1974 CIS Airbox replacement questions

[TRACKS]

Hi all -
This is my first posting here.
Been around here a while reading all the great info.
I am in the process of replacing a blown Airbox on my '74 ( surprise surprise )
The car has 75,000 miles on it. Sportomatic transmission.

Over the last year , my father-in-law and i have been getting it running.
We had been suspicious that the box was a little cracked ... and then one cold morning it popped and finally gave out.
Before that, the engine was running pretty smooth once warmed up.

So now, the old box has been removed as well as all the connected items, hoses etc.
I've been ordering parts for a couple weeks in preparation for the big reinstall.
New Airbox was ordered and received last week.

I'm replacing some things while I am in there such as the old breather lid gasket and old breather hose.

QUESTION :
Does anyone know the torque spec for the bolts on the oil breather lid ?


I also was going to get a new O-ring for the cold start valve but I'm thinking that the new Airbox actually came with that O-ring ( when i received the Airbox i remember it coming with O-rings and the plastic adapter that mounts to the cold start valve )
Can anyone confirm that ?
I don't have the stuff in front of me right now to look at it.

Also , my old oil pressure switch and oil temperature switch were operating correctly at the time I started removing the CIS system. I was thinking about just replacing the gasket / seal for those and keep my temperature switch and pressure switch.

At this point I am cleaning and/ or replacing every part i come across and waiting on parts to arrive.

thanks for any help -

Kevin

[ninelevenick]

Welcome to your official debut on the Forum. I'm not sure what you mean by the "oil breathing lid." On my '79 there is an oil breather hose that attaches indirectly to the air box. The only other idea that I have is the crankcase breather hose mount located on top of the engine. Not sure what the torque specs are for that.

[TRACKS]

Nick -

Yes , its the oil breather hose that connects on top of the engine. That connection is the oil breather lid / cover.

I believe its 4 bolts on top.

On this link , #37 is the lid I am talking about and #39 is the gasket I am replacing.
http://www.porscheatlantaperimeterparts.com/showAssembly.aspx?ukey_assembly=472369

thanks
Kevin

[ninelevenick]

I just poked through my Bentley manual. Couldn't find the torque specs.

[Dpmulvan]

8.1 ft lbs or 11nm.

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Dpmulvan -

thanks !

[TibetanT]

Breather lid torque specifications is 6 lbs ft.

Hope this helps

[TRACKS]

uh oh -

8.1 or 6 ???

[jason2guy]

the torque? really
with all the resources available at ur fingertips you should have 4 or 5 manuals for the car on ur computer in pdf form.

look around

[gazzerr]

When I got my new airbox it came with all the o-rings. You also get 2 pink phenolic housings for the cold start injector. One is blocked off and one is not for the intake bypass. You need to make sure you install the right one for your year of car.

[47silver]

since you have access:
oil cooler o-rings.
fuel injector o-rings and inserts
oil pressure switch that is on top of the engine.
o-ring on engine mounted thermostat.
rubber connectors.
rubber supports for the air box, they get compressed.
rubber tie down straps on the air box.

[gomezoneill]

You don't need a torque spec for a certain cover or part you can get the spec's for the fastener size. most 6mm torque spec is the same 8'lbs as are 8mm,10mm and 12mm so forth.

here's a link that will help.

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&cad=rja&uact=8&ved=0ahUKEwjpyoec_NvLAhUCCz4KHefHBbEQFggfMAE&url=http%3A%2F%2Fwww.dansmc.com%2Ftorque_chart.htm&usg=AFQjCNEv0h_0n3bgyGpzeXyT6xl2bmkHKA&sig2=QCPD5CXGQoVIEXyCCf5w2A

[TRACKS]

thanks everyone -

gomez - thanks , thats very cool - I've never knew about OR have seen that before.

47silver - I've got everything you mentioned except the rubber supports for the airbox, thats a good idea. Mine are kinda soft.

gazzerr - thanks for the reply on what comes with the air box, I will make sure I double check that housing connector - that would suck to put the wrong one on

I should be hitting this pretty hard in the next week or two.

Kevin

[gazzerr]

Sure no probs good luck. One of the other guys accidently installed it and if I hadn't of read that post you can be assured I would have done the same thing. It's not obvious until you look inside the housing .

One other thing I discovered I just remembered. There is a drain hole in the box for earlier cars under where the air sensor plate sits. You need to seal that too. You can tap out the plug from the old box and reuse it (at least my old box had a plug). My new box didn't come with one. I figure you don't want any unfiltered air getting sucked in through that drain.

So worth doing your airbox and replacing all the seals, hoses and injectors and o-rings. My car purrs now.

[TRACKS]

Hey gazzerr -

I took a look at my new Airbox and in the center in the back there is indeed a hole - looks like a drain hole.
I looked at my old box and it has the same hole.
If you look underneath the box, that hole goes into a plastic tube a few inches long.

Neither my old box or the new one has the hole plugged.

Are you sure its supposed to be plugged at all and not left open ?

thanks
Kevin

[E Sully]

The drain hole went to a metal cylinder, part# 911 108 021 02, with a rubber flap valve, part# 253 260 180, on the end. The rubber valve allowed oil from the air box to drain out and prevented air from being drawn in.

[gazzerr]

If you don't have the metal cylinder I'd plug it so you aren't getting unfiltered air sucked in. Mine was definitely plugged but mine is an '82.

[47silver]

Newbie Air box oil leak ,,,, no drain pipe?

[theiceman]

also don't forget about the throttle plate bushings, it sits right there on top and is easy to get to , I am assuming your 74 is the same as my 78.

[TRACKS]

theiceman - are you talking about the throttle body O-ring ? If so , yes , I'm replacing that.

or is it something inside the throttle body on the throttle plate cam ?