Another exhaust manifold thread

[leorest]

When the time comes to replace the ageing manifolds I'm contemplating making my own. I'll need to buy welding equipment so the main question is MIG or TIG? The first set will be mild steel but if that is successful I want to be able to do it again in stainless. I'm familiar with MIG, gas & arc welding but think TIG will give better results, especially for stainless. So the next question is how much do I need to spend to get equipment fit for purpose?
Bearing in mind this is for a standard 3.5 engine is there anything to be gained by changing the design from standard?

[stainless_steve]

Tig for stainless,you can buy single phase HF sets for £300 prob less.Not sure how long some of the cheap sets will last though.

[GV]

I'd also consider a crash course in welding unless you are already proficient. Might save on wasted costs...I would love to do the same thing but have opted to buy a set modded to avoid touching the chassis when the time come to replace.

There's a feature in Practical Classis covering the subject of welding and which kit is the best...hope it works out for you.

[rev-erend]

As you know - I've been making a new set for mine .. and I'd say .. run a mile, dont do it. Buy off the shelf.

It's a very difficult task and is also expensive.

Best place for bends and all parts is JP Exhausts

http://www.jpexhausts.co.uk/

Prices are not on the web - so just call them.

Once you add up the price of all the angle bends, tube, collectors and joiners .. you will realise that the cost of buying off the shelf actually looks very reasonable.

Don't contemplate a 4 into 1 - it's nearly impossible.

Best bet is 4 - 2 - 1 with either 1 1/2 " or 1 5/8 "
1 3/4" is too big unless you have 5 litres plus.

Cylinders 7 & 8 fire sequentially - so the primary tubes need to be longer for that pair.

[rev-erend]

rev-erend said:

As you know - I've been making a new set for mine .. and I'd say .. run a mile, dont do it. Buy off the shelf.

It's a very difficult task and is also expensive.

Best place for bends and all parts is JP Exhausts

http://www.jpexhausts.co.uk/

Prices are not on the web - so just call them.

Once you add up the price of all the angle bends, tube, collectors and joiners .. you will realise that the cost of buying off the shelf actually looks very reasonable.

Don't contemplate a 4 into 1 - it's nearly impossible.

Best bet is 4 - 2 - 1 with either 1 1/2 " or 1 5/8 "
1 3/4" is too big unless you have 5 litres plus.

Cylinders 7 & 8 fire sequentially - so the primary tubes need to be longer for that pair.

Editied to add that I initially used MIG with Stainless but could not get a consistent weld that was gas tight. So in the end I got a local guy to TIG them.

[gsx600]

Does this mean they are done then Alan

[rev-erend]

gsx600 said:

Does this mean they are done then Alan

No - same as before Christmas .. it's just to cold to go out there.

[gsx600]

Yep is a tad cold for working on the Wedge

Need to fit the rear SH tie bars sometime

[leorest]

Thanks for the info Alan/Steve.
Initially I've been looking at Machinemart's offerings and it looks like £300 should get me something. Is there anything I should look for, or avoid, when choosing welding equipment?

Alan - Did you make any jigs to help?

I've got some experience/training in mig, arc and gas welding from way back when, when I was an apprentice scrote, but if I can find a course in tig welding I'll definitely go for it.

[rev-erend]

No need for JIGS unless you plan on making loads of them ..

It's all basic Trigonometry to start with - to calculate the angles you need ..

Re the equipement - I looked for a TIG but it did seem that a decent one would cost a grand .. so that was a no go.

A guy down the road lets me use his TIG (Cebora) but I'm just such at amateur - so I let the expert do it.

[quattrophenia]

How much are these to hire for a couple of days. You could even make a couple of sets and flog them to recover the hire cost.

[rev-erend]

quattrophenia said:

How much are these to hire for a couple of days. You could even make a couple of sets and flog them to recover the hire cost.

You make it sound so easy

[leorest]

Agreed. I expect two days work wont get close to starting making the first set!

The stories I've heard so far lead me to believe that any of the bought manifolds wont fit without cutting and/or hammering. So I'm not going to pay top dollar for something I'm going to have to re-engineer myself. It may cost more but at least it will fit properly. The bonus is I'll have a set of welding kit left over at the end.

[stainless_steve]

leorest said:

Thanks for the info Alan/Steve.
Initially I've been looking at Machinemart's offerings and it looks like £300 should get me something. Is there anything I should look for, or avoid, when choosing welding equipment?

Alan - Did you make any jigs to help?

I've got some experience/training in mig, arc and gas welding from way back when, when I was an apprentice scrote, but if I can find a course in tig welding I'll definitely go for it.

A 180amp Cebora is around £400 new off a mate of mine,he sells them for a living.He says the cheaper ones don't last so he won't sell them.

[wooly350i]

Yes i bought a Cebora 190 mig welder for £500 off a dealer in Reading and have been using extensivly since for all sorts of jobs,dunno how i managed without it!How ever when i bought my manifolds off David Gerald a few years ago i found we had to dry fit them,cut the bottom single pipe with the flange on,apply heat(oxy acetylene)to bend the down pipe a little away from the chassis then and re tack the bottom pipe in position before romoval to weld up complete then finally refit,that was easier cheaper and quicker than manufacturing from scratch.I can imagine alot of welding,cutting,welding cutting,swearing,welding,cutting,bad moods,welding,chucking it around,sleepless nights!Put you right off ya stroke!!!