Printable Version of Topic

Click here to view this topic in its original format

914World.com _ 914World Garage _ Overheating

Posted by: ash00 May 2 2016, 12:15 PM

Hi All,

After a month and a half of business trips, I finally got to drive my the 1970 914 that I'm still learning about.

One thing is clear, that the restoration was half-assed, and rather than blaming the PO, I have to figure things out the hard way. Hopefully before the fact. I'm trying to not let this leave a bad taste in my mouth of the 914 experience.

The recent issue is overheating. This is my first car in the aircooled world, and the car was equipped with a rebuilt 2.0L with the weber downdraft setup in place of the FI. It runs well when warmed up, but during driving, I can't drive it for more than 10 minutes without the gauge being pegged to the red. I'm hearing things of "false air" and such.

Pardon my ignorance, but I need a place to start looking for info. Is there any documentation or info out there on how the air cooling is managed, and what hardware is there for me to test / check? Any tips are appreciated.

Thanks,
Ash

Posted by: Porschef May 2 2016, 01:18 PM

welcome.png

Hey Ash,

You might want to check the gauge for accuracy first, then make sure there's no mouse nests/ obstructions in the cooling fins and that the flaps are operating properly. Also, that the oil cooler has air flow.

I have a kitchen thermometer with a long probe; something like that might be able to tell you how hot your oil is by putting it down the dipstick tube.

If you're over say, 220-230, then there's other issues at stake.

Good luck.

Posted by: ash00 May 2 2016, 01:29 PM


Great Idea. i have a fluke with a TC. I'll try that out. I'll first check at startup, idle for a few minutes, then driving for a bit and seeing what it is at halfway, then 3/4 then at red.

Posted by: injunmort May 2 2016, 01:35 PM

after checking what joe suggested, i would first check the timing. then check jetting in the carbs. i would not drive it until you get a handle on this problem, if the gauge is right and timing and jetting is off, you can easily hole a piston.

Posted by: ash00 May 2 2016, 01:37 PM

Definitely.

What should timing be set at?

Posted by: injunmort May 2 2016, 01:44 PM

34 degreess btdc fully advanced. good tech article on pelican parts site on the procedure.

Posted by: SirAndy May 2 2016, 02:25 PM

Also make sure your cooling flaps are installed and operating correctly.

There is a LOT of misinformation about those floating around and i have even seen "rebuild" engines where they had been removed completely.
wacko.gif

Posted by: injunmort May 2 2016, 02:28 PM

i had a rebuilt engine in my dd that had the flaps removed. needless to say i replaced it over the winter.

Posted by: brant May 2 2016, 02:59 PM

top of my head.... I thought factory timing was supposed to be 27degree's

usually on a carb'd car with any cam in it... slightly higher than stock is good for power
especially at altitude
but sea level, maybe not so much

Posted by: injunmort May 2 2016, 03:16 PM

i think 27 degrees is for stock distributor advance fi. i did mine according pelican with stock cam and new dist. at 34, weber 40's and it runs about as well as it can with the cam/carb combo. did not like 27 degrees at all.

Posted by: era vulgaris May 2 2016, 03:33 PM

Since this is your first air cooled car, let me ask what RPM do you typically cruise at?
If the answer isn't between 3k and 4k rpm, then you're doing it wrong. The cooling fan is bolted to the crankshaft, so in order to get enough cooling air moving, you need to cruise at higher rpm than a water-cooled car.

Also, there's a valve (can't remember what it's called - oil pressure relief/oil pressure release...something like that) that allows oil to bypass the oil cooler when cold to aid in warm up. Over time it can get worn out and not allow enough flow to the oil cooler when the engine is warm.

Also, just FYI, the temp gauge only measures oil temp. Not sure what you mean by "false air".

Posted by: ash00 May 3 2016, 11:34 AM

I appreciate all the help guys! Looks like I'll have to do some digging. I have to find what the flaps look like and see if I do have them.

I'll have to run the temp test on the oil. If that is the oil temp I'm reading, then I have to see what is restricting or causing it to get hot quicker than normal.

Any links or pictures as to what the cooling flaps are supposed to look like so I can compare?


Posted by: SirAndy May 3 2016, 11:58 AM

QUOTE(ash00 @ May 3 2016, 10:34 AM) *
I have to find what the flaps look like and see if I do have them.

This should help:
http://www.914world.com/bbs2/index.php?s=&showtopic=193479&view=findpost&p=1732173
smile.gif

Posted by: era vulgaris May 3 2016, 12:09 PM

You won't be able to see the actual flaps as they're under the cooling tin. But you will be able to see the bar that links both flaps together. It'll run across the engine behind the oil filler tower. You can see it in the pics SirAndy linked to.
If you do have the cooling flaps installed, then you should also check to see if you have the thermostatic bellows that operates them. The thermostat is kind of below the pushrod tubes on the drivers side, it looks like a set of bellows, and there should be a wire that runs from it up through the cooling tins and connects to that crossbar that the flaps are attached to.

Posted by: ash00 May 3 2016, 02:23 PM

Awesome- that helps.

I assume that the flaps are actuated from red lever by the shifter?

Posted by: Racer Chris May 3 2016, 02:37 PM

QUOTE(ash00 @ May 3 2016, 04:23 PM) *

Awesome- that helps.

I assume that the flaps are actuated from red lever by the shifter?

No, the flaps are automatic.
The red lever opens the flappers on the heat exchangers to move heat into the cabin.

Posted by: era vulgaris May 3 2016, 04:41 PM

QUOTE(ash00 @ May 3 2016, 04:23 PM) *

Awesome- that helps.

I assume that the flaps are actuated from red lever by the shifter?


No, as I mentioned, the flaps are actuated by the thermostatic bellows, which is attached to the lower part of the engine on the driver's side, kind of below the pushrod tubes. The bellows open and close with the heat of the engine, closing the flaps when the engine is cold and opening them when it is warm. This process is completely autonomous of any input from you.
If your thermostat is missing or broken, or if the cable from the thermostat to the flaps is broken, the flaps automatically default to the open position to prevent overheating of both the cylinder heads and the oil, as the flaps deflect cooling air to the cylinder heads and the oil cooler. That's why it's necessary that you have flaps if you have the stock oil cooler, because without them cooling air will not be directed toward your oil cooler.

Posted by: Elliot Cannon May 3 2016, 05:18 PM

QUOTE(SirAndy @ May 2 2016, 01:25 PM) *

Also make sure your cooling flaps are installed and operating correctly.

There is a LOT of misinformation about those floating around and i have even seen "rebuild" engines where they had been removed completely.
wacko.gif


My flaps aren't removed but are locked in the full cool position. It just takes a little longer to warm the engine up. "Full cool". I like that. biggrin.gif

Posted by: r_towle May 3 2016, 05:22 PM

QUOTE(Elliot Cannon @ May 3 2016, 07:18 PM) *

QUOTE(SirAndy @ May 2 2016, 01:25 PM) *

Also make sure your cooling flaps are installed and operating correctly.

There is a LOT of misinformation about those floating around and i have even seen "rebuild" engines where they had been removed completely.
wacko.gif


My flaps aren't removed but are locked in the full cool position. It just takes a little longer to warm the engine up. "Full cool". I like that. biggrin.gif

Super cool

Posted by: boxsterfan May 4 2016, 09:55 AM

QUOTE(Elliot Cannon @ May 3 2016, 04:18 PM) *

QUOTE(SirAndy @ May 2 2016, 01:25 PM) *

Also make sure your cooling flaps are installed and operating correctly.

There is a LOT of misinformation about those floating around and i have even seen "rebuild" engines where they had been removed completely.
wacko.gif


My flaps aren't removed but are locked in the full cool position. It just takes a little longer to warm the engine up. "Full cool". I like that. biggrin.gif



Yep, my understanding is that it is better to have them in the default open "cool" position then none at all. Just a little longer warm-up time as you mention...

Posted by: ash00 May 4 2016, 10:23 AM

Well, I had a chance to head to the shop and check out the engine bay. No rod between the engine, as shown from the pictures from the link. I can only assume that the flaps are removed, but I have to figure out a way to remove the shroud and check.

I think I need to look into an aftermarket oil cooler as well

Posted by: SirAndy May 4 2016, 11:14 AM

QUOTE(ash00 @ May 4 2016, 09:23 AM) *
Well, I had a chance to head to the shop and check out the engine bay. No rod between the engine, as shown from the pictures from the link. I can only assume that the flaps are removed, but I have to figure out a way to remove the shroud and check.

The good news is that you probably found your overheating problem.

The bad news is that you'll have to get up close and personal with your car to fix it. You'll have to drop the engine and transmission in order to get to the guts of the engine and check/replace the flaps. It's actually a lot easier than it sounds. With practice, you can drop the combo in under an hour.
http://www.914world.com/specs/tech_engdrop1.php

Also, i don't see why a stock oil cooler wouldn't work for you?
idea.gif

Posted by: era vulgaris May 4 2016, 11:14 AM

QUOTE(ash00 @ May 4 2016, 12:23 PM) *

Well, I had a chance to head to the shop and check out the engine bay. No rod between the engine, as shown from the pictures from the link. I can only assume that the flaps are removed, but I have to figure out a way to remove the shroud and check.

I think I need to look into an aftermarket oil cooler as well


If the rod isn't there behind the oil filler then it's doubtful you have flaps. The stock oil cooler is more than adequate for a 2.0 or smaller engine. The problem you're having, if you don't have flaps, is that air isn't getting pushed through your oil cooler, hence the overheating.
Going with an external oil cooler requires a number of modifications to be made. Not just to mount the cooler, but you'll need to run new lines, and fabricate a blanking plate to cover the "hole" that's left where the stock oil cooler was so that you don't loose air going to the 3 and 4 cylinders.

Here are some images that may help you better understand how the cooling system works and how air gets to the stock oil cooler.


Attached thumbnail(s)
Attached Image

Attached image(s)
Attached Image Attached Image Attached Image Attached Image

Posted by: era vulgaris May 4 2016, 11:17 AM

more


Attached image(s)
Attached Image Attached Image

Posted by: era vulgaris May 4 2016, 11:20 AM

And this is the thermostatic bellows that controls the flaps. Likely missing since it sounds like you don't have flaps.


Attached image(s)
Attached Image

Posted by: ash00 May 4 2016, 11:33 AM

Wow, thanks for the great photos! I'm loving this forum already!

Looks like I have a busy weekend ahead of me, but I guess this is one step closer to solving all of the issues of a half-assed restoration. This is why I never trust anybody but myself!


Posted by: ash00 May 4 2016, 11:45 AM

Well, the news gets better.

I just texted the PO:

"as far as I could see the flaps we permanently closed and thermostat removed. A common warm climate (california) modification to help with cooling"

So...doesn't look like its helping much.

I guess the options are:
1) Source out the necessary hardware to get that thermostat / linkage in place

2) Remove the restriction and open the flaps permanently?


Posted by: stugray May 4 2016, 12:00 PM

It Might still be that none of your oil is getting to the Oil Cooler regardless of how the flaps are positioned.

Read the post #11 about the oil pressure relief valve getting stuck.

Posted by: ash00 May 4 2016, 12:14 PM

I'm going to check this valve as well.

I guess It's not like a thermostat where I can dunk it in hot water to see if it opens. Anyway of testing this valve?

Posted by: r_towle May 4 2016, 03:43 PM

If you removed the thermostat, the flaps fall into a default position which provides the best cooling, so I suspect you do not have that condition.

It would help if you took some pictures and posted them here so others could advise you.

Rich

Posted by: era vulgaris May 4 2016, 03:55 PM

QUOTE(ash00 @ May 4 2016, 01:45 PM) *



I just texted the PO:

"as far as I could see the flaps we permanently closed and thermostat removed. A common warm climate (california) modification to help with cooling"




You should tell the PO that that is pure misinformation. Removing the thermostat and disabling the flaps will accelerate wear on your engine as it takes longer for the engine to warm up and get to operating temp. There is no benefit to cooling. Once the flaps are open, cooling is the same whether they are fixed in the open position or whether they opened via the thermostat.
It's more likely that he couldn't find a thermostat during the restoration, as it's not a readily available part.

I'm assuming that's a typo about the flaps being closed...or he doesn't know what he's talking about. No one would permanently close the flaps. If he did, that's your problem right there.

Posted by: ash00 May 4 2016, 04:05 PM

First off, thanks you all for all the help. Its all making sense now.

I'm definitely going to take some pictures after work and hopefully get more feedback.

Just in my walk over to the shop at lunch, I took a peek and couldn't find the oil pressure switch, instead there is a EMPI oil breather kit, which is tapped from the center oil reservoir on the middle of the cylinder bank. The output of that is looped back into the breather box.

The PO was a vintage car racer, so I assumed he knew what he was doing. I can only assume the worst, and after texting him- he said the flaps were closed permanently. I can't trust anymore after everything else that has gone wrong. I'm trying to understand if there is anyway of inspecting visually, other than no flap shaft between the banks. No thermostat either based on pictures, and I found one on Ebay I might get. It just doesn't sound right when I heard that comment that the flaps were closed.

First off, let me get some pictures.


Posted by: SirAndy May 4 2016, 04:10 PM

QUOTE(ash00 @ May 4 2016, 03:05 PM) *
The PO was a vintage car racer

That explains a lot! biggrin.gif


They usually don't care much about longevity or day to day drive-ability. What is good for a race engine is (most of the time) not so good for a street engine.
shades.gif

Posted by: stugray May 4 2016, 04:43 PM

If you had a $13 USB Endoscope you could look in through the vanes in the fan and see if your flaps were even installed in the fan housing.

It's nice having a borescope in my toolbox...

Or you could take the fan off and reach in there.

And:

QUOTE(ash00 @ May 4 2016, 04:05 PM) *


Just in my walk over to the shop at lunch, I took a peek and couldn't find the oil pressure switch, instead there is a EMPI oil breather kit, which is tapped from the center oil reservoir on the middle of the cylinder bank. The output of that is looped back into the breather box.



The oil pressure switch is down through a hole in the engine tins right next to the distributor.
It has nothing to do with the breather box where you pour the oil in.
That port is where the stock pressure switch should be installed.
If he was a racer, he may have extended that port out of the tin where one woudl install a oil pressure sender.

Does the car have an oil pressure gauge?
It would be good to know what oil pressures you are seeing when it starts and once it gets "too hot".

Posted by: ash00 May 4 2016, 06:12 PM

Attached ImageAttached ImageAttached Image

Here are some quick pics that hopefully will help. I am in the market for a scope, so now I have a reason!

Posted by: r_towle May 4 2016, 06:39 PM

Well, it looks like you do not have the flappers as you already confirmed.

I would suggest you pull the motor ( couple of hours the first time) and without having to remove the tranny you can pull all the head tin, replace those flappers, and make sure the rest of the tin is in place.

There are (I bet) more key pieces missing that you will find once you remove the head tin.

Posted by: The Cabinetmaker May 4 2016, 07:10 PM

Not the easiest job, but the upper cylinders tin will come off in the car allowing access to install rod and flaps. Afternoon project if you have everything you need. Besides the rod and flaps, there's a spring on the rod, a linkage inside the passenger side of the fan shroud, two retaining tabs and screws for those two empty screw holes on the shroud next to the hole where the rod enters the flap compartment.

Posted by: ash00 May 5 2016, 08:28 AM

Looks like I need to go into the classifieds and look for those thermostat and flap parts. Are they all the same for engine size (1.7, 2.0)?

Posted by: rhodyguy May 5 2016, 09:06 AM

1.7 1.8 2.0, the same thermo assem. I've never seen a BB plumbed in that fashion.

Posted by: era vulgaris May 5 2016, 09:34 AM

QUOTE(rhodyguy @ May 5 2016, 11:06 AM) *

I've never seen a BB plumbed in that fashion.


agree.gif
How is it breathing without some way to vent? I've always seen them either with a vent on the breather, or with a hose run back to the carb air filter.

What's that hose that's going above the center of the engine case? The one zip tied to the throttle cable.

Would also be interested to see a shot of the underside of the engine on the passenger side. Just to verify that the stock oil cooler is still there.


Also, here's a writeup on removing the oil pressure relief valve. It's on the underside of the engine near the oil filter. It looks like a big flat head screw.
http://www.ephotomotion.com/914engine/page08.html
It's something you might want to check.
Tangerine Racing sells an improved version of it in case yours is worn out.
http://www.tangerineracing.com/oilpressurerelief.htm
I have it installed on my car. Works great.

Posted by: ash00 May 5 2016, 10:27 AM

Exactly!

I thought the whole point of venting is to vent towards ambient..but that raised the red flag initially.

Im going to have to pull the motor for sure. Lets see if my boss lets me take Friday off.

Things to check:
1) Flaps and positioning: If they are closed, and I can't piece together the hardware to make it adjustable - is it better to just leave them open (increasing warm up time)?

2) Oil pressure switch: Check condition

3) Routing of the EMPI breather

4) Overall inspection of everything

5) Once back in: Adjust timing and check carb jetting/vacuum check

Posted by: rhodyguy May 5 2016, 10:35 AM

The foam element in the BB traps the vapors. Oil puddles in the bottom of the box and it drains back to the engine. If your heads have the vent tubes, you can use them as the flow back route for the puddled oil.

Posted by: ClayPerrine May 5 2016, 10:41 AM

I have lots of sets of cooling flaps for your motor. If you pay the shipping, I will send you a complete set for free.

But I don't have any thermostats. sad.gif


Posted by: stugray May 5 2016, 11:16 AM

QUOTE(ash00 @ May 5 2016, 08:28 AM) *

Looks like I need to go into the classifieds and look for those thermostat and flap parts. Are they all the same for engine size (1.7, 2.0)?


I believe I have a complete extra set of flapper & thermostat parts.

Posted by: SirAndy May 5 2016, 12:13 PM

QUOTE(era vulgaris @ May 5 2016, 08:34 AM) *
How is it breathing without some way to vent?

The breather box is supposed to have a gap on the top lid to allow for venting. There should be a foam piece in the box that traps the oil vapors and lets the oil drain back into the case with the engine off.
popcorn[1].gif

Posted by: ash00 May 5 2016, 12:21 PM

Wow- you guys are incredible! I love how supportive the vintage car community is, like the ones for my bmw 2002's and mini's, as compared to new cars which bash you for modifications that aren't to "their" liking. Cheers to that!

I would be more than happy to purchase the entire flap/thermostat kit from anybody + shipping. Please email me at aashish.dalal@gmail.com.

Thanks!

Posted by: Cracker May 5 2016, 12:21 PM

Man. You AC guys make it so complicated... blink.gif

T

Posted by: ash00 May 5 2016, 12:23 PM

I have to take a look at the wiring in detail also... just noticed that he wired the electric fuel pump to jumper from the ignition coil +.

I'm probably scratching the surface with the flap issue. Wish me luck!

Posted by: SirAndy May 5 2016, 12:36 PM

QUOTE(ash00 @ May 5 2016, 11:23 AM) *
I have to take a look at the wiring in detail also... just noticed that he wired the electric fuel pump to jumper from the ignition coil +.

Unfortunately not that uncommon ...
barf.gif


This should help:
http://www.914world.com/specs/SirAndyCarbFuelPumpRelay.php
smile.gif

Posted by: rhodyguy May 5 2016, 02:06 PM

That is the best way to power your carb pump. The stock pump circuit will work but you may need to change the wire end to spade terminals.

Posted by: ash00 May 5 2016, 02:07 PM

Silly question -

I have a full machine shop / welding / fab equipment - but before I use all that and add to the time variable, how do you guys hold the trans/motor when its out of the car? Are there any engine cradles or such for these that I can buy? I can't believe this'll be the first time out, but will also need one for my 65 bus.


Posted by: rhodyguy May 5 2016, 02:11 PM

Get a furniture dolly at Home Depot or the like. Block it up with dunnage. Easy to move by yourself.

Posted by: Racer Chris May 5 2016, 02:25 PM

Engine Lift Plate

Attached Image

Attached Image

Posted by: ash00 May 6 2016, 04:53 PM

HI all,

Maybe I'm missing something here, but it looks like I can take off the tin shroud by the flap area off with the engine still in the car. I can visually inspect of the flaps are closed, open our or even there.

Is there something I'm not seeing?

Posted by: stugray May 6 2016, 05:11 PM

QUOTE(ash00 @ May 6 2016, 04:53 PM) *

HI all,

Maybe I'm missing something here, but it looks like I can take off the tin shroud by the flap area off with the engine still in the car. I can visually inspect of the flaps are closed, open our or even there.

Is there something I'm not seeing?


The front half of the fan shroud is very difficult to split when it is completely off the car. you would have to remove all three engine tins (I think) and the alternator.

Then you would have to split the halves leaving one side behind.


Posted by: era vulgaris May 6 2016, 05:33 PM

I think he's just talking about the two main tins over the cylinder banks so he can visually verify that the flaps are there. I've heard people say it's doable with the engine in the car.
I don't think you'd have to split the shroud to install the flaps, do you? Maybe I'm wrong?

Posted by: ash00 May 6 2016, 05:45 PM

Yes, sorry for the confusion..just for the tins and inspection of the flaps. I tried to use a scope through the hole but it still wasn't clear

Another shot in the dark, but if there is no shaft, how would you couple the flaps? The previous owner said they were "permanently" closed. I don't know if you can just put them in there loosely without any connection.

Posted by: SirAndy May 6 2016, 06:16 PM

QUOTE(ash00 @ May 6 2016, 04:45 PM) *
I don't know if you can just put them in there loosely without any connection.

You can but it's going to be ugly. I once bought a "rebuild" 2.1L engine that had the flaps glued(!) in there with gobs of god knows what and then they forced a bunch of sheet metal screws through them and into the surrounding shroud/tin for good measure.
barf.gif

Posted by: stugray May 6 2016, 06:46 PM

QUOTE(ash00 @ May 6 2016, 05:45 PM) *

Yes, sorry for the confusion..just for the tins and inspection of the flaps. I tried to use a scope through the hole but it still wasn't clear

Another shot in the dark, but if there is no shaft, how would you couple the flaps? The previous owner said they were "permanently" closed. I don't know if you can just put them in there loosely without any connection.


Oh sorry.

Yes you can remove the passenger side engine tin with the engine in.
It's a PITA and you have to manhandle the front tin a little, remove the intake manifold and the distributor. Some of the wire harness goes through that tin as well, but if you just want to look under, you wouldnt have to pull those wires out.

And I found the shaft with the drivers side flap attached, the passenger side flap, and two thermostat brackets, the pulley and maybe a intact piece of cable.
I think the only thing I am missing is the little arm that connects the shaft to the pass. side flap. Still looking.

Posted by: Porschef May 7 2016, 08:08 AM

Ash, I'm gonna have to agree.gif with all who've suggested pulling the engine. Looks like now is the time to do it right, drop the eng/tranny, and take a little time to assess everything; I'd be very surprised if you didn't find a couple other things to correct.

How does it shift? If not great, change all the bushings. Get Tangerine's firewall unit, makes a big difference.

Are the push rod tubes leaking at all?

Any exhaust leaks?

CV joint condition?

Speedo cable? More importantly, clutch cable?

Factory nylon fuel lines? Get RID of those, replace with stainless steel.

Very nice offers from Clay and Stu, take them up those, make sure you have everything you need before diving in and you'll have an opportunity to rectify a whole bunch of stuff. The engine drop is not a big deal (so simple I can do it) and you'll learn tons of valuable information about your car. And your not gonna want to drive the car as it is now anyway.

Good luck. smile.gif

Posted by: ash00 May 7 2016, 09:54 AM

Totally! I had about a half hour yesterday to let things sink in and yes, I do need to pull the engine to give myself a better understanding of things. I want to look at an aftermarket oil cooler as well and check things out for certain. Hopefully this week!

As far as the shifter, it has the JW west one but I would like to explore the linkage. I lve been in a car when the clutch cable snapped so that's another thing I want to inspect.

I'll probably need that engine plate for certain and need to pick up a furniture dolly. Hopefully I'll have no more business trips to get in my way!

Powered by Invision Power Board (http://www.invisionboard.com)
© Invision Power Services (http://www.invisionpower.com)