PCV Conversion, still confused.

[Guest]

So tell me if I understood this correctly for a 1960 thunderbird. I pop off the back of the smog tube coming out of the manifold. Then I get a convertor to run the new port to the manifold to the carb and install a pcv valve that doesn't make sense why don't you just run the smog tube to the aircleaner and be done with it why do you need a pcv valve?

Does that old smog tube just pop off or do you have to cut it off?

[Alexander]

RE: PCV Conversion, still confused.

The smog tube (blowby pipe) is attached to the transmission by one bolt on the passenger side. If you rock it back and forth while pulling it gently rearward, it will pop out of its hole on the manifold. It is just a friction fit. Lubricate the hole with WD40 beforehand will make it easier.

You cannot connect the blowby tube to the air cleaner. Most of the blowby is unspent hydrocarbons (raw gas) that get past the piston rings. If you connect the blowby tube to the carburetor then if you ever have a backfire through the carburetor, you will ignite these hydrocarbons and have a big explosion in the crankcase. Your motor may explode. Don't do it!

Besides, the engine will not run right without a positive crankcase valve in between, because you will upset the air-fuel ratio with the raw fuel in the blowby gas. At idle and low speeds the engine vacuum is high. Without the PCV valve, the engine would run too rich. It would then lean out on acceleration and higher speed.

For details on how a PCV valve works go to: http://www.hastingsfilter.com/engine...tsb_94-2r.html .

Pictures of the PCV valve conversion I did on my 1959 Thunderbird are here: http://www.squarebirds.org/pcv_conversion.htm .


Alexander
1959 Hardtop
1960 Golde Top

[Guest]

RE: PCV Conversion, still confused.

Ok I am still confused, I understand so you connect the breather tube to the airfilter. Make the 3 port connector a 4 port and connect it to the brake booster, but what do you do with that hole in the back where the smog tube is, is this where the new pcv valve goes? Where does the bad exhaust go up thru the breather? If you could draw it out I think I would understand better.

Thanks Matt

[Alexander]

RE: PCV Conversion, still confused.

In the hole in the back of the manifold you need to put in a fitting that will attach to hose that will connect to the PCV valve. 1963 Fords had these stock, but it may be hard to find this part. It should not be diffult to make from scratch. The other end of the PCV valve will connect to a brake line that then connects to the four-way port on intake manifold in the front.

Alexander
1959 Hardtop
1960 Golde Top

[Guest]

RE: PCV Conversion, still confused.

My car came with the fitting at the rear of the intake,pcv valve and connected to a nipple on the rear of the carb spacer plate. Is that as good a location for vacuum as the manifold post in front? The oil fill cap was as you described,connected to the air cleaner.

I changed it to the down draft tube,but I am going to close it back up.Thanks

Randall
1960 Hardtop

[Alexander]

RE: PCV Conversion, still confused.

That is another good option. That spacer plate I believe is what they used in 1966. I do think they now reproduce that spacer with a PCV port.

Alexander
1959 Hardtop
1960 Golde Top