FE-FC Holden Discussion Forum

I have a stock cast iron single carb inlet manifold on a 179 HP block and can't find a bolt or inlet hole for the brake booster hose I am trying to fit.

It has a single inlet/outlet for the rocker vacuum hose in the middle of the manifold facing facing the left front guard but no others.

Where do I fit the brake hose?

Cheers
Dave

any ideas at all? Do they usually have to be drilled or is there a hidden bolt?

Dave

AFAIK the vacuum hose always attached to a fitting on the side closest to the firewall on single carb manifolds, stock or otherwise. The setup I have now is two brass fittings piggy-backed, one for the rocker cover and one for vacuum. I reckon a wreckers would be your best bet, otherwise Redline may have something.

Hi Guys.

EH & HD cast iron intake manifolds only have one hole for vacuum take-off, The one you mentioned, just below the carby on the passenger's side.

These models don't originally come with a PCV from the factory, they have a vent pipe shaped like a walking stick. This vacuum fitting is then used for power brakes or auto trans modulator, or both.

It is not good to T-piece the PCV with the power brakes, so don't share the fitting. The vacuum available to the power booster will not be enough.

You could drill & tap a new hole or use a later alloy manifold that has provision for both. Another way is to use a PCV adaptor at the carby base. These were supplied in TRW type PCV conversion kits (in the 60s & 70s). You can't buy them new any longer, but a search of the wreckers may unearth one.

Dr Terry.

Thanks Stinky and Dr Terry,

I have a genuine alloy Holden manifold for twin strommies that I will be fitting in a few months - I assume it has the correct fittings for a vacuum hose.

In the interim, do you think I could get away with removing (and plugging) the rocker vacuum hose and using the single manifold hole for my brake booster?

I need the brakes for rego so I can move the car around to get the head and twin carbs fitted.

Surely the rocker vacuum takeoff can't make the car undrivable?

Dave

You can plug the rocker vacuum hose (for the PCV valve) but you will need a walking stick to direct the fumes generated at the rocker hole (where the actual PCV valve sits).

The hose from the rocker cover to the manifold is used to burn off any oil smoke produced in the engine crankcase, but original Holden 6 cylinders used a bent pipe to evacuate these to atmosphere. - nickname walking stick. I wouldn't think that they would be an easy thing to get these days - I was lucky enough to get a brand new one a few years back that had spent its life pulling shut a roller door in a panel shop!!

Here's a shot of my standard 149 including walking stick.

Thanks Craig,

sorry i didn't quite understand what Dr Terry meant by walking stick but now its all too clear.

I should be able to get something made up at a local brake engineering place I use.

Once I've made something to get rid of the sump gas, I should be able to use the original vacuum fitting for the booster...right?

Cheers
Dave

Yep, the orginal fitting should be fine for your power brakes. If you wanted to check get a vacuum guage and check to see if you have around 12"Hg at idle.

IMHO a vacuum guage is one of the most useful tools you can have - use 'em to set timing, fuel mixture, check for mechanical faults, EVEN check if your manifold connection is right for you booster  ;D

Good Luck,

Craig.

Cheers Craig! Sounds like a plan  8)  Might go and out and shout myself a guage... you can never have enough tools  ;D

Dave

Hi Guys.

You should still be able to get 'walking sticks' 2nd hand at wreckers, they were used on EH, HD & early HR (up to mid-67), that's over 1/2 million cars.

By the way Craig, you mentioned vacuum at idle for a Grey motor. A good motor, with it's original cam & in a good state of tune should get around 17" to 19" hg.

Dave_EH mentioned using an X2 manifold, these again have provision for a power brake vacuum fitting, but no provision for PCV. Don't 'plug-off' the PCV hose, find a walking stick or vent it to atmoshere, with no valve in the line.

Dr Terry.

Thanks Dr Terry

I'm happy now :D

I went to the wreckers today (Early Holden spares and repairs, Greenslopes - Brisbane)...  He had heaps of "walking sticks" hanging up ready to go.

Apparently people come in for them "all the time"

Dave

hi y'all, on a similar note, is it a requirement to have the hose (pcv) running from the rocker cover back into the inlet  manifold on a 186 ( not sure of vintage) or can i get by with a aftermarket mesh type breather/air filter. similar to a K&N. motor was previously running single carb with hoses running to both brakes and pcv valve.
im running twins and on the manifold there is only a single outlet for vacuum
any suggestions.
thanks
dean

Here's a pic of the fittings on my manifold, for both brake vacuum and PCV. I had no trouble with set-up on a Torana for a few years, hopefully it's the same in the FE. Not sure where it came from though, my mechanic fitted it.

headers look sweet stinky are they jet hot coated ??

ive got  a similar valve floating around the garge if i remember, question is though is it a requirement for rego or necessary for engine perfomance/ economy to use the pcv valve or as mentioned can the fumes from the rocker cover just be 'vented'. pardon the ignorance.
just trying to clean up the engine bay a bit.
cheers

We have a place called PowerKote in Adelaide that does the ceramic coat. $200 later, my only regret is that I should have detailed the headers first as there are a few bits of welding spatter from manufacturing.

As to the PCV, not sure about rego requirements, but it saves a mess on the rocker cover if you intend to run a breather cap.

cheers mate  ;)

Stinky,
The fitting in the pic looks like its for a brake vacuum hose and a auto trans vacuum modulator hose.
As Dr Terry says in a previous post" It is not good to T-piece the PCV with the power brakes, so don't share the fitting. The vacuum available to the power booster will not be enough"
In most cases the P.C.V. fitting is mounted under the carby or in the centre of the manifold to disperse the crankcase fumes evenly.
Smithy,
You could use a "walking stick"on your engine or drill and tap the manifold.
Hope this helps,
Regards ACE  8)

Cripes Ace, thanks for that, now that I think of it there is a carby spacer I have for this set-up that is drilled and fitted for the PCV hose. I clean forgot about it.
Thanks again, now I gotta find the bloody thing  ???

just another question, as discussed that there might not be enough vaccuum to operate the booster, i found the piggy back piece in question, one thing i did notice is the outlet for the booster is the correct diameter ( a J bent pipe coming off the fitting) while the second is a smaller diameter hole / tube above the J bend which i assume is for the PCV valve. question is would this setup suffice as there should be enough vaccuum to operate the booster while drawing through vapours from the tappett cover???
i will try and post a pic if anyone is interested or to show the setup better better
dean