No slicks without dry sump?

[Steve L]

Recently I read a thread in a German forum about loss of oil pressure and slicks. The point was that with the extra grip of slicks, there is more risk of oil in a wet sump sloshing away from the oil pickup, and that if you want to use slicks at a track, you had better have a dry sump.

One contributor cited an article on the Caterham home page, but I could not find it.

Do any of you have experience with this matter?

And is the issue relevant for lower-horsepower Sevens? (I have a 91 Westy SE with 125 hp.)

[Mike-SEiW]

It depends very much on sump design, more than anything else.

Shallow sumps are by nature more difficult, and require special baffling and so on, but are by no means "impossible". There's always the risk of baffles breaking, trap doors not closing etc., so if you have an engine you've invested lots of time and ££ into, dry sump is probably better to safeguard your investment. If you can live with it breaking, and know you have a proven sump design, I would stick with a wet sump.

If you like me have a £200 junkyard engine, it's not worth the risk of oil surge to buy a £700 dry sump just for that. I'm contemplating dry sump for other reasons (ground clearance: imagine hitting the curbs on the track and smashing the wet sump - 5liters of oil covering the rear tires, on the track, risking others lives - that I wouldn't want to live with).

I hope that answers some of your concerns.

[Mark Purves]

Here we go again.

I run slicks when I can on track days and have done for several years. Just making sure there is a good oil level.

XE Redtop fairly high spec fitted with a Westfield shallow sump.

   

[Guest]

the usually reason for running a drysump on a race engine is more to do with a power increas over a wet sump rather than oil surge issues , a good wetsump correctly baffled is fine , there are many race cars in different series running wetsumps and slicks i have run slicks with a wetsump for years with no issues ..... the slicks=wetsump is a pure mith

[Mike-SEiW]

I have been quoted figures of 5-15HP gain from going dry-sump on race engines because of less oil drag on the crankshaft.

[RICHARD+PHILIP]

I'd be supprised if it was much higher than 5bhp

don't forget that some race series don't allow dry sump systems.

All in all it's a good idea especially if you have a standard sump

[Kevin Wood]

Whether you get problems with oil surge also depends entirely on the engine and car, wet sumped K series in Cateringvans being notorious.

Kevin