Putting a bored & stroked 1275LS onto a mk2 cooper s g/box if I drill it out for the breather on transfer case is that enough for the bottom end or put additional ones on either the timing chain cover or adapt one where fuel pump would go

don't drill one big hole in the transfer case - just in case you drop something on it.... mine has a big hole and I'm always very careful

I reckon you need at least two, I have the transfer case, and one on the rocker cover. Rocker cover is easiest and doesn't get in the way like a timing cover version....

on a side note, I recently re-installed my PCV, and the oil leak from around the timing cover has stopped

I have only the one on the flywheel housing, to a manifold PCV, and for road use it's plenty. Stock Cooper S only had one.
A well known Mini racer runs a 1330 with NO breathers. And nope, it doesn't blow any oil out.

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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.

And the Rover 1275s got two breathers. Transfere case & timing chain cover. And mine still leaks

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No speakers, no bodykits, no six-inch spacers, no spak filler, no bullshit

My 1275LS has the clutch and timing chain setup. Used to leak a bit until I changed the hoses. The old ones looked like the originals and were blocked inside with old oil buildup to the point of not letting the air through. Now works a treat and only the occasional spot of oil...

Car runs a heap better too. It seems everytime I find something that has been undermaintained by a previous owner and fix it, the car works that little bit better. Gregorys is no good in this regard. The version I have (02) has nothing on the 1275LS..

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Cheers
Alec
1275LS - July 78 - XNFAD18Y/102918

Many of these old crankcase breathers on 1275LS etc are clogged up BAD.
I rip the old `mesh' (swarf really) out and replace with a S/S pot scouring pad.
The little pillow shaped ones fit good.

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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.

Also found this on my 1152 also but it was the one on the tappet chest on the rear. gave it a spare with degrease and then another 5 and gave up. Let it sit for the week and pulled it all out and re packed it. Ill also be doing this to my motor for the van also. Purchase a breather repack it..you have no idea what its had to breath

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Stop Licking the Dog...I Don't Care Who Started It

I don't think my breathers are set up properly.

I have one on the rocker cover and one on the flywheel case. They are both just plumbed into a filter.
How should it be set up?
Should I have a PCV? What do they do?

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Ryan Filippi
Minis In The Gong
[email protected]
www.minisinthegong.com.au

'Positive Crankcase Ventilation' - it uses a one way valve between the inlet manifold and the breathers. When there is vacuum in the manifold, the valve opens and sucks the fumes out of the motor

I think Coopers were the only ones with them fitted as standard, and 1100's

... and the Mighty Morris 1100S and 1300 auto.
If you have the vacuum ports on the side of the carbs you can tee into those instead of fitting a PCV valve.

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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.

How would you plumb in the breather to a weber manifold?

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"Investing my Super in a Cooper" &
"Re-living my Surfing Past in a Woody"

Here's mine- I have a small balance tube (3/8 hose, 3/16 bore fittings) you can see there so that it doesn't need the idle mixtures set different to run properly.

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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.

Just be careful not to drill too close to the clutch side or else you can drill through and come out of the the casing onto the wrong side.....

How do I know ?? Well I don't think I'd need to draw pictures !...
Thankfully fixed with devcon.... but better if it hadn't happened at all.

I did that too, and one day the Devcon let go at Wakefield Park. I drove 150 miles or so home with a clutch housing 1/2 full of oil.
It didn't slip but felt very soggy.
Now been TIG welded, all is good.

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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 it has we have pictures

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Stop Licking the Dog...I Don't Care Who Started It