Derrington Four branch copy

[kotemaori]

extractors will be made in Australia, stainless or mild, pipe sizes optimised for each stage of the extractors, hoping to do it all in mandrel formed bends, we have already cut the plate that bolts to the engine and standard inlet or twin carbs will fit (or supercharger inlet manifold)

No questions about when, if, how much at this point

[PeteMorrisMinor]

Email when they're ready. My 1950 tourer would be a different car with the keinig head, the monaro exhaust and the extractors... just need to mortgage the house to get them....

[kotemaori]

Would anyone be able to provide dimensions for Derrington 4 branch headers. Im not looking to copy them but to confirm that am on the right track when producing them in Australia

Required is:

- Length of primary tubes,
-ID of primary tubes
-length of secondary tubes
-ID of secondary (collector) tubes
-ID of exhaust pipe to muffler
-ID of tailpipe

Thanks

[kotemaori]

We have finally produced a set of extractors that allow use of twin carburettors or supercharger manifold, welds to ground and to be coated with vitreous 'silver' finish both for appearance and efficiency, it doesnt allow as much heat to escape the walls of the tubing.

Next is to match up a 'straight thru' type muffler from a manufacturer in Brisbane, this was the type of muffler originally used with the rest of the Derrington equipment.[frame][/frame][frame][/frame][frame][/frame]

[RobThomas]

N I C E !

I must confess to having not even thought about having a cut-out section for the inlet part. Bloody good idea!







Soooooooooooo......when do you think you might have prices for the bits and pieces?

[austinmorris]

I am slightly confused, there are two postings of the same item...

Keith, Are you out there, how similar are these 4 branch manifolds to your Derrington original....plus how is your Derrington copy project going....

[RobThomas]

New manifold backplates laser cut. I also TIGged a larger flange onto a standard '51 inlet to allow a later H2 carb to fit on it. The studs are actually wheel studs off an old Midget[frame][/frame]

[RobThomas]

Plate welded over the hotspot. TIG welding cast iron is a b1tch!

I binned the previous version of the combined manifold and it has given me the incentive to improve on the old idea. This method, copied from the Antipodean version, allows the exhaust to stay in place whilst the inlet gets removed. This method also saves on buying proper exhaust gaskets! A couple of half-moon blocks will allow me to pack out the other half of the area where the manifold nuts sit, if you see what I mean. All I have to do now is line up some new exhaust tubes and to TIG them onto the new backplate.


[frame][/frame]

[RobThomas]

Just discovered that our lowlight used to live 3hrs out from Brisbane, somewhere past a place called Toowoomba?

[kotemaori]

theres a lot of rust free lowlights west of Toowoomba, have exported a few of them to Europe.

Heres another idea, you may want to bin the latest project too as this manifold, although off a racer, could give you some fresh ideas.[frame][/frame][frame][/frame][frame][/frame]

[RobThomas]

Do you recognise this one? Must've been exported back here in about 2004.
It was slightly odd in that it had glass rear and side windows instead of flexible plastic.

[frame][/frame]

[RobThomas]

Moved on to pre-war sidevalve Morris engines. I've found a new Laser Cutting service who can bore holes in 10mm steel plate that are 0.3mm diameter. Now THAT'S ACCURATE!

[irmscher]

Some realy nice engineering

[chrisryder]

what do you need a 0.3mm hole for?

[TvdWerf]

At my company, we do this with waterjet cutting.
see http://serconmetalproducts.nl/metal-pro ... -1?lang=en for a video
It is possible to cut 12 cm steel, or 13 cm plastic.
The difference is that there is no heat necessary to cut.
So we can cut also plastic, and multilayer products.

But after welding, you need to make also a 10 mm plate flat again, laser cut, or waterjet cut.

[RobThomas]

I had some waterjet cutting done before but the cut line walks around a bit and the finish wasn't as good as the laser cutter. The small hole is to act as a pilot for the 8mm hole that the studs go through. They don't like to cut 8mm holes for some reason and so they either lase an "X" or lase a hole right through.
I'd hate to be in the room if one of those machines went mad!

[kotemaori]

Have had 8-10mm holes cut on a water jet with no problems, have you thought of using a mill?

[TvdWerf]

The reason from a walking line with waterjetcutting, is a higher speed....
When you do not like this, set the cutting speed lower for a perfect result.
But in most of the times a little bit walking line is not a problem.

[RobThomas]

The cost for using the Laser was the same so I went with that. The micro holes were hit with a centre punch to widen them and then drilled with a slightly larger drill and then opened out to 8.5mm to ensure a clearance from the plate when it gets hot. I did this with a pillar drill and it all slips together very nicely. In fact, the hardest part of the whole job was having to learn how to use CAD programs and then having to learn a new one when I discovered that the Laser computer couldn't read the file type I had been using for my measurements. Doh!

[RobThomas]

Silly question time.

Would anyone be interested in a kit of a backplate and a load of mandrel-bent tubes to make their own systems? You'd need to cut the tubes to length and then get them welded up but the time consuming part would be done. Something like 4x 90 degrees for the exhausts plus a couple more for jiggling and the inlet would be a double bend in one piece onto which you'd add a stub and a carb flange which could be included in the kit. Not quite an 'Airfix' but with a modicum of effort you'd have a decent system.

Would come out at about £100, hopefully. (Not guaranteed, but likely) I'm just curious as to whether there would be enough orders to make it a bulk buy.