I have just bought a cylinder head temp gauge to fit on my 1970 1500cc beetle.
Is any body able to give some advice on what the readings should be for standard running conditions and what is considered to be too hot to keep the engine running?
The gauge is in Fahrenheit but that's easily converted if you only know the temps in Celsius.
If people aren't aware of this type of gauge to keep an eye on the engines temp let me know and I'll try to give as much information as I can for others to make up their mind whether they think it's an worthwhile investment....

from memory...
and if You are reading USA etc it will be in Fahrenheit..

I can remember 190 degrees up to 200 of oil temperature
over that its too hot...

I'm thinking that this IS in Fahrenheit.??

BUT Heads get VERY VERY HOT...

there are many many excellent items you can read on this subject..

the bottom line is - Most people who have done this...
disconnected the sender etc before they had a nervous breakdown... as the temperature goes UP & Down all the time... as you drive....
from EXTRA HOT to EXTREME HOT
to HOW COME IT DOESN'T MELT HOT....

best to keep check on the oil tempertature... lol

cheers

LEE

See if You can find any of Bob Hoover's sermonettes on the subject...

also check out; vw-resource.com Rob & Dave's site..

If Rob see's this post he will no doubt give you his thoughts....

cheers

LEE

Lee, thanks heaps for your reply. I was tossing around the idea of an oil gauge but have heard issues around the best place to fit it to get a true reading of how hot your engine is really getting etc.
I plan to fit it on the no 3 cylindar as this has the most difficulties keeping cool.
I live in Adelaide but could only find over seas companies advertising to sell one & as you are no doubt aware we are going to have a very hot summer & wanted something that will let me know just to pull over for a while as the engine is getting too hot. I'll take your advice though & look into fitting an oil temp gauge as well.
Cheers
Aaron

300 F is slow down

Yeo. 300 F is max from what I've heard and gone by.

Cool thanks for that, now I at least know what to look for before the engine cooks.

I had one fitted for a while.It made me drive slower and slower and the gauge kept showing hotter and hotter! When i stopped and turned it off then started it again (without letting the engine cool down) the gauge would show some 30 degree jump in temp. If i were cruising the temp was 240 degrees depending on the temperture of the day.At night with cool air 220 degrees.Overtaking going up a hill and shes around the 250/260 mark!
I dont have one fitted any more so i can drive with both eyes on the road and without feeling guilty.

Up to about 350 is fine for a performance vw motor (under load) .....................VW powered aircraft get up to 450 on take-off, and that is deemed acceptable

A standard beetle probably wouldn't see over 300.

Thanks lohoon & Craig, I found some information on the bus-boys web site that said something about up to 350 being okay but over that it's running hot, bus boys are really about kombis so you are right the bug shouldn't get that hot. I really only want something fitted as it's an every day car & don't want to find that I'm running it while it's so hot that it's about to melt.

Trickling around Adeliade in 40C in a standard 1500 Bug you will be fine. Have you checked every other aspect of your cooling system...?
All tinware present and correct?
Oil cooler clear?
Fan housing fitting properly?
Fan clean?
Fan belt tight?
Heater tubes in place (or heater holes blocked off)? Engine sealing rubber in good condition?
All screws done up correctly?
No other gaps?
Soundproofing secure to firewall?

All that is more important than a number on a gauge

You raised some good points VWCOOL, all of that should be of acceptable standard as I get it serviced 6 monthly or 3000 mile, whichever comes first.
The motor is standard and I've put no chrome or other fancy items on it so there should be no reason for it to over heat I just want something to warn me in case something does go wrong and it does over heat. Much the same that I carry the fire extinguisher in my car, I don't expect the engine to go up in flames but it's there just in case.

I was wondering do you have to have all the tinware or just the fan shroud and piston covers and also does chrome work aswell as normal, also where do you get the gages.

I have had oil and head temp gauges fitted to my kombi's (2L) for the last 6-7 years. I assume you also have a VDO bi-metal one?

BIG things to note, firstly all gauges vary in the actual temp they read, as does the actual temp depending on where you fit it. They also vary relative to ambient temp!! (they read cooler in summer, warmer in winter when the head is at the same temp)
SO, you just need to keep this in mind when you use the gauge! As has been mentioned above, the gauge is a guide, if you have a known good engine with everything INCLUDING tune up to spec, start to keep a record of what temps you see. This then is your base to compare to.

Another word of warning, putting the ring on a spark plug (No3), even though a great place to read the higest temp, I found it a real pain. Not only do you wear the ring every time you pull the plug, it can also easily get jambed and prevent the plug seating correctly. Luckily the kombi head has a blind hole for the EFI temp sender right next to No3 plug, that's where I mount mine now.

The best thing I have found driving with both gauges is to see what your driving style does to both temps. In general keeping the revs up tends to push oil temps up and head temps down. Lugging the motor tends to do the opposite. Tune will also greatly affect head temp, especially timing and advance curve.

For actual temps, I have found them to be reasonably stable, but then I have also learnt to drive to make that possible. I have rarely had a temp abve 300F (ring on No 3 plug) even though I have heard 350F to be "normal" for a kombi. I now have ceramic coated heads and the sender next to the plug and never see temps above 250F.
I would expect a stock beetle to run a little cooler.

Oh, one more point, it's also interesting to note the factory thermostat also does help quick heating of the motor come winter!! For most Australian conditions that's about all it does do though.

Nice findings there Andy.

What sort of variation did you experience when relocating the sender from the sparkplug to the efi temp sender location?

Thanks Andy,
that's a lot of good information and help, you are right about it being a hassel going onto the number 3 plug as this is seated for the beetles and takes a bit to get in and out. I plan to have it mounted to the engine case when I need to take the tin ware off next time.
I was put onto aircooled.net and sent them an email, they stated, (and I do find this to be extreme) anything up to 425F is acceptable. I haven't seen mine go over 300F yet and that's going up steep hills on warm days.
With the ceramic coated heads, I take it you have your sender somewhere other than on the ceramic coating? If that is the case I'll definately look into getting the heads and headers ceramic coated.

Dekkerboy,
It's best to keep all the tinware on the motor as this is designed to keep the engine cool and maximum air flow through the oil cooler etc, don't use chrome on anything engine wise like rocker covers etc as chrome increases the heat dramatically.
Take a look at
http://www.vw-resource.com/valve_covers.html 
Rob and Dave talk about this subject.
You can order one from aircooled.net, I'm also planning on installing an oil gauge as well for peace of mind.

Unfortunately I don't have good readings for that. It would be at least 50F cooler BUT a lot of things changed besides the location.

It was on a different motor fully re-built including carbs, ignition etc AND ceramic coated heads to name just a few things. The only similarity is they were both completely stock 2L motors.

Gixer, the ceramic coating is in the combution chamber only (and top of piston), so has no affect on the contact between the sender and head, but should reduce the heat going into the head. For a stock motor it was purely to (hopefully) increase the life of the heads, not performance. I certainly noticed no performance differece to the the original motor which was sound but far from new. I did notice the heaters worked a little better though!!

Nicely done and thought out. Now all I need to do is see if I can find anyone in Adelaide with enough knowledge to know what they are doing to get the same done.

It was the culmination of a few years reaserch and extensive sourcing of NOS parts. Heads were NOS, so I wanted to give them them the best chance in life.
Has done ~100,000 klm since, only drama has been blown head gasket (VW actually went away from them, so I guess I should have listened).
A few other "non stock" bits were a molly coating on piston skirts and valve springs (helps with lubrication)
As I said, most people said it's overkill for a stock motor, but I'm happy I did it. I would have done a lot more if $$ were not an issue

Adelaide has a good following on VW's, so I'm sure there will be people to help out!

We used to have a good following as well as a good stock of parts until the scene died off and everything was sold to Europe.
It's starting to build up again though which can only be a good thing.