Heat Proofing/Insulation

[Morton]

Hey y'all

I'm in the process of whipping up a cheap little CAI, 'cause I'm drawing in air at 70 degrees plus on a hot day, and I was looking for a way to insulate my piping. Some of it gets DAMN hot sitting directly above the exhaust manifold, and next to the cooling lines.

I've heard heat wrap can be expensive... does anybody know otherwise? What about a combination of something like foam and foil?

I'll upload some pictures of my CAI tomorrow once the sicaflex cures properly. It's nothing fancy, but I think it's going to work a dream

[immortality]

fit some pacies with ceramic coating would be the best way to go. some sort of heat shielding would work also. FIT does some sort of heat shield forthe l67. maybe you could adapt it to your ride somehow? header wrap isn't that expesive per roll but you would need a fair bit off it. you can also insulate the intake duct with header wrap also. also consider insulating your fuel lines and fitting a fuel cooler also

[Morton]

Yeah, some good points there. New extractors are far out of the question through cost. I'll look further into header wrap for the intake duct.

Am I correct in assuming that air would gain around 10 degrees between the airbox and the throttle body, or would this gain be greater?

[Not_An_Abba_Fan]

Yeah, a heat shield would be the cheapest option. Just make up a piece that maybe picks up on a couple of manifold bolts. In all honesty the heat of the intake pipe has little effect if you have a hi flow filter and CAI. The speed at which the intake air moves is fast enough not to heat up that much. And it's only about 5% of the air that is heated as it is only this small amount that is in contact with the plastic intake. Actually in theory, the hotter the air is the faster it moves because there is less resistance so the the bit of heat that is there is a trade off for the amount of condensed air your engine can cope with anyway. The colder the air the better for sure but short of refridgerating the intake tube there is really little difference that amount of heat will make. Unless of course you are idling or moving slowly for prolonged periods.

[immortality]

Yeah, some good points there. New extractors are far out of the question through cost. I'll look further into header wrap for the intake duct.

Am I correct in assuming that air would gain around 10 degrees between the airbox and the throttle body, or would this gain be greater?

you cold wrap your cast exhaust manifolds but it would be a pain in the *ss to do. maybe go the route of the heat shield. not sure how much the intake charge is heated after going through the airbox. not sure anybody has ever measured it. just a little side note, header wrap apparently causes the metal to rust out faster, most aftermarket header manufactures won't honour there gaurantes if header wrap is used. heres some pics of the FIT heat shields

[Morton]

That heat shield looks alright. Certainly cheaper and easier than coating the factory headers in wrap, and it won't cause them to disintegrate

Abba, you're pretty damn right about the air only heating up on the circumference. I didn't think of that. Since I whacked the CAI on this morning, the general airflow is a good 30 degrees cooler anyway. You can feel the difference when driving. The throttle doesn't feel so 'doughey' when warmed up. When the car's been parked for five minutes, the induction piping gets stupidly hot, but after running the car for a while, it cools back down with the movement of the fresh air through the ducts.

I think the best go would be some sort of dodgy metal shield next to the runner over the extractors, or something like what you posted, immortality. I'll upload some pics in a sec.

[immortality]

i'm thinking it's time to get some aluminium sheet and start making a heat shield. can't be that dificult

[Morton]

I've been thinking that myself, hey. But having felt the huge difference the new CAI is making in the hot weather, I don't think a heat shield would even do much for me. I'm not noticing any real loss of power from cold start to full operating temp any more, so perhaps the ambient engine heat doesn't have such a great effect on induction temperatures.

Either way, thermal wrap proved to be too expensive. If I start thinking about that aluminium heat shield now, though, it may get done in the next few years

[immortality]

I've been thinking that myself, hey. But having felt the huge difference the new CAI is making in the hot weather, I don't think a heat shield would even do much for me. I'm not noticing any real loss of power from cold start to full operating temp any more, so perhaps the ambient engine heat doesn't have such a great effect on induction temperatures.

Either way, thermal wrap proved to be too expensive. If I start thinking about that aluminium heat shield now, though, it may get done in the next few years

i just picked up two bits of alloy, 400x220x1.6mm for $27. couple hrs cutting and drilling some holes and it should be all done etc. gonna do 2, 1 for the VN and 1 for the VS, it already has the super6 CAI but it definitly won't hurt anything having a heat shield in there

[FXST01]

I did this about 8 months ago, if you have no plan, then get a sheet of stiff plastic and use that as your template, you can mark and cut it as required or tape pieces back on until you are happy with it, then trace the template around your alloy sheet.

Clark Rubber sell insulating foam with foil which comes with adhesive backing (5mm and 10mm), then i use flashing (flashtac i think its called at Bunnings) for the overlap and some cable ties.

Can do pictures if required.

[immortality]

I've been thinking that myself, hey. But having felt the huge difference the new CAI is making in the hot weather, I don't think a heat shield would even do much for me. I'm not noticing any real loss of power from cold start to full operating temp any more, so perhaps the ambient engine heat doesn't have such a great effect on induction temperatures.

Either way, thermal wrap proved to be too expensive. If I start thinking about that aluminium heat shield now, though, it may get done in the next few years

i think the heatshield works to stop the heat soak when sitting idle in traffic or your waiting to stage at the drags etc

I did this about 8 months ago, if you have no plan, then get a sheet of stiff plastic and use that as your template, you can mark and cut it as required or tape pieces back on until you are happy with it, then trace the template around your alloy sheet.

Clark Rubber sell insulating foam with foil which comes with adhesive backing (5mm and 10mm), then i use flashing (flashtac i think its called at Bunnings) for the overlap and some cable ties.

Can do pictures if required.

mine is mostly done, i just removed the rocker cover and measured it up etc. quiet simple, just in the process of cutting some holes for the plug leads. i'm thinking maybe some insulted sleaving for the leads where their under the heat shield as there is going to be a lot more heat there now. i'll post some pics when i'm done.

[Morton]

Good point on the heat soak, you'd be dead right there. I'd be interested to see how these shield ideas look in fruition. Keep us posted

[stocky]

hmm i may need to look into this too. my intercooler pipe runs fairly close to my passenger side extractor

[immortality]

just finished mine, looks good at the mo, now to see how well it handles the heat. i think i might have made it a bit to close the the centre header pipe as it comes out around the back one etc. here some pics. one shows the clearance between the heatshield and center header pipe. enjoy

[Morton]

That's pretty groovy, hey. You put some bloody work into that alright. Looks sweet as

(oh, and yellow headers? lol)

[immortality]

That's pretty groovy, hey. You put some bloody work into that alright. Looks sweet as

(oh, and yellow headers? lol)

yeah, they were actually red to begin with (local brand called coby) the paint used obviously isn't heat resistant as it's turned into a yellow type powder that actuallly rubs off. nobody had pacies in stock here for a manual VN for a reasonable price, had ordered a set but after waiting 10 weeks and then not showing up i got the local ones instead. there not that fantastic though. i need to remove them and check the port sizes etc cause there not pipe through flange etc. can't be bothered at the mo cause the drivers side was a pain to get in and i don't wanna take em out again. pacies next time i've also done mine different to the FIT design. i've put the plug leads through the side using grommets etc it will make it more of a pain in the *ss to remove and change the plugs etc but the FIT design has the plugs going down from the top(sharp bends under the heat shield) and also has the leads sitting against the side of the the heat shield where it's going to rub and damage the insulation on the leads etc.

[FuzzayD]

My friend did this to his vk but his heat shield has piping that leads out the bonnet, he said the heat doesnt fall under the car when idling and just heats up the alloy and sends it back into the engine hotter than it would be without it.
Im thinking of something like this do you think a thicker piece of alluminium or two thin pieces the second one being heat insulated?

[immortality]

i've got a thermofan bypass switch which allows me to run the thermo fan at any time, with the bonnet up and thermo fan running you can feel the heat behind the exhaust shield, i've tucked the edge of the shield in and the air seems to flow down around transmission tunnel quiet nicely. i've had it for almost a year now and things seem to be holding up quiet well

[PaRaDoX]

looks good.... my biggest issue is the heat is comming up into the inlet manifold and soaking that 23kg mass of alloy with heat

[immortality]

looks good.... my biggest issue is the heat is comming up into the inlet manifold and soaking that 23kg mass of alloy with heat

HPC coatings is about the best solution. they can put a thermal barier coating on the manifold including inside the runners to help keep the intake charge cool, they can also apply an oil repelant coating underneath so that the hot oil doesn't hold onto the manifold and heat it up as much.

another trick i've seen is they actaully make a steel shield that sits underneath the intake held by spacers on the bottom of the intake manifold, again to keep that hot oil from splashing up underneath.

other then that about your only option is to design some sort of CAI that blows cool air down the runners

[PaRaDoX]

i know hpc coatings arnt the cheapest, i was thinking a dual plane is the easiest and cheapest way out with a custom twin throttle jig

[immortality]

the hot manifold is the only problem i have also. just drove 20km down the motorway, got home, popped the bonnet and the entire intake system up to the elbow after the TB was still cool to touch