Hello everyone,

Last year I upgraded the exhaust on my 71 from my stock SS Heat Exchangers to a header from MSDS. There were warm air guides that attached to the heat exchangers to assist with engine cooling.

Should I create new warm air guides to attach to the headers? I'm planning on installing the floor pan air deflectors from 914 rubber to help with cooling, but aside from that, is there anything else I need to do?

Thanks in advance!

I wondered the same thing, but couldn't find that anyone has ever added warm air guides back when running headers, so I am also running without them. Havent noticed it to be an issue and I have ran that way for ~15 years

Thank you for your reply! It doesn't seem to be that big of an issue I guess since hardly anybody has commented.

When you look at the shape and location of the warm air guides it appears they are intended to guide the cooling air from above the cylinders down and around the underside of the cylinders. I assume this is to extract heat from the undersides of the cylinders. If not in place the cooling air would be free to pass between the cylinders without being routed around the underside. How effective are they? I don't know.

tin-ware located above those guides and the pushrods and fitted closer to the underside of the cooling fins and heads does the job of deflecting the air around the bottom of the cylinders.

its debate-able what the lower guides achieve in reality. been an argument since the 80s at least to have them or not have them.

you want to make sure you have that upper tin ware above the pushrods.

i think maybe what the lower guides do is "try" and guide the exhausted cooling air (which is heated and quite hot) that has finished its job towards the rear of the car where it can "theoretically" escape, this applies when the car is sitting still in traffic, esp on hot still days. its the mid engined problem particular to the 914 and not an issue shared with the rear engined vws and porsches. problem is the heat still builds up.
the rear trunk and rear wheel wells form nice bubbles to trap the hot air in regardless.
the cars have always had that inbuilt design flaw, makes life hard for the fuel pump and fuel lines when the pump is in the original location under the engine. maybe the guides were meant to help with that. if so they didn't do much good.

we get a lot of hot still days in aus in summer - thats when you notice just how the heat can build up under the car and just how hot it can get. the tops of the rear guards and the flanks just behind the doors get quite hot to the touch. so much so i avoid driving my car in those conditions. i'm talking ambient temps in the high 30 to low 40 deg centigrade. you do not notice it at all in winter down here.

its interesting that the sixes don't have lower air guides. neither do 911s. just have the little deflectors between the cylinders the guide/curve the air flow under the cylinders which is a less extensive piece of tin ware than the deflectors vw used for type 4 motors.

i can think of only one vw engine where the bottom tin ware guides were important - the type 3 pancake engine. in a type 3 there is no sealing tin that separates the lower engine from the upper engine bay. if you don't have the bottom tin in those cars you get a very hot engine bay. it does not affect cooling air or intake air as both are ducted in via boots, but it can cause you real headaches with fuel vaporisation.

Thank you for the replies. All of the tin (other than those air guides) is in place and intact. I try not to drive the car in really hot weather, but if I do, I make sure to keep the RPM's up to keep the air flowing. Hopefully I won't see any significant change in head temp/oil temp/oil pressure. If I do, maybe I could add something to help with air movement.