Thread: now the alternator

Originally Posted by rick130

exhaust wrap kills mild steel in no time at all. It just fatigues it like nobodies business.
HPC or Jet Hot coating on the first three feet of the dump pipe is better. Doesn't retain as much heat as the wrap so doesn't fatigue the base metal, while still significantly reducing radiant heat.

had it on both my disco and shorty for 2+ years now on std pipes with no problems at all. (dare i say it the way things are going...)

stainless steel definetly cannot handle wrap, but freeform steel exhaust tube usually handles it fine...

one of the best things i have ever done.... wrapped them from the bottom of the manifold to the back of the gearbox ....

way less noise and a lot less heat into the cab in both vehicles..

will be doing it to all vehicles i own in future...

Originally Posted by incisor

had it on both my disco and shorty for 2+ years now on std pipes with no problems at all. (dare i say it the way things are going...)

stainless steel definetly cannot handle wrap, but freeform steel exhaust tube usually handles it fine...

one of the best things i have ever done.... wrapped them from the bottom of the manifold to the back of the gearbox ....

way less noise and a lot less heat into the cab in both vehicles..

will be doing it to all vehicles i own in future...

Strange contradictions there are, The owner of Genie exhuast here in the west runs a drag car in which the extractors are all wrapped, when I enquired about wrapping the rangies for the same reason you described less heat and noise he said no because the metal corrodes at a prolific rate under the wrap.the drag car gets new extractors every couple of meets...he advised ceramic coating but at a horrific expense..
Have you checked under the said wrap, ie a light tap here and there..

yeah, on the shorty i have, and it looks perfectly fine.

never seen any evidence of acidic reactions, ever.

it is usually the constant annealing of the metal that causes the molecular structure to fall to bits, which is why stanless cant cope, constant annealing makes it work harden and the intergranula corrsion proceeds until the metal fatigues.

i used to fit out marine engine rooms for a living... say hello matilda fleet on sydney harbour, and all exhausts were wrapped then lagged then sealed... i have never seen freeform mild steel exhaust tube with any of the symptoms described above...

i have only seen stainless steel, high silica cast iron and maleable iron fatique under fibreglass or asbestos header tape.

but i am not an engineer, i am only a lowly fitter, and it is only my observations....

i will do a visual on the disco whilst i am installing my new alternator... yep new denso alternator goes in this afternoon, if i dont hit any more chinamen on the way home... the old one is screwed... oh well.

gunna have to keep the dam thing the way it is going...

lowly fitter huh---

just bite your tongue/bullet and buy the RR,,,


what could possibly go wrong on a hundred grand vehicle???

welp

alternator fitted. got old one checked at bashi auto elect and it was only putting out 15amp. picked a denso unit up from MR autos as i need the vehicle on the road. took an hour or so to fit it. no dramas except the heat reflector doesnt fit ... or didnt till i made a bracket to support it..

the box is marked denso, the alternator has a denso sticker, but the castings and housings have magnett marelli on them :P






all done, all working....

now for a drive....

full size pics in my gallery....

ho ho!!

nice.

[quote=DirtyDawg]Strange contradictions there are [quote]

peeled back a bit of the tape on the disco exhaust, pristine, no visible difference to the rest of the pipe, cept it is marginaly cleaner.. i didnt get a pic, my neibour dropped over for a chat before i got a chance... will try for a pic tomorrow...

Originally Posted by DirtyDawg

Strange contradictions there are, The owner of Genie exhuast here in the west runs a drag car in which the extractors are all wrapped, when I enquired about wrapping the rangies for the same reason you described less heat and noise he said no because the metal corrodes at a prolific rate under the wrap.the drag car gets new extractors every couple of meets...he advised ceramic coating but at a horrific expense..
Have you checked under the said wrap, ie a light tap here and there..

that's my experience as well with the old race car. The primary tubes started to crack up after two seasons using header wrap. I still have a few new rolls left, but have never been game to use it on a roadie or the Landy, even though I've been tempted a few times and even dug the boxes out of the shed, twice.
I know the theory says it shouldn't happen with mild steel, but I've heard too many reports, and had my own experience with it.
<edit> the primaries didn't corrode but literally cracked up. It looked OK, then lots of fine cracks just spider webbed everywhere. </edit>