Omega Owners Forum

Chat Area => General Car Chat => Topic started by: MartinP on 14 November 2009, 23:47:56

Title: Alternator inc vac pump
Post by: MartinP on 14 November 2009, 23:47:56

This might be the answer to one of my challenges on the kit car.

I have a 3.0 ltr V6 and will have no brake servo, so I need to generate a vacuum from somewhere to operate the multi rams

I have found a couple of alternators with a vac pump on the back end.
I will be mounting it in the position of the power steering pump as I have no use for that either  ;)

Anyone had any dealings with a Bedford rascal or one of the small Mitsi's with one on?

Martin

Title: Re: Alternator inc vac pump
Post by: Kevin Wood on 15 November 2009, 10:01:23

Why can't you still use the vacuum from the plenum? :-/

It's still there regardless of the brake servo. :y

Keivn

Title: Re: Alternator inc vac pump
Post by: Marks DTM Calib on 15 November 2009, 11:57:26

Yep, engine vac is there......the servo uses the vac, it does not generate it.

The alternators with the built in vac pumps are for diesels.

Title: Re: Alternator inc vac pump
Post by: Elite Pete on 15 November 2009, 18:02:53

Quote

Yep, engine vac is there......the servo uses the vac, it does not generate it.

The alternators with the built in vac pumps are for diesels.

Yep, there's one on my Rover 25 diesel ;)

Title: Re: Alternator inc vac pump
Post by: MartinP on 15 November 2009, 22:32:12

Thanks guys.

How is the vacuum generated?

I still need to get a small alternator as the dirty great big one is in the way of the steering column.

Martin

Title: Re: Alternator inc vac pump
Post by: Kevin Wood on 15 November 2009, 23:52:29

Quote

Thanks guys.

How is the vacuum generated?

I still need to get a small alternator as the dirty great big one is in the way of the steering column.

Martin

By the pistons trying to suck air in through a closed or partially open throttle. :y

The inlet manifold on any petrol engine will be a partial vacuum under all conditions except full throttle running (hence the reservoir on the multiram system). It's a convenient place to tap off a vacuum supply for the brake servo and other ancillaries.

Diseasels don't have a throttle, so pull no vacuum, so need a pump.

Kevin

Title: Re: Alternator inc vac pump
Post by: Marks DTM Calib on 16 November 2009, 08:44:11

Even under WOT there is still a partial vaccum thanks to restrictions in the inlet.

Small alternator....maybe a Corsa one?

Might have a smaller Cav one here you can have (might want new bearings or a reg though)

Title: Re: Alternator inc vac pump
Post by: MartinP on 16 November 2009, 19:00:13

Thanks for the info.

I don't need the alternator just yet, may give you one back as I think I have 3 off Omega's in the garage now.

Martin