Cosworth Sump Baffles
26 February 2008, 05:14 PM
#61
jd,
No we haven't spoken to them yet.
Re: 'the narrow sump' - I don’t believe so. A capacity increase would possibly cure the issue. However in doing so (designing & fabricating a new sump) there would be less need for the baffle plate. It would be interesting to see if purposely overfilling with oil changes the results we have measured.
Duncan's already had 4 oil changes and his car has travelled less than 40 feet. Brings new meaning to the phrase "one careful owner"
Must remember to stamp his service book 
No we haven't spoken to them yet.
Re: 'the narrow sump' - I don’t believe so. A capacity increase would possibly cure the issue. However in doing so (designing & fabricating a new sump) there would be less need for the baffle plate. It would be interesting to see if purposely overfilling with oil changes the results we have measured.
Duncan's already had 4 oil changes and his car has travelled less than 40 feet. Brings new meaning to the phrase "one careful owner"
Must remember to stamp his service book 
26 February 2008, 05:42 PM
#63
okay
Just come off the phone to Eric at Cosworth USA. He was extremely helpful and keen to get this resolved. Thanks Eric
They havent experienced the issues themselves but have only tested on a widebody sump so would be holding an awful lot more oil than the std sump. They do have some customers/dealers over there that may have used on the twin scroll sump (ie the narrow one) that should be able to share their pressure test results.
He fully accepts that the results that we have experienced are purely down to the baffle plates and not install issues. He is therefore looking to do some flow/drain down tests within the research facility to see if they can replicate & cure the issue and will report back to me.
I will post these up when I get them.
In the meantime, it is being re-used as a nice tea tray
Just come off the phone to Eric at Cosworth USA. He was extremely helpful and keen to get this resolved. Thanks Eric
They havent experienced the issues themselves but have only tested on a widebody sump so would be holding an awful lot more oil than the std sump. They do have some customers/dealers over there that may have used on the twin scroll sump (ie the narrow one) that should be able to share their pressure test results.
He fully accepts that the results that we have experienced are purely down to the baffle plates and not install issues. He is therefore looking to do some flow/drain down tests within the research facility to see if they can replicate & cure the issue and will report back to me.
I will post these up when I get them.
In the meantime, it is being re-used as a nice tea tray
Last edited by dynamix; 26 February 2008 at 06:04 PM.
26 February 2008, 06:03 PM
#67
I think that issue is being masked in the ones they have done in the states as they have been on 8litre sumps where it doesnt matter if 2 or 3 litres of oil is delayed in coming back down as there is still plenty there.
It does raise the question as to how it is curing blowby issues though if the oil is still trapped above the sump and free to slosh around.
26 February 2008, 08:28 PM
#68
Well done on following through with another test, it's well worthwhile even though it's a pain in the *** time and money wise. I'm surprised they have only tested on an 8 litre sump?
Dont forget the oil pickup is efectively sitting higher up in the sump by the thickness of the baffle plate also, how thick is it? You can work out the extra oil capacity needed to make up that change in height. (wont be much in the big scheme of things)
This baffle plate wont solve blowby issues at all, what it should do is stop oil surge issues out of the main rear block breather under hard acceleration because it will stop the major volume of the oil getting to that breather point in a wave type form. Imagine having a pan of water that you move rapidly, you get a large mass of water surging to the rear of the pan and flowing over the edge, now stick a dish with water in it on top and repeat, the volume on the top wont cause as much of a wave, so you get less surging to the back and the plate stops the main volume in the pan getting out.
The design of this baffle plate goes against what you normally try to achieve with a baffled sump, where you have a direct feed from the oil being returned from the heads and crank into a surge tube placed around the oil pickup, you then have baffling around this surge tube both to the sides and top letting oil acumulate into the main sump area around the surge tube, yet unable to exit under cornering/accel G. Having a flat plate with flaps in it above the oil pickup is counter intuative to me.
Dont forget the oil pickup is efectively sitting higher up in the sump by the thickness of the baffle plate also, how thick is it? You can work out the extra oil capacity needed to make up that change in height. (wont be much in the big scheme of things)
This baffle plate wont solve blowby issues at all, what it should do is stop oil surge issues out of the main rear block breather under hard acceleration because it will stop the major volume of the oil getting to that breather point in a wave type form. Imagine having a pan of water that you move rapidly, you get a large mass of water surging to the rear of the pan and flowing over the edge, now stick a dish with water in it on top and repeat, the volume on the top wont cause as much of a wave, so you get less surging to the back and the plate stops the main volume in the pan getting out.
The design of this baffle plate goes against what you normally try to achieve with a baffled sump, where you have a direct feed from the oil being returned from the heads and crank into a surge tube placed around the oil pickup, you then have baffling around this surge tube both to the sides and top letting oil acumulate into the main sump area around the surge tube, yet unable to exit under cornering/accel G. Having a flat plate with flaps in it above the oil pickup is counter intuative to me.
26 February 2008, 09:24 PM
#69
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We've now fitted and tested the baffle plate on JD's car, and it's showing no problems at all! It started up with its usual 6.5 bar oil pressure, settling to 4 bar at 900 rpm hot. I watched it like a hawk all the way home (25 miles of mixed driving) going fast and slow, with a few quick starts and stops and quiet roundabout action. It sat at 7 bar @ 3500 rpm.
The car goes great on the SimTek! first proper chance I've had since Martyn mapped it.
I have no idea at all why Dynamix's has that issue, but I can see so far that JD's doesn't. Before anyone starts, I am casting no doubt at all on the very good work done by the chaps at Scooby Mania. I've been there before, many times, where something is going on that defies initial logic. There has to be an answer for this, but I just haven't heard one that convinces me yet.
The baffle plate doesn't alter the position of the pick up at all John, as it sits in a hole in the plate. I'd say you are correct about the "oil up the breather" issue. When we run the Murtaya on a standing start, we most definitely get oil in the breathers, and the result can be seen when you fire it up the next time! That alone is a good enough reason for us to want to fit one.
The car goes great on the SimTek! first proper chance I've had since Martyn mapped it.
I have no idea at all why Dynamix's has that issue, but I can see so far that JD's doesn't. Before anyone starts, I am casting no doubt at all on the very good work done by the chaps at Scooby Mania. I've been there before, many times, where something is going on that defies initial logic. There has to be an answer for this, but I just haven't heard one that convinces me yet.
The baffle plate doesn't alter the position of the pick up at all John, as it sits in a hole in the plate. I'd say you are correct about the "oil up the breather" issue. When we run the Murtaya on a standing start, we most definitely get oil in the breathers, and the result can be seen when you fire it up the next time! That alone is a good enough reason for us to want to fit one.
Last edited by Alan Jeffery; 26 February 2008 at 09:28 PM. Reason: typo!
26 February 2008, 09:36 PM
#70
The baffle plate doesn't alter the position of the pick up at all John, as it sits in a hole in the plate. I'd say you are correct about the "oil up the breather" issue. When we run the Murtaya on a standing start, we most definitely get oil in the breathers, and the result can be seen when you fire it up the next time! That alone is a good enough reason for us to want to fit one.
How large is your sump Alan?
If you are still routing your breathers into the inlet system and getting away with it, then you havnt got much power and arnt launching hard, the big power boys are getting a litre of oil up the block breather on a single launch, hence why they all run breather systems that return the oil to the sump.
26 February 2008, 09:55 PM
#71
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Corrected, I thought you were referring to the actual pick up pipe position, not the sump position. The plate is roughly 2mm thick from memory. I dare say you can figure out the implications of that one. The dipstick level is self correcting of course, as the level is set by the block and not the sump. The sump on JD's is standard.
I haven't said anywhere that we were attempting to run big power from our customers road cars, although we are seeing a lot more now in our 400 plus club!
We don't run Time Attack cars for customers, (yet) and the needs of those are clearly very different.
We are getting oil up the breather from the Murtaya as it only weighs 900kg.
330 bhp was enough for 0-60 in 3.5 at Trax! We were interested in the baffle plate as a means of correcting that issue. It looks like we have concensus on the need for some means of stopping oil shooting up the breather!
I haven't said anywhere that we were attempting to run big power from our customers road cars, although we are seeing a lot more now in our 400 plus club!
We don't run Time Attack cars for customers, (yet) and the needs of those are clearly very different.
We are getting oil up the breather from the Murtaya as it only weighs 900kg.
330 bhp was enough for 0-60 in 3.5 at Trax! We were interested in the baffle plate as a means of correcting that issue. It looks like we have concensus on the need for some means of stopping oil shooting up the breather!
26 February 2008, 10:14 PM
#73
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JD's car is an 04 UK model, which I assume means it has the bog standard sump the same as most of the others? it looks familiar!
26 February 2008, 10:21 PM
#75
Indeed. The problem now is we have one that isn't working as expected. Hopefully the guys at Cosworth can come back with some info on what they find with a small sump capacity.
One point Mike made that's worth exploring further in this, is that one of the rubber baffle flaps had been sucked through it's hole and was stuck on the wrong (top) side of the plate.
Now if that's happening in Dynamix instalation, then it tends to sugest that there could be some airflow issue that is sucking the flaps shut. This could be the source of the problem, because if that is happening then there is very little in the way of apatures for the oil to enter the sump.
So i guess the next question is, how does the bottom end differ to a stock instalation on Alans car and on the cars Cosworth has tried to date?
First question is ,should (or even can) this baffle plate be used in conjuction with the OEM windage tray?
Could the problem be caused by the fitment of a return to sump breather system, and with this plate in place a vacumn is being created in the crankcase, causing air to be sucked down the return to sump pipe, with the resultant airflow both churning up the oil in the sump and also closing the return flaps and limiting the oil return capability?
One point Mike made that's worth exploring further in this, is that one of the rubber baffle flaps had been sucked through it's hole and was stuck on the wrong (top) side of the plate.
Now if that's happening in Dynamix instalation, then it tends to sugest that there could be some airflow issue that is sucking the flaps shut. This could be the source of the problem, because if that is happening then there is very little in the way of apatures for the oil to enter the sump.
So i guess the next question is, how does the bottom end differ to a stock instalation on Alans car and on the cars Cosworth has tried to date?
First question is ,should (or even can) this baffle plate be used in conjuction with the OEM windage tray?
Could the problem be caused by the fitment of a return to sump breather system, and with this plate in place a vacumn is being created in the crankcase, causing air to be sucked down the return to sump pipe, with the resultant airflow both churning up the oil in the sump and also closing the return flaps and limiting the oil return capability?
26 February 2008, 10:24 PM
#76
Could the problem be caused by the fitment of a return to sump breather system, and with this plate in place a vacumn is being created in the crankcase, causing air to be sucked down the return to sump pipe, with the resultant airflow both churning up the oil in the sump and also closing the return flaps and limiting the oil return capability?
Head
That might be it JF.
Still not going back on the car though - running without breathers or without draining back to sump is not an option for me.
26 February 2008, 10:34 PM
#77
If that is the problem, then this obviously needs to be known about, if not to save other people from destroying an engine if they have a similar setup. It needs some R&D time to check it out and get to the bottom of what's happening.
26 February 2008, 10:45 PM
#78
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I did wonder about the return to sump position on Dynamix's car. Apparently his taps in at the sump bung? please excuse if I heard this wrong! I've been involved in after market turbo systems for decades via Turbo Technics. Road cars, not race cars, so different forces involved! I was always under the impression that if you want to put oil back into the sump, like from a turbo drain, you do so above the natural oil level, by tapping in high up the front of the pan. The breathers we used were mainly concerned with keeping a slight negative pressure in the crank case, by using a three way breather, picking up from the rocker box, feeding some into the air filter, and tapping into the plenum via a non -return valve for vac. The object was to prevent oil escaping past the turbine ring seal, and burning in the downpipe. The effect of this was dramatic on certain V6 Fords! RS Turbos use the same system for the same reason. Scoobys are entirely different of course, having the boxer layout. A litre is a hell of a lot of oil to deal with in one shot. Funnily enough, I can understand why there could be a problem with D's oil pressure under the stress of being fired from a cannon, but not sat in the workshop!
26 February 2008, 10:56 PM
#80
Return to sump from turbo drains is completly diferent to return to sump from a breather system. The turbo return has positive oil presure forcing the oil into the crankcase, so you dont have to worry about relative presures.
Breather systems, epsecially on high boost turbocharged engines (which presurise the crankcase under load due to blowby) need to have the return from the breather condensor (catch can on single can setups) returned below the oil level, if you dont do that the presurised crancase gasses try and escape up the breather return pipe, and you end up with oil being expelled out of the catchcan and nothing getting back to the sump.
The amount of oil flowing through these catch can/return systems can be very high, a few laps on a 700BHP engine can see a couple of litres of oil coming out the breathers and being returned to the sump.
Take a look at a WRC spec Escort Cosworth with its magnesium sump pan and you will see the breather oil return entry point below the oil level, i used to run one 10 years ago now.
Breather systems, epsecially on high boost turbocharged engines (which presurise the crankcase under load due to blowby) need to have the return from the breather condensor (catch can on single can setups) returned below the oil level, if you dont do that the presurised crancase gasses try and escape up the breather return pipe, and you end up with oil being expelled out of the catchcan and nothing getting back to the sump.
The amount of oil flowing through these catch can/return systems can be very high, a few laps on a 700BHP engine can see a couple of litres of oil coming out the breathers and being returned to the sump.
Take a look at a WRC spec Escort Cosworth with its magnesium sump pan and you will see the breather oil return entry point below the oil level, i used to run one 10 years ago now.
27 February 2008, 12:09 AM
#81
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When I say "cannon" I mean the effect of a 1 second to 60 ft start!
and that's not an invitation to split hairs...
A lot of turbo drains are actually gravity led, and hardly under any pressure at all, due to some very small restrictors, but point taken about the effect of very high boost on breathers. I didn't suggest that breathers were the same as oil drains, I'm merely surmising. I fully accept what you say about 700 bhp cars. There is clearly a problem with the fitting of the baffle plate on D's car, but not JD's, and the only difference I can see so far is the breather set up, but there may well be something else going on.
Hopefully Cosworth will provide enlightenment!
and that's not an invitation to split hairs...
A lot of turbo drains are actually gravity led, and hardly under any pressure at all, due to some very small restrictors, but point taken about the effect of very high boost on breathers. I didn't suggest that breathers were the same as oil drains, I'm merely surmising. I fully accept what you say about 700 bhp cars. There is clearly a problem with the fitting of the baffle plate on D's car, but not JD's, and the only difference I can see so far is the breather set up, but there may well be something else going on.
Hopefully Cosworth will provide enlightenment!
27 February 2008, 12:30 AM
#82
The main point was that the presure out of the core is always going to be greater than the crankcase presure even with maximum blowby, so you dont have to worry about the oil being forced back the other way, which you do with a breather system that is running at atmospheric presure at it's final exit/inlet port and you can have crankcase presure of more than atmospheric.
27 February 2008, 08:09 AM
#83
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Our next move will be to fit one to the Murtaya, we'll have that completed in a week or so, then we can test to see if it cures the problem we were trying to solve in the first place!
27 February 2008, 12:26 PM
#88
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Or an issue with that particular plate...unfortunatlely you need to replace with another cosworth plate to eliminate this potential variable.
27 February 2008, 12:41 PM
#89
I cant be bothered now tbh 
- and will be looking to get a baffled sump made to do the job properly. It just doesnt work on my set up.
I would still be interested to see whether it works in solving surge issues Alan.
What are the criteria that you will be measuring for determining whether an improvement has been made?
- and will be looking to get a baffled sump made to do the job properly. It just doesnt work on my set up.I would still be interested to see whether it works in solving surge issues Alan.
What are the criteria that you will be measuring for determining whether an improvement has been made?