Vacuum hose

J

jetthedog

New Member
Hi all, I'm on with converting my p6 from su's to holley and need to change/modify a few vacuum hoses etc, does it have to be made out anything spaecial because I've got a reel of rubber air hose that will do the job perfectly, it's the sort of stuff that we use to make air tool hoses up with about 4 mm wall, it might even be the same stuff that's used for oxy acetylene bottles, any advice welcome,
 
Hello Jett,

As long as the hose that you have won't collapse when subjected to a vacuum and the internal diameter is appropriate, then it will most likely be satisfactory.

Ron.
 
jetthedog said:
Hi all, I'm on with converting my p6 from su's to holley and need to change/modify a few vacuum hoses etc, does it have to be made out anything spaecial because I've got a reel of rubber air hose that will do the job perfectly, it's the sort of stuff that we use to make air tool hoses up with about 4 mm wall, it might even be the same stuff that's used for oxy acetylene bottles, any advice welcome,
Click to expand...

Hi Jet

You can just join the two hoses from the rocker covers and plumb them into the back of the air filter housing (inside the filter). This will have a small amount of suction to remove harmful gasses from the engine. Don't forget to use the flame traps.

There is also a thought amongst 4 barrel owners to fit a PCV valve in the N/S cover and run it into the Base of the Holley (if it has A PCV port). This will dispell a lot more rubbish from the engine, and would be better for it. The O/S can be plumbed into the back of the filter again. This has the effect of sucking harmful gasses out through the PCV valve, and replacing the air through the O/S cover - filtered by the air filter. On WOT, there may be too many gasses for the PCV valve to handle, so they may be pushed back through the air O/S hose and back into the air filter - again being fed back into the engine.

I hope that makes sense :?
 
Cheers Ron, that's what I was thinking too, I reckon it will do the job it looks like good stuff! It will definately do to get me going anyhow!
 
Quattro, what I was going to do was join the 2 out of the rocker covers and plumb them in to the pcv port on the carb, and plumb the other one (the one that goes in to the crank case) in to the inside of the air filter (another fitting to make!) How does that sound?
I had it running briefly last night but still need to plumb in the radiator properly, tonights job, thanks for the advice
 
Hi Jet

You need to use a PCV valve or it will just suck your engine inside out :shock:

OK it's not that bad, but you won't want to expose your crankcase to full engine vacuum.

Richard
 
I was kinda thinking i haven't got one now (have I? Not right sure what I'm looking for to tell you the truth!) so I wasn't going to bother.
If I do go down that road do I just join the hose from the back of the crank case and the one without the valve then plumb them into the filter? I thought i had it all sorted lol!
Dan
 
Just connect one of the rockers cover breathers, through the flame trap, to the air filter and the other one to the PCV port through a PCV valve.

You can blank the rear one off if you like.

Connecting it without the PCV just entails you plumbing the two rockers covers with a T peice, then up into the air filter. The rear one will allow air to enter the crankcase so should have a small filter put on it. Most people just blank the rear one off and connect the other two to the air filter.
 
In my 4 barrel situation I have just joined the rocker covers and rear crankcase pipes together and run a pipe to the outside world (under the car). What are the implications for this set up other than non compliance with emmision control laws?


graeme
 
ghce said:
In my 4 barrel situation I have just joined the rocker covers and rear crankcase pipes together and run a pipe to the outside world (under the car). What are the implications for this set up other than non compliance with emmision control laws?

graeme
Click to expand...

The PCV (Positive Crankcase Ventilation - although it works on negative pressure :shock: ) just cleans out the gasses in your crankcase. It keeps your engine cleaner and healthier.

The standard P6 system draws contaminated air out of the rocker covers by the vacuum at the carbs and allows it back in through the rear crankcase breather thereby cleaning out impurites and burning them in the engine.

By not having any of this, it can just allow the impurites to make a mess (quicker) in your engine.

I opted to fit a PCV system, many don't. I don't think that it's a lot to worry about, but others may disagree.

Richard
 
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