ccarlisi

In an effort to reduce the amount of hacking I have to do/pay to be done to the firewall/transmission I want to try to lower the motor as much as possible without eating into the ground clearance too much. With that in mind I have taken a closer look at the oil pan in the 20b, FD, and RX8. Here is what I have found. All measurements were taken from the deepest point.



RX8: 45mm -RX8 forum member



RX7: 85mm -Rotary News article stating that the RX8 pan is 40mm shallower than the FD pan.



20B: 101mm. -Measured by RotorMtr's father at the deepest point. He said 'about' 4" so I don't have a lot of faith in this number. If someone can confirm I'd appreciate it. Otherwise I'll have the engine builder verify it later this week



If the above info is correct the RX8 oil pan is less than 1/2 the depth of the 20b pan. Is there any reason the 20b pan cannot be reduced to 45-50mm while still having an adaquate safety margin for oil slosh under high Gs? Bear in mind that the stock 20b pan does not cover the length of the block (see attached pics).

inanimate_object

What we do with the motorbike engines to stop oil surge is insert a baffle plate between the engine and sump. You could also weld a little cylinder around the pickup which would further help, provided it doesn't stop the flow.







Mark

j9fd3s

the rx8 pan isnt deep but its almost square, you need to keep the right amount of volume in the pan too.



put the engine in the car, and build the pan around it.

GreyGT-C

dry-sump.. you cheap ***.

ccarlisi

[quote name='GreyGT-C' date='May 30 2005, 10:04 AM']dry-sump.. you cheap ***.


[/quote]



To reduce the height by 2.5" it costs ~$500. To reduce the height another 1.5" it costs $2,500 Thanks, but I'll leave you to explore the 20b realm of diminishing returns.

inanimate_object

There's not a whole lot of room under the bonnet of the car I'm building, so this issue pops up regularly with builders. The main solution is to shorten and square it off to keep the capacity, and some effective internal baffling. If that's not enough you can weld wings to the sides, and shorten it more but bear in mind you're not going to be able to shorten the bell housing! Don't know about rotaries, but most engines can stand to lose a little capacity.



Mark

inanimate_object

And $500 is way to much if that's a steel sump.



Mark

ccarlisi

[quote name='inanimate_object' date='Jun 1 2005, 12:31 AM']And $500 is way to much if that's a steel sump.



Mark


[/quote]



Thanks for the Reply Mark. Does the Baffle reduce oil slosh by eliminating the free space that is normally between the oil and the block?



I am concerned about reducing the capacity. Hopefully I can make up for the drop in capacity with two large oil coolers. You're right I could also expand the pan laterally.



I agree, $500 is conservative. However, given the way things are going it wouldn't surprise me if it cost 2x as much.

inanimate_object

[quote name='ccarlisi' date='Jun 1 2005, 02:03 PM']Thanks for the Reply Mark. Does the Baffle reduce oil slosh by eliminating the free space that is normally between the oil and the block?



I am concerned about reducing the capacity. Hopefully I can make up for the drop in capacity with two large oil coolers. You're right I could also expand the pan laterally.



I agree, $500 is conservative. However, given the way things are going it wouldn't surprise me if it cost 2x as much.


[/quote]

It doesn't eliminate the free space, just under hard cornering etc. it stops it sloshing past it - in the picture I posted if the plate wasn't there all the oil would be free to slosh all the way up the engine.



Someone who's able to weld shouldn't have any problems with it if you know what you want.



Mark

93 R1

[quote name='ccarlisi' date='Jun 1 2005, 09:03 AM']Thanks for the Reply Mark. Does the Baffle reduce oil slosh by eliminating the free space that is normally between the oil and the block?




[/quote]



The baffle keeps the oil near the pickup at all times so you aren't sucking air.