Hate revisit this thread but I must.
Have reverted to SUs so no longer have the rocker cover vented straight to the Weber's Pierce intake. I went back to OEM routing of rocker cover to air filter housing. I now have more oil out of the vent tube. Wondering why still, too much blow-by I guess. Maybe a catch can on the vent tube? I could tap the SU's intake and introduce more vacuum but I hate to pull it all apart and the thought of "oil injection" into the intake doesn't really appeal to me very much.

Didn't I see someone offering a catch can kit? I swear I bookmarked it but well.....

I have a catch can that I'm not going to use. Brand new if you want it. Send me your info in a PM and you can have it.

It's a pretty blue too. It will match your engine nicely!

AS always late on the scene, sorry about the can, guys the later 1098s had a can on the lifter cover that looks just like the can on the timing cover of the 1275 timing cover, thats a way better set that the draft tube, it would be worth finding, maybe someone need to start making aluminum lifter cover for you guys like we do for the MGBs. That was dumb idea by the factory, but I still stand by the ring statement. maybe yoiu need to take leak down test on your engine, that will answer the questions of if the rings are sealing or not.

Catch can is a bandaid used by DPO's!

Tony, I don't think you know what I speaking of, this is factory piece, get with the program man :), remember me, I'm the guy who told you about A series rod offsets The factory lifter can were just like the can on the factory 1275 timing cover, they had the brillo pad material in them. As far as pulling crankcase fume from the engine tru your fuel delivery, go ahead, I choose to take it it elsewhere, you see Tony I perfectly understand why the factory did what they did, I know these motors, MGBs too, it doesn't mean I have to follow the factory in thier mistakes.

All 10CC motors had the can on the lifter cover from the factory, you know Tony the 2" 1098s, like the race crank I working right this minute.

Oh, you're talking about that little can built onto it! Sorry...I was thinking about one of the racing-type catch cans as an add-on. My bad..

Thats the better set up of all (a vented catch tank), a place to deposit any dripping and still breath the secret is to make sure the catch is well vented, I noramlly built custom aluminum tanks, sometime use store bought, then vented with one of the SBC valve cover vents, no it not very stock looking,and something alot of Spridget folks would not want on their car, but sooooooooo much better than sucking fumes thru your fuel, the PVC system works fine as long as your engine is sealing good, but when it doesn't guess where that oil goes, that why racers don't use PVC systems, now exhaust crank case evacuation that another deal, not allowed in most road racing groups, but the drag racer love that, you get the best of both world, killer vaccum, and no chance of messing with the fuel charge.

So Hap, on the 1275, this would be redundant of the catch can on the timing cover? Also, I have an alloy valve cover. Should I tap and vent it? I want this engine to be fully aspirated!

Alot of the alloy valve cover have the venteed cap for street engine that is plenty fine, but you could pick your spot carefully, you may want to make a baffle on the inside of the cover, ofcourse make it has clearence. The breather can on the 1275 on the timing cover, is in a weird place, well no so good palce but it ok for a street car and the rpm it put out, I always gut the can n ym rebuilds, in otherwords remove the brillo material and wire clip. On the race car because of the increase rpms and the longer time period they run those rpms we vent the living crap out them, I use alot 1" hose, check out the black race car as for venting.

Great stuff.
I'm trying the after market add on can like this . Not sure exactly how to plumb it in. Was thinking cut the draft tube way short, hose from there to catch can mounted somewhere, other hose to atmosphere or maybe a vacuum source like the air filter? and maybe, just maybe I can come out of the bottom of the can and back in where the fuel pump used to be? So I don't have to empty it?
First thoughts, maybe stupid ones.

Yes, rings may need doing, compression was good but that only a dry test. Even if rings are bad, it's going to wait so catch can it is.....and looks like rear tranny seal now too.....
BTW my alloy rocker cover's chrome cap wasn't vented, I drilled it last year already, very tiny hole though. I could always put the OEM rocker cover on it, I have one, with VENTED cap.

Is it leaking from the rear scroll seal. ie driping from the bottom of the bellhousing hole?

No, that's the one place it isn't leaking! I get spots right beneath the draft tube and under the frame right behind it. I once put a hose on it and ran it up to see how much it caught, it filled up and blew all over the underside of my bonnet (this was while there wasn't any vacuum pulling on the valve cover) so yeah, I should probably rebuild it, but it's a 1098cg so I'd do better to throw in a 1275 I suspect.

Leak was horrible when the valve cover line wasn't hooked in (loose fitting)
Got better after that was tightened up and routed to Weber's intake but still leaked there a bit.
Weber is gone, SUs on now valve cover line goes to air filter housing (less pull I'd suspect) leak is a little worse again, thus my coming back to this thread.

You'd think the scroll seal would be one of the first places I'd see it leak wouldn't you? Don't jinx me, I don't need another leak.

When you need a rebuild the engine pumps oil out the draft tube. Plain and simple, rings and head rebuild along with bearings.

hmmmm, winter project then I guess, maybe I can carry the block down to my shop in the basement and have at it in piece and comfort all winter long

Should not take too long really.

One day pull engine and tranny.

one day disassemble engine.

Take to machine shop for boiling, rebuilding of head and such, have them check cylinders and hone or what ever. Polish or grind bearings. New freeze plugs of course.

,,,,,,,,,,,,,,,,,Wait.

Paint all.

Order new parts and gaskets.

..................Wait.

One day assemble new engine.

One day to install engine and tranny.

One day to adjust whatever.

Enjoy for a long time

If you want to just get thru the summer with less oil leakage then hook a hose between the fuel pump vent and the rocker cover vent and "T" off a hose from near the bottom of the hose up to the aircleaner intake. This will allow most of the oil in the connector hose to drain back into the fuelpump hole but still vent into the aircleaner.
It would be a cheap and easy experiment, I did it to a 1098 CG motor a long time ago (punched a hole in the pan for the lower vent) and it helped a lot.
---This is not intended as a permanant fix! but it won't hurt anything either.
BillM

Sorry to be so late to this question, but I don't agree that the compression
is fine. I was taught that if compression is off by more than 5 lbs between cylinders, check it out. Your #3 is WAAY off.
I'd guess #3 has a burnt exhaust valve and/or bad rings or worse. One or two broken rings, a damaged piston, or a head gasket leak each will increase crankcase blowby to unmanageable levels.
If you go with the gulp valve, remember to use a proper vented cap, seal the dipstick with a rubber o-ring. You can collect fumes from the timing cover, the valve cover, an added fue pump vent or all of the above "t"ed together before the valve. Plug up the rocker chest vent or replace with another ventless one. Done right, you get an A-series engine that doesn't mark its territory.
Dealing with the turbocharger and the damage they can do to rings and pistons has taught me a bit about crankcase ventilation.

Good luck with it.

Glen Byrns

Again cheap and dirty!! I currently have a worn 1275 in my "driver". No vent or PCV to carbs. Heater hose looped up and vented to air from timing gear cover. Heater hose from late model emission valve cover vent tube that has been drilled out and vents to air under car. I'm with Hap, if it can get rid of leaked pressure it won't push oil out.( Quallify that, its british!!!). I'd try a late valve cover with drilled out vent till you can get around to an overhaul.
KA

Good, you found my compression numbers back, guess I did drizzle some oil in there. Yep, #3 was off. Maybe that's my culprit. I can put on a new headgasket for fun before I get too crazy.