Hi
Fred here from Sweden.
I run a homebuilt Locost from the book, powered by a Yamaha R1 -06(5vy) engine.

On two occations, during track days, when pushing the engine to the max(rev limiter) and with Toyo R888 tires on the car it spits out oil like crazy through the vent pipe?

Yesterday it spit out about 500cc in one day.

I Have the baffle plate installed to keep the oil in the pan and a small catch tank at the end of the vent pipe, venting through a filter to the open air. I do overfill the engine some to never have an oil problem(as advised).

Is this normal for track inspired driving?

Can some sort of limiter or screen be put inside the hole to slow the drain of oil?

Anyone with similar problems and hopefully solutions, please let me know.

/Fred

Have you done the breather mod?? Open up the read valves on the top of the cam cover and route a pipe into the top of the catch tank from them, then put a drain pipe from the catch tank into the breather. I hav ethis on my race car but have on;y ever suffered from oil blowing out when i have over filled the engine. I find the R1 sets its own oil level, you can put as much in as you want, but it will spit anything it doesnt want out.

Agreed. You eed to do the breather modification. There's a thread HERE with pictures.

[Edited on 24/9/12 by adithorp]

There's nothing on that thread , has it been removed?

Link works for me.

Last post on page 2 for the modification.

Others have spoken more wisely than I can, but you simply need to do the breather modification.
Boils down to taking off the cam cover, drilling and tapping the air pump holes prior to plugging with an M8 grub screw. You then drill through the cam cover within the reed boxes to let the crankcase breath.

On my track car, I returned the oil vent header to a boss welded on the sump. 5VY sumps are made of reasonable quality alloy, unlike the crap Suzuki use, it welds very nicely. The rear crankcase breather is then allowed to vent into the header tank as well.

No problems after the modification, but an oil spray before!

Thanks all

Can't get anything in that thread either??

It's just an empty spot.

Could you post the entire url?

Cheers

Fred

http://www.locostbuilders.co.uk/viewthread.php?tid=110223&page=2

Just checked the link and it works for me.

The problem on the 5vy R1 is that despite a baffle plate a lot of the oil is above the baffle. Cornering hard this can flow high enough to reach the crankcase breather on top of the gearbox. Crankcase gas pressure then pushes the oil out. If you still have the breather venting into the airbox it can get sucked into the cylinders and cause a hydraulic lock and break the engine

The cure is to allow crankcase gasses to vent from the cam cover as well as the gearbox so when oil does reach the g'box breather the gas vents via the cam cover rather than push the oil out.

The AIS valve covers come in handy for this. First remove the AIS control solenoid (it causes no fault code in the ECU) Then remove the cam cover. Remove the AIS reed valve boxes from the cover and remove the reed valves from the plates inside. Block the ports in the cam cover to the exhaust using either pins or grub screws or even chemical metal. Dril hole through from the AIS valve housings into the cam cover. I drilled mine in the lower corner so that any oil that got in could drain back. Refit the cam cover and the valve boxes. Connect the two outlets from the AIS valves to a T piece and run a pipe from that around another T. That T branches to a catch tank and to the gearbox breather. Either vent the catch tank to atmosphere or into the airbox.
I put stainless mesh folded up (or bits of stainless pan scrub would do) in the top of the boxes above the empty valve plate and into the pipe coming off the gearbox. This gives something for any oil mist to condense of and run back into the cam cover/gearbox.

This set up has now been on my car for 4 years with no issue. All I ever get in the catch tank is oily water/condensation if doing short runs in damp weather although you could plumb into the bottom of the tank so it'd empty back into the gearbox but I prefer the water out.

This works http://www.locostbuilders.co.uk/viewthread.php?tid=110223

Cheers, Nick

[Edited on 24/9/12 by Nick DV]

Found it now!

Thanks All for this help.

You just may have saved me an engine

Luckily our tracks aren't as fancy as the British or Hungarian( as per vid in the thread) so that might have saved my engine too. Ours is shorter and twistier, damn environmentalist crap saying it makes noice and pollutes! They have no idea how much joy it brings to run your homebuilt R1 monster round and round, just wish they were nicer and longer.

It made me smile from ear to ear for 2 days straight.

Thanks for a great forum with great people!

Winter work setting in as the nights start to freeze up here in the north.

Cheers all

/Fred