there is a very simple fix,that i didnt think would work,but the dyno guy did it and its been great ever since.thats experiance for ya
Catch Can
Started by
_rorym_
, Oct 11 2008 02:53 PM
149 replies to this topic
#26
_moot_
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Posted 15 October 2008 - 08:25 AM
the problem isnt oil drains.its crank case pressure.it doesnt matter how many breathers you have,a big hp (and stroke) engine will still pump oil out of the breathers.
there is a very simple fix,that i didnt think would work,but the dyno guy did it and its been great ever since.thats experiance for ya
there is a very simple fix,that i didnt think would work,but the dyno guy did it and its been great ever since.thats experiance for ya
#27
_The Baron_
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Posted 15 October 2008 - 08:37 AM
I have adjustable 1.65 crane "rocking rollers", the thin cork gasket and all is well.
I measured first and found I needed a clearance of about 17-18mm, so I set the baffle height at a max of 15mm.
I also figured that I could dent the baffle slightly if I need more clearance.
I paid what I consider is a hefty price for the work ($250) but the result is worth it.
Take note of the weld bead you can se through the hole. I had this done so the fitting could never be pushed through the grommet to the point it would seal off the hole in the PVC or hose fitting.
I measured first and found I needed a clearance of about 17-18mm, so I set the baffle height at a max of 15mm.
I also figured that I could dent the baffle slightly if I need more clearance.
I paid what I consider is a hefty price for the work ($250) but the result is worth it.
Take note of the weld bead you can se through the hole. I had this done so the fitting could never be pushed through the grommet to the point it would seal off the hole in the PVC or hose fitting.
#28
TerrA LX
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Posted 15 October 2008 - 07:29 PM
the problem isnt oil drains.its crank case pressure.it doesnt matter how many breathers you have,a big hp (and stroke) engine will still pump oil out of the breathers.
there is a very simple fix,that i didnt think would work,but the dyno guy did it and its been great ever since.thats experiance for ya
gonna share?
#29
_rorym_
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Posted 15 October 2008 - 07:35 PM
Here and there Grant...thinner oil drains quicker...I will try it and see if the answer solves the problem...for every solution there is a problem...need to find the compromise.
R
R
#30
_82911_
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Posted 16 October 2008 - 07:02 AM
If you have an air gap manifold, or a valley tray similar to theMorrison manifold in my post on the previous page, you can plumb the breathers into the valley.You need an awfull lot of crankcase pressure to pressurize the valley area on a Holden engine.
#31
_moot_
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Posted 16 October 2008 - 11:16 AM
you can plumb a breather straight into the top of any manifold,but it wont solve the crankcase breathing problem
#32
_The Baron_
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Posted 16 October 2008 - 04:21 PM
You have our attention MOOT.
Care to share?----Dry sump?..........Slick 50 and no oil?.................Thin grease?........Never seize?
Care to share?----Dry sump?..........Slick 50 and no oil?.................Thin grease?........Never seize?
#33
_waz355_
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Posted 16 October 2008 - 06:30 PM
You have our attention MOOT.
Care to share?----Dry sump?..........Slick 50 and no oil?.................Thin grease?........Never seize?
6 litres of Jonsons baby oil.
#34
_moot_
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Posted 16 October 2008 - 08:12 PM
thats hard won info. rory will know what i'm talking about
rory will know what i'm talking about
#35
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Posted 16 October 2008 - 10:56 PM
I wont tell.
#36
_82911_
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Posted 17 October 2008 - 06:18 AM
I'm calling BULLSHIT on that one.
An engine is an air pump, both top and bottom, any blow by from the induction and compression process has to be vented to atmosphere provided the holes are large enough to relieve the pressure adequately. The only other proviso is that the vent is above a level that oil reaches, otherwise oil will be pumped too.
Putting a vacuum in the sump by either a sealed motor and a dry sump scavenge pump or one of the comercially avalable vacuum pumps doesnt stop blow by or crankcase pressure, all it does is pull air at a rate greater than that which is added by the leakage from the combustion process.
ALL engines leak to the crankcase....ALL OF THEM. In NASCAR which is arguably the most highly developed V8 class in the world, the % of blowby is in the order of 2-3%. Everyone else leaks more...
MOOT.. if you have found a way to gain perfect ring seal.... QUICK, patent it because you are going to be rich!
Otherwise I'd like to hear this "magical" theory....
ALL EARS MATE.....
An engine is an air pump, both top and bottom, any blow by from the induction and compression process has to be vented to atmosphere provided the holes are large enough to relieve the pressure adequately. The only other proviso is that the vent is above a level that oil reaches, otherwise oil will be pumped too.
Putting a vacuum in the sump by either a sealed motor and a dry sump scavenge pump or one of the comercially avalable vacuum pumps doesnt stop blow by or crankcase pressure, all it does is pull air at a rate greater than that which is added by the leakage from the combustion process.
ALL engines leak to the crankcase....ALL OF THEM. In NASCAR which is arguably the most highly developed V8 class in the world, the % of blowby is in the order of 2-3%. Everyone else leaks more...
MOOT.. if you have found a way to gain perfect ring seal.... QUICK, patent it because you are going to be rich!
Otherwise I'd like to hear this "magical" theory....
ALL EARS MATE.....
#37
_moot_
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Posted 17 October 2008 - 07:52 AM
of course all rings leak comp into the crank case,a school kid will tell you that.and venting is needed BUT if you just stick breathers everywhere it will stink and possibly blow oil out of them.fine for a race car but not a street car
our problem was mulitplied by ultra thin rings and gas ported cp's,with some decent comp.
infact the car in question got used to get to half track at wsid and have smoke bellowing out of it,it was towed back twice cause of how much oil was in the engine bay,and that was with a catch can.
now,the car doesnt have a catch can at all,doesnt have any problems with smoke or fumes.
and it doesnt have any of the commonly tried things like,oil returns in the back of the heads,pipe cleaners in every second pushrod,tricky lifters etc
our problem was mulitplied by ultra thin rings and gas ported cp's,with some decent comp.
infact the car in question got used to get to half track at wsid and have smoke bellowing out of it,it was towed back twice cause of how much oil was in the engine bay,and that was with a catch can.
now,the car doesnt have a catch can at all,doesnt have any problems with smoke or fumes.
and it doesnt have any of the commonly tried things like,oil returns in the back of the heads,pipe cleaners in every second pushrod,tricky lifters etc
#38
_82911_
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Posted 17 October 2008 - 08:58 AM
5 Litre Holden with a blocked off lifter return? Built By Ned? Think I know the engine you speak of.
If that is the one, I would be interested to know how you resolved the problem.As it was "quite a breather"
PM if you like.
If that is the one, I would be interested to know how you resolved the problem.As it was "quite a breather"
PM if you like.
#39
_moot_
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Posted 17 October 2008 - 10:35 AM
this one wasnt built by ned but dynoed by him,and the advice from the oil problems come straight from him.
top guy,and he really knows what he's doing.
top guy,and he really knows what he's doing.
#40
_rorym_
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Posted 29 October 2008 - 04:35 PM
OK..after lots of soul searching...I decided I am using the new release Fuchs Titan XTM 15W40 performance oil. The engine was originally run in on Fuchs so am more than happy to return to it.
Point..Local distributor is the Holden dealer...Having seen the car in the paper...the boys got all excited and decided I get the oil at wholesale...$27.50 for 5L..Thats cheaper than Magnatec on special...also..oil filters..genuine AC Delco are $5.20....Bonus day for me!!
R
Point..Local distributor is the Holden dealer...Having seen the car in the paper...the boys got all excited and decided I get the oil at wholesale...$27.50 for 5L..Thats cheaper than Magnatec on special...also..oil filters..genuine AC Delco are $5.20....Bonus day for me!!
R
#41
Litre8
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Posted 29 October 2008 - 06:07 PM
It just doesn't get any better.....unless they donated it!
#42
turbotrana
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Posted 30 October 2008 - 10:50 PM
Moot, if your not going to tell the forum what it is, you might be better off not posting anything at all.
I've built a few catch cans(a can with a hose in it is a waste of time). Basically three chambers with the middle chamber filled with stainless scrubbing pads. I also have a drain in the bottom with a line running to the sump so it requires no maintenance. These are on 6cylinders. I have also put extra baffles in the rocker cover.
The more you make the crankcase air turn the more oil you can pull out of it.
If the rockers are filling with oil then you gotta improve drain back within engine and/or reduce oil to the top as no catch can will do the job
I've built a few catch cans(a can with a hose in it is a waste of time). Basically three chambers with the middle chamber filled with stainless scrubbing pads. I also have a drain in the bottom with a line running to the sump so it requires no maintenance. These are on 6cylinders. I have also put extra baffles in the rocker cover.
The more you make the crankcase air turn the more oil you can pull out of it.
If the rockers are filling with oil then you gotta improve drain back within engine and/or reduce oil to the top as no catch can will do the job
#43
Evan
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Posted 31 October 2008 - 07:52 AM
My mate used to have a pipe from the front of each rocker cover to the sump. This was on his 253 speedway car. Seems pretty simple and worked.
has anyone here done this ?
Evan.
has anyone here done this ?
Evan.
#44
_moot_
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Posted 31 October 2008 - 07:52 AM
why should i post the engine builders ideas? customers pay good money for his input,and if he doesnt want it passed on,i'll respect his wishes.
as for not posting anything,well i'm sure that the people i've helped through pm's would still be in trouble.
as for not posting anything,well i'm sure that the people i've helped through pm's would still be in trouble.
#45
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Posted 31 October 2008 - 09:15 AM
turbotrana: I heard that draining back to the sump can contaminate the oil, do you think this could be an issue at all? What capacity should the catch tank be?
#46
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Posted 31 October 2008 - 09:41 AM
Only contamination issue I could see would be from condensation?
#47
_rorym_
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Posted 31 October 2008 - 10:05 AM
Looking at the oil...with condensation....that came out of my catch can there is no way in hell I would connect it back straight to the sump.
R
R
#48
micklx
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Posted 31 October 2008 - 10:31 PM
I agree with the above post - after seeing what comes out of my catch tank, there's no way I would direct it back to the sump.
#49
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Posted 03 November 2008 - 01:26 AM
Depends on how you have designed the catch can. A properly designed (hi rpm blowby)catchcan is really only operational under heavy throttle positions. At all other times the PCV valve should be sucking any blowby back thru the intake and air should be sucked into the engine from the catchcan. So no it should not cause any problems.
An incorrectly designed one not using PCV, there could be an issue with gunk.
You can also have a catchcan on the PCV side that operates under normal driving. Can be an issue if draining that back into engine as it has alot of water condensate on this side.
I think alot of guys dont really know what is happening in this department and putting (hi rpm blowby) catchcans in the wrong places
Re capacity: if draining back you dont need much capacity, just need to make sure that the catchcan design can blow the required amount of air so that it does not pressurise the insides of the engine
An incorrectly designed one not using PCV, there could be an issue with gunk.
You can also have a catchcan on the PCV side that operates under normal driving. Can be an issue if draining that back into engine as it has alot of water condensate on this side.
I think alot of guys dont really know what is happening in this department and putting (hi rpm blowby) catchcans in the wrong places
Re capacity: if draining back you dont need much capacity, just need to make sure that the catchcan design can blow the required amount of air so that it does not pressurise the insides of the engine
Edited by turbotrana, 03 November 2008 - 01:28 AM.
#50
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Posted 04 November 2008 - 10:01 AM
turbotrana: Do you think it would be possible to get some sort of diagram of your setup as it might make it easier to understand the way you have done it.
I need to make something up soon for my turbo 202, I would like to keep it sealed if possible to keep things legal. Is yours fully sealed?
Thanks
I need to make something up soon for my turbo 202, I would like to keep it sealed if possible to keep things legal. Is yours fully sealed?
Thanks
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