Has anyone ever really taken into consideration how hot our intake manifold gets?

One of my VW buddies is working on a project where he is gasket-matching everything on his intake and exhaust side. Hes re-welding everything on the outside to get rid of all of the inner welds, and somehow squeezing roughly 30% more volume out of the manifold for better flow.

Hes got a VR6 and its the same kinda boat as us, the intake manifold runs over half of the engine and soaks up heat instantly. It doesnt really matter how cold of air we throw in our engine, its gonna go flying through an extremely hot manifold and heat up regardless.

Hes putting this halon stuff all over the under-side of the manifold, supposedly will help blocking the heat a bit. This is where my question starts. Has anyone ever thought about doing this?

Hes also talking about phenalic spacers? This is something like a gasket i guess that would be between the intake manifold and the head, and supposedly you would get no heat transfer through it. He said VR6 guys show extremely good results when doing the heat treatment, gasket-matching, etc... dyno'd for ~9 on the intake side and 10 exhaust side after gasket-matching and re-welding the exhaust manifold/downpipe.

Has anyone ever considered or tried stuff like this? Ive seen stuff like this done on much more high-performance applications, but never heard any orgers talk about it. All-motor guys and boosted guys alike chime in please...

hmm, interesting. I think it might help a little bit, but it seems like a substantial amount of work, more than it may be worth. Also, even if that spacer is in there to reduce heat transfer, the IM is still going to get hot, the engine bay isnt going to cool down just because that space is there. So if the engine bay is still XXX degrees then the IM will still get hot. I've tried insulating the intake piping and the filter, and while it did help, eventually it didnt. As I kept moving the pipe stayed *cool* but when I parked it, and returned the pipe got hot again. So basically what I did was the reverse of waht you're talking about. Heat tranfer still occured up through the intake, but it blocked out much of the heat present in the engine bay.

true- im trying to dig some posts up on the vwvortex forums about this... this is becomming more and more popular over there and theres some proven temperature results to show for it too--ill see if i can find the posts.

IMO, Spraying halon and welding to help minimally isn't that cost effecient. And when you say about ~9 on the intake side and 10 on the exhaust side, what exactly do you mean?

sorry, i meant to say top end horsepower, i was in a hurry typing earlier. i can't find the thread with the dyno results, but i'll find it eventually

it might not be that cost-effective, but for guys who have pretty much done everything all-motor that they can do, why not try something a little different? especially if you have access to a welder