Head temp gauge. Need to know if running hot.

[Skulptorchaz]

Well, I want to finally pull the trigger on a head temp guage and my first question is, which do you guys recommend?
Secondly, the reason why is that since I built my buggy, I have only really drove on roads, streets and US Highways and oil temp stays at around 180*. On the interstate, it climbs to 225-230 in about 15 - 20 minutes, I won't push it past that.
That has been just fine with me so far but, I want to drive it from So. East Indiana to Pismo in May. I am planning on US-50 the whole way because of not wanting to do the interstate but, I'd kinda like to bring Rt.66 back and that can bring some interstate driving.
So, which gauge would you guys recommend and what kind of head temps are acceptable?
Thanks.

[PatJr]

dunno

I got one for my van.
It's supposed to have the ring under the spark plug thing. Yea, don't do that it sucks, or blows I guess.

imho I think first question should be is where are you going to mount the thermocouple?

If was going to get another one I would probably try one of these
https://www.dakotadigital.com/index.cfm/page/ptype...prd347.htm

lots of posts on TheSamba about this, be sure to read up on it.
TheEZGZ says he doesn't use them. Some folks have said that your really need 4 of them if you're going to install them. I was going to try and hook up and arduino but it's proving to be more of a project then I'm capable of.
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1970 Transporter a orange one
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[Skulptorchaz]

In was planing on mounting under a head bolt on cylinder #3. That is what I have read anyway.
Looks like the Dakota Gauge is going to be about $200.00. I know they are pretty good stuff but.....
I'll search a bit thru the old posts.
EZGZ?
Thanks!!

[PatJr]

youtube

https://www.youtube.com/@TheEZGZ

and
https://www.youtube.com/@vwdarrin
https://www.youtube.com/@JWClassicVW

and tons more
even found some info on replacing my front leaves, dreading that job
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1970 Transporter a orange one
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[oprn]

Those oil temps are virtually the same as what my Type 4 engine runs at in my Manx copy. Anytime I have checked the heads with a heat gun (not the best) they run between 250 and 275*F.

The head temp gauges on light aircraft put the red line at 375*F. Sounds reasonable for our engines too.
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We had the stone age, the bronze age, the industrial age and now we are in the age of mass deception and mind control for corporate profit. (The mass media age)

[Skulptorchaz]

Thanks OPRN. I appreciate that. I really don't know what is acceptable and I definitely don't want to ruin my engine. I would think there would be some sort of publication that tells pretty much exactly what is acceptable but, I still haven't found it. I was hoping someone here might have run across one and I could put this to rest, in my head at least.
Thanks again buddy!!!!!!!!!!!!!!!!

[vwracerdave]

30 years ago I installed all the VDO gauges on my 1985cc engine. All I ever did the entire time I drove the car was worry about everything. I removed all of them and started enjoying driving my car again.

If you get away from the VW geniuses and read what the oil companies say about their oil you will find 225-230 oil temps are normal and perfectly safe. 180 oil temps are too cold to boil off water, acids, and other contaminant. Screw the VW people that say 180 is plenty hot enough to evaporate out the water. There are acids and other minerals contaminants that require to be boiled out.

The exposed engine in a Dunebuggy will always run cooler than the enclosed engine in a Bug or Bus.

If you feel your engine is overheating, you should address everything before wasting money on gauges. Compression ratio, oil viscosity, timing and carb tuning all have factors on engine temps.


I've never seen and info on what actually is acceptable head temps for a VW engine.
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[oprn]

[sailtexas186548]

I run some ($40 each) Amazon thermocouple temp guages, bought them and then got the longest k type thermocouples with 14mm (stock spark plug) ring ends. They work great, and normal street driving including WOT in 4th gear as fast as I can go on the freeway, In sub 80*F weather I see 105-135*F head temps. I do not run a power pulley, but do run a stock dog house oil cooler and have my tins fit up real well. I can actually see the temps drop when I let the engine turn more rpm Vs lugging it at a lower rpm.

I have an oil pressure guage, and oil temp light that comes on at 235. I’ve never seen it come on

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[oprn]

[sailtexas186548]

Fahrenheit, and it is correct, in my picture you can see they even match the thermostat in my garage right at 73°. I drove to work this morning and my heads did not get up over 108F after 8 miles, it’s 53F here. I was surprised how cool they run, expecting closer to 180-220. I spent a lot of time on the cooling system for this engine which is a factor, and these are mofoco heads, which are good after the casting flash is removed, are advertised to run extra cool. The Internet (non mofoco head owners) loves to say “not believable that they cool better”, well go buy some and find out…

The heads will come up near 160-220 after the engine shuts off and heat soaks if run hard. I can jump out and touch them with little issue, indicating they are at or below 140F, similar to marine engines that operate in that range. The heads are finned heat sinks that have a ~5hp cooling fan blowing cool air on them, in an engine making maybe 70 hp in an open buggy. I’m sure once temperatures come up this summer my head temperatures will increase 50°, But that simply isn’t the case at the ambient temperatures I listed.

I also have a Manx with an eco-tech swap that has a radiator mounted under the package tray, and everyone loves to tell me how it won’t work, but guess what, it does, and it stays right with a 185* thermostat even in August at 3 PM on the freeway or in traffic, or at a red light, in fact it will over cool down if the fans don’t cycle off.
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it's more fun loud and dirty

[vwracerdave]

[Skulptorchaz]

Are you sure your gauges aren't in celsius?
72 Celsius = 161.6 Degree Fahrenheit. That would be closer anyways.
Not critisizing, just sayin.....

[MrGoodtunes]

Cylinder Head Temperature gauges that use a bi-metal thermal sending unit are actually measuring voltage, potential voltage difference between the two metals, which will be only as accurate as its wiring can provide. Excess resistance in wiring will hide true voltage from CLT gauge, giving low temperature readings. None the less, my CLT has saved my engine's life more than once.

I had to prep the sending unit to fit VW head, as well as to allow a spark plug socket fit.

I also used a Dremmel to remove some head material (at 12:00).

In the end, it just barely fits.

True Story:
Driving on a highway thru a snow blizzard with only one lane moving (over a foot of unplow'd snow in other lanes), CHT gauge caught my eye as it was going over 400°F toward 425°!! Pull'd off to side where snow was only 6"~8" deep, and found that my cool air collecting scoop was completely fill'd up with thick snow blocking air from being ducted to fan shroud inlet.

Long ago, I learn'd the hard way that the Mini-Camaro kitcar body configuration causes hot air, even exhaust air, to get recirculated into fan shroud. So I built that scoop with a duct such that the only air getting into fan shroud inlet has to come in thru there. More recently, I increased the duct inlet from 5" to 7". More on that is here:

https://www.thesamba.com/vw/forum/viewtopic.php?p=8739263&highlight=#8739263

[Skulptorchaz]

Thanks Goodtimes.
I was also under the impression you could put it under a head bolt. If that works as well (???), that would be overall, less hassle.

[MrGoodtunes]

Head bolt (or actually, I guess, under a head stud nut?) would not be as hot. There is a temperature gradient from highest temperature points (e.g. outer circumfrence of exhaust valve, or tip of #3 spark plug) on out to outer edges of cooling fins. The closer you can get to the hot spots, the better. Still tho, once you got used to how it reads under normal conditions, you could probably notice an over-heating issue, and it might be soon enough to avoid damage?

On the other hand, anybody ambitious enough to have come up with an adjustable bowden tube front mount set up as clever as this...

https://www.thesamba.com/vw/forum/viewtopic.php?p=8018955

...should be able to get the sender under a spark plug.

[Skulptorchaz]

HA!!
Thank you Goodtunes! You have a good point! I would want the best reading posible but, tis true, it is all relevant. I know my bathroom scale is not perfect either but yet, it is what I use and can keep track.
I can not believe you remember my little contraption!! You must have a steel trap for a mind. Mine is more like jello. That brings a smile to my face on a "black day" Thank you.
Thanks again buddy!

[clonebug]

I love electronics.....especially when it gives you good information.

That said I have spent a considerable amount of money getting info from my engine to keep it running all the way to 26 lbs. of boost and driving reliably for many miles locally and long distance.

I feel the best electronic tool you could invest in is an AFR gauge. They are not that expensive in the grand scheme of things and will give you lot's of info to keep your engine running reliably and for a long time.
I bought a PLX Combo gauge and it's been completely reliable since 2013. It tells me exactly what AFR I am running real time. That in itself will allow you to get your fueling issues set perfectly and eliminate that equation from your temperature problems.
I also spent money on Fuel injection due to having a turbo and wanting more power than a carb could supply reliably. From there it just continued because I kept turning it up and needed a Water/Alcohol Injection system to cool the inlet air and then after even more boost needing an intercooler to help the W/I. The EFI Computer allows control of everything in order to succeed in what I was trying to accomplish.
I also wanted reliability along with that power so that money was well spent.

Was it expensive????? I don't know......it's cheaper than a new car and I put more miles on it than I do my 2000 GMC Sierra truck.
What does maintenance cost on a new car?????? I spend about $800-1000 per year in.....what i call ...Upgrades....to my buggy. Upgrades are anything I do to my buggy after I originally finished building it in 2004 and cover everything from seats and disc brakes to a Digital Dash and Power Management Unit.
It's meant to make it better and is worth every penny in that it makes it more reliable and more fun to drive .....if it even needed that to make it such.......

I like electronics so much that I am now on my 4th ECU.......not because I had to upgrade....but because I wanted to upgrade......I sold my first one for a decent price so the second one didn't cost too much more to upgrade to. The third one didn't even get installed before I bought an even bigger and better one along with a bunch of other electronic stuff to get to where I am now. I now have more info that most anyone could need but .....gosh...I just absolutely love it!!!!!!
I consider it education......at 62 I still like to learn something new every day and this allows me to fulfill that.........I'll spare you the details but everything I've done to my Buggy since 2009 in is my build thread below.

I consider carbs and distributors to be dead........if you are looking to upgrade a reliable daily or semi daily driver there is no reason to stick with the aforementioned items since there is so much better stuff out there.
A crankfired ignition and computer that is capable of FI is worth every penny and allows you to concentrate on other aspects of your build. In the 50,000 miles I have been Fuel Injected and turboed I have never had an ECU or ignition related failure.
I've had one wire break that left me 1.5 miles from home locally but otherwise the failures were transmission or rotor related......the transmission was due to trying to contain the power I'm putting out by upgrading to a Super Diff which just causes more problems than it's worth if you drive long distances. I ended up pulling the Super Diff and going back to stock which fixed that issue.
Cheap China rotors are what have caused both of my tow home issues......whether it was my fault for not torquing them beyond stock spec or not remains to be tested. I have now tightened the everliving sh** out of them to 330 plus Ft lbs. of torque and am seeing if that fixes it.
They went 8 yrs without issue so why it happened 1000 plus miles from home is a question...........

Apologies for the rambling.........
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[MrGoodtunes]