SR3 dry sump question

[Richard7K]

Hi Everyone,

I've just completed a big engine upgrade on my SR3 from my trusty Gen 1 1300 to a pretty wild 1441cc.
One of the changes has been moving from wet to dry sump.

But, (and there always a but somewhere in an engine swap, right?) the system wants to purge into the catch can. At first I thought that it was because too much oil in the system, but it soon became apparent all the oil wanted to make a break for freedom. Because we were keeping a close eye on things on the dyno we caught it before anything bad happened. Whew.

The system is plumbed from the scavenge pump, to the cooler then on to an (old) Radical dry sump tank.
One thing I have noted that probably is wrong, is that I have the crank case breather going into a T with the oil breather line; but I don't think that is the reason for what I'm seeing, and I am changing it over the weekend.

There is definitely pressure blowing out of the oil breather line; and above 5000 RPM a trickle of oil develops, which becomes quite a flow at high revs. This is of course not a good thing and I need to sort it out

Has anyone had this sort of thing happen and can offer any advice please?

Thanks
Rich

[Josh Smith]

Do you have a picture of the install?

Crankcase breather should go into the top of dry sump tank. Head drain into sump pan.

How full is the dry sump tank?


Josh

[Richard7K]

I started out with 6.5l in the system, which was approx 2/3 full in the tank one the system had charged.

[Josh Smith]

That's normal.

[MK3 Dan]

The old tank won't help if its a small capacity one.

The 1440 will breath more, did you window the barrel?

Your breather, from the breather pot, should go to the dry sump tank. Your tank then breathes to the catch tank.

Have you run the engine in and checked for stripping to ensure there is no excess crankcase pressure? Have you carried out any breather mods to the engine?

There a number of things that can be causing your problem! How old is your scavenge pump? What year is your car?

[Richard7K]

The dry sum tank breather does go to the breather pot.
The car is a 2003 car. The engine is all new and professionally built and was run in on the dyno.

I'm separating out the crank case breather from the oil can breather today.

The whole dry sump system is brand new.

The only external breathing mod is a Schnitz Racing low profile crank case cover.What do you mean by "checked for stripping" please?

Thanks
Richard

[MK3 Dan]

The crankcase breather needs to go to the dry sump tank, then the tank from there to the over flow tank.

I would consider also changing that breather back to the standard pot.

By stripping I mean bore scoping the engine and checking that the piston rings have bedded into the barrel and not caused any scoring/marks that would give excess crankcase pressure. I would also check that you do not have a cracked bore that is causing excess crankcase pressure.