rihwoods

After reading many threads re cooling questions/temp gauge accuracy,yesterday,I ordered a Raytek Minitemp MT-4 IR gun to measure a few points on my engine.I received it this evening,so I read directions,loaded battery,and 15 minutes later after shutting Vette down,I got these results:
First of all my Vette temp guage was reading 201 degrees after 10 mile drive home.Ambient air temp outside was 90 degrees.
1.Upper rad hose 2" off thermostat housing = 206 degrees (F)
2.Lower hose approx 4" from Radiator = 179 degrees (F)
3.One spot on radiator driver side just off center = 158 degrees (F)
4.Exhaust manifold (forward) drivers side = 296 degrees (F)

I did not get intake,or other locations as my wife had dinner ready....I will now sit down and make a data sheet to record more detailed readings.(I am satisfied at this point my temp gauge is relatively accurate,but need more data.)
Please make suggestions of your thoughts on getting data,and I will note readings and post here.
This IR gun cost $89.00,plus $6.90 tax,and $3.95 UPS ground to my door. This is a laser gun which allows aiming accuracy.It measures surface temperatures.

Lee H

My recently aquired IR gun confirmed my 65 vert temp gauge reads about 30 degree high. Great tool.

rihwoods

Forgot...not tech...oh well....nice to be here over in general...at least DEP did not catch me...

GDaina

That's a good price, where did you get it?

Bullshark

Rich, Good tool to have in your toolbox
I just bought the MT-6 off of e-bay and have been playing with it all week. Very handy tool for isolating clogged fuel injectors that may be leaning out. I wonder if it will help me do the barbecuing? Not my strong suit

rihwoods

Raytek refered me to this distributer: FLW,INC Costa Mesa, CA
PH (714) 751-7512 (I made phone order and live in San Diego)
If you call Raytek direct at 1-800-866-5478 they can refer you to a distributer nearest your location. That is what I did....

rihwoods

Funny...I have been running around the house taking readings....refrig..complete. Ha Ha.
Just thought of another use: Autocross.Tire temps after a run...you can take sweep or spot readings...
BTW: My son says to get a internal temp thermometer for your steaks...

SanDiegoPaul

Yea those things are interesting. My temp gauge showed to be almost right ON which surprised me. Over 200*, it's actually erring on the safe side so I don't mind it at all.

RE the 300* exhaust? That must be w/manifolds not headers. My car pegged teh gauge when I put it on the headers after coming off the dyno and all I got was errors.

rihwoods

Stock manifolds,your right...But now I'm going to take a series of readings...some during warm up...and after warm up with engine running....last night only had time for readings right after shut down....better to get readings with it running..to check gauge...
Also,after warm up,want to get "sweep" readings of rad to check for hot spots..this will be done right after shut down... my Mt-4 can read up to 525 (F).

Paul..do you have chrome or painted headers ? Reason I ask is my instructions for IR gun say this :
Emissivity...not recommended for use in measuring shiny or polished metal surfaces(stainless,aluminum,....they say to put masking tape on those parts,and read tape once it is at same temp as part..

danno12345

Hmm, I think I'll go throw some masking tape on my manifolds and see what happens...

Too bad there's not a smiley with its hair on fire...

I'd love to get one of those guns, but haven't felt the need to plunk down the cash yet.

Have fun!!
Dan

mox 77

Bought mine at NAPA for around $65, as best I remember. Sure was handy after a mini-rebuild to check temps at various locations and determine uniformity.

Older Than Dirt

Do a froogle search........you can buy the Raytek MT4 for less than $50.00, there's one place less than $60 with free shipping......

rihwoods

Well,just got done with readings with engine running....with thermostat open,and system stabilized...I got this:
Exhaust manifolds pegged meter (above range of 525 (F)
Thermostat housing read 175-180 (as it was modulating) but important is my temp gauge was reading same in car...180...Happy days and I never suspected my gauge was far off anyway...at hwy speeds of 70,my gauge is at 200+- depending on conditions....
Think it important to know thermostats "modulate" near their rated (calibrated) operating temp...and mine was this morning...
Now for the rad sweep....just for benchmarking..

DJ Dep

GOTCHA!!!

It's a good thread and I wish you did post it in tech!!!!



Dep...still trying to decide which fuzzy dice make C3s go faster.

rihwoods

Dep...I DID post it in tech first...but they moved it as soon as my fingers got off the keys.....and it wasn't like I did not think where to put the thread...it is technical,I think,and more so than..."my vette overheats,what is wrong" ha ha ha.....think the mod seen it as "boarderline"........

rihwoods

Maybe they mean.....trim rings....

Sacredgrooves

love my mini-temp. I use mine for work(inspect houses-check a/c differentials, etc) sure has alot of other uses and well worth the money! btw if you want to make sure your cooling in the proper range, temp at the intake and the return vents and you should have 15-20 degree differential. much more than 20 usually means filters are dirty and less than 15 indicates a freon leak...just an fyi while everyone is playing with their toys

rihwoods

Thanks for info...great tool and having fun with it..house and car....going to read my Vette ducts next with A/C on driving...ought to be interesting...

DJ Dep

Hmmmm.....oh well. It's their call.

Red 69

That tool is super, definately on my list of tools to own. While discussing a rebuild on my tach and speedo, I inquired about my high temp readings and gague accuracy. The fella I was speaking with professionally repairs Corvette gauges, so he had my attention.

He told me if your gauge reads higher than actual temp, you need to put a resistor in the line. Radio Shack has them in packs of 5 for about $2.50. He recommended starting with a 47 ohm resistor and moving up or down to dial the gauge in. This info is for a 69 SB with a sender on the drivers side head, but should work for all similar systems. Just put the resistor somewhere along the line from the sender. This will drop your gague reading down to actual temps, but be sure your tool is accurate. I have the resistors, but haven't tried it yet. Bigger fish to fry. A wire connector should work well splicing one into the line.