Recently fitted a new set of heat exchangers and wondered if it would improve their efficiency by covering them with exhaust bandage, then silicone bandage on top? eBay items 291493630929 and 221797130335 Silicon bandage rated to 260degrees, is this enough? Would sealing in the insulation with the bandage cause condensation problems?
It might possibly accelerate rot of the exchangers. As above, if you've got original ones, they should belt out enough heat anyway.
These are NOT originals (I wish!) , but aftermarket typically poor quality ones. I don't want to accelerate rust so will probably not now insulate them, thanks for the tips guys.
Just my experience. I covered my exchangers and also the 4 into 1 tube on the exhaust . After a few days I noticed the engine temp started going quite high. Someone explained to me that you need the air flow accross the system to dissipate the heat and wrapping it will only make it wamer ? Anyhow took it all off and temps went back to normal so I suppose it sort of made sense . Sent from my SM-J500FN using Tapatalk
Not enough air flow for the wrap to decimate heat . In my opionoin , ive wraped small block chevy engine headers ,in the past and noticed a small percentage of the head heating up. And thats water cooled.. My motobike .air cooled aluminium heads ,has the wrap which is great because the wind cools the head with the wrap having more "mass" to the exhaust pipe .,,,,,obviously pictures below ,,,,ive brought the temp diwn a few percentage from that., If vw didnt do it you shouldnt as well. Paint them with high heat paint , thats the way to go.,make sure to cover every bit of surface ..find the pricier brush on , not the spray can,,,with the wrap after driving in rain if left up damp . will rot them eventually...
There is a consensus that VHT paint wont bake off properly on heat exchangers - might be worth a paint in smoothrite or something similar. The pipes after the exchanger should have insulation wrapped along them - if not then foil bubble wrap stuff would work nicely.
From what I understand, VW originally insulated the exchangers. However, because of my concerns about rust, I have recently insulated everything downstream of them with this: https://www.ebay.co.uk/itm/162053964008 Only cost about a tenner, and enough left to insulate front, doors, sides and hatch too! Still have option to insulate exchangers, but with the cables properly adjusted, it is pretty hot up front.
On most bit of the heating piping to the front, you can wrap several layers of the stuff, i used silicone tape to secure it at the ends to avoid the funnel-effect of tie-wraps: https://www.ebay.co.uk/itm/272313958150 With 20/20 hindsight, i should have jetwashed everything beforehand, the amount of stuff i got into my eyes even with safety glasses....
Now I understand what you meant; I thought you were talking about insulating the exhaust after the heat exchangers.
Original exchangers have insulation and a reflective layer inside. I cant see an issue with insulating the outside instead, particularly if they are aftermarket exchangers where there is less mass in the fins around the exhaust headers. I wouldnt wrap the downpipe part though!
I painted my heat exchangers, tins and rocker covers in black gloss Rustoleum combicolor , which has stood up well to heat and dirt. I would be concerned that wrapping the heat exchangers could cause them to get too hot and overheat the engine. As said it may be better to source some original more efficient ones.