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Boards => Technical => Topic started by: John Nguyen on June 26, 2019, 05:55:31 PM

Title: Manifold Air valve to move in active positions
Post by: John Nguyen on June 26, 2019, 05:55:31 PM
I'm trying to get the Manifold Air valve in active moving again, it is frozen now

what is the best way to have the Air Valve moving in Open & Close mode.

Thanks
John
Title: Re: Manifold Air valve to move in active positions
Post by: Scott Montoney on June 27, 2019, 07:37:53 PM
Well, I suppose the first thing I would try is to soak it in penetrating oil for several days.  Put some heat to it from time to time, maybe lightly tap the ends of the shaft, all trying to get any movement at all.
Once there is even a little movement, then you know that the oil will be able to continue to get deeper.
Keep working it and I expect it should eventually loosen up.

Another option might be to grind away the spot welds that hold the flap to the shaft, and then press the shaft out, but I'd still make every effort to get the shaft loose first.  Once it is all apart and cleaned, when re-assembled, just re-weld the plat to the shaft.

Title: Re: Manifold Air valve to move in active positions
Post by: Ted on June 30, 2019, 10:58:17 AM
What happened to mine: after weeks of soaking, little heat and gentle tapping, it never moved. More soaking, hammering /through a brass piece, not to damage it/ - nothing. The story ended with the torch. A skilled friend heated it red and with just a little tapping it moved. But he carefully heated it, little by little and not just the spot, as the cast may crack.

BTW I read somewhere it was useful /more or less/ for the old, low octane fuels. And the modern fuels don;t need it, so it may stay closed. Is that right?
Title: Re: Manifold Air valve to move in active positions
Post by: CraigS on July 01, 2019, 04:55:22 AM
The purpose of it was to close off the exhaust manifold so that warm air was directed into the engine, thereby warming it up faster. Once the bi-metal spring warmed up, the valve opened and exhaust was directed to the rear of the car. Appropriate for cold climates, but not much use in Australia. Not really fuel related. There is no harm in having it working, but you will need the appropriate grease to keep it working.