Dry Sump Questions
Discussion
All,
Due to some unique packaging constraints on my vehicle I will have to take a slightly different approach with the Dry Sump system. I'd appreciate answers to my questions in order to determine if it will work for me:
1) I will need to mount the pump on the cylinder head - will mounting the pump at this level cause any problems?
2) I need to drive the pump from the existing 6 rib axillary belt (same as water pump) - will this be an issue?
3) The tank will be mounted in the boot - will this be an issue?
Thanks,
Mark
Due to some unique packaging constraints on my vehicle I will have to take a slightly different approach with the Dry Sump system. I'd appreciate answers to my questions in order to determine if it will work for me:
1) I will need to mount the pump on the cylinder head - will mounting the pump at this level cause any problems?
2) I need to drive the pump from the existing 6 rib axillary belt (same as water pump) - will this be an issue?
3) The tank will be mounted in the boot - will this be an issue?
Thanks,
Mark
It's really not going to scavange very well mounted that high, you will certainly need a "rootes" type scavange pump (to pull enough vaccum to scavange, a "gear" type is unlikely to work) I would not recommend it at all tbh. Is there no way to get it lower??
A FEAD belt will probably drive a small pressure and scavange pair, but you need to look at getting the correct gear ratio (usually approx half crank speed) and belt wrap / pully dia to avoid slip. You also may need to run the system at a higher than normal tension to avoid slip (especially when cold/wet etc0
As for the tank in the boot, no problems as long as you a large capacity tank (say 12l ish)and run nice big pipes fore and aft to avoid large pressure drops (espec on the oil feed line0
A FEAD belt will probably drive a small pressure and scavange pair, but you need to look at getting the correct gear ratio (usually approx half crank speed) and belt wrap / pully dia to avoid slip. You also may need to run the system at a higher than normal tension to avoid slip (especially when cold/wet etc0
As for the tank in the boot, no problems as long as you a large capacity tank (say 12l ish)and run nice big pipes fore and aft to avoid large pressure drops (espec on the oil feed line0
Edited by anonymous-user on Monday 20th June 20:24
Thank you. The pump I'm looking at is a Barnes 5 stage (used on Nascar engines) http://www.barnessystems.com/9017.htm I wanted something that will create a vacuum in the crankcase so that I may completely remove the PCV system.
The engine in question is a Ford Zetec, and problem I have is that I am adding A/C in to an already cramped engine bay. The belt configuration looks like this:
I have purchased an electric steering pump which leaves the PAS pump 'slot' free ('1' on diagram) and this prompted me to ask the questions you answered. Given what you have said I will look into space around the existing oil filter area (near number '4' on diagram), I will need to relocate that anyway when fitting the dry sump system.
The engine in question is a Ford Zetec, and problem I have is that I am adding A/C in to an already cramped engine bay. The belt configuration looks like this:
I have purchased an electric steering pump which leaves the PAS pump 'slot' free ('1' on diagram) and this prompted me to ask the questions you answered. Given what you have said I will look into space around the existing oil filter area (near number '4' on diagram), I will need to relocate that anyway when fitting the dry sump system.
Edited by mwstewart on Tuesday 21st June 13:35
Yea, ditch the integrated oil filter housing, put in a "remote" one after the pressure pump (assuming you are not using the std proessure pump and just using the "dry sump pump" for scavanging). that should easily free up enough room to put the pump stack down by the sump!
If you want to go for a completely sealed CC you need to consider a couple of things:
1) if your turbo uses std seals, these leak like heck, and unless you seperately scavange the turbo CHRA then it will ruin your low vaccum capability
2) you need to get the pump size and drive ratio correct, otherwise your scavange flow will not match your Blowby flow.
3) it's a good idea to install a "make up air" line, with a pressure regulator that prevents you CC from going too low. Much below 30kPa and you need special lip seals (as the std crank/cam lip seals getting pulled inside out)
4) with a boot mounted tank, you need a decent tank volume to ensure you always maintain a suitable feed to the pressure stage
In general, if you are not making the best use of a dry sump system by "lowering" the engine (which in a fwd case also requires a special bellhousing / transmission arrangment) it is generaly better (cheaper, lighter, just as capable) to simply use a well designed baffled wet sump. (the exception being for race cars that pull > 1g that really cause a lot of oil control issues)
Here's the "sump" on my car:
20mm deep (35 inc oil fittings) and allows the engine to sit 3mm off the subframe cross bars (in fact the 6.5" dia flywheel actually "Overhangs" the back of the subframe ;-)
At peak power rpm (7800) my engine runs just about -20kPa, which we found to be worth only 2.2kW on the dyno compared to running at atmospheric. Really not worth the effort on it's own tbh, and you would need to design a properly seperated "chambered" crankcase to make the best use of it. (obviously, that loss does not include "paddlewheel" slosh losses you might get when cornering etc, where the oil in the sump splashes up and hits the crank etc causing greater windage. But a well designed "scraper plate" would sort 99% of that type of issue.
If you want to go for a completely sealed CC you need to consider a couple of things:
1) if your turbo uses std seals, these leak like heck, and unless you seperately scavange the turbo CHRA then it will ruin your low vaccum capability
2) you need to get the pump size and drive ratio correct, otherwise your scavange flow will not match your Blowby flow.
3) it's a good idea to install a "make up air" line, with a pressure regulator that prevents you CC from going too low. Much below 30kPa and you need special lip seals (as the std crank/cam lip seals getting pulled inside out)
4) with a boot mounted tank, you need a decent tank volume to ensure you always maintain a suitable feed to the pressure stage
In general, if you are not making the best use of a dry sump system by "lowering" the engine (which in a fwd case also requires a special bellhousing / transmission arrangment) it is generaly better (cheaper, lighter, just as capable) to simply use a well designed baffled wet sump. (the exception being for race cars that pull > 1g that really cause a lot of oil control issues)
Here's the "sump" on my car:
20mm deep (35 inc oil fittings) and allows the engine to sit 3mm off the subframe cross bars (in fact the 6.5" dia flywheel actually "Overhangs" the back of the subframe ;-)
At peak power rpm (7800) my engine runs just about -20kPa, which we found to be worth only 2.2kW on the dyno compared to running at atmospheric. Really not worth the effort on it's own tbh, and you would need to design a properly seperated "chambered" crankcase to make the best use of it. (obviously, that loss does not include "paddlewheel" slosh losses you might get when cornering etc, where the oil in the sump splashes up and hits the crank etc causing greater windage. But a well designed "scraper plate" would sort 99% of that type of issue.
Edited by anonymous-user on Tuesday 21st June 14:31
Thank you, your responses are always appreciated.
>>1) if your turbo uses std seals, these leak like heck, and unless you seperately scavange the turbo CHRA then it will ruin your low vaccum capability
Thanks. I could use the 5th stage to scavenge from the Turbo
>>2) you need to get the pump size and drive ratio correct, otherwise your scavange flow will not match your Blowby flow.
If I can keep the pump close to the sump then I should be able to run the dry sump pump manufacturers pulleys. I will start looking in to it.
>>3) it's a good idea to install a "make up air" line, with a pressure regulator that prevents you CC from going too low. Much below 30kPa and you need special lip seals (as the std crank/cam lip seals getting pulled inside out)
Thank you. I see that Moroso sell a vaccumn regulator device:
>>4) with a boot mounted tank, you need a decent tank volume to ensure you always maintain a suitable feed to the pressure stage
Thanks
>>In general, if you are not making the best use of a dry sump system by "lowering" the engine (which in a fwd case also requires a special bellhousing / transmission arrangment) it is generaly better (cheaper, lighter, just as capable) to simply use a well designed baffled wet sump. (the exception being for race cars that pull > 1g that really cause a lot of oil control issues)
I'm running a production gearbox casing so unfortunately I cannot lower the powertrain any further. I don't actually need a dry sump; I'm fitting one because the Zetec Oil pump gears shatter at the sort of cylinder pressures my setup will be generating. This is believed to be caused by crank nose flex.
Nice sump!
>>1) if your turbo uses std seals, these leak like heck, and unless you seperately scavange the turbo CHRA then it will ruin your low vaccum capability
Thanks. I could use the 5th stage to scavenge from the Turbo
>>2) you need to get the pump size and drive ratio correct, otherwise your scavange flow will not match your Blowby flow.
If I can keep the pump close to the sump then I should be able to run the dry sump pump manufacturers pulleys. I will start looking in to it.
>>3) it's a good idea to install a "make up air" line, with a pressure regulator that prevents you CC from going too low. Much below 30kPa and you need special lip seals (as the std crank/cam lip seals getting pulled inside out)
Thank you. I see that Moroso sell a vaccumn regulator device:
>>4) with a boot mounted tank, you need a decent tank volume to ensure you always maintain a suitable feed to the pressure stage
Thanks
>>In general, if you are not making the best use of a dry sump system by "lowering" the engine (which in a fwd case also requires a special bellhousing / transmission arrangment) it is generaly better (cheaper, lighter, just as capable) to simply use a well designed baffled wet sump. (the exception being for race cars that pull > 1g that really cause a lot of oil control issues)
I'm running a production gearbox casing so unfortunately I cannot lower the powertrain any further. I don't actually need a dry sump; I'm fitting one because the Zetec Oil pump gears shatter at the sort of cylinder pressures my setup will be generating. This is believed to be caused by crank nose flex.
Nice sump!
WHy not save yourself a HUGE amount of hassle and do 1 of two things, either:
1) get some steel oil pump gears hobbed (won't be that expensive, or you could get some spark eroded using the orginals as parterns)
or
2) just fit a remote "pressure stage" driven by the FEAD, but keep the oil in the std sump as per usual
If there is enough TV (torsional vibration) at high BMEP to cause the oil pump gears to fail, then surely the crank itself isn't going to be too far behind???
1) get some steel oil pump gears hobbed (won't be that expensive, or you could get some spark eroded using the orginals as parterns)
or
2) just fit a remote "pressure stage" driven by the FEAD, but keep the oil in the std sump as per usual
If there is enough TV (torsional vibration) at high BMEP to cause the oil pump gears to fail, then surely the crank itself isn't going to be too far behind???
Max_Torque said:
WHy not save yourself a HUGE amount of hassle and do 1 of two things, either:
1) get some steel oil pump gears hobbed (won't be that expensive, or you could get some spark eroded using the orginals as parterns)
or
2) just fit a remote "pressure stage" driven by the FEAD, but keep the oil in the std sump as per usual
If there is enough TV (torsional vibration) at high BMEP to cause the oil pump gears to fail, then surely the crank itself isn't going to be too far behind???
There are after market pump gears available including billet steel gears, but even they have been broken. My first question after hearing this was "what do the mains look like?", but my builder has examined the mains in his 500+ builds and all are prefect, some even after a 10k mile examination. The exact root cause isn't known for the failures as there are so many variables that aren't well documented (removal of harmonic balancer, lightweight flywheel etc.), the thing known for sure is that running the standard pump beyond 400bhp/8k RPM is a risk that is mitigated by fitting a dry sump system. It's a small price to pay so I don't mind.1) get some steel oil pump gears hobbed (won't be that expensive, or you could get some spark eroded using the orginals as parterns)
or
2) just fit a remote "pressure stage" driven by the FEAD, but keep the oil in the std sump as per usual
If there is enough TV (torsional vibration) at high BMEP to cause the oil pump gears to fail, then surely the crank itself isn't going to be too far behind???
There hasn't yet been a crank let go, although I may look at a steel option if I decide to change the Turbo and go beyond 600bhp.
I have a Pace dry sump system on my pinto engined mk1 escort classic saloon race car. After a ten minute race the catch tank from the oil tank breather in the boot has just over 1 litre of oil in it. This is acceptable until I do a twenty minute race and 3 litres of oil has breathed its way out of the system leaving me short of oil. The catch tank is slightly higher than the main tank, 19mm pipe work to and from tank, 3 scavenge pump with return through 15 row oil cooler and second return through remote filter into engine running 45-50 psi.
I have tried various volumes of oil in the system to reduce the overflow without success, changed the tank and pipe work also. The engine has had a major rebuild and an annual re-fresh since 2008 wth no signs of internal damage.
Any help appreciated.
I have tried various volumes of oil in the system to reduce the overflow without success, changed the tank and pipe work also. The engine has had a major rebuild and an annual re-fresh since 2008 wth no signs of internal damage.
Any help appreciated.
Is the engine "sealed"?? i.e. do all the "blowby" gases have to exit via the drysump "scavange return" pipe, and into the boot mounted tank, and then out of a breather on top of the oil tank and into the catch tank??
if so, then i suspect that this long return run is really mixing the return oil and the blowby gases up into a fine oil mist, and your tank volume in the boot is simply insufficient to allow the oil to settle out of the mixture. (especially if your engine breaths hard etc)
If so, then a simple fix would be to use a "centrifugal oil seperator" to "spin" the heavier oil out of suspension, and return it to the oil tank. Various modern cars use these to reduce oil carry over:
(especially on 4x4's which lean all over the shop when off-road (and sometimes when on-road too......;-)
if so, then i suspect that this long return run is really mixing the return oil and the blowby gases up into a fine oil mist, and your tank volume in the boot is simply insufficient to allow the oil to settle out of the mixture. (especially if your engine breaths hard etc)
If so, then a simple fix would be to use a "centrifugal oil seperator" to "spin" the heavier oil out of suspension, and return it to the oil tank. Various modern cars use these to reduce oil carry over:
(especially on 4x4's which lean all over the shop when off-road (and sometimes when on-road too......;-)
Thanks for the reply. The engine has Ford crankcase breather and cam cover breather to 2 litre catch tank which doesn't fill up with oil.
Revving the engine and watching the oil return to the tank via the top of the tank filler; it splutters into the tank right enough but its hard to see how it manages to chuck out so much. I thought that the volume of oil retuning to the tank might be more than the volume being sucked out causing the tank to overflow through the breather.
Revving the engine and watching the oil return to the tank via the top of the tank filler; it splutters into the tank right enough but its hard to see how it manages to chuck out so much. I thought that the volume of oil retuning to the tank might be more than the volume being sucked out causing the tank to overflow through the breather.
You might find that as you engine is not "sealed" the scavange system is actually pulling a lot of air from the crankcase and pushing it backwards to the boot mounted tank, hence no oil in the front catch tank (as actually air is being sucked in!) and then this air entrains the oil being returned to the rear tank and hence the high carry over ??
I would get a vacuum gauge, connect it to the engine crankcase and try fitting either a restrictor, or better a PCV valve in the breather pipe at the front. you need to set the system up to just hold a small amount of vaccuum on the CC (say -10kPa etc)
I would get a vacuum gauge, connect it to the engine crankcase and try fitting either a restrictor, or better a PCV valve in the breather pipe at the front. you need to set the system up to just hold a small amount of vaccuum on the CC (say -10kPa etc)
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