New Builds - Learners

Good Evening all new builders learners.


Dont be afraid to ask any questions you want answered on here, the worst reply you can get is no answer, we wanted to get my dad out this year (ie if things were available we would be out for mallory or cadwell)but due to not being able to make parts or being able to get hold of certain parts off the shelf it will end up being a new season.

Keep Pressing on as we arent giving up!


Kind Regards


Eddie

Reading your last comments Ed I appreciate your struggle to get the Plot together and actually working.

Fortunately at the time we built our first Bantam (Icarus-1) I had Ford engineers, Derek Neil doing the engine, Les White our machining and I had oxy-acteylene welding equipment in my garage at home in Barking.
If I remember aright I used 20SWG (3/64ths") mild steel sheet for exhaust pipes which was fairly easy to bend to shape but more difficult to gas weld because of heat distortion. When making a cone (or parallel portion) I´d add a half-inch onto each edge which I´d turn sharply outward at 90° to the outer surface which could be clamped -- even screwed together -- to enable getting the cone to be finally persuaded into its correct shape. Then, when satisfied the cone was a proper cone, release the clamping and except for an inch at either end cut the additions down to an eight" high. This enabled the ends to be clamped and the 1/8" seams protruding above to be melted as weld without the use of filler -- starting at the MIDDLE and working outward to the clamped ends.

Of course, those with electric arc will say it is better than gas but I would argue that arc can burn holes more unexpectedly and quicker than gas and the edge preparation described above allows for a bit of filler-rod to be used when a hole does appear.

Has anyone experience of using aluminium sheet & TIG welding for exhaust pipes...?
OR IS THAT A DAFT QUESTION??

Cheerrs!

hi all,i was just wondering which fairings you guys are using on your bantams,i like the look of a naked one but it's always good to have options many thanks adam.

Hi Adam,

How's progress going?

With regards to fairings we have what i call a mike powell fairing, tank and seat but thats probably well updated by now. Not sure on what the 175 guys one is called, could be a fred launchbury but i may well be wrong.


Kind Regards


Eddie

hi eddie,things slow but still moving,i've not done a great deal just the odd job here and there's too much other stuff on at the moment, i've heard of the launchbury fairing it's quite rounded at the front not like mike's which is more pointy, andy checkly did tell me at cadwell what the fairing on his other bike was but i can't remember what he said (sorry andy) anyway you up at cadwell at the end of september ?

Hi Adam honda rs125 fairing on both bikes one is pre 95 the other 2003/4 Andy

Hi Adam,


Slow progress is better than none, hopefully we are going to be at cadwell even if its just spectating.



Kind Regards


Eddie

Good Evening All,

Well fingers crossed the metal rollers turn up tomorrow and we can finally get around to making up some exhausts.


Eddie

john bass wrote:

Reading your last comments Ed I appreciate your struggle to get the Plot together and actually working.

Fortunately at the time we built our first Bantam (Icarus-1) I had Ford engineers, Derek Neil doing the engine, Les White our machining and I had oxy-acteylene welding equipment in my garage at home in Barking.
If I remember aright I used 20SWG (3/64ths") mild steel sheet for exhaust pipes which was fairly easy to bend to shape but more difficult to gas weld because of heat distortion. When making a cone (or parallel portion) I´d add a half-inch onto each edge which I´d turn sharply outward at 90° to the outer surface which could be clamped -- even screwed together -- to enable getting the cone to be finally persuaded into its correct shape. Then, when satisfied the cone was a proper cone, release the clamping and except for an inch at either end cut the additions down to an eight" high. This enabled the ends to be clamped and the 1/8" seams protruding above to be melted as weld without the use of filler -- starting at the MIDDLE and working outward to the clamped ends.

My way: yep, definitely 20SWG. I don't use rollers for the simple reason that I don't have any, but instead use 3/4 o.d. tube bolted through to a length of angle iron. Start a slight bend on the sheet of steel that you've cut out and clamp it between the tube and the flat part of the angle iron so that the edge with the slightly pre-formed bend will be the last bit to come round.

Bend in very small increments, moving the sheet and re-clamping the tube as you go. When the two edges of your cone are within half-an-inch or so remove it from the tool and put two or three large Jubilee clips round it to pull them together. Pop it back in the tool, adjust the clips and then tack weld it, ie by putting the point of the flame smartly on the spot where the edges meet, using no rod at this stage and starting from the centre as John says. Take time to ensure the edges are perfectly parallel. Join using a no. 1 or 2 jet without any sideways movement of the torch. Keep the filler rod constantly in the flame and use it to absorb excess heat Finally, if required, dress the cone on a dolly such as a length of steel bar. Hope this is of help.

Hi John & undredseesee,

Thanks for the comments and advice, might have to outsource the welding as havent done it in years and wasnt very good then. May do some practise first and come to a conclusion.


Kind Regards


Eddie

Welding´s fun once you get the hang of it -- I understand you can buy a small kit for gas-welding -- from DIY outlets -- which means you don´t have to have two massive steel bottles in your little garage(?) like I did... In the long run it might be better than out-sourcing -- you can make a bob or two doing bits of welding for other people. On second thoughts, in my case, that is wrong -- I could never charge BRC lads who often came late at night before a meeting or going to the Island...

All the best Ed -- keep at it!

Hi Edward & Malcolm,
If you get stuck with the exhaust then let me know and I am sure we can arrange something for you! I will even take the time to come down to you to show you how I do the biz. It is relatively easy once you have seen the technique and had some practice. Take a look on the main site in the "Bantamracer articles" to give you more help.
If you have a design I will even make you patterns and send them down to speed the job up.
More help here than ayou can imagine...
I also have a previous exhaust if you want it to get started with??
Cheers,
Alan

Hi Alan,

Thank you for the kind offers, we are going to be at Lydden to watch the racing so wouls like to come and have a chat if you are going to be there.


Kind Regards



Edward & Malcolm

Head pipes.

There are various options in the case of the head pipe. If you’re aiming for a diverging pipe the options are to fabricate it in sections or it can be hydraulically formed with seams - if you can lay your hands on a pump. If it is to be parallel the options are either to cut and bend, which results in that horrible lobster-back appearance, or it can be bent hot.

The latter method whilst expensive in gas does give a smooth bend with a constant radius and no internal lumps and bumps from weld penetration. It is possible to achieve really short radius bends, ie bends that are remarkable tight. Weld a plate over one end your length of (16 swg) tube leaving a small gap where the weld starts and finishes to allow the escape of air. Fill the tube with fine sand (such as silver sand), which must be bone dry, tamping it down as you go. When the tube is near to full, drive in a length of bar that must be an interference fit in the tube. Hammer the bar in hard, and thump the tube on the floor to aid settling the sand. When the bar will enter no further, the tube will itself have the feel and appearance of a solid bar. Tap it anywhere along its length with the hammer and it will ring (if it doesn’t it’s because there are air pockets within, and the tube when heated will flatten and collapse when you attempt the bend).

Put the bar end of the prepared tube in an engineer’s vice or a pipe vice and make sure it is done up really tight. A large welding nozzle can be used but a cutting torch is better (leave the cutting trigger alone!). Play the flame uniformly along the length of the required radius. Don’t be tempted to lean too heavily on the tube or you will get creases; it will begin to bend of its own accord when it’s ready. Check the bend against your profile or pattern, such as a piece of bent wire. When done the pipe will have a hard, black, annealed finish that protects it against rust.

I have to admit I rarely use this method nowadays because my exhausts are a constant work in progress, resulting in much cutting and welding. I am somewhat bemused when I see chrome plated expansion chambers. How can people be so certain they’ve found the optimum dimensions? Or is it that they are prepared to settle for less, aesthetics being more important to them than performance?

hi,gentlemen firstly thanks andy c for refreshing my failing memory . eddie are you going for a over or under exhaust ? is there an advantage with either one apart from the ground clearance best regards adam.

Hi Adam,

The one i have a pattern cut out for and i am trying to roll is for an under exhaust but have also had some very kind help and advice on doing an over exhaust aswell from chatting with people at lydden. Maybe someone like alan or trevor maybe able to explain advantages and disadvantages for either. Ive found its alot easier to get information from being at the meetings as not everybody has time to post on here.


Kind Regards


Eddie

Hi Edd

spot on comment - "you just got to get to a meeting to really be in the know", so many different views and idea's, and so many just dont have time for computers ?, so the best help comes at a meeting between races, or during dinner time.

Regards Derek

Hi Derek,

Very true, we got to lydden early as we stayed over nearby as we missed the first race at cadwell on the second day and didnt want to do the same. Also if it is a lot of info then sometimes it is better to talk in person and things can be shown.

Hope your enjoying your holiday.


Eddie

Morning All,

Any new builders/learners with progress reports? We have a few things to sort on the red one including getting the front brake to work properly and trying a krober or kart rev counter as the smiths one just doesnt work properly. hopefully have a look at the carb at the weekend and try some ideas we have been given on load testing. over the winter we are gonna look at finishing the blue one (might be easier trying to source a pre done rear for foot rest hangers and seat adaption).


Kind Regards


Eddie

I know I am out of date Ed but ask me a question and I´ll try and answer it.

Remember there are some contributors on here who don´t like more than one line posting for them to reae on here so go easy on a poor old (out of date Old Hat) Gitt.

Actually that´s a bit silly because I am on a plane to Blighty on Thursday morning
and whilst Snetterton, Cadwell, Brands, Thruxton, Lydden ...etc...etc... and all
them bits of road... flaashing under the wheels didn´t finish me off a terrorist could do....

So maybe this is goodbye....

We didn´t finish 1st order balancing -- perhaps Trevor will speak on that.

Cheers!

Wonderful knowing a lot of blokes who are/were as daft as I (or me??) to cock a hefty leg over the saddle of a racing Bantam -- Oooooh my Druids elbow hurts as I type this ....

Cheers!

Edward Pickering wrote:

Morning All,

Any new builders/learners with progress reports? We have a few things to sort on the red one including getting the front brake to work properly and trying a krober or kart rev counter as the smiths one just doesnt work properly. hopefully have a look at the carb at the weekend and try some ideas we have been given on load testing. over the winter we are gonna look at finishing the blue one (might be easier trying to source a pre done rear for foot rest hangers and seat adaption).


Kind Regards


Eddie

I might give it another go in the next couple of years, need a front end and a baby sitter oooops and nearly forgot.....WONGER

Edward Pickering wrote:

We have a few things to sort on the red one including getting the front brake to work properly


Eddie

Eddie when I saw the photos of your Dad circulating on the red one, I thought "No way would I want to be chining the tank with that brake to stop with at the end of a long straight"

Hi Ned,

Well as we are new to this full stop dad wanted to get out and give it a try but as he said " the brakes didnt work after the first lap so he didnt bother using them and he wasnt going fast enough to need them!" maybe its the incentive to get the proper one done that will have disk brakes.


Kind Regards



Eddie

HOW DO I LOOK AT THE PHOTO'S NED IS TALKING OF as I CAN NOT SEE A POST ? WITH A PHOTO ON

Regds Derek

Hi Derek,

The pictures that Ned is talking about are on page six of my Engine Opinion's Topic.



Eddie