Underhood temps.

In the interest of KR reduction and cooling the engine bay, I'm getting a coated Plog and crossover from ZZP. Curious about the real effects on engine bay temps, and what the surface temp diff is compared to the stock exh manifold. I have a Raytek non-contact infrared temp gun, and when I get home at noon today, will check the surface temp on the stock manifold and crossover. Will be interesting to compare it next spring when I do the coated Plog install.

BTW, if anyone is interested, we sell Raytek MT4 infrared thermometers where I work. and I can sell 'em for $50 + shipping. I'll post some specs if there's interest.

Interesting indeed. My opinion is the Powerlog will run hotter than your stock manis. The reason being, they're thinner. The ceramic coating makes them cooler compared to uncoated, but next to the thicker cast iron manifolds, I bet they'll be hotter. My headers seem to run way hotter than my stock manifolds. There's just less material to absorb all that heat. The solution would be to wrap the Powerlog with header wrap, after you do the tests of course.

Hmm, I was thinking the coated Plog might run cooler than the stock manifold. Worth a look at ZZP site too, in case they have posted similar info already... off I go.

Even if it runs hotter, the flow benefits should be worth having. As long as the IAT is looking good, and coolant/tranny temps are fine, higher underhood temps don't concern me that much.

the plog should cool down faster after you turn the car off, but i'm guessing the well-insulated cast iron will radiate less heat when running.

I'm not worried about the Plog running hotter, just curious what the operating temp diff will be. It will certainly cool faster when not running, the cast iron really holds heat in, bad for performance. I checked the CI manifold when I got home, and #1 and #3 runners were both right around 400deg F. while #5 ran 40deg cooler. The crossover surface was around 200. SC top surface at 130.

for comparison- i just read mine with a Raytek MT and it is around 93* out right now. i just got back from class so i was at my normal operating temp.
s/c casing - ~ 160
TB - 150
intake box - 130
manifold tops;
#1 - 285-310max
#3 - 295-322
#5 - 260-275
crossover - ~250
i did have my a/c ON during the ride home, so the coolant fans were on too. also i tested them after turning the car OFF and i ran inside to get the temp scanner, so it had about 2 minutes to cool down before i read temps.
i have stock mani's btw.

Ok, that explains the lower manifold temps. I tested with engine still running. It's only about 50deg here, and my airbox surface was 84deg.

93 there, huh? Sorry to hear that.

no its great :roll: the coolest i've felt in awhile. the ride to school/work is fun for me in the mornings, (~75*) i cant wait till its 50 out

Mr.Riviera wrote:

no its great :roll: the coolest i've felt in awhile. the ride to school/work is fun for me in the mornings, (~75*) i cant wait till its 50 out

Yeah, I'm a 50-90 deg kind of guy myself. I don't mind cold if it isn't windy, and I don't mind hot if it's not too humid.

as a free mod you can remove the rubber cowl insulator at the back of the hood.

I figured I'd do that next spring, instead of heading into winter.

1998 Riv wrote:

Mr.Riviera wrote:

no its great :roll: the coolest i've felt in awhile. the ride to school/work is fun for me in the mornings, (~75*) i cant wait till its 50 out

Yeah, I'm a 50-90 deg kind of guy myself. I don't mind cold if it isn't windy, and I don't mind hot if it's not too humid.

It was 45 degrees out when I got out of work yesterday. Its going to be 85 degrees out on monday here. What a difference one week makes!


Welcome to new england folks!

How about 85 to 45 in 8 hours?!! I'll never forget April 3rd of this year:

https://rivperformance.editboard.com/everything-else-f9/what-a-beautiful-day-t565.htm