Intake manifold temps???
 

I would like to know what kind of temps an intake manifold would see for normal driving and possibly on overheat. I understand that the 12A manifolds are water "cooled" (warmed) and should be around the water temp. Would they remain a higher temp if the water passages were blocked off? What about header bleeding (heat coming from header to intake mani)? I would like to see at least an educated estimate on temps. I would like some numbers please. TIA

-Ian

5,000,000 degrees under normal driving. But that's only during summer here in NM.

hmm, thats a little warmer than I was thinking.

Yeah, but that's the ambient tempurature around here ;)

i'm sure with a rb header setup you would see over 100degree intake temps.... heat wrap and shields are your best friend and lower intake temps make a good difference... not only for power, but reliability. blocking off the coolant passages will probably cool the temps if anything. i've done it for years; got tired of refilling my cooling system every time i took the manifold off :p:

How'd you block them off? I hear a quarter (Or some other common coin) and some RTV fits into the passage well to block it off...

Not bad for a $0.50 mod.

Bump

Anyone else have any ideas? FBII, I bought the intake manifold from you a while ago and was thinking about a couple different ways of getting it to look better. Would 500 degree paint be ok? If I powdercoated it and it was baked at 400 degrees would it warp it?

hmm i dunno, it's aluminum so i guess it depends on how that process works with this kind of metal. i would just use the vht 1500degree paint. costs like 8 bucks a can, but it's worth it.

Does it come in black chrome?

black yes..... black chrome... :( i wish. talk to whoever would be doing the powdercoating.. see if cast aluminum will change/ expand under those temps. i dont think it will, but you never know.

I am doing the powdercoating. I just havent done aluminum yet (I have a vert spare wheel to try it on). I figure if I can balance it, then it didnt warp it too bad lol. I may make a call to the machine shop. They should know that stuff. Real quick, did you ever get that intake planed flat after you got done with all the welding and whatnot?

which intake? :p: have you seen my current setup?

The one you sold me. It was a hogged out stock manifold and the coolant passages were completely removed.

yea i know, i thought you were talkingn about something of mine currently. lol sorry. everything on that manifold is good to go. just do the quarter trick for blocking the coolant passages on the engine block just to be double sure you dont get a leak between the motor and manifold. but it's not warped.

Are you talking about intake air charge temp or temp of the metal on the manifold? I have a nonstock mani, but my IAT sensor shows around 130 degrees with an outside temp of about 80-85 or so, after warmup.. I dont have any heat shields on the exhaust manifold, though. I am sure it is getting hotter by the time it hits the bottom of the manifold.
I did the freezeplug trick to block my coolant ports, but that idea sucks as far as I'm concerned. They are a PITA to work with and still leak. Next time I will drill and tap the coolant holes and plug them proper.

I heard using 20mm Frost plus with jb weld works alright, Imma try it out tomorrow.

Let us know how that works out in this 6 year old thread :lol:

i've looked into this a little bit, and it depends on WHERE in the intake you're talking about.

the PP is the most extreme, so i'll use it as my example.

right by the carb, at idle, the intake will actually get cold to the touch. at the engine side though, since the exhaust is so close to the intake, it'll be hot enough to almost burn you....

wrapping the bottom of the intake made a HUGE difference.

less of a difference on a side port, as the exhaust is further away

I'll put in my .02¢ and mention the ACV port should be blocked off before any frost plugs are ever installed because the ACV port contributes more to intake manifold heating than the coolant ports do (if using a stock manifold).

So i installed the frost plugs but one is sideways so im going to try and remove it and get it straight.. Any other suggestion on blocking these off so I dont have to drain y coolant everytime I take off the Intake Manifold??

Tap the botched one it a little further and tap in a new one, this time being ultra careful and use a little RTV because it acts like a low speed lubricant to allow easier installation and then seals any imperfections. Or thread in a long coarse wood or sheet metal screw, and using a vice grip or some sort of slide hammer attatchment, you could slap out the bad plug and tap in a new one. Or use a series of washers on the outside of the housing so as you tighten the screw, it slowly draws the plug out as the screw tightens against the washers.

The only one of these ideas I've used above is the first one when I had a plug that went in funny. Didn't feel like trying to remove it so I tapped it futher in and grabbed a second plug. Seemed to work but I neglected to use any RTV so it had a very small seep you could see when you were in the middle of swapping intake manifolds. Just a drip every few minutes so nothing to worry about. All my other installs have had RTV and they've sealed perfectly.

im sure most of the big auto parts stores have a freeze plug install kit that they rent out, makes driving them in straight much easier.