Loss of Oil Pressure on Right Turns

[rgh0]

The problem comes when going hard through a long right hand corner, typically 180 degree plus corner. The precise condtions do not occur often on a race track and it was really only one corner on all the tracks i raced on where it occured badly with the standard sump. This has a right left right combination of 180 degree mid radius bends that got the oil sloshing side to side and finally away from the pick up for major oil pressure loss.

Overfill the sump by around 5 to 10 mm and watch the pressure through any long right hand corners and back off if you see any problems. Lots of Elans do track days without sump mods and never have any problems.

cheers
Rohan

[msd1107]

It may be more important for a street car to have a baffled sump or dry sump than a race car.

As Rohan says, on a track there are very few corners that will overwhelm a nominally baffled sump.

On the street, freeway interchanges often have 270+ deg entrance ramps. Even 40+ years ago, I had no trouble pegging the oil needle in the wrong direction. With modern tires, the situation is much more severe. I adapted by just not using the Elans' cornering ability.

I asked Col if his baffle system would stand up to constant 1.15G cornering without losing pressure, but have not yet received a reply.

Just in case you think these figures unreasonable, even non-Lotus cars can pull transient cornering Gs in excess of that figure.

If I visualize what is happening under those conditions, when taking into account the roll angle plus G forces, the oil is literally piled up against the side of the engine. Almost makes the agony of installing a dry sump system worth while.

David
1968 36/7988

[Rob_LaMoreaux]

The one that got my engine was an autocross skid pad when I forgot to top up the oil at the beginning of the day. If I had added the extra oil it would have been fine. With the weber engine I added an Acusump to take care of the problem, but I need to check it's air pressure or it leaks down and the same problem happens. The oil presure Light I added helps a lot since the gauge is harder to notice than a very very bright red LED.

Of course this is with sticky Yokohama A032Rs. With the Michilen MX4 granite tires the car does a four wheel drift before the oil can slish to the side.

Rob

[quaybook]

Many thanks guys. I'll overfill as suggested and enjoy the day.

Vernon

[rgh0]

I asked Col if his baffle system would stand up to constant 1.15G cornering without losing pressure, but have not yet received a reply.

David
1968 36/7988

I dont think anything but a dry sump system will withstand constant 1 G plus cornering in a single direction for ever. The gated baffles system of the type I and Col use will ultimately leak enough oil across to behind the baffle to potentiually expose the pickup.

All I can say is that in the real world on race tracks and road corners that caused looss of oil pressure the gated baffle system maintains pressure in a range of twin cams installed in Sevens and Elans. One of the keys is the relocation of the pickup back to the centre of the sump so you dont get the RH corner weakness and even with the oil sitting at 45 degrees plus in the sump the pickup is still under the oil


cheers
Rohan

[Jeff@Jae]

Some vintage groups will not allow a dry sump system on cars not originally equipped here in the States. We have a fabricator that remakes the standard sump into a very effective race quality fix. It has a trap door pick up box,full windage tray,custom pickup and an extension on the side of the pan opposite the oil pump for added volume.They have always worked quite well with no starvation and great anti aeration/oil slinging qualities.No one we know of has ever had a problem after installing one of the these extensively modified sumps.Expensive, but far less than a damaged or ruined engine.No need for all that plumbing and a place to install a dry sump tank. A dry sump is the best way to go but these sumps are certainly the very next best thing. Sump cores are our biggest issue now.

[ceejay]

Sorry guys... have been involved in other things and not reading the forum posts... Rohan pretty well summed up
about the gated sump baffle, and as said previously, nothing can equal a dry sump lube system, but these gated sumps
come damn close. I have yet to find a corner or sweeper taken at high speed where I can induce oil surge.

Having a "G" meter on board would be a good exercise...if only to see what G forces are being produced in the elan
during high speed cornering.

But at the moment I am more than happy with the gated sump baffle setup, which also incorporates a curved windage
tray. It all fits neatly into the standard sump, if you weren't told, you would not know what is inside the sump... ideal
for historic racers where Dry sump systems are not allowed.
Col.