What CLTs are you seeing with Mario's sensor?

[andy198712]

Hi all.

Hooked up Mario's head sensor to number 3 tinware lug on the head and it works great and helps with warm up no end!

Just wondering what sort of temps are people seeing?

Sat idling mine goes up to about 135 degrees C ish if sat for a while, cruising it's around 90-100 C. Some times a tad more

Just wondering what others were getting? Anyone seen a pattern between that and head temps under the plug?

Cheers

Andy

[rubenski]

I have a cheap ebay digital screen one.
I have 80-90 when i let it idle a while.
Mostly 70-80 at highway and going to 100 in agressieve street traffic

Mine is mounted at the cyl 3 top screw on the tinware where the plug goes trough.
Since it was not possible to get the ring and wire under the plug...

I use it only as a guide for temperatures. Just good to know since my vdo oil temp gauge barely indicates something. Only when i drive it verry long i get oil temps over 70ºc

Not mario's and not FI. Just a 110hp 1641cc.

Ignore if not relevant.

[andy198712]

all good to know! is your bolted against the head or the tinware then the head..? mines 044 CB heads i guess it makes a difference...

i was just curious and after a spectrum or temps

have you got a deep sump? my 2110 seems to run a lot cooler oil temps then the 1200 it replaced but thats only going by dipstick feel! yet to buy a real gauge lol and with a deep sump so will take longer to heat up all that oil!

[rubenski]

The sensor had the size of a spark plug so i wiggled it between the head and tinware above it.

If i ever get under the car again i will make some pics!

No deep sump. Just a verry cool running engine

[Clonebug]

I just checked a log from driving home the other day in 65-70 degree ambient temps.

At a cruise of 2200-2600 rpm my CLT shows a real steady 207-213 degrees F.
My AFR's are almost rock steady at 14.1 during steady state cruising.
At one spirited pull with boost limited to the stock wastegate setting of 6-6.3 lbs., the head temp went up to 220 degrees F.
I have it installed on the tin bolt above the #2 cylinder just because packaging worked out better that way. Also the stock heads I had last year during the install happened to have a couple of the bolts broken on the #3 side so I never had anything in those holes. With the new heads I just left the wiring where it was since it is nice and clean looking that way.

[Chip Birks]

Mine is also located on #2. Looking at a nice long log, it averaged about 200*F while cruising at an average of 3300rpm and around 65mph over 5 minutes or so of sustained freeway speeds. If the car idles, it increases a little peaking at 244*F on this 20 mile drive. Average for the whole drive was 196*F. The car was running on E85 for this trip.

[andy198712]

They're pretty much similar to mine then which is cool, not been on any long trips yet though, making new manifolds at the minute so it's bee sat for a week now!

Cheers for the ball park input, just what I was after!

[Clonebug]

Just checked with the computer running logs and I am now seeing 253 degrees after a 10 mile drive with outside temps of around 80-85 degrees.

[andy198712]

thats 121*c thats not bad!

[petew]

I use it only as a guide for temperatures. Just good to know since my vdo oil temp gauge barely indicates something. Only when i drive it verry long i get oil temps over 70ºc

Not mario's and not FI. Just a 110hp 1641cc.

Ignore if not relevant.

Interesting what you say about your VDO oil temp gauge. I'm having the same experience. It's in my deep sump and it barely goes above the lowest reading which is 50degC. The highest it ever got was sitting in traffic for ages on a warm day. 70degC.

As for the OP, I've got Mario's head sensor and even on super hot days over here (35+degC) the head temp barely get's up to 120degC. That's having run on the freeway then idling. I'm really pleased with how cool the motor appears to run... or is that denial?

[Clonebug]

On my trip to Big Bear California I saw some pretty high CLT temps when we hit the hot desert area of Barstow, Ca.
I had adjusted my timing up a fair amount due to the 8000 ft elevations we were driving in for a day and a half.
It was running really nice until it got down into the hot dry air west of Barstow and started pinging under load when climbing a grade.
I had to retard the low boost section back to my local driving tune and richen it up.

I saw head temps on the TS gauge at 330 Degrees when I shut it down to swap tunes.......

[petew]

Yeah that's hot. Although people tell ACVWs are safe up to about 180degC (356F).

[Piledriver]

Yeah that's hot. Although people tell ACVWs are safe up to about 180degC (356F).

That's valid only if measuring it under the plug with a TC, that setup responds ~infinitely faster.
375F safe upper limit in that case.
The other sensor mount locations are usually only useful or warm up.
They are not safe to go by if you are looking for head safety, as they can lag by minutes and a hundred or more degrees.

My setup doesn't lag noticably... It does have a fan-speed related temp offset that appears consistent.
I have an open element sensor (~same GM sensor Mario modifies) mounted in the hot exit airflow under the head by the exhaust port on my T4
At ~cruise it tracks very quickly and accurately to an under-the plug TC, but with about a 75F offset @3400 RPM. It is around 3mm from the head.
(Under-engine tin present and well sealed)

In 100 degree F weather at 75 MPH, I see ~250-260F running in flatland (low rolling hills), also showing 320-330F under the plug (don't have a dash gauge for the TC, only used for validation, use my DVM, as it needs to float as the sensor is grounded)

At idle it shows up to 340F but has almost no offset to under the plug at low fan speeds.
Its zip-tied to a pushrod tube, and has been for ~80K miles, through 3 different ECU setups.

EDIT:
I should note that the T4 exhaust ports are probably hotter than under the plug: that's frequently where they crack.
I don't know if the T1 has a directly equivalent spot, haven't looked at a T1 head in ages.

[petew]

Mmmm, interesting.

[gtmdriver]

I'm using the OEM VW sensor in one of the later cylinder heads with the integral tapped boss.





I calibrated it before fitting.



My engine seems to idle at around 90C and run at around 110C.