Hornet
|
| posted on 22/12/03 at 02:02 PM |
|
|
Exhaust bends
Anyone know of a supplier of Exhaust bends?
Preferably from up North.
Cheers 
|
|
|
|
|
blueshift
|
| posted on 22/12/03 at 02:08 PM |
|
|
your local exhaust centre skip.
it's a hacksaw party!
|
|
|
Hugh Paterson
|
| posted on 22/12/03 at 03:20 PM |
|
|
Hornet, Stainless or mild steel?
Shug.
|
|
|
VinceGledhill
|
| posted on 22/12/03 at 04:44 PM |
|
|
If you are making your own exhausts then why not in stainless. Here's a copy of an article I wrote some time back for the cobra club.
After discussions with northern cobra club members on Sunday, and the recent post from Jesus in Spain, I thought I would explain how to manufacture
your own exhaust manifolds from stainless steel. Or at least how I made mine.
Disclaimer..
These are not flow tested and will not give you every last bit of horse power. And if you've NEVER even seen a welder before then maybe you
should think about paying for some.
As you all know I'm a tight git. That's not strictly true but I have had to watch the pennies because I have a wife, two kids, and a
large mortgage to support. This made me think about ways which I could save money during the build. The manifolds are a very expensive item, and
discussions with other cobra club members in the northern area made me understand that I could indeed save some money on my build by making these
myself.
The engine you chose will dictate the size of pipes that you need to flow the exhaust gasses away. All I can tell you is that I used 1.5 inch
(outside diameter) tubes on mine. (Rover 3.5 A friend of mine used 1.75 inch on his 5.7 chevvy)
The flanges themselves can be purchased from custom chrome. However, when I ordered mine they were out of stock for two weeks. I couldn’t wait any
longer and decided to have a go at welding the mild steel flanges to the stainless tube. This worked very well indeed and would recommend saving
another few bob by going down this route.
To start with, the body needs to be fitted to the chassis. Take one of your flanges and bolt it to the engine. I started with number 8 cylinder.
The idea was that I needed to come out of the engine and then round in an S shape to where the collector would be. (this is where all four go into
one)
It was clear that the pipe needed to come out and immediately bend towards the front of the car. For this I used a 1.5 inch O/D dairy bend. Dairy
bends come like the diagram below, with a straight section at both ends of the bend. One of the straights needed to be cut off in order to meet the
clearance requirements of the body. I then marked where the first welds needed to be. I then removed the two items and tacked the bend to the
flange. Once they were tacked in place I replaced them loosely onto the manifold. I double checked that all was OK and then welded it all the way
round.
The second bend within the S shape now needed to go on. Both straights on the two corresponding dairy bends were not enough for the distance that
needed to be covered so a piece of flat tube was used as a “fill in”.
I continued in this manner, building up a jigsaw of dairy bends and straights until I had a set of manifolds like in the pictures below. They were
bolted to an old rover manifold so that the stainless steel didn’t warp during the welding processes.
I used a “TIG” welder which is the ideal machine to weld stainless. I know what you are thinking… the price of the welder would make it not
worthwhile…. However there are some reasonable welders available from Machine mart and this job will more than pay for your “TIG” set-up. I would
recommend a TIG welder to anyone taking up this hobby. You can weld stainless or mild steel with it and it is much better than the cheaper MIG
welders on the market.
Dairy bends are available from RS components but are much cheaper from specialist suppliers like Hygienic Process Equipment Ltd. Hillside works,
Whitehall Road, Cleckheaton, West Yorks, BD19 4DW, Telephone 01274 852752 http://www.hpe.co.uk
To make a really neat job “weld good”. Alternatively if you are a learning welder like me, then use filler rod. Ensure that you have a proud joint.
Then grind and sand out the welds later. Use successively finer grades of emery cloth then finally polish out with a polishing mop fitted to a bench
grinder. One thing I will say about the polishing mop and bench grinder is to buy the best one that you can afford. There are about 5 different ones
to chose from in machine mart. I bought the number 4 in terms of price (second to dearest) and thinking about it should have gone for the one with
the most HP.
The job is a very long one indeed. It took me three full days to do mine. This “labour” is what you are paying for when you purchase them from
custom chrome or one of the kit manufacturers.
The finished result will be in direct proportion to the time and effort you put into the job. I for one would definitely recommend the job to anyone
who would like to save some money on their build and has the confidence to tackle the job. Let’s face it. If you believe you can do it, then you
will find a way to make it happen.
Regards
Vince Gledhill
Time Served Auto Electrician
Lucas Leeds 1979-1983
|
|
|
ChrisW
|
| posted on 22/12/03 at 05:23 PM |
|
|
Very interesting Vince, especially as I'm at this point now. Any chance you have a copy with the diagrams and photos in? Be great to have it
available for download on here.
Chris
My gaff my rules
|
|
|
VinceGledhill
|
| posted on 2/1/04 at 06:10 PM |
|
|
Send me a U2U with your e-mail address and I'll attach the photos I have.
I am going to be making mine for the locost very soon and can take some more photos if you like.
Regards
Vince Gledhill
Time Served Auto Electrician
Lucas Leeds 1979-1983
|
|
|
