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Jul 27, 2010 14:00:18 GMT
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I'm wrapping my tubular manifold tonight and was just wondering if anyone has any tips? space is a bit tight under the bonnet and the turbo is quite big and not a significant distance from the air intake so I want to drop temps down a bit. Ive seen some how-to vids but they're for straight motorbike pipes or 4-2-1 manifolds but mine is a 'bunch of bananas' 4-pipes-to-turbo-flange stylee and not sure what the best method is other than to get the wrap wet, dunk it in a bowl of water for an hour or so before I start ya reckons? I have stainless tie wraps to fix it in place, just not sure on how much to overlap or if there is a preferred direction to overlap? Please no 'it'll make nuns eyes burst into flames - I read it on a forum somewhere' style posts - seen plenty of succesful race and rally cars with exhaust wrap - I just want to make sure I do it 100% correctly
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Stu_B
Posted a lot
Investing in rust!
Posts: 1,266
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Jul 27, 2010 14:06:39 GMT
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Wrap them individually from the flanges but as they start to bunch together just wrap the lot as one.
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PhoenixCapri
West Midlands
Posts: 2,685
Club RR Member Number: 91
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Jul 27, 2010 14:11:45 GMT
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I've never wetted it to be honest, just wrapped it on with 20/30% overlap, dry, in which ever direction seemed to work best for the manifold I was wrapping. But it is 10 times easier off the car! I'd wrap 3 of the tubes with some "left over" to were they join together, then the 4th all the way to then cover the ends of the other 3. But really its a bit of trail and error. not sure there is a 100% correct way - just make it cover the whole manifold and look as neat as possible Words of warning though. I've had it on steel manifold and had it get damp during use (rain, dew etc), after a year or so it rusted the manifold so badly it cracked open! So best not to let it get wet, then dry out, then get wet - this also gives you a very rapid temp change which is great for cracking welds etc. Also I've heard its bad to use it on Stainless manifolds as it can cause them to get too hot and again crack welds, especially if they are taking unsupported weight from the system or a turbo. Hope this helps a bit
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Jul 27, 2010 14:25:13 GMT
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If you are going to do it on a daily driver then I wouldn't bother.... it is done on rally and race cars to improve the performance, but as written above this is at the major cost of service life of the manifold.
Most heatwrapped manifolds last very little time due to moisture trap and the extra heat reflected inwards by the material. I know of cars to get less than a year or two out of a heatwrapped manifold.
Not trying to put a dampener on your plans, but if your manifold is a nice expensive tubular jobbie then it is worth knowing that the heatwrap may decrease its lifespan quite significantly.
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- '80 Mk1 Vauxhall Cavalier Saloon, 3.0l 12v... in progress with some special plans ahead - '94 106 Rallye, Endurance Rally Car
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Jul 27, 2010 14:54:16 GMT
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I used heatwrap on my rotary, manifold cracked within 12months. Heat levels my be higher with a rotary but it's worth noting.
Have you thought of using VHT paint or have it ceramic baked?
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Jul 27, 2010 15:49:16 GMT
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Not too bothered if the manifold cracks in a year or two, managed to get it cheap and apparently if you spray the wrapped manifold with some silcone sealant it makes it repel water? Cermaic coating is well expensive! Gonna wrap it methinks, there was a wrapped turbo drag racer at the Pod the other week and he said it was well worth doin it so, I'm gonna go for it Thanks for the advice guys:)
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Stu_B
Posted a lot
Investing in rust!
Posts: 1,266
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Jul 27, 2010 15:57:42 GMT
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[vaguest post ever] Silicone sealant realeases acid (or something) when its in contact with steel (apparently) [vaguest post ever/]
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Jul 27, 2010 16:14:46 GMT
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Moisture trap? When the exhaust is hot the wrap will be bone dry. I applied my wrap wet and within literally 2 mins of the engine running it was bone dry.
Also the failure argument is a bit circumstantial – most people wrap tubular exhaust manifolds, tubular exhaust manifolds usually crack at some point in their life. I split a runner on mine and it hadn’t been wrapped.
Its some special copper coating your thinking about which apparently improves the effectiveness of the heat wrap and also makes it less prone to going brittle and falling apart
Fitment wise, soak the wrap (keeps dust down, and clings to the pipe) work out how much you need for each runner and for 1 of the runners you will want extra length to wrap around the 3 other runners once you reach the collector – keeps it all neat. Once you have worked out the lengths, start at the engine end wrap the wrap around the runner and secure with a zip tie, then wind your war down covering about ¼ of the wrap as you go, then secure the end with another zip tie. Then do the others. What I then do is cut the zip tie, with the wrap still wet and twist it hard onto the pipe (like your doing a Chinese burn). Once it’s all nice and tight secure it with some stainless strap ties.
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Jul 27, 2010 17:12:13 GMT
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Moisture trap? When the exhaust is hot the wrap will be bone dry. I applied my wrap wet and within literally 2 mins of the engine running it was bone dry. Also the failure argument is a bit circumstantial – most people wrap tubular exhaust manifolds, tubular exhaust manifolds usually crack at some point in their life. I split a runner on mine and it hadn’t been wrapped. Thats fine, believe what you wish to believe as I can't be bothered to wheel the books out in the name of science like I usually would. The main mechanism of damage is the reflected heat inwards which rapidly degrades the manifold. Cracking should not occur on an unwrapped manifold if the system contains a flexible joint as is usually standard. However, all I know is that a few of the rally boys with mild steel tubular manifolds wrapped them up, a year later they unwrapped them to replace the material only to find that the wrap was basically all that was left of the manifold... Best of luck Jason
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- '80 Mk1 Vauxhall Cavalier Saloon, 3.0l 12v... in progress with some special plans ahead - '94 106 Rallye, Endurance Rally Car
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Jul 27, 2010 17:55:56 GMT
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makes sure you wear gloves, its nasty stuff if it gets on your hands. wrap as much as u can of each tube then give a good over lap where they meet, welding wire is good to use to keep it in place temporally, before u tie it properly.
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MrSpeedy
East Midlands
www.vintagediesels.co.uk
Posts: 4,789
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Jul 27, 2010 18:06:21 GMT
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Wear gloves and long sleeves. Above all - resist the temptation to wipe your brow whilst doing it ! I know this from experiance. lol I usually use strands of copper wire stripped from industrial 3phase cables to tie off, and aim for approx 50% overlap. Make sure it's the last job of the day because you WILL want to have a shower straight after.
Not sure about the cracking/rotting issue. I wrapped the mild steel down pipes of the Sprintfire i used to have approx 7 years ago. Was stored outside and never had a problem with it rusting or cracking.
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Last Edit: Jul 27, 2010 18:08:09 GMT by MrSpeedy
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Jul 27, 2010 23:30:04 GMT
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Jeee--zues....!!!!11111
3 and a half hours Ive been trying to wrap the bloody thing!!!! didnt move from the spot and have literally been trying to do it the whole time and no luck. I think I may have to abandon it to the pile of rubbish in the corner marked "at least I gave it a go"
It just doesnt seem to be possible to wrap it right the way to the turbo flange, the way the tubes have been welded together makes it nigh on impossible for a tight fit. All Ive gained is some very itchy skin, ruined work trackies and a half wrapped manifold. Now its late and I think I'm gonna eat some unhealthy food and watch some curse word on the telly...... THE. MOST. FRUSTRATING. THING. EVAR.
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Jul 27, 2010 23:39:55 GMT
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may I just add NEVER AGAIN!! going to buy some VHT and be done with it. I don't want to go back in the garage to get it all off now without a bee keepers costume so I don't get that bloomin fibreglass on me again! ....
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Right. so how important is it that the wrap extends right to the turbo flange, or can it literally be just the majority of the runners? I've heard things about gaps and fires hence why I wanted it done properly but there's no way I can wrap the entire manifold, where the runners weld together for the turbo flange i just cant get it right. Here are some pics, dunno if the problem is obvious from them though but I'm very tired and should be in bed!
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