|
|
Oct 11, 2009 16:18:27 GMT
|
good evening all! for a university project of mine, i intend to design and build a dry sump system, start to finish. anyway, there's just some things that you don't learn in school, things that people who have had a bit of hands on experience will know. this is where you very learned people come into play. so then, anything of interest would be nice, links, places. i don't want you to do any work for me, but a few pointers would be nice i'm looking at fabbing it up myself, as i'm pretty nifty with a TIG, but any info on design, shape etc would be brilliant
|
|
|
|
|
|
|
Oct 11, 2009 16:50:13 GMT
|
It's just an oil system, like any other pressure oil system. Nothing magic or spooky.
The same laws of physics apply.
One half of the pump sector pulls the oil out of the pan (scavenges), the other half pressurizes the oil galleries of the motor.
The oil is drawn from the pan. Most builders make a low-spot trough somewhere in the pan, just like in a wetsump pan, for centralised collection of the oil. See a DFV or a racing YB drawing for a good example of pan design.
Do an in-line filter. Run hoses. Figure a drive belt. Gear for correct speed.
Boom. Done.
|
|
Team Blitz Ford Capri parts worldwide: Restoration, Road, or Race. Used, Repro, and NOS, ranging from scabby to perfect. Itching your Capri jones since 1979! Buy, sell, trade. www.teamblitz.com blitz@teamblitz.com
|
|
|
|
Oct 11, 2009 17:58:02 GMT
|
They're a pain in the on a road car, they take up to much room and add complication for almost no benefit.
|
|
Volvo back as my main squeeze, more boost and some interior goodies on the way.
|
|
The Doctor
Club Retro Rides Member
Posts: 3,434
Club RR Member Number: 48
|
|
Oct 11, 2009 18:44:38 GMT
|
i can't contribute anything technical to this topic, but i thought about this movie i saw a few weeks ago.
THAT is why you need drysump on track ;D
|
|
|
|
|
|
Oct 11, 2009 23:14:40 GMT
|
A dry sump is done for packaging more than anything else. The wild thrashing about can starve a dry sump system as well as a wet sump system. The dry sump, is, um, dry, after all. You are merely relocating the "wetness" to a reserve tank, it can starve for oil as well, if things go all puddy pie.
For many years there have been aids to wet-sumpers who wish to protect against dry pick-up syndrome. Pivoting pick-ups which slosh with the oil. Pre-pressurized accumulators. Etc. Laws of physics and requirements of the motor don't magically change with one versus the other.
Damn cool video though. ;D
|
|
Last Edit: Oct 11, 2009 23:15:24 GMT by Team Blitz
Team Blitz Ford Capri parts worldwide: Restoration, Road, or Race. Used, Repro, and NOS, ranging from scabby to perfect. Itching your Capri jones since 1979! Buy, sell, trade. www.teamblitz.com blitz@teamblitz.com
|
|
dugong
Posted a lot
One Of Us Will Live To Rue The Day We Met Each Other (Wire : 2008)
Posts: 3,292
|
|
Oct 11, 2009 23:56:14 GMT
|
A dry sump is done for packaging more than anything else. The wild thrashing about can starve a dry sump system as well as a wet sump system. The dry sump, is, um, dry, after all. You are merely relocating the "wetness" to a reserve tank, it can starve for oil as well, if things go all puddy pie. For many years there have been aids to wet-sumpers who wish to protect against dry pick-up syndrome. Pivoting pick-ups which slosh with the oil. Pre-pressurized accumulators. Etc. Laws of physics and requirements of the motor don't magically change with one versus the other. Damn cool video though. ;D Norm I've always been a bit intrigued by dry sump set ups. When you say 'for packaging', wtf gets in the way of a sump, it has to be at the bottom, yes? I can see why for oil starvation purposes, but I thought that's what baffled pans were for.
|
|
|
|
|
|
|
wtf gets in the way of a sump Stuff like the roadway, crossmembers, but mainly getting the CG of the vehicle lower, as the drivetrain gets lower. Which often means the whole sportscar can stand lower, and following on, have a lower roof, etc etc, as one thing spins off the other in design...
|
|
Team Blitz Ford Capri parts worldwide: Restoration, Road, or Race. Used, Repro, and NOS, ranging from scabby to perfect. Itching your Capri jones since 1979! Buy, sell, trade. www.teamblitz.com blitz@teamblitz.com
|
|
dugong
Posted a lot
One Of Us Will Live To Rue The Day We Met Each Other (Wire : 2008)
Posts: 3,292
|
|
|
wtf gets in the way of a sump Stuff like the roadway, crossmembers, but mainly getting the CG of the vehicle lower, as the drivetrain gets lower. Which often means the whole sportscar can stand lower, and following on, have a lower roof, etc etc, as one thing spins off the other in design... Fair play, that does follow.
|
|
|
|
|
|
|
|
They're a pain in the on a road car, they take up to much room and add complication for almost no benefit. Being able to fit a 6.9 into one of these is a pretty big benefit!
|
|
1982 Mercedes 280TE
|
|
|
|
|
|
I did say almost no benefit
|
|
Volvo back as my main squeeze, more boost and some interior goodies on the way.
|
|
|
|
|
it'll be for a race car though popup surely when using a dry system the tank can be designed much taller therefore reducing a dry pickup? and in the tank surely the pickup is at the bottom instead of the top? surely that makes a MASSIVE difference right? that video is awesome BTW
|
|
|
|
|
|
Oct 12, 2009 10:29:38 GMT
|
it'll be for a race car though popup surely when using a dry system the tank can be designed much taller therefore reducing a dry pickup? and in the tank surely the pickup is at the bottom instead of the top? surely that makes a MASSIVE difference right? that video is awesome BTW Better than a stock sump, but as Norm says there are ways to cure oil surge in a wet sump, and adding wings on the side of a wet sump will increase capacity as well, the main reason for dry sumps is to save space, i have heard that a dry sump releases some horsepower as the crank isn't rotating in an oil bath, but i dunno how much drag that saves, i guess its easier to change the oil in a hurry as well?
|
|
Volvo back as my main squeeze, more boost and some interior goodies on the way.
|
|
|
|
Oct 12, 2009 12:10:45 GMT
|
Highly mounted, vertical tanks with 3 or 4 large dia braided steel hoses filled with oil is not exactly paring down weight, 79. Nor does it help with lower the CG.
There is also about the same parasitic loss from driving a gear pump off the nose (where a LOT of wet sump oil pumps are driven anyway these days) for a dry sump as a wet sump.
Nobody wins races because they have a dry sump and the other guy has a wet sump, except for packaging reasons. Bottom line.
The comment on the cited website with the build tips is typical of the excessive enthusiasm for dry sumps as "magic", when he types that they prevent motors from going bang and running dry of oil. Huh? Know how many dry sumped motors have gone bang from oil starvation? Tonnes.
External line leaks, pump failures, oil level fubars, pressure sector overdriving scavenge sector, priming failures, detonated filter cases, etc etc.... lol, it's magic!
Norm, with 4 dry sump motors in his life and not in a dreamworld about their virtues.
|
|
Team Blitz Ford Capri parts worldwide: Restoration, Road, or Race. Used, Repro, and NOS, ranging from scabby to perfect. Itching your Capri jones since 1979! Buy, sell, trade. www.teamblitz.com blitz@teamblitz.com
|
|
|
|
Oct 12, 2009 14:34:03 GMT
|
so apart from packaging benefits, weight distribution, having no resistance on the crank, lowering the CoG (i'd imagine moving an engine 3-4" lower is a LOT more of a difference than having a tank higher up), stopping oil surge, theres not any benefits right? ;D
|
|
|
|
|
|
Oct 12, 2009 16:12:07 GMT
|
so apart from packaging benefits, weight distribution, having no resistance on the crank, lowering the CoG (i'd imagine moving an engine 3-4" lower is a LOT more of a difference than having a tank higher up), stopping oil surge, theres not any benefits right? ;D All important for a race car, on a road car though your adding extra cost for components (don't forget more oil capacity also means more expensive oil changes) more failiure points with the extra pipes and connections, less boot space if thats where the tank is mounted and usually less room in the engine bay with the extra pipes and an external oil pump hanging off the engine. I know you said its for a race car, but as with everything theres a balance to be had, if you add a £1000 dry sump system, how many seconds per lap will it get you compared to say an extra £1000 on tyres? or better shocks? or racing lessons? or more power? Its not one of the things i'd add unless i was at the point where the wetsump wasn't up to the job or where i had bought all the more obvious stuff or my sponsor was telling me to spend more money etc etc.
|
|
Volvo back as my main squeeze, more boost and some interior goodies on the way.
|
|
|
|
Oct 12, 2009 16:21:21 GMT
|
;D i do agree, but didn't really start a topic on the validity of the cost and the daily uses of one, merely the benefits (regardless of application) of using one, and any experience you knowledgeable people have on the subject, it's definatly an interesting enough subject for me to want to dig deeper, and there's definatly enough for me to cover about doing one from scratch, specific heat capacities of the engine, pump design and flow, pressures etc. and that's without actually knocking something up
|
|
|
|
|
|
Oct 12, 2009 16:54:24 GMT
|
so apart from packaging benefits, weight distribution, having no resistance on the crank, lowering the CoG (i'd imagine moving an engine 3-4" lower is a LOT more of a difference than having a tank higher up), stopping oil surge, theres not any benefits right? ;D Well, I'm the guy who first brought up those advantages in my post. Except for "no resistance on the crank". How do you figure that? Any dry sump system (except one powered by an external power source - like solar ;D) is going to be parasitic, running meshed gears like most wet-sump systems. In fact, they are largely remotely mounted wet-sump systems.
|
|
Team Blitz Ford Capri parts worldwide: Restoration, Road, or Race. Used, Repro, and NOS, ranging from scabby to perfect. Itching your Capri jones since 1979! Buy, sell, trade. www.teamblitz.com blitz@teamblitz.com
|
|
|
|
Oct 12, 2009 17:05:55 GMT
|
either way you're going to need a pump, wet or dry right, obviously pumping to the rear of the car (or in this case about 2 foot) is going to require more force, but lets say the difference is negligable for this argument.
oil is quite a viscous material, when the crank has to push it out the way this requires energy. with a dry sump there is less oil to push out of the way, which means less resistance, which means less force wasted......
|
|
|
|
|
|
Oct 12, 2009 17:41:33 GMT
|
Dang, wished I knew your name. 79, seems like impersonal. Cuz don't want to sound professorial or preachy...
But if you mean by "pushing it out of the way" what we call in the states "roping" of oil around a spinning crank, then that isn't something that a dry sump cures over a wet sump. Let me explain what I mean a bit.
You can do a scraper to wipe the rope off and drop it in the pan. The same oil, before excavated can re-rope onto the crank, whether wet or dry sump system. A wet sump system, properly designed for side-loads, will manage the slosh via one-way doors and baffling to channelize the oil for the return tube pick-up.
Roping of the oil is an effect more from the drain-back into the pan than a function of the oil pressure/excavation system (whether wet or dry). One way I manage oil roping in my systems is via an external drainback from the heads, whereever possible. But down low, in the lifter valley and obviously at the crank itself, you have to live with it. Wet or dry is irrelevant.
|
|
Team Blitz Ford Capri parts worldwide: Restoration, Road, or Race. Used, Repro, and NOS, ranging from scabby to perfect. Itching your Capri jones since 1979! Buy, sell, trade. www.teamblitz.com blitz@teamblitz.com
|
|
|