Datsun Roadster Forum-311s.org

Thanks Phil,

If you mean are the holes in the plate to hold it? Yes, I made the wooden die longer both ends, so that the finished halves could be trimmed to remove the holes after the half is formed.

Do you think I should start a new thread and explain how it is made, rather than take over this thread?

What do you think Alvin?

Rob

rp975 wrote:Thanks Phil,

If you mean are the holes in the plate to hold it? Yes, I made the wooden die longer both ends, so that the finished halves could be trimmed to remove the holes after the half is formed.

Do you think I should start a new thread and explain how it is made, rather than take over this thread?

What do you think Alvin?

Rob

Please explain, Rob! It is artwork!

notoptoy can move the post (I think) if you / they want....It's in engine swaps and under VQ35HR so I think it fits....easier to find when searching.

Did you use a router to finish the flat plates on a wood template? I have seen that done on the internet and have done it myself....works trick....My woodworking buddy just shakes his head when I bring some metal over....I did buy my own carbide bits...lol......
I have used a router to open up the center hub hole on wheels.

Are the holes in the end of the intermediate plate to locate it and it gets welded on both sides-runners and chamber.

Thanks for sharing.

OK Here goes....

I started with a 20mm thick plate of aluminium, I traced the previous manifold gasket onto the plate and thendrilled the holes and used a hole saw to cut larger holes for the ports.
I then used a die grinder with a special bur for aluminium to open up the more square oval shapes.



next I bought 3 180 degree bends in 3mm wall thickness and 50mm OD, when cut halfway through the bends this gives me 6 x 90 degree bends, then I had to squash the sides of these bends in my press to give an oval cross section that was close to the port shape. I used a vernier to help make sure that each was pressed the same amount.







Next I used the die grinder to recess the oval pipes into the 20mm plate about 3mm in depth.



Here you can see the pipes in place and my bonnet height maked on a template piece of wood.



Next I used a compound saw with a 100 or 120 tooth blade to cut the correct angles on the ends of the bends, each end had a different angle, I made a guide with a block of timber.

You can see here that this gives a low height for clearance (Clarence)



here the pipes in situ showing that they are staggered, so three are longer than the others.









I should mention that this is a turbo motor, I wanted the lowest manifold with the least number of bends for the air to travel after the twin throttle body.

I then cut out the next flange from 15mm plate, this will be where the air is diverted to the runners from the plenum.



Next I drew a plan of the actual size for the plenum looking at what length gave me the lowest throttle body position.

From this I cut out the timber die from 50mm thick hardwood, less the 3mm wall thickness each side, I also made the timber longer than I needed so that I could have room to trim the pressed aluminium form.

Next I carved out the contours I wanted in the hardwood.



Next I wade another timber part from 13 ply to hold the formers to press the valleys into the plenum.

I bent some 10mm x 5mm strips into the correct shapes, then drilled and tapped them so that they could be held in place firmly from behind with cap screws. After that I used my die grinder to contour the strips into a vee shape.

Now when pressing the first pressing I removed the outside two formers from each side, so started with just the center former, if I didfn't do this there would be too much stress on the dies, it is too much to ask of this kind of setup. You have to think of the aluminium as flowing when pressing, so in this case it was drawn into the center only.

The next pressing I put the next formers on as well and so on for each pressing so that the metal had somewhere to go, the previous formers were in place to keep the form they had already made.

I should mention that I annealed the aluminium before each time I pressed it so that it would flow better.



I should also mention that I supported each side, outside of the timber dies so as not to put unwanted flex on them, in my case I had some 25mm thick steel plates I could use.

Once I had pressed two lots of this I drilled holes through and screwed both dies and the aluminium together so that any further pressing would not change what I had formed here.

Next we are going to press the plenum outer shape, this is a bit more difficult as the curves on the outside are compound curves, meaning that they are going in two different directions so it is a lot to ask of both the dies and the metal.

When I cut out the hardwood die I kept the end offcuts as they are to become part of the next die.

I mounted these outer parts onto another 13ply piece of timber and also gave each one three positions from just outside the center die (5mm) allowing for the thickness to the metal and a bit to maybe 15mm each step out so that when I pressed I would start with these formers at their outermost positions and move in for each next pressing.

You can see that I used tow pieces of angle iron to support the entire length if the outer die and steel blocks top and bottom as well.



I cut the outer edge of the aluminium a similar distance from the timber die so that their was an even amount of metal being moved when pressed, if you have an uneven amount of metal the metal will find it harder to move and will distort more, not good.





Here the metal is being formed.



Once you have formed as much as you can with this setup you have to take the dies and metal out as one piece and put it into a vice to hold so that you can now use a hammer to get the metal down to the correct for against the die.





Because the metal has been asked to form on two differing directions there is some distortion in the ends and some of the drilled holes for the screws will have been torn apart, this is OK as we left extra length so that we could trim.

Sorry I have to backtrack a bit here is the metal partly formed.






Here we have the two halves of the plenum pressed..wow nearly finished....not.



and here just sitting on the engine for inspiration to see how it is going.

Next I had to trim the two halves so that they came together giving the final height needed for each end, being the throttleboby and the runner flange, then off to the welders as I am rubbish at welding.











Next I trimmed the ends to get rid of the nasty bits and also trimmed the outside shape of the runner flange, leaving an extra mounting hole on each end that will be used to hold some of the pieces together when they are being welded.









Now it is starting to look pretty.....











The inlet pipes have now been recessed into the flange as well.

Here I have put it together to see what it will look like.







Now it is time to get the runners and flanges welded so I have a couple of steel brackets bolted together and some wires holding some of the runners until it is tacked together.









Now off to the welders again.

Now back from welding....











So all runners welded from inside and also on outside at outer ends where there would be tension.

Next I used a die grinder to clean up the inside of the ports and a router to radius the inlet side of the inlet flange where the plenum joins. I also removed the two holes each end of the flange that were used to hold it together.



Engine side ports.



Plenum side ports.

Now back from welding...







I then machined the bottom surface to remove warping from the welding.





Next I made a 20mm thick flange for the throttle-body and had it welded on.



Here you can see it bolted on to check clearance.

Then another flange for the inlet tube.







Next I bought a 180 deg bend 3" (funny measurement) OD with a 4mm (thats better) wall thickness.
I cut it on an angle and the squashed it at the end to give an oval shape to cover the two 45mm butterflies.







I wanted to try to split the airflow into both butterflies so I fitted a curved divider into the end, you can see that the flow wont be great here but I have 20mm of thickness in the flange to blend the airflow before the butterflies.

So here we are with the manifold finished , I had a few alloy nipples welded on for the vacuum lines, or in this case pressure lines and the large inlet pipe has another curved section with the blow off valve mounted underneath as well.

here is a mock-up of how it all sits together.







I am thinking I will do a bead blasted finish on the outside of the manifold to finish it off.

So if someone wants to put a VQ or similar motor into a roadster this would be a huge benefit, although a lot of work, but if you like a challenge it could be worth it.

Rob

ps I also have pictures of an alloy twin fan shroud I pressed for my radiator.

That is INCREDIBLE fab work!!

fj20spl311 wrote:notoptoy can move the post (I think) if you / they want....It's in engine swaps and under VQ35HR so I think it fits....easier to find when searching.

Did you use a router to finish the flat plates on a wood template? I have seen that done on the internet and have done it myself....works trick....My woodworking buddy just shakes his head when I bring some metal over....I did buy my own carbide bits...lol......
I have used a router to open up the center hub hole on wheels.

Are the holes in the end of the intermediate plate to locate it and it gets welded on both sides-runners and chamber.

Thanks for sharing.

Too be correct, any moderator can move it. I think it's fine here if Alvin is cool with it, which I'll take by his response he is.
This is amazing work, and you have my admiration that's for sure!