30 replies to this topic

[MINI 1]

ye , its the two brass pipes in the center facing each other.

[blue redtop]

[Bungle]

also theirs two brass pipes which pretude each other from just below the damper pots what are they for?

they are where you connect the engine breathers

[MINI 1]

so i need to put a air filter on each of them or block them off air tight? but why

another pic

Edited by MINI 1, 04 January 2008 - 11:01 PM.

[Bungle]

if your not using crank case breathers then blank them off

if you don't blank them air will be sucked into the carb and weaken the mixture

[MINI 1]

ok, thanks

ash

[minimender]

so i need to put a air filter on each of them or block them off air tight? but why

another pic

Could you just put a link pipe across the carbs ?

just a thought .

[blue redtop]

if i was you i would connect them up as there meant to be(but its totally up to you).

the crank breather is meant to me connected to the carbs.

the two brass pipes facing each other are meant to be connected to the crank breather.
the crank breather is on the passenger side of you 998 engine just at the back.
it looks like a black round can with a pipe sticking up.
i have a pic but i dont know if its much use as the breather has been remover but is sort of tell you where it is meant to be.

[dklawson]

As mentioned by others, the upward pointing brass tubes on the carb bodies just below the vacuum chambers are for emissions. I have never seen them on a pair of Mini carbs but they were certainly used on other BMC cars like the Sprite/Midget... and probably later Minis than mine. You'll probably see the connections for the emissions components in an "early" Haynes manual. I remember them being shown in the AutoBook manual for the Mini by Kenneth Ball.

I couldn't find an online picture of the tube/Tee I mentioned in my previous post. If you have a copy of Parnell, open to pages 32, 35, 63, and 773. (Incidentally, you won't see the emissions tubes that are on your carbs on any of the pictures in Parnell). Succinctly, the original Cooper/-S carb fuel supply tube/Tee was bent into a "J" to feed the rear carb. The straight part of the J was bolted to the top of the intake manifold. When it reached the front carb the pipe makes about a 30 degree slow bend toward the firewall and is pointed in the direction of the wiper motor. Just after the bend the "T" portion points to the lid on the front carb's float bowl. The open end of the pipe pointing towards the wiper motor is connected by rubber hose to the supply pipe from the fuel pump. It goes without saying that this pipe is connected to both float bowl lids with short lengths of rubber hose. Regardless, you don't have to do it this way. The method shown in the pictures above will work equally well. HOWEVER, keep in mind if you're going to flog this car that a common complaint about dual carb Minis in corners is occasional fuel starvation caused by the float moving "high" in the turns. Should this happen to you, experiment with turning the float bowl lids in 120 degree increments until you get the problem to go away. Longer bits of rubber hose make this possible.

For the overflow holes... they must be somewhere on the float bowl lids you have. On cars like mine these are small holes (maybe 1mm in diameter) located just below the inlet hose brass tube on the bowl lid. Your bowl lids are different than mine so the overflow vent holes may be positioned elsewhere... but they must be there somewhere. Look on the lid for any small drill hole you can't explain. Don't be looking for something you can attach a hose to.

As for why the intake manifold isn't heated... I don't know. I guess on the cars with dual carbs BMC thought it wasn't necessary.

[dklawson]

Sorry, I should have added another comment about the angled emissions tubes.

On page 25 of AutoBook (mentioned above) the two angled tubes are shown connected to each other with a "Y" and the remaining leg does go off the a crankcase breather as mentioned by BlueRedTop. However, the picture in AutoBook that shows that connection is also showing in the sketch an air pump, a gulp valve, and the big honking air filter housings used on Sprites/Midgets. I'm not saying that this setup was never used on a Mini... just I've never seen it like this. If you have any friends who own Mk1 or Mk2 A-H Sprites or Mk1 Midgets you may want to look them up or visit a club for these cars so you can see how the early HS2 carbs with these fittings connected them.

However, my thought would be to retain whatever crankcase breathers and emissions controls you currently use on your engine and cap those two ports on the carbs. It certainly would be the easiest thing!

[MINI 1]

ok , thanks will have a read.


ash

[MINI 1]

ok , i have though about what i can do with thease pipes and alot of people have have suggested blocking them off insted of connecting them to the crank case breather. i just thought if i connected a braided hose from each pipe leading to one and other this would have the same effect as blocking them off , am i right? and would look cosmeticly better.


ash

Edited by MINI 1, 05 January 2008 - 07:17 PM.

[partsguy1]

Plumb your breathers to the Carbs, I did this and the difference is great. This will eliminate all those emission gases from entering the car which makes you smell like Petrol. You will however need to richen the mixture 2-3 flats.


Terry

[minimender]

ok , i have though about what i can do with thease pipes and alot of people have have suggested blocking them off insted of connecting them to the crank case breather. i just thought if i connected a braided hose from each pipe leading to one and other this would have the same effect as blocking them off , am i right? and would look cosmeticly better.


ash

I would go with that

[dklawson]

Terry ! Welcome !!! It's good to see you here !