Hi guys
Looking for some thoughts on the best solutions for resolving oil building up in rocker cover during high rev in my race engine. I understand that 1100s block are prone to bad oil drain down.

first solution would be to restrict oil flow into rockers , I understand this can be achieved buy fitting a grub screw with small hole drilled in it to rocker post to restrict flow, does anyone have some sizing that has worked in the past.

Next option would be to improve the ability of the oil to return to the G/Box via extra drain lines , one article suggested feeding it back via fuel pump oil in casing ,

Cheers Mal

Mal

Yes a you can restrict the oil coming into the rocker gear area, make sure
cam bearings have been fitted correctly....also the factory fitted a breather
off the timing cover to help these issues you mentioned also.

AB

A piece of feeler gauge with a pin hole under the first rocket post will restrict the flow. And easily implemented in the field. Like AB says, cam bearing may not have been offset properly - just restrict the flow and next time you overhaul the engine correct it.

I put a 12mm OD drain line off the rocker cover down to the drop gear housing. Not that I have a drainback problem.
My PCV valve is connected to the rocker cover, it works fine provided it's not directly above a rocker.
It's a road car, but has seen 8000 rpm on track days.
Some folks drill the pushrod holes bigger for drainage on race motors.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Yes similar too what the good Doc says,
we fit a drain pipe from either end of the rocker cover,,, low on the cover like the Doc has
we take the drivers side one down to the breather-spot on the primary case with a "Y" piece half way down allowing breathing to a catch can

& the passengers side drain (again from low on the rocker cover) down to the fuel pump hole in the back of the block
& again with a "Y" piece half way down to the breather catch can

it ends up looking like it has 2x handles either end of the engine but works a treat
even with Stews fire breathing 1600cc Arden cross-flow mini engine with 145 hp
i have done things this way for the past 30 odd years with all our 1415cc & 1510cc stroker engines
& not one issue
easy-peasy

_________________
No offence intended here but--> anyone writing a book about minis 30 years ago may not have experienced such worn or stuffed-with components as we are finding these days.

You should put your heart & soul into everything you do.

We need to get a little minion in there to work out the volume. I think Mal was after a measurement something like put the grub screw in the feed up to the pedestal and and put a 1/16th hole in it( what size is a pin hole ( to reduce volume ) (Mal this is just an example i have NO IDEA so do not use this measure) . You would think with the lifter bores and holes in the lifters it should escape? but not at full revs

I've never had a problem with the top end getting too much oil, but I do make sure the front cam bearing is the right way round. If not, you can get a full flow feed, not just an oil pulse once every cam rotation as is normal.
[I get GR to fit my cam bearings...]

_________________
DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Is there a guide or a picture for the installation of the cam bearings? All the manuals I have don't go into specifics for how they should be oriented or installed.

Thanks

I have check bearing installation and it is correct, I think my problems are being caused by excessive oil pressure , currently it is running at 85 hot , I have installed a shorter spring and it now runs 75 cold, which I can adjust if necessary .

Another issue that may be contributing , is the MED heavy duty pushrods I am using, they are have a much bigger dia which restrict return flow.

I am wondering how the Nb guys manage return flow @7500 rpm, none if the cars over in WA run a return line form the rocker cover

A couple of images of cam bearing installations, slot aligned with gallery to crank bearing, small hole aligned with gallery to top of block

The oval hole in the bush faces the main bearing housing (oil entry).
Hard to see in your pic.

_________________
DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.