Lotus Elan and Lotus Elan Plus 2 Forums

For the past couple of years I have used an "Accusump" to maintain oil pressure through hard RH corners when racing with very good results. Unfortunately these devices have been banned from this year in my historic racing category. The reason given is they were not invented at the time of my category ( 1960 to 69) but the real reason is just classification bureaucratics exercising their mussle :angry: . The category also bans dry sump arrangements so I need to improve my current wet sump baffling which consists of a top cover plate and cross baffle in front of the pick up in combination with the original longitudinal baffle in the middle of the sump.

I my first race this year last weekend I had to overfill the sump by about 1 Litre to hold oil pressure in the 2 RH corners on the Phillip Island track. My next race at Winton will create much bigger problems with its much harder and longer RH 180 degree hairpin corners so I am seeking a better solution.

In looking for ideas on sump and pick up modification that eliminate the oil pick up problem on RH corners, the two ideas I have so far are:

1. Making something like the Dave Bean swinging pickup which is unfortunately not currently available ( maybe if enough people ask for it he will do another run of them)

2. A set of baffles and swinging trap doors like described on the GGLC web site. If anyone has a picture or dimensioned drawing of one of these or similar that they know worked in serious competition it would be nice to see it.

Any other ideas / comments / hints on what people have done would be appreciated

Rohan

Rohan -

I'd go for the trap doors - simple and effective.

I have such an arrangement in a racing pan from my Sprite. I could post a picture, but I'm down in Sunny Atlanta, so I don't have my parts inventory handy. If you still need info I'll take some pictures when I get home.

IIRC the box is about 6" on a side, positioned with the sides of the box at 45deg to the length of the pan. Baffles from the box to the sides of the pan force oil into the box. Again IIRC the trap doors are about 3"-4" long and 1-1/2"-2" high. Material for box and dors is approx .060 steel, .040 would probably be OK. Doors should swing very freely and don't need to fit/seal especially well.

- Bill

last summer i sent my oil pan to dave bean for conversion to full racing baffles. they did a terrific job for about $150 (dont think i could have done local / myself any cheaper). i also use accusump for racing, maybe you could hide the unit and plumb into the oil cooler. tech inspectors typically dont trace all lines. sounds like they are making a dumb decision! mike

There are some baffled sump design drawings on the Gold Gate Lotus site that you might find useful.

I got one that was recommended to me by Jay Ivey of Ivey Engines, it was sold by JAE in California - looks great, and adds about a liter capacity in a protrusion on the left side. It's fully baffled and trapdoored, with the oil pickup relocated to the center. Ivey had 2 Twin Cams in the shop at the time with that sump on them and said they were great, only problem was the time it took to get mine rebuilt - you had to provide a core, and they told me about a month; turned out to be 3 months since the guy that had been doing the work had moved on to other things and they had to find a replacement; it also ended up being about $500 US!! I can't speak for how well it works myself yet, since it took so long to get I ran out of time to get the car together for that summer, and used one of my other cars instead - and still haven't got the engine back in!
Dave
[email protected]

I had similar problem racing in FIA events in Greece. Of all daft things problem was caused by dip stick tube slipping down front cover so when dispstick shows full - actual is only 75% full. Several other people in England whosaw my letter about this found same problem. Suggest start by checking disptick with 4.25 litres of oil + up to litre for cooler and factor of safety!
It works
Richard

What was the Acusump like to fit and run? Did it really work?

The accusump was easy to fit. I have an oil cooler in front of the radiator. I just put a tee in the supply hose to the cooler and a check valve in the line from the pump before the tee. I mounted the accusump low in the nose just ahead of the radiator. I have a lightweight steel frame that bolts to the chassis just below the radiator in that location that I made to carry the horns, air cleaner and a front towing eye and the accusump bolted easily to this


I pressurised the accusump with 20 psi air when empty. This meant that it ran two thirds full at 60 psi with the engine running at normal oil pressure. I could see it working through long hard right hand corners when you could watch the oil pressure slowly drop from 60 to around 50 psi over about 10 seconds as the accusump provided the oil flow when the pump lost suction.

When the engine was shut down the accusump would take around 30 to 45 seconds to discharge. I fitted a solenoid valve to the accusump discharge so I could block in the oil before engine shut down. Then I could open this and have instant oil pressure before cranking the engine.

If your regulations allow it well worthwhile in a competition engine for engine protection. How useful it really is for a normal road going car harder to judge and would depend on individual driving style. However the ability to have instant oil pressure before cranking certainly is beneficial for any engine that may sit for a while between being used and have the oil drain away from the pump and bearing surfaces.

regards
Rohan

Hi Rohan
A mate of mine ,Steve Smith from Twincam Sportscars in Sarasota Florida showed me a modified oil pump and sump which does away with the normal pickup and runs a new pickup from a welded boss on the pump direct to the bottom of the sump.

I am in Florida at the moment but will post a pic of an oil pump I have modified the same way.

This gives a virtual dry sump system but with the oil still wher the scrutineers want it!!

I also looked at a dry sump pump and pan with the addition of a normal pan to act as the tank welded over the drysump pan. This should also work because I've not heard of any specifics for type of oil pump allowed.

Cheers
Dave Hughes
26-R-9

Rohan,

You might want to check with Col at elantrickbits as he has a very proven baffle design. On the plus side he is in your part of the world.

I have a baffled pan from DB and it does very well also but does not have the swing door as Col's pan.

Mark

Colin at Elan trickbits developed his modification package from information I gave him a few years ago as a result of the work I did back in 2003 when I first made this post to develop a trap door style system for the Elan after the accusump approach was banned in our historic racing. I and a few friends racing twincams have used this style system now for the last 7 years with good results.

The "dry sump system in a wet sump" that revived this old post sounds interesting and I look forward to seeing some photos

regards
Rohan

The "dry sump system in a wet sump" that revived this old post sounds interesting and I look forward to seeing some photos

I have heard these described as a "California dry-sump" b/c they frown upon a dry sump on the left side of the country - the right-side is ok with a drysump elan .

see attached

George

Hi all
Just trawled through pics on my pc and found pic of the pump with oil cooler adaptor.

Dave Hughes
26-R-9

Guys,

Just read this as Rohan gave me those pics and help and I made his sump with doors etc. Not run it yet, car still in build.
However, I have one of the sumps/pumps that you describe with the pickup pipe fastened to a standard pump. It was on eBay about 3/4 years ago. I bought the complete kit out on interest only. Someone had really put some work in. All sorts of wafer fins to catch the oil as it runs back and I can hear at least 3 doors when shaking it. Pipe from the sump up to a fitting, alloy welded, on the normal oil pump. It is in the garage. I seem to recall it was from a Lotus Cortina. I will have look. Interesting!
At the time I saw the concept it looked good but was not sure how it would be viewed. Not even sure it would fit an Elan with the cross member. I was even tempted to cut into the bottom of the pan I was so intrigued. It even has gauze set inside the side entry pickup to prevent anything being pulled to the filter. I think I posted on here at the time to see if it was someone who had made a batch.

Mike