can. Don't cap one http://img368.imageshack.us/img368/1381/catchcan0fl.jpg |
Originally Posted by luiml73
Well, What happened?
Based on some very spirited 10-20 minute canyon runs the results look very promising. Not a drop of oil in the catch can whereas before the can would be ~1/2 full of oil on the same runs. Now the only fluid in the catch can seemed to be pure gasoline based on the smell, feel and look of it. I'd have about an 1/8" of this by the end of the day in the can. I'll update after my track day...providing the money-pit/never-ending-project is ready this time.
Originally Posted by luiml73
Based on what I read, this is only a big problem for road racers. If you just a street car that goes down the 1320 once in a while, you can just vent the lines to atmosphere or to catch can if you want correct?
Originally Posted by luiml73
I assume he means this hole on the center plate
I'd use both vents as only using one of these may not vent enough and you could end up blowing smoke out the exhaust. |
The trick to make the block vent gasses without a lot of oil in the line is to use huge lines from the block to the catch can. The minimum line is normaly a #10 but that's just for a regular setup. You guy's should be using at least a #12 or what I do is weld two #10 fittings on the oil filler neck and plumb two #10's to the catch can.
When you use small hoses from the block it creates vacum and pull the oil up into the catch can. I know people that are using two #12's and in one instance a #16 line. Also that Moroso catch can was designed mainly for dragracing so you might need to design one a little bigger. I made one that was a 4inch tube about 2 foot long that I attached the Moroso can to also, so basicaly the big can acted lke a hurge sump and the little one did the venting. |
Originally Posted by Asleep
Carl,
What are your findings with the "T" in the drain? A couple of us GT40r users have had issues with excessive blow-by...threads in other places and other forums. Been thinking about adding a vent to the rear iron and the T into the drain line. So far running a AN10 vent on the oil filler neck has cut my blow-by down. Also, adding a supply side oil restrictor has contributed to the decrease. I see 100psi above 3000rpm to redline. Tried different weights in oil. Car likes the thinner stuff. But it seems to run happier with the heavy oils on the hotter days. My capacity is 7qts. I run a single 34 row Earl's oil cooler with AN10 lines, bypass, and remote FRAM HP2 filter (that holds near a quart by itself.) Still have the blow-by...just alot less now...maybe 1/10th what it used to be. Used to be a couple of 20psi 2500-redline pulls would fill it. Now I can run do a gas tank full of those runs and have to empty the can. Tony The orginial vent hose is 1/2" tapped into the oil filler cap and AN-10 hose into the can. I am still pushing more oil out then I would have thought. Still not happy. I switched turbo manifolds and went from a low mount to a higher and hence the oil drain off the turbo is longer. I am thinking of going to AN-12 drain hose and no 45 degree connection. Weather is cold and I picked up performance in spool up time in the GT40r, but seem to have taken a small step back in term of oil vented. Tony |
Well I finally got around to getting the car on track over the weekend. The results were exactly as I had hoped. Not a drop of oil was in the catch can. Problem ELIMINATED :D
I quoted all my relevant previous posts with pics for easy reference to anyone interested in the what/why/how details.
Originally Posted by RX-Heven
This week I will be drilling and tapping a 1/2 npt hole with -10 line into the front cover to vent the right-front side of the engine. The exact location on the S5 front cover is represented by the green dot in the pic. The green arrow shows the path of our turbo oil return path and location (for TII's). I have the mop removed and run pre-mix but I'm sure this could still be done with the mop crap in place. I am not sure about 3rd gen front covers but something similiar could be figured out for those slowpokes if needed.
For us 2nd gen guys, this means removing the oil pan which in turn means supporting the engine with a hoist since the passenger side engine mount has to come off for this. A little involved but easily accomplished in less than a day while drinking beer. I am positive this will work. There will be absolutely NO oil in that location to be pushed out. For starters it is located in the front and during acceleration and under boost is when we encounter the problem, particularly during right hand corners. All the oil will want to go towards the back of the engine under acceleration leaving the front cover location unobstructed. Additionally, it is on the right side to alleviate the right hand corner problem with blocking all of the pre-existing vent paths with oil such as the oil filler tube and/or center iron. I also have a 3/8 npt swivel fitting with a -8an line coming out of the top of my oil filler cap for the left hand turns that has been in place for a couple years. Originally it was -6 line but I would still blow out my dipstick. Switching to -8 line cured that but I still pushed out just under a quart of oil in 20 minutes on tracks such as Infineon and Laguna. There is also a baffle plate between the pan and engine. I have a quick drain fitting attached to the bottom of a 1 quart capacity catch can to make draing a cinch, but I want the oil in the engine where it belongs. I will do a short write up with pics after completion and will let you know how it works out when put to the test on the track. https://www.rx7club.com/forum/attach...hmentid=139411
Originally Posted by RX-Heven
Well I got around to installing the breather line in the front cover today. It came out pretty good...hopefully it works.
Here is where I drilled the hole for the 1/2" npt to -10 an fitting. This is obviously a 2nd gen front cover and I have the mop blocked off since I use pre-mix. I'm pretty sure it would work with the mop installe too. This location does not interfere with the turbo drain line or anything else for that matter. https://www.rx7club.com/forum/attach...hmentid=141911 The casting of the front cover is just thick enough to get some threads into it from a tap for the npt/an adapter. https://www.rx7club.com/forum/attach...hmentid=141912 Here is my modified GReddy oil catch can. I enlarged the two side openongs towards the top for 1/2" npt and 3/8" npt to -an adapter fittings. On the top is a large K&N breather. On the bottom of the catch can is a quick drain fitting. https://www.rx7club.com/forum/attach...hmentid=141913 The hose attachment for the quick drain fitting is permanently located in the frame rail and protrudes out the bottom for quick and easy draining. Here you can see the top of the hose and its screw on fitting. Of course I unscrew the hose so the catch can is sealed when driving about and drain it between sessions. https://www.rx7club.com/forum/attach...hmentid=141914 Here you can see where the orange hose from the quick drain protrudes through the rail out the bottom of the car. https://www.rx7club.com/forum/attach...hmentid=141915
Originally Posted by RX-Heven
Here you can see it all installed. There is also a -8an line coming out the top of the oil filler cap that goes to the oil catch can that I had previously installed.
https://www.rx7club.com/attachment.p...d=141916&stc=1 https://www.rx7club.com/attachment.p...d=141917&stc=1 I thought of teeing into the turbo oil return line as some others have suggested but decided against it. The reurn line is obviously used for returning oil so in turn the line will contain oil...duh. These lines are not under any pressure, or should not be in any case, otherwise you will be pushing oil past the seals in the turbo. Because the line is not supposed to be under pressure, it might work but I wanted something I can be sure of. The return line sees the same pressure as the inside of the oil pan. I figured the necessary venting would just push some of the oil that is always present in the return line into the oil catch can since it's role would become dual purpose if t'eed into. T'eeing into the drain line may also hinder the lines abilty to properly drain oil from the turbo as the vented air is pushing in the opposite direction the oil needs to be draining in. In the end, it would probably help, i cannot see how it wouldn't. However, I want to eliminate the problem of pushing oil into the catch can, not just reduce it. I will report on the results in late January after Laguna Seca |
:bowdown:
Great news! |
So how well did it work? I need an improved breather in my PP race motor.
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Originally Posted by speedturn
So how well did it work? I need an improved breather in my PP race motor.
Neil
Originally Posted by RX-Heven
Well I finally got around to getting the car on track over the weekend. The results were exactly as I had hoped. Not a drop of oil was in the catch can. Problem ELIMINATED <SNIP> |
Sorry, I missed his words of success at the top of his post; I was going by his final words at the bottom of the post.
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