I don't know what this is... (A15 related)

[Fitz]

Sorry for no (quality) pics! (shop is closed at 5)

 

So I have these 1/4-1/2" stainless pipes coming out of the sides of my exhaust manifold ('Sides' being the relative front and back of engine). They run up and over the valve cover and end capped off. Also on the bottom of the manifold is a wire&fabric 2" 'pipe' coming off. My old A14 had a 2" port in the same spot, but it was on a metal cover for the manifold, and you could see the manifold through/underneath of it.

 

Crappy pics: http://imgur.com/a/oqNsp

 

 

Is this some sort of exhaust turbo set up, or what? There must have been some reason for wanting to pipe into the exhaust...

[datsunaholic]

EGR piping, or the air injection system. Both are emissions systems.

[Eagle_Adam]

emission stuff

 

Edit: datsunaholic beat me

[Fitz]

So........... It just has these plastic caps on it, they might pop off. Any way to remove it, or make it more 'aestetically pleasing'?

[datzenmike]

So I have these 1/4-1/2" stainless pipes coming out of the sides of my exhaust manifold ('Sides' being the relative front and back of engine). They run up and over the valve cover and end capped off.

 

After every exhaust pulse there is a small vacuum pulse. This vacuum pulse can be used to suck filtered air into and mixed with the exhaust.This extra oxygen helps the catalytic converter burn off waste hydrocarbons. To prevent exhaust backing up the pipe into the air filter a one way reed valve is installed. This system is passive and requires no power to run it and is has zero effect on the motor power.

 

 

Also on the bottom of the manifold is a wire&fabric 2" 'pipe' coming off. My old A14 had a 2" port in the same spot, but it was on a metal cover for the manifold, and you could see the manifold through/underneath of it.

 

This sounds like the warmed air systrm for the carb to speed engine warming and prevent carb icing. There is a vacuum operated valve in the air filter snorkel that opens when it's cold and draws warmed air from a sheet metal covering on the hot exhaust manifold. There is a metalized pipe running from the manifold up to the air filter snorkel.

[ggzilla]

The fabric tube is for the heated air cleaner. It helps most in the winter. Maybe all year in the 'Couve BC.

Here is it in aftermarket silver:

[ggzilla]

Yes, the stainless pipes are for the air induction system. They are 1". You can remove the pipes and cap off the opening. I used a nickle on each side.

[Fitz]

Okay, heated air cleaner makes sense. I've read about it on here that it 'maintains' a constant temperature or whatever. How would I set that up with my Weber though?

[LenRobertson]

Okay, heated air cleaner makes sense. I've read about it on here that it 'maintains' a constant temperature or whatever. How would I set that up with my Weber though?

 

Here is a How-To on adapting the stock air cleaner to a Weber: http://community.rat...page__hl__weber You may or may not like the look and quietness of the stock version vs the little open air filter usually found on Webers. As far as I know, the wire/fabric tube from the lower exhaust manifold is primarily to prevent carb icing (although I suppose the warmer intake air may have had some smog control benefit). I've experienced icing twice - with my '70 Maverick and with my '79 200SX. Both were running the stock aircleaner, but without the fabric hose to the manifold. Both times the conditions were outside air temp right at freezing and a really wet snow falling. I suspect if it is colder and drier, the carb wouldn't ice, but don't know for sure. When a carb ices up, it acts like the choke is stuck on - starts chugging and bucking and running really bad. Eventually, you have to pull over to the side of the road cause you don't have power enough to keep going. If you sit there a few minutes, the engine heat melts the ice and you are fine to go - for just a few more miles till it ices again. So you can probably limp home, but it will ruin your day. Depending on temp/humidity where you drive, you likely will never experience carb icing. If it is something that worries you, one idea would be a modded stock air cleaner for winter driving and an open Weber version for warm weather. Or maybe Webers are immune to icing.

 

Len

[datzenmike]

Yup. It's a simple thing that make driving more enjoyable. If you live where it gets down to below 40F and is damp you need this.

[Fitz]

Well, it gets down to about -30F at some points.......

 

Okay, is there a newer alternative to a modded stock air filter? I don't have the original. It'd just be some cutting work in the bottom, right?

[ggzilla]

The purpose of the heated air clean if to be found in your Datsun owner's manual. It is primarily to keep the intake air temperature a constant temp summer or winter. Even in hot places like California. The constant temp allows razor sharp jetting for maximum Fuel Economy with minimum emissions.

 

Secondarily it also helps prevent carb icing, which can occur as warm as 39 degrees ambient. Before the 1970s this was the primary purpose.

 

Your weber carb is probably not precision jetted so you won't notice any difference.