Engine Bearing Failure

[bazza]

Originally Posted by Dessertrunner

Agree,
You would use a flat pice of Ally for the main plate the fab the well then weld it into the main plate. A bit more stuffing around but things like bolt holes will be perfect due to the fact they are CNCed.
Lets see what you come up with on disegn.

Is your guy going to CAD in 3D?
Also have you settled on a pump yet if so do you have the measurments?

Tony

Yeah, he will take my 2d cad effort and make it 3d.

[Dessertrunner]

Correct me if I am wrong,
If you intend on running a suction from each rocker cover you will need more then a 5 rotor pump as you will need 2 rotors for the sump (some are using 3 on 4 cyclinder engines) and 2 for each head. That only leaves 1 for the rest of the job. So if you want to run a oil cooler etc or 2 rotors to the pressure side its not enough.
What ever happens you need to be supplying the bearings with more then the existing pump.

My question is have you worked out the circut for the plumbing yet if so how many litres per minute are you aiming at suppling to the bearings.

From what I can see the Cosworth dry sump is by far the simplest.



Tony

[Dessertrunner]

Also the plate over the top is very simple.
Tony

[bazza]

Originally Posted by Dessertrunner

Correct me if I am wrong,
If you intend on running a suction from each rocker cover you will need more then a 5 rotor pump as you will need 2 rotors for the sump (some are using 3 on 4 cyclinder engines) and 2 for each head. That only leaves 1 for the rest of the job. So if you want to run a oil cooler etc or 2 rotors to the pressure side its not enough.
What ever happens you need to be supplying the bearings with more then the existing pump.

My question is have you worked out the circut for the plumbing yet if so how many litres per minute are you aiming at suppling to the bearings.

From what I can see the Cosworth dry sump is by far the simplest.

Tony

The fellow in the U.K. running his 1000 bhp EG33 runs the 5 stage pump which is good to know. He is using the Dailey pump which has only 1 rotor for the oil pressure and if I'm not mistaken they also run a pressure regulator to keep the pressure at acceptable limits. I'll most likely aim for 80 odd psi (as that is what the engine clearances are designed for) so I'd expect the flow to be the same if not more than the Subaru pump.

I'll most likely stick with the stock oil cooler and then even if it's not enough I can easily reduce the water temp going through the oil cooler cool the oil more - currently it receives water probably around 75'C ish after flowing from the pump along the lower water pipe within the engine... drop that water feed into the oil cooler to 25'C and it's a huge difference in cooling effect. Obvious a few factors as you don't want cold engine oil - but you get the point.

Also given I'll have around 12L of oil in the tank/engine - that's a lot of oil to keep warm and also a lot of surrounding aluminium to keep warm - the aluminium will suck a ****load of heat out of the oil, plus given the pump is far more efficient it won't heat the oil up like the stock pump does at high pressure.

[bazza]

Good stuff, DIY:

http://performanceforums.com/forums/...p-construction

[Dessertrunner]

The one concern in the back of my mind is what is the maxium oil flow that can be pumped through the motor.
My logic for asking you about the different pressure at different revs would tell us the amount of oil that can be pump throught the existing system.

In simple terms if you find the point at which the oil presuure fails to increase inspite of increase reves then using that rev number we can calculate the amount of oil the system can handle.

Also don't know if we have all agreed but it seems that high clearance on the bearings is far better. Is that accepted or not?

Tony

[oab_au]

Originally Posted by Dessertrunner

The one concern in the back of my mind is what is the maxium oil flow that can be pumped through the motor.
My logic for asking you about the different pressure at different revs would tell us the amount of oil that can be pump throught the existing system.

In simple terms if you find the point at which the oil presuure fails to increase inspite of increase reves then using that rev number we can calculate the amount of oil the system can handle.

Also don't know if we have all agreed but it seems that high clearance on the bearings is far better. Is that accepted or not?

Tony

I think that is the crux of the matter Mate. It is the flow that gets to the big end slipper that is the main point.
If the flow is reduced as it flows through the gallery and the holes through the crank, then the pressure won't help. There has to be enough flow to cool and lube the big end.
Increasing the bearing clearance will be detrimental if the flow can't keep up the supply, the oil will fling out of the shell faster that it can be supplied.

Look at the way the oil has to flow from the gallery, to the main bearing cap groove, into the main journal, through the crank to the big end shell, it's not just a pipe!

Harvey.

[Dessertrunner]

Have done the DXF of the sump plate for the dry sump so if anyone wants one let me know.
Tony

[Dessertrunner]

Here is draft sump pdf itss #D so double click and you can rotate to see the under side. As I say its a draft so all input appricated.
Tony

[icingdeath88]

Originally Posted by Dessertrunner

Here is draft sump pdf itss #D so double click and you can rotate to see the under side. As I say its a draft so all input appricated.
Tony

Maybe you should make the fittings for the lines come out of the side, rather than the bottom. God forbid it gets snagged on a rock or something. Or maybe it would still be too high up for that?

[Dessertrunner]

Did draw it from the side and it just didn't look right but your point is correct. The bolt on bit is 50mm deep by putting the entry into the base I should be able to cut it back a bit.
Tell you the truth I haven't got a clue what I need and don't need all sorts of questions come to mind like,

How much volume does the well need to be?
Should I make it 2 sections (maybe yes so one put rotor doesn't run dry)?
Why do they ghave two suctions?
Counting the head suctions you are talking 4 suction is that what is needed?
What do you do with the exist pump?

so help.
Tony

[oab_au]

Originally Posted by Dessertrunner

Did draw it from the side and it just didn't look right but your point is correct. The bolt on bit is 50mm deep by putting the entry into the base I should be able to cut it back a bit.
Tell you the truth I haven't got a clue what I need and don't need all sorts of questions come to mind like,

How much volume does the well need to be?
Should I make it 2 sections (maybe yes so one put rotor doesn't run dry)?
Why do they ghave two suctions?
Counting the head suctions you are talking 4 suction is that what is needed?
What do you do with the exist pump?

so help.
Tony

I think the basic set-up would be the best starting point, and go from there.
If you used an external pump, to pump from your sump, to a tank, with gravity feed to the orignal pressure pump, it would solve the surge problem.

Whether this will fix the bearing problem or not will be seen.

Harvey.

[bazza]

Originally Posted by Dessertrunner

Here is draft sump pdf itss #D so double click and you can rotate to see the under side. As I say its a draft so all input appricated.
Tony

That is absolutely brilliant mate - I'm in awe, really top stuff

[Dessertrunner]

When I designed the main plate on the dry sump I have a 20mm slope so the oil will move away to the suction resonablly fast. Due to the viscusity of oil it doesn't move fast on a flat surface. Looking as all the current dry sumps aviable for the EG33 they are flat from the edge to the centre.

Further head thoughts.
1 - We have the ability to fin the outside of the sump to enable some cooling of the oil by the air passing by. This will require no more material it would mean less cnc cutting.
Do we want to design this feature in?
2 - I understand why there is 2 suctions in the sump. The pressure side of the dry sump pumps is often bigger then the single suction side. Also the return oil has great volume due to the amount of air present in the oil. Therfor there is a risk of the amount of oil increaseing in the sump and getting up to the crank etc which could kill the engine.
We have to have 2 suctions.
3 - Need to have a baffle between these suctions so both lobes get feed oil otherwise one might run dry then it would lock up.
Baffle in dry sump well needed.
4 - The well has to be high enough to hold small surges of oil while the pumps catch up.
The size I have is enough, in the case I need more its just a matter of replacing the bottom section of the sump.
5 - Give suction in each head and two in the sump plus one pressure pump I need 5 stages.
5 stage pump it is just as bazza said.


Question I don't have a answer for yet,

What pressure do we supply?
What volume of oil do we need to pump?
Were or how will we fit the pressure relief valve?
Do we remove the existing pump (I feel the answer is yes)?
How do we drive the pump and from were on the crank?

All suggestion greatly appricated.
Tony

[Dessertrunner]

Alum plate to make the dry sump will cost $300. So now just need to decide if I am going to build one.
Tony