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Posted by: era vulgaris Dec 25 2013, 06:40 PM

I'm trying to source the lower air guides for my cooling tins, since they are missing. How much difference is there in these parts from model year to model year? I'm guessing the difference is due to the change from tail shift to side shift, or?

I'm running into different info from different sources.
For example, Pelican Parts' diagram says that the passenger side tin is good for all years, but the driver's side tin is split into two variations: 70-72 and 73-74. http://www.pelicanparts.com/914/parts/engine/engine_compartment_sheet_metal_large.htm
They say that 022119356A is for 70-72. But Auto Atlanta says that part is for 73-74. http://www.autoatlanta.com/Porsche-022119356A-srch.html

Who is right?

BTW, I've got a '72 1.7 but it's been modified to side shift. So which one would I want - 022119356A or 022119356B, or does it matter?

Posted by: rhodyguy Dec 25 2013, 07:23 PM

#3 in the diagram @ pp is for tail shifters. pictured item in the link @ aa is the drivers side for 73-74 heat exchangers 1.7/1.8 or 2.0 and a ss trans. you can prob source one in the classifieds for less than $64. whether that 64 includes shipping and handling i have no idea. shipping should top out $8 or less via priority mail but not in a flat rate box.

Posted by: euro911 Dec 25 2013, 08:30 PM

My wife's '71 has those tins. I'll need to swap the driver side for a side-shift style tin after the 'new' trans goes in, but I don't run with them on the 'BB'. I think they're more effective for the cold climate areas, no

Posted by: McMark Dec 25 2013, 09:42 PM

Three different variations:

Tailshift - This version has the tin go under the shift rod on the DS.
Sideshift - This version has the tin go over the shift rod on the DS.
* These two are the same on the PS, IIRC.

75/76 cars - This version is completely different on both sides.

Posted by: r_towle Dec 25 2013, 10:24 PM

I think Mark may mean that the 75-76 tins are unique due to different heat exchangers.
Those years had both the 1.8 and 2.0 liter motors.

Early 1.8 motors had the same heat exchangers and tins as the 1.7 and 2.0 liter motors, with the specific differences being the transmissions.

Posted by: McMark Dec 25 2013, 11:25 PM

Ah, I never was exactly clear what cars came with that exhaust. Just looked at that area in the PET. It's 75/76 cars regardless of engine just like you said.

Editing above...

Posted by: rdauenhauer Dec 25 2013, 11:25 PM

Posted by: era vulgaris Dec 25 2013, 11:32 PM

I figured just by searching for images of 73-74 that that one pictured at aa was the one for the ss trans. My concern is the part number. I've found both part numbers from other sources for about $25, I just want to make sure I'm ordering the right one. Being that the only difference in part number is the letter, I'd assume that "a" being earlier than "b" is for 70-72, but the aa part number/pic disagrees with that. That's where my confusion stemmed from.




Have you had any overheating or running hotter than normal issues not running the lower air guides? This is my first type 4, but I come from the type 1 world and not running lower air guides on a type 1 does make a difference in temps. I'd think they'd make more of a difference in hot climates since they're used for channeling hot air away from the engine, but I might be wrong.

Posted by: euro911 Dec 25 2013, 11:46 PM

Valid question and I'll defer to someone more knowledgeable, but my temps appear to be well within safe boundaries

Posted by: McMark Dec 26 2013, 12:15 AM

Actually, I think the lowest air guides are meant to keep cooling air from blowing downward with as much force. Seeing a 914 driving on a dirt parking lot illustrates why. The cooling fan can blow dirt everywhere. In my experience, most cars aren't running them.

Posted by: rhodyguy Dec 26 2013, 07:54 AM

some degree of protection for the push rod tubes too. they tie the heat exchangers to the case rather than the only connection points being the exhaust studs and rear hanger. the smart guys at porsche put the guides on for a reason.

Posted by: McMark Dec 26 2013, 11:16 AM

I'd say the exhaust connection is more about a convenient mounting point for the tins, and off no support whatsoever for the exhaust.

Posted by: Cap'n Krusty Dec 26 2013, 11:20 AM

I'm sure Bruce Stone has a few. Give him a call or PM.

The Cap'n

Posted by: rhodyguy Dec 26 2013, 12:58 PM

fwiw. my paper aa catalog shows 3 numbers for the dr side warm air PLATES. p 178 part #6. #039 119 354 for 2.0 right (should be left) 1975-76 2.0. for right (should be left) 1970-72 #022 119 356. for left (got it right this time) 1973-74 1.7/1.8 (should include 2.0 4 cyl) #022 119 356 A. you'll need to ask exactly the right ?s to get the correct part. would you want me to post a couple of pictures of the correct PLATE?

don't recall stating the PLATES support the exhaust (muffler). to me the exhaust connection is the heat exchanger to muffler which has nothing to do with how/where the PLATES connect to the heat exchangers.

Posted by: rdauenhauer Dec 26 2013, 01:59 PM

OK Ill bite.. Kev do you have a pair of the LATE (75-76) lower plates out in your shed o' parts?

Posted by: r_towle Dec 26 2013, 03:06 PM

Never thought of that, and I have the right parts....
I have had them on and off over the years...currently on the bench

I suppose putting them back in place just went on my list again.
Camshaft first....
Need to try a new one...see how close to un-drivable I can make it...
Welding a bit, hopefully during the break in action this week.

rich

Posted by: euro911 Dec 26 2013, 03:30 PM

So then, if they push air rearward, they'll provide more forward thrust ... no need to paint your car yellow

Posted by: era vulgaris Dec 26 2013, 04:28 PM

Cool, I'll ask him. I think I just bought a taco plate with the temp sender in it from him.




That would be awesome if you have a picture so I know which one I'm looking for!




They actually push air forward. These engines were designed to be rear mounted in the 411, 412, 912E, and I guess they never redesigned the tin when they flipped the engine around for this car, hence the need for the air deflection plates at the bottom of the fire wall to move the air that's flowing under the car out of the way of the air coming out of the cooling tin.

Also something I was thinking about…without the air deflection plates (which I also don't have) is air going to be rushing the wrong way up the cooling tin if I do add these lower air guides?

Posted by: euro911 Dec 26 2013, 04:54 PM

I don't remember which way they deflected ... never saw them (anywhere) until we got my wife's car and been a long time since I've been underneath there.

I thought they were open facing towards the rear of the car though


I'd think the plates would be different on a 411 or a 912E anyway - since the engines are rear mounted in those cars, the shift rod doesn't pass by the engine.

Posted by: era vulgaris Dec 26 2013, 08:56 PM

They are definitely open facing forwards, pushing air towards the front of the car. The same as if you mount a type1 engine in a 550 replica.
The air guide plates only face towards the rear of the car in rear engine applications.

Consider where part #20 is in relation to part #27 in this diagram:
http://www.autoatlanta.com/porsche-parts/hardparts.php?dir=porsche-914-parts&section=115-05
#20 is at the rear of the engine deflecting air forward across part #11 (the lower air guide). Likewise, part #21 is deflecting air forward across part #12 over on the driver's side.
The air from the cooling fan flows in a sideways U-shaped direction. From the cooling fan towards the back of the car, across the cylinders above the baffle plate, and then downwards and back forward above the lower air guide towards the front of the car.

Posted by: euro911 Dec 26 2013, 10:24 PM

Well, another good reason not to use them then

Posted by: Cupomeat Dec 26 2013, 10:43 PM

The lower air guide(s) also help to keep the thermostat at full open position without outside air hitting it and causing it to shrink and reduce the air flow from the fan.

I have them on and would stick with what the smarty pants engineers designed at the factory.

Posted by: reharvey Dec 26 2013, 11:26 PM

Posted by: rhodyguy Dec 27 2013, 12:02 AM

rich, i might have a few pieces in the ducting bins. no pictures of the late ones. why would i have any?

anyway…you want a plate that looks like this. first picture is of the bottom side. the rear rod sits below the half tunnel in the end view.


Attached thumbnail(s)

Posted by: rdauenhauer Dec 27 2013, 12:13 AM

no. the late ones

Posted by: rhodyguy Dec 27 2013, 12:17 AM

like i wrote. there must be some pictures in the $9.14 parts thread.

Posted by: euro911 Dec 27 2013, 12:51 AM

Understood. I guess if I resided in a cold climate, I'd be concerned and would probably have them. Living out west, it doesn't appear to be a problem from what I see. A lot of us don't run thermostats either ... we just pin the flaps full open.

Curious though, if the T4 engines (and all the tin air ducting components) were originally designed for a rear-mounted application, why did the engineers create these plates to 'exhaust' forward when utilized on a mid-engine application?