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RE: PCV valves and MGB's

To: tooze@vinny.cecer.army.mil
Subject: RE: PCV valves and MGB's
From: sfisher@Megatest.COM (Scott Fisher)
Date: Wed, 9 Feb 94 09:58:36 PST
> Hey, whats going on....now I'm completely confused!!!

I did the unthinkable last night... I Read The Factory Manual (how
about *that* for a last-minute cleanup?).  Marcus is in luck, because
the actual pictures in the Bentley manual for the MGB show a motor
with "1275" clearly cast into the side.  The Haynes manual shows the
B Series engine, which is largely similar except that of course it
has 1800 cast into the side (and the breather comes off the cam
cover, which doesn't exist on the 1275).  

> Let me describe the current system I have installed right now....
> 
> Crankcase breather tube from block to PCV valve....PCV valve
> installed to allow gas (not petrol gas) to flow from block to carbs and
> not the other way (to prevent backfireworks). 

My mistake.  Take out that PCV and replace it with a barb fitting of
the appropriate sizes on either end.

> This is a 74 Midget....and as far as I can tell from the manual....this
> set up (apart from  the PCV valve ) is correct.

Sounds like what the manuals say.  It turns out that on the MG motors of
the early '70s, the whole MOTOR is the PCV valve, more or less.  That is,
there's a flow *from* the canister *to* the valve cover (on what John 
Ross calls "system 2" PCV setups), through which vapors from the carb
float bowls get pushed through the motor and out the breather and then
get pushed back into the carbs (on S2 motors).

> Let the battle commence.......

Sorry for the confusion.  

--Scott "Dang, the manual was right again..." Fisher


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