Breathing from timing cover...
Discussion
Since starting to turn the boost up, mine is pushing a bit of oil past the front crank seal and also 'sweating' from one or two other seals/gaskets. In due course, I will re-ring it as the bores do have some miles on but, in the meantime, I might have a go at rigging another breather off the hole where the dizzy used to be. It's been a while since I had the timing cover off so can anyone confirm how interconnected the timing chest area is to the rest of the crankcase volume? I remember boring a couple of oil drain holes from the valley into the timing area a rebuild or two ago but can't immediately recall other what other openings there might be...
Pete - YHM
Thanks for the responses; not so much concerned with how to tap in there (although the existence of an adaptor already made is helpful), but whether there is actually sufficient actual or potential gas movement through the timing chest to make it worthwhile. guess the fact enough pressure is building to push oil past the crank seal gives the answer...
Thanks for the responses; not so much concerned with how to tap in there (although the existence of an adaptor already made is helpful), but whether there is actually sufficient actual or potential gas movement through the timing chest to make it worthwhile. guess the fact enough pressure is building to push oil past the crank seal gives the answer...
Pupp said:
Pete - YHM
Thanks for the responses; not so much concerned with how to tap in there (although the existence of an adaptor already made is helpful), but whether there is actually sufficient actual or potential gas movement through the timing chest to make it worthwhile. guess the fact enough pressure is building to push oil past the crank seal gives the answer...
There is more than adequate volume in there to vent to the crankcase and up to the recent dizzy port Gary IMO Thanks for the responses; not so much concerned with how to tap in there (although the existence of an adaptor already made is helpful), but whether there is actually sufficient actual or potential gas movement through the timing chest to make it worthwhile. guess the fact enough pressure is building to push oil past the crank seal gives the answer...
Would be very difficult to get a fixed breather off the nearside rocker cover on mine due to the charge-cooler being right above that one (covers have been swapped over so filler is now at the rear of that side - I could tap the filler cap but that would make checking/filling oil even more of a pain as it is pretty obscured by dump valve and throttle cage; maybe there's some form of trick QD coupling I could use).
The other side breathes to a stainless separator via a 19mm elbow and line, and that is drawn into the turbo inlet. So far it is staying relatively clean (suspect the separator is boiling off evaporate as it sits above the offside manifold and does get toasty). I'm thinking a line off the timing cover teed into the separator feed should not exceed the depression in the turbo inlet nor overwhelm the separator.
Plan B could be a mechanical vac pump driven off the serp belt...
The other side breathes to a stainless separator via a 19mm elbow and line, and that is drawn into the turbo inlet. So far it is staying relatively clean (suspect the separator is boiling off evaporate as it sits above the offside manifold and does get toasty). I'm thinking a line off the timing cover teed into the separator feed should not exceed the depression in the turbo inlet nor overwhelm the separator.
Plan B could be a mechanical vac pump driven off the serp belt...
Pupp said:
Some light commercials run mechanical rotary pumps for brake vacuum; nothing like as expensive as a Moroso unit so maybe worth a try
Yep vacuum pumps for the brake servo (diesels dont have vacuum unless they have a throttle butterfly) they need a separate oil supply and a drain back to sump you can get diaphragm style but they are shorter lived than the vane type usually driven from the back of the alt 
but I can see that being an issue with lack of clearance on these cars 
KateV8 said:
Yes Daz it changes the octane content and can cause knocking. This is basically the downward spiral that killed Kate's engine eventually leading to the Powers rebuild. In our case though it was pushing past the rings rather than being ingested via the breather system.
I have the standard system with a tank fitted just before it goes back in to the plenum before and after the butterfly . I`m not sure if it does anything because the container is empty What is the answer ? I thought the system needs to recirculate back in to the engine, i think the pipe behind the butterfly lubicates the throttle disc.
Ah, the eternal crankcase presurisation problem, I've been planning out a resolution to this before I commit to forced induction and having had some experience of commercial vehicles has given me a steer.
For a proper valved crankcase breather/separator you can't beat a Pro Vent 200 from Mann & Hummel, I've seen one fitted to a tired old Volvo F10 tractor unit and it really helped clean up it's act.
A Pro Vent 200 is a properly engineered solution to managing crankcase vapors, it is infinitely superior to the ally breather/separator efforts you see bolted to modded cars, despite all the marketing bull these are often barely any more sophisticated than a basic catch tank.
https://www.mann-hummel.com/en/corp/products/crank...
Don't underestimate the importance of the valves shown in the above image, the Mann Pro Vent range are designed specifically to resolve/help breathing & blow by issues on super high compression turbo diesel engines.
You can see it working here, ignore the enviro waffle & pay close attention to the valve function element of the presentation:
https://www.youtube.com/watch?v=FrvciHy2wD8
The Pro Vent 200 uses a quality replaceable fiberglass element filter so not only will offer unparallelled protection of your valuable turbo but is a cinch to service, just replace the filter every 6,000 miles or so and clean out any residue in the oil trap.
Mechanical vac pumps work well by all accounts, but evidence suggests you shouldn't waste your time or money trying to use a diesel brake servo pump as the vanes simply aren't designed to cope with oil contamination so it just wont last (1,000 miles probably less).
The specific crankcase vac pumps sold in the States are often just a modified servo vac pump, the pump body is dissembled and carbon fiber vanes and Rulon wipers are added which are far more tolerant to caustic crankcase oil vapors.
The VP102 Sportsman Vacuum Pump from GZ Motorsports is well reviewed, from what I've read it should last 6,000 miles before a rebuild is required, GZ Motorsports offer this service at reasonable cost.
The pump itself will probably cost you around £300 by the time to brought it into the UK.
My plan for managing excessive crankcase pressures under forced induction is to add a Citroen Saxo elcro/hydraulic power steering pump, this would release room to mount the VP102 Sportsman Vacuum Pump siting it where the mechanical/hydraulic power steering pump currently sits.
This combined with the Pro Vent 200 should represent a very comprehensive solution.
A cheaper option would be just to start with the Properly Valved Pro Vent 200 and see if it resolves the problem, my guess is being properly valved it would go a long way to improving things and could well be a solution in itself.
A cheap alternative to a vac pump & the other proven way to create a source of vacuum is to plumb into your exhaust post turbo, you'll need to create a venturi in the exhaust gas flow to amplify the vacuum but very inexpensive kits are available from Moroso and many others that are proven to work.
These exhaust flow extractors don't really do anything at all at idle but the over pressuring of your crankcase is not going to be an issue at idle, by the time you get to 3,000 rpm you should find the exhaust flow extractor will be pulling 2-3 inches of vacuum which combined with a correctly plumbed Pro Vent 200 is probably all you need.
http://www.summitracing.com/int/parts/mor-25900/ov...
http://www.inlinefilters.co.uk/Filters-Air/Breathe...
Problem solved for £200
Good luck with it Gary
For a proper valved crankcase breather/separator you can't beat a Pro Vent 200 from Mann & Hummel, I've seen one fitted to a tired old Volvo F10 tractor unit and it really helped clean up it's act.
A Pro Vent 200 is a properly engineered solution to managing crankcase vapors, it is infinitely superior to the ally breather/separator efforts you see bolted to modded cars, despite all the marketing bull these are often barely any more sophisticated than a basic catch tank.
https://www.mann-hummel.com/en/corp/products/crank...
Don't underestimate the importance of the valves shown in the above image, the Mann Pro Vent range are designed specifically to resolve/help breathing & blow by issues on super high compression turbo diesel engines.
You can see it working here, ignore the enviro waffle & pay close attention to the valve function element of the presentation:
https://www.youtube.com/watch?v=FrvciHy2wD8
The Pro Vent 200 uses a quality replaceable fiberglass element filter so not only will offer unparallelled protection of your valuable turbo but is a cinch to service, just replace the filter every 6,000 miles or so and clean out any residue in the oil trap.
Mechanical vac pumps work well by all accounts, but evidence suggests you shouldn't waste your time or money trying to use a diesel brake servo pump as the vanes simply aren't designed to cope with oil contamination so it just wont last (1,000 miles probably less).
The specific crankcase vac pumps sold in the States are often just a modified servo vac pump, the pump body is dissembled and carbon fiber vanes and Rulon wipers are added which are far more tolerant to caustic crankcase oil vapors.
The VP102 Sportsman Vacuum Pump from GZ Motorsports is well reviewed, from what I've read it should last 6,000 miles before a rebuild is required, GZ Motorsports offer this service at reasonable cost.
The pump itself will probably cost you around £300 by the time to brought it into the UK.
My plan for managing excessive crankcase pressures under forced induction is to add a Citroen Saxo elcro/hydraulic power steering pump, this would release room to mount the VP102 Sportsman Vacuum Pump siting it where the mechanical/hydraulic power steering pump currently sits.
This combined with the Pro Vent 200 should represent a very comprehensive solution.
A cheaper option would be just to start with the Properly Valved Pro Vent 200 and see if it resolves the problem, my guess is being properly valved it would go a long way to improving things and could well be a solution in itself.
A cheap alternative to a vac pump & the other proven way to create a source of vacuum is to plumb into your exhaust post turbo, you'll need to create a venturi in the exhaust gas flow to amplify the vacuum but very inexpensive kits are available from Moroso and many others that are proven to work.
These exhaust flow extractors don't really do anything at all at idle but the over pressuring of your crankcase is not going to be an issue at idle, by the time you get to 3,000 rpm you should find the exhaust flow extractor will be pulling 2-3 inches of vacuum which combined with a correctly plumbed Pro Vent 200 is probably all you need.
http://www.summitracing.com/int/parts/mor-25900/ov...
http://www.inlinefilters.co.uk/Filters-Air/Breathe...
Problem solved for £200
Good luck with it Gary
Edited by ChimpOnGas on Thursday 23 April 09:52
Dave how do you think the vane type vacuum pump is lubricated then? 
why do you think they have a pressured oil supply from the motor its also why they have a drain back to the sump the vanes are a fibre material and impervious to oil a pan evacuation kit may be the way forward its what the big HP drag boys use in the states, my brother in law used one on a BB Chevy on NOS with good results
why do you think they have a pressured oil supply from the motor its also why they have a drain back to the sump the vanes are a fibre material and impervious to oil a pan evacuation kit may be the way forward its what the big HP drag boys use in the states, my brother in law used one on a BB Chevy on NOS with good results Edited by Sardonicus on Thursday 23 April 13:32
Sardonicus said:
Dave how do you think the vane type vacuum pump is lubricated then?
Teflon wipers, self lubricating, conventional brake vac pumps won't last long sucking & pushing out caustic crankcase vapors.Sardonicus said:
Why do you think they have a pressured oil supply from the motor its also why they have a drain back to the sump
Bearing lubrication & cooling, actually a lot of brake servo vac pumps have sealed bearings these days so no pressure feed lines needed.The point is the oil side & air side must remain completely separate, and the oil sensitive Teflon wipers reside in the air side of the vane pump.
If the oil pressure line ran directly into the air chamber where the Teflon wipers reside it would just fill up with oil in seconds, not much air being shifted there then
The Teflon wipers in such pumps are specifically designed to move air not oil, which is why crankcase vapors would kill the wipers in no time.
Quote from Greg Zucco, owner of GZ Motorsports, the biggest builder of crankcase evacuation pumps in the US:
Question from DragStuff.com: Why not use an OEM air pump?
Answer from Greg Zucco: "The only problem with an OEM pump direct from the factory is that the components inside were designed for oil-free air"
Sardonicus said:
a pan evacuation kit may be the way forward its what the big HP drag boys use in the states, my brother in law used one on a BB Chevy on NOS with good results
If 3" of vac is enough fine, but if you need more you'll need to get pumping.Have a read up on me...
http://www.dragzine.com/tech-stories/engine/tech-h...
http://www.dragstuff.com/techarticles/vacuum-pumps...
And here's the evidence showing how a vac pump can actually gain you HP & Torque not lose it.
http://www.hotrod.com/how-to/engine/ccrp-9903-moro...
Another way to create vacuum is to go electric, try a Delco 215-425 used by GM as a secondary air injection pump to save the dolphins, but again these pumps are designed to move air not nasty caustic oily crankcase vapors.
This little 12v unit will pull up 4" of mercury while drawing just 12amps, until it gets all gummed up
An engine driven vane type vac pump will suck a lot more though and the VP102 Sportsman Vacuum Pump from GZ Motorsports is designed to cope with crankcase vapors. Even with the carbon fiber vanes and Rulon wipers it will still only last about 6,000 miles which is why GZ Motorsports offer a rebuild service.
Of course the negative pressure side of a turbo sucks like a black hole, you just don't want it sucking it all that nasty crankcase vapor, enter the properly valve managed Mann Pro Vent 200 to separate out the muck.
Forget all the Pan E-Vac systems & pumps for a minute, the Pro Vent 200 is such an effective separator it might actually be all Gary needs to solve his problem?
Sucky Sucky, Five Dolla
Well, more accurately about £120 for a Pro Vent 200
Are you sure Dave? try to remember what occupation I have held for the last 30 years 
the chamber does not fill with oil its metered and bled the oil also improves the suck of the pump obviously often referred to as a wet pump, yes I know there are dry vane versions also anyway I dont think you should have to resort to this anyway lots of high performance engines dont need vacuum pumps to purge the crankcase I just think the stock RV8 system as limitations I for one am going over to a PCV valve system like the majority of the US V8's use 
the chamber does not fill with oil its metered and bled the oil also improves the suck of the pump obviously often referred to as a wet pump, yes I know there are dry vane versions also anyway I dont think you should have to resort to this anyway lots of high performance engines dont need vacuum pumps to purge the crankcase I just think the stock RV8 system as limitations I for one am going over to a PCV valve system like the majority of the US V8's use Edited by Sardonicus on Friday 24th April 00:08
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