4722 replies to this topic

[Nev]

I have a load of honeycomb in the shed if you want some to add that for strength instead? It’s what they use for composite panels...

 

That kind of you, what depth is it please?

 

I did consider alu honeycomb, but wondered how you'd stop the cells from filling up with resin when you lay a new sheet of glass on.  

Edited by Nev, 08 May 2018 - 03:12 PM.

[Nev]

The manifold to turbo joint on my car had been getting slowly noiser over the last 6 months, so it was time for me to get in there and have a poke around.

 

This time one of the metal gaskets had snapped and was the cause of the gas leak/noise. I have taken the 2 old gaskets out and not installed any back in, maybe just leaving them out will improve things as they seem to fail/burn out every year or so.

 

Taking the bulkhead panel off was a pain, it had got so hot that it had melted to the resin on the edges of the OEM panel and had to be levered off. I need to buy some nimbus or some-such and make a propper chimney for the turbo + exhaust.

 

Also checked my oil after a long time, it was down to the last marker on the dip stick. Was going to change it and then discovered I'd run out, so I've just bought 5 x 4.5 litres of 50 grade. I'd prefer 60 grade in the summer but it's hard to find at a decent price.

 

 

Edited by Nev, 10 May 2018 - 10:18 AM.

[ditonics]

Time for a V band Nev and some gold reflective heat tape.

[Nev]

I'll gladly swap to v-band, if you buy the new turbine and manifold for me, should only be about £2000. I am hoping my new beefier up gearbox mount will stop this happening again, as I suspect it's the asymetric sideways leverage that is doing this I think. It's surprising that nobody has ever noticed this issue with our engine/box; then again, maybe it's not.

 

As for that gold reflective tape, I doubt very much it would be effective, it would peel off in 60 seconds. It might serve to glitz up a few chav cars, but it certainly wont deal with the equivalent of 100 single bar electric heaters within 5 inches. Nimbus is the only thing that I find that can really deal with heat, and maybe alu/steel sheet can at 40% of it's effectiveness.

 

Edited by Nev, 10 May 2018 - 10:41 AM.

[ditonics]

So all the tin top series cars I'm around a lot put the gold on the bulkheads to look glitzy 😂😂😂 Nev if you get the right stuff it works well. There is a reason NASA use it and coming down the scale people like McLaren use it quite a bit in their engine bays. It's not an insulator in the traditional trapped air sense, rather it reflects the radiation (heat) away from what it's attached to.

[ditonics]

If you were ever serious about swapping to v band it's only the hot side housing and that's no where near £2000 😂😂😂 Take a look https://www.owendeve...urbine_Housing/

[Nev]

If you were ever serious about swapping to v band it's only the hot side housing and that's no where near £2000 😂😂😂 Take a look https://www.owendeve...urbine_Housing/

 

Roughly speaking:

hotside = $500

v-band = $50

New exhaust manifold = £600 to £1200, depending on which.

Changes to downpipe (inc wastegate position change) = £200 to £300.

 

It will easily reach £2000 at a guess. Hopefully my new/modified engine mounts and recent exhaust pipe bracing will avoid me having to change the config. Time will tell.

 

Edited by Nev, 10 May 2018 - 12:16 PM.

[Nev]

So all the tin top series cars I'm around a lot put the gold on the bulkheads to look glitzy 😂😂😂 Nev if you get the right stuff it works well. There is a reason NASA use it and coming down the scale people like McLaren use it quite a bit in their engine bays. It's not an insulator in the traditional trapped air sense, rather it reflects the radiation (heat) away from what it's attached to.

 

 

I reckon the air temps near the turbo and wastegate reach 300 degrees C, quite possibly more when the car is near stationary, I can't see how any adhesive would survive that. I've used some of the sticky gold stuff on the rubber vac pipe for the wastegate and it didn't last long, maybe 3 months before there was no evidence of it.

 

I think you underestimate just how hot things get in Nipper, once you get your driving your own I think you'll see. Just imagine 380 electric bar heaters in my/your engine bay...  

Edited by Nev, 10 May 2018 - 12:15 PM.

[ditonics]

Nev you would cut the old flange off and weld a v band one on. £2000 is totally rediculous

[Nev]

Nev you would cut the old flange off and weld a v band one on. £2000 is totally rediculous

 

Yea, that would be great if the metal at the collector of the manifold is still weldable. However, after seeing what the heat had done to my 304 baffle in the exhaust (further + cooler downstream) I am worried it might be too brittle and un-weldable. The manifold has the advantage of being 321, so maybe that will have become less brittle over time. I have an aerospace welding friend who can weld it in an argon bath/box, but even then I'm not sure how well he would get on. If push comes to shove I might ask him.

 

At the moment, spending a couple of hours swapping out the gaskets seemed preferable than the above agro, but the threads in the manifold are getting tired now, so am hoping the new stiffer engine mounts will resolve the issue... though deep down I suspect it might occur again as I think 1/2 the problem is the heat, rather than any engine movement. Time will tell.

Edited by Nev, 10 May 2018 - 04:34 PM.

[Nev]

It seems my Nortech exhaust manifold has cracked again.

 

Apart from my engine borewashing itself to death 5 years ago, this thing has been the bane of my life. I have got a magnet out and tested the bends, which are deffo a good steel (probably 321 as specced originally) as the magnet has almost no pull on them.

 

However the flange is mediumish magnetic so this is probably only 304 steel. Also, just looking at the way it delaminates and erodes it was never up to the job. Inspecting the turbo flange and it is nigh on perfect, no signs of errosion at all, which highlights the good quality high nickle steel that Garret use. The turbo has been faultless for 8 years now, a really good indictment to USA engineering. Sadly it's my UK made manifold which is letting me down.

 

This time I think I am going to cut the whole flange off and put a new one on, ideally made of 321 steel. Looking online though, nobody seems to make steel 321 T3 flanges, so I'm getting a quote off a chap in Sheffield to make me one bespoke.

 

This is the crack, it runs right around the left side of the T3 flange if you look closely.

 

 

 

Anyway, before I cut it off, I need to make up the current flange's exact location, as the new one has to be welded on within about 1mm precision or else my wasgate + downpipe unions won't align. To this end I've build a temporary wooden jig, which I can mark out the 4 holes of the flange on. Then when I cut the old flange off, I can introduce the new flange and align it (hopefully) perfectly, spot weld it and then take the jig off to seam weld it.

 

 

 

Edited by Nev, 15 May 2018 - 03:19 PM.

[chris_uk]

is it the flange or the welds which have cracked? 

[Nev]

Spent 45 mins in the garage this morning beefing up the jig with a side brace, I can't afford for it to snap/break once I've chopped the flange off, as I'd never be able to accurately reweld the new flange on.

 

Also, I've now drilled the 4 critical locator holes that pin point the flange (the 4 black bolts in the pics).

 

The guy who promised to phone me back yesterday with a quote and lead time for the 321 grade T3 flange didn't (of course). I suppose I might get a 304 steel one, but it's very hard to know what quality you're buying, as there are variations of 304 anyway. And then there are selfish fukwits who sell 301 and mild steel ones under the pretence of them being made from 304 grade steel, without the slightest concern about the long term impact that will have on peoples projects.

 

*Not sure what I will buy yet, will mull it over in my mind today.

 

The jig as it currently stands:

 

 

[ditonics]

If you are worried about the Ebay'ites then buy the flange from Owens, universal turbos etc

[Nev]

If you are worried about the Ebay'ites then buy the flange from Owens, universal turbos etc

 

Yeppers, I'd not use random eBayers for sure.

 

I'm still ringing round laser cutters to see if someone can make me one up from 321. Hardly anyone seems to even stock 321 though, let alone 12mm sheets of it.

 

Edited by Nev, 16 May 2018 - 10:06 AM.

[ditonics]

If it's not commonly used in the motor sport industry there is a reason.

[Doctor Ed]

or weld on a v-band...

[Mattyboi]

I wouldnt trust a V band in that location. I've done a huge amount of work on V bands in turbo applications and I wouldnt advise it.

[Nev]

Well I've finally found a guy who actually writes the CNC software that makes batches of these flanges and asked him for the spec of the sheet metal he uses (to which he was rather surprised). Anyway he went away and found the spec was T304 1.403 which I've looked up online. It's got quite high chrome in it which is good as it will resist the acid fumes and a fair bit of nickel for the heat. Simply knowing that it is genuine 304 is better than some random poorly described flange from somewhere else.

 

So I've bought 2 flanges; one with threaded holes and one without. I can then clamp the non threaded one to the other during welding to reduce the chance of warpage.

 

Should be with me by Friday and was £34 inc postage. If I can get my aerospace welder friend to come round with a big bottle of gas on Friday night we can knock it out so I can get out for my Sat + Sun dawn run to Wales.

 

I suppose I could have had some 321 flanges made up, but in all likelihood it would have taken weeks. I don't want the car off the road for that long during the summer as I want to be able to jump in and go when it's sunny. If it were winter I might have gone down the 321 steel route, however during summer expediency and pragmatism rule in my head.

 

Edited by Nev, 16 May 2018 - 11:59 AM.

[Nev]

The new flange arrived today, so I've cut + ground off the old flange with an angle grinder and fitted it up to the jig. The gaps to be filled between the new flange and collector are bit larger than I was anticipating, I hope that won't be a problem.

 

As I was grinding the old flange off it it became apparent that it had deformed in a horizontal (flat to the face) plane, clearly it's been repeatedly twisted, which implies the gearbox mount really needed beefing up. I am now considering taking the new (2.5 times stronger) DIY side engine mount from the gearbox side and replacing it with a near solid mount, so as to stop this issue. Clearly my flexi isn't working as it should, which baffles me somewhat as it is 12" long and free to move with ease, though it is too far downstream from the turbo area probably.

 

Doing the chopping was quite a scary thing really, if this doesn't work (i.e. doesn't fit to the existing downpipe + wastegate pipe) accurately I am in trouble. Ditto if the welds fail again!

 

Oh well.

 

 

Edited by Nev, 17 May 2018 - 01:17 PM.