PCV valve installation

[NigelT]

I'm slowly making my way through the SB100 process for my newly acquired 98 Caterham 1700 crossflow. We failed the smog exemption test due to lack of a pcv valve. Seems they're not letting this by anymore. Apparently I need to have two holes drilled in the valve cover (or find a special oil filler with a tube vent and drill just one hole), run one tube from there via the pcv valve to a vacuum source and the other to the air filter box. I don't fancy doing this myself.

Any recommendations for somewhere I can have this done in the LA area?

Any general advice on this topic also welcome.

NigelT

[Doug Liedblad]

What engine do you have?

I have a Zetec and there is a canister on the left side of the engine that the PCV valve is located. Typically all you need to do is route a hose from the PCV valve to the air intake, so any blowby is drawn thru the throttle bodies.

I don't know exactly how Duratec's do this but will check someone that had to do the same thing earlier this year. (V-Robb)

Doug

[NigelT]

What engine do you have?

I have a Zetec and there is a canister on the left side of the engine that the PCV valve is located. Typically all you need to do is route a hose from the PCV valve to the air intake, so any blowby is drawn thru the throttle bodies.

I don't know exactly how Duratec's do this but will check someone that had to do the same thing earlier this year. (V-Robb)

Doug

It's a Ford Crossflow - circa 1966 design hence no provision for a pcv valve.
Nigel

[Doug Liedblad]

Nigel

Usually even the older blocks have some sort of crank case vent.

The PVC would go from there to the carbs or throttle bodies. If not from the valve cover should work too.

Are you in the LA area?

Do you have a temporary permit so you can drive it legally?

If so try to make Super Car Sunday in Woodland Hills this Sunday. We'll take a look and figure it out.

Doug

[NigelT]

I think you may be right about there being a breather tube directly from the crankcase (I need to check). That would save messing with the valve cover if I can get an oil filler cap that can vent to a tube and take that to the air cleaner, I think (current cap has just a tiny hole venting to the outside, which is a no-no apparently). I still need to figure out how to plug the crankcase vent into a vacuum source via a pcv valve.

Unfortunately(?) I'm flying to Hawaii tonight so can't make Woodland Hills, but thanks for the offer. Maybe we can hook up when I get back in a week. But that assumes I can take care of my other problem - insurance. That is also a work in progress.

Nobody said this would be easy...
Nigel

[Doug Liedblad]

You don't really need a vacuum source. It just vents into the intake track before the carbs.

The purpose is to run any crankcase emissions thru the combustion chamber and burn it off.

I just took my car to State Farm and they had no problem with insurance.

[escondidoron]

On the Kent engines, as delivered from the factory, I think that there is a small canister on the distributor side of the block, somewhere around cylinders 3 and/or 4. When removed from the engine it looks like this:



The large end pushes into the block and the small nipple end is where you would connect a hose to the engine air intake, typically to the bottom side of the air cleaner. A PCV valve is installed in-line on this hose.

If the canister is not present, not to dispair, just make a tubing adapter so that an appropriately sized hose can be fitted to the port on the block and route the hose, PCV in-line to somewhere convenient on the engine air intake side, best if upstream of the butterflies.

If you can find a '66 or later Cortina, Anglia or Capri or Pinto with the x/flow engine they would have had just such a system.

[NigelT]

What you are saying makes sense to me but the inspector was adamant that it needed to be a closed system hooked up to a vacuum source. I may just have to go back to him for clarification.
Nigel

[Doug Liedblad]

By all means get clarification.

My suggestion is to plumb the PCV valve either from the breather can on the block or the from valve cover to the intake (before the butterflys). This should be the only outlet for the block (closed system) so all fumes go thru intake (vacuum source) and into the combustion chambers.

You should then pass when you get there.

Which one did you go to?

Several of us have used the one at Pierce College.

[NigelT]

Doug,
I went to Pierce College. I believe the system you describe is not actually a closed system in their minds because the oil filler breather cap is vented. The inspector showed me photos of a system similar to the one you describe on a Caterham that went back to him after he failed it initially for having nothing and he failed it again with this system installed. He told me they used to let this fly in the past but are no-longer doing so.

I'll let you know what I find out when I go back to him.

But, again, I see your point. The only purpose the vent on the cap serves is to draw air in to replace the gases drawn out through the pcv valve when opened by the vacuum. Normally I think this is supposed to be filtered and one of the systems he showed me ran a tube from a vented oil filler cap to the inside of the intake filter box. Now that makes perfect sense to me. What doesn't make sense was that he said the tube didn't have to go into the filter box, rather abutting the outside of the filter would suffice. What purpose that serves beats me.

Nigel

[Doug Liedblad]

As long as the tube vents next to the air filter, it will draw any crankcase fumes into the intake manifold and run them thru the combustion chamber.

I don't think the PCV valve needs a vacuum to open, it's actuated by the pressure in the crank case. I've put my hand on one in the past when the engine was running and you can feel it pulse.

If I remember when they used to retrofit PCV valves to cars you had to replace the breather cap with a sealed one. The PCV valve actuation allows air in or out of the crankcase. I think.

Anyhow, listen to the guy at Pierce and you'll pass. Once passed you won't need to be reinspected every two years.

Doug

[slomove]

More Detail

[Doug Liedblad]

More than I want to know.

[slomove]

Knowledge is Power

[Sean]

It would seem to me that if one is registering under Section 44017.4 of the California Health and Safety Code by chassis and not engine, and claims the intent to replicate a Lotus Seven from 1960 or earlier, then a PCV valve should not be required, as they were not in use on passenger vehicles before 1961. Or have I missed something? :confused:

edit - linked text replaced "SB100"
edit 2 - fixed goofy link, but you have to search on your own