Radiant heat readings on a 355 after a drive

Tires after coming off a race track:: 203dF
Headers after coming off a race track:: 1100dF
Water temperature on the last lap:: 228dF
Oil temperature on the last lap:: 285dF

Your readings are perfectly normal.

 

I'd be interested to know if each cylinder is the same temperature. Can you measure each header right at the exhaust exit? I've been meaning to try that on my car.

 

Wouldn't a lean running cylinder run hotter than a healthy one? I'd think it would be a way to check the health of your engine.

 

well I can say I have been working on my SDL.

It does seem that Something is wrong with the system. My cats are outside temp right around operating temps so its not overheating. Im right in the 400f-500f range on them.

But when I check the headers the RH side is showing me outside temps of 450 it is conciderably higher than the LH side.

But you have the heat coming off the oil tank and the radiator fan blowing in that area so I am wondering if that reading is correct for the headers and not the ambient air temp in that area.


With the Insulation and shields on the headers I think its very hard to get individual accurate readings with a IR temp gauge.

I am going to smoke test mine and see what I find before I freak out or go any further on mine.

I thought I had a Cat issue but I am not seeing abnormal temps with my cats.

My temps were after a 20 Min drive and still running.

My tool is not the one from harbor freight but I also don't know who made it off the top of my head.

 

After running the proverbial snot out of the car for 25 minutes;
and taking the temperatures without taking a slow-down lap immediately when stopped in the hot-pit area.

 

That seems consistent with other threads that talk about the inside cylinders going bad sooner than the others with lower compression and worse leakdown numbers? Is this proving that the #2 and #7 cylinders run leaner than the others?

 

I too am seeing much higher exhaust header temps on the RH side, by about 100 degrees, topping out at 585 on a warm day, after shut down, and not a hard drive.

Top of oil filter, 195 degrees.

Maybe we should agree on a standard set of measuring points to be able to compare temps?

Rk

 

Sounds good.

My Exhaust is completely stock so I have the heat shields and insulation still.
Thats where I think we will have a hard time getting good readings.

 

I did some readings today about 5 minutes after she came home and shut the car off. Fabspeed headers so possible to measure each one. I saw temps 50 degrees or more higher on the inside cylinders compared to the outer ones. It was only a quick check and I didn't write anything down or get real precise.

 

If you've got the stock heatshields (I have the Ricambi rebuilds inside), perhaps the hollow between the front most and second exhaust outlet? I'll post a pic soon.

I use the very top of the oil filter (for ease of aiming).

Any other spots (or better than these) we can standardize on?

RK

 

You've got stock rebuilds with heat shields.....what temps are you getting across the heat shields?.....perhaps take 3 readings per side.

 

for comparison, when I had the oem headers (with heat shields) I measured at 3 spots on the top of each header (evenly spaced) and my readings were between 500-575 degrees f per side....with the engine hot and running.

 

and with unshielded but coated (2000 degree black coating) headers I consistently got 700-750 degree f on the individual header tubes per side......with the engine hot and running.

 

It will be interesting to see different temperatures among different headers/cars/areas. Sub'd!

I know numbers are going to vary depending on a multitude of factors, but maybe we can get a thread going comparing different headers and different styles of heat protection and their temperature readings?

 

You think we're kidding when we tell you the 355 runs freaking hot?

Heat management and dissipation should be the primary concern for any 355 owner. Your engine will last longer, I am sure.

The good news is that goth is well aware of this and has made it his life's work to mitigate heat in the 355 engine bay.