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Currently setting up a dry sump system on a track car. Assuming the engine is sealed therefore producing vacuum from the dry sump pump. I have read that a boosted car can blow by to the crank case up to 6%. My engine would only be mildly boosted. Do I require a one way valve in the block or cam cover to exhaust the blow by/pressure if it happens? If I do would I run a vertical tube from the crack case and vent from there, my thinking is it would let the oil from the head drain in the event of pressurised crank case.
It won't hurt to run a near zero cracking pressure check valve if you're going to try to do a sealed system. The only way for you to find out on your particular setup is to build it and put sensors in to find out the hard way.
Making the source for the check valve somewhere off of the bottom end is a good idea as this will still allow full and proper drainage from the head like you mentioned. BUT in the case of a dry sump, you will still be moving lots of volume via the scavenge pumps. So even if you do start to get some excess pressure or blow by, it will be nowhere near what 400WHP engines are venting out of just the valve cover alone, and will likely do just fine with say a -10an breather going from the valve cover, to the check valve, then dumping into the top of the dry sump tank. But if you figure out with your pressure sensors that the crankcase always operates in vacuum then it's just dead weight.
I don't think you'll find anyone here that has actually run a sealed setup like that. Most road course implementations still have breather lines coming off the valve cover to the dry sump tank, and then of course the main tank vents to a smaller catch can with steel wool in it then that catch can usually vents outside the vehicle. Mounted in a fashion that doesn't allow the oil to drain out of the venting system in case of a rollover.
It won't hurt to run a near zero cracking pressure check valve if you're going to try to do a sealed system. The only way for you to find out on your particular setup is to build it and put sensors in to find out the hard way.
Making the source for the check valve somewhere off of the bottom end is a good idea as this will still allow full and proper drainage from the head like you mentioned. BUT in the case of a dry sump, you will still be moving lots of volume via the scavenge pumps. So even if you do start to get some excess pressure or blow by, it will be nowhere near what 400WHP engines are venting out of just the valve cover alone, and will likely do just fine with say a -10an breather going from the valve cover, to the check valve, then dumping into the top of the dry sump tank. But if you figure out with your pressure sensors that the crankcase always operates in vacuum then it's just dead weight.
I don't think you'll find anyone here that has actually run a sealed setup like that. Most road course implementations still have breather lines coming off the valve cover to the dry sump tank, and then of course the main tank vents to a smaller catch can with steel wool in it then that catch can usually vents outside the vehicle. Mounted in a fashion that doesn't allow the oil to drain out of the venting system in case of a rollover.
Thank you for your response. after talking it over with an engine building group on Facebook. I,ll build the sump with the option to run a check valve along with a provision for a pressure sensor. You’re right I need to run sensor to know what’s going on in there.
thanks again
The reason for the dry sump is I’ve taken 25mm out of the this sump and raised the pick up, I have raced for the year with no problems but figure a dry sump would be the best option for long engine protection. Currently buying parts for the forged boosted engine.
Photo of the track baby😀
why are your scavenge hoses going around in circles?
when I've built & worked on a ds setup the pipes are usually direct & as short as possible
I'll be following with intrest as ds is something I'm considering for my 1.7 itb'd hillclimb car build
Rich.
Hi Rich, I found that if the hose was very short (~50mm) there is no room for error so if i made them 3-5mm too short or long they just wouldn't line up to do up fittings. Further to this I mounted the pump on the alternator bolt so the belt tension is adjusted similar (swinging through an arc) to the alternator. Not bolted solid to the (bracketed off the) block, so there is movement when the adjustment is made (hoses must flex). Simply, I believe it is not good practice to make very short hose runs, they need to flex. Hope that make some sense.
Hi Rich, I found that if the hose was very short (~50mm) there is no room for error so if i made them 3-5mm too short or long they just wouldn't line up to do up fittings. Further to this I mounted the pump on the alternator bolt so the belt tension is adjusted similar (swinging through an arc) to the alternator. Not bolted solid to the (bracketed off the) block, so there is movement when the adjustment is made (hoses must flex). Simply, I believe it is not good practice to make very short hose runs, they need to flex. Hope that make some sense.
many ways to skin a cat I suppose
I'd noticed you'd used of the alternator mount, not something I could do due to the steering gear on my rhd Eunos.
interesting to see though as ds is uncommon on mazda's
I've a similar pump (made by Titan) on a Vauxhall 2L 'XE' rallycar engine, its solid mounted with push-fit / jubilee-clip fitted scavange pipes so not as posh as yours!
was thinking of fitting this engine in my Eunos but it would have shifted me out of roadgoing classes (hillclimb) so decided against
it worked? not realy much else to say
the engine it's fitted to hasn't run for a few years so I've no recent feedback apart from the above, they seem reliable and are quite common on competiion engines so something must be right
tho other 'common' 3 stage pump is a Pace offering although Pace have a lot of diferent pumps available
I'm actually watching a secondhand Titan pump on ebay but it'll probably go past my budget, if its cheap enough then I'll be dry-sumping my 1.6(ish) B6
Tracked it for the 1st time with the dry sump. 15 minutes qualifying, 2x 15min races and 1x 20 min race. Was a worry, waiting for oil leaks or something to put me out for the day. But all good, it went well. I had to adjust the oil pressure down a bit, was running a bit high. I have to look at the log but I think its now running at around 50-70 PSI. Takes a bit of time to heat the oil now, but that's part of running an external oil tank.
Sounds like a lot of old pressure when hot. I would personally back it down to about 50 lb hot at a maximum and enjoy the free horsepower and not making additional heat.
apart from possible pressure adjustment, is there anything else you'd do or change?
I've just bought a Pace CD2000 3-stage pump and am looking into fitting on the 1.6 B6 engine
been looking into plumbing & thinking of feeding in through the front of the cylinderblock, this has the added advantage of using the standard oilfilter mount so less pipework foor a neater install (hopefully!)
pressure pipe will run between pulleys / inside the alternator belt from the exhaust-side mounted external pump,
3/8"nipple for test purposes, will be using 1/2" & 5/8" hoses & fittings.
I'm looking into bracket designs and think it'll be solid mounted with spacers (between block & mount) to adjust belt tension, well what go's for tension as they run with hardly any!
I'm going for a twin-trough steel sump pan and will be using a Mazda 323 item then chopping & welding.
the headache is where to put the oil tank, probably where the mx5's heater blower motor lives
and I've been diggin in the garage, found a few Vauxhall 20XE (2.0L 16v) including the drysumped engine with the previously mentioned Titan pump.
I'm getting pressured by friends to bin the mazda engine & fit this as it's an already built & proven unit with reliable power (200+hp) but I like the 1600 class
Sounds like a lot of old pressure when hot. I would personally back it down to about 50 lb hot at a maximum and enjoy the free horsepower and not making additional heat.
Cheers sixshooter for your input, I'll take that on board. I'm going to log the oil pressure at next weekends race. I'll know a bit more then.
Zed, as for the oil in, for me it's here. The other hole is old feed from the now deleted OEM oil pump. You can see this blocked in the modified oil pump - photos above.
11-06-2019, 07:18 PM
DRY SUMP VACUUM AND BOOST BLOW BY
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