Tamiya 1/12th Scale Lotus 49B

[sico24]

Ok, having built the Jim Clark Lotus 49 (see previous posts), I decided I wanted to build the 49B variant. So, once again, on Ebay I bought a partially completed box of bits (almost all there) of the Tamiya 1/12th Lotus 49B (Original Big Scale no. 4 not the re-issue).

 

Then having the fantastic Michael Oliver "Lotus 49 Story of a Legend Book) I had to decide which version to build. After long deliberation I decided to build Chassis 49/R6 that Graham Hill drove in 1968 - particularly the US GP at Watkins Glen on 06 Oct 1968 when he raced with number 10.

 

Below is a picture of the 49/R6 (although it is captioned as R5 in the book, but number 10 was raced by Hill so I think it might be a rare captioning error) - I hope there are no copyright issues.

 

 

 

 

[sico24]

So looking at the various photos of the 49B (Chassis 49/R6 is a Mark III) the main differences from the standard kit are;

 

1. Hewland Gearbox (not ZF as in the kit) with thicker drive shafts

2. Different exhaust mountings

3. Much thicker and squarer upper rear suspension mounting bracket

4. Bottom of the main body tub has recessed channels each side to carry water pipes

5. Mounting points of the rear lower radius arms are further forward and in the recessed channels mentioned above

6. The upper suspension wishbones (rocker arms) are now swept foward (to increase wheelbase and presumably help with front wheel caster).

7. Larger front suspension fairings

8. Electronics are now in the "V" of the engine rather than behind it (as in the original 49 and in the kit)

9. Water piping behind engine now goes to both heads (and has a new reservoir design)

10. Piping to oil tank is different from the kit

11. Front nose cose is now built in two halves (upper and lower)

 

So all these had to be addressed and I will try and descrive how I did them all. Unfortunately the memory card in my phone went corrupt (!) so I don't have pictures of all the stages as I only backed up periodically. I will therefore also use pictures from the final build where necessary.

 

[sico24]

1. Hewland Gearbox.

 

This is completely different from the kit, which has a ZF box. Therefore I had three options: (i) Built a Hewland gearbox from scratch (ii) Buy a Hewland Gearbox kit (available but expensive) or (iii) get a Hewland gearbox from another kit. Luckily for me, someone was selling a very incomplete Lotus 72 Tamiya kit on ebay for £20 so I bought this just for the gearbox (cheaper than option ii) and modified it.

 

As bought (with Lotus 72 engine (not using this as the 49B one is fine) and driveshafts (not using these either as 49B kit ones are actually about the right thickness)

 

Lotus 72 Gearbox side plates had to be removed

 

 

I had to rebuild the side plates to match the remaining parts. Then spray it all in dark gunmetal paint. You can see the finished version here (other pictures on corrupted memory card!)

 

1. Hewland Gearbox.

 

This is completely different from the kit, which has a ZF box. Therefore I had three options: (i) Built a Hewland gearbox from scratch (ii) Buy a Hewland Gearbox kit (available but expensive) or (iii) get a Hewland gearbox from another kit. Luckily for me, someone was selling a very incomplete Lotus 72 Tamiya kit on ebay for £20 so I bought this just for the gearbox (cheaper than option ii) and modified it.

 

As bought (with Lotus 72 engine (not using this as the 49B one is fine) and driveshafts (not using these either as 49B kit ones are actually about the right thickness)

 

Lotus 72 Gearbox side plates had to be removed

 

 

I had to rebuild the side plates to match the remaining parts. Then spray it all in dark gunmetal paint. You can see the finished version here (other pictures on corrupted memory card!)

 

[sico24]

1. Gearbox continued...

 

Here is the finished version in the model - note the decal which I made myself. I was very proud of this (!) - I had to find the correct logo on the interweb, copy it, resize and print it. You can just glimpse the scratch built starter motor  between the exhaust and gearbox (I copied the way I had done the one for my Lotus 49 build)

 

Compare to the original from Michael Oiver's book;

 

You can also see the different exhaust mountings (no. 2 on my list) on these

 

Edited June 29, 2020 by sico24
Forgot something!

[sico24]

2. Exhaust Mountings - see previous post

 

3. Upper rear suspension (shock absorber) mounting points are much more substantial in the kit (which is from a Lotus 49). See below for the real version from the book;

 

 

So I had to measure where the mounting points were and the scratch build the square sectioned beam from plasticard, sprue and cover it with "Bare-Metal" chrome foil.

 

Notice also there is a new lower wishbone mounting bracket (you can just see it on the rear view picture from the book in the previous picture). I had to scratch built that and also modify the wishbones very slightly (only finished photo is available);

 

 

 

 

[sico24]

4. Bottom of tub has recessed channels

 

Unfortunately, this is where the missing photos from the corrupted memory card would have helped. I got some plastic 8mm channel;

 

 

I then cut approximately 5mm off of the bottom of the sides of the body tub, and 8mm off the sides of the bottom panel of the tub (I hope that makes sense). This is because the channels are shallower when seen from the side that when viewed from the bottom. This was extremely time consuming to get right, but I managed and then filled the joins. I only have completed photos available but you can see  bottom view with the water pipes (for which I bought 2.5mm aluminium tubing and some 2mm mesh tubing).

 

 

Edited June 29, 2020 by sico24
Wrong word!

[sico24]

5. Lower rear radius arm mounting points

 

As the rear radius arms are further forward, the radius arms must be extended. I did this by adding in some extra spare plastic of the right diameter and then covering in the chrome foil and then re-attaching the eyes that allow the radious arm to be joined to the suspension (original on left, modified on right)

 

 

Then these were mounted in the channel discussed in the last post. I had to make the mounting brackets (in the channel) out of plasticard

 

 

 

 

[klubman01]

Looking good thus far.

The 49, and all the variants, were great cars.  I saw them race at the '68 Grand prix at Brands Hatch.

Good luck with the project.

Trevor

[sico24]

In the previous post you can also see the modified water pump etc on either side of the engine. These were a combination of the kit parts, some bits from the Lotus 72 and scratch built parts. They are subtly different from those I built for the Lotus 49 project but seem to work OK. The starter is also easy to see, and the actuator rod (?) - this was the only bit where I guessed a little as I didn't have any really clear photos of that part so apologies if it not entirely right. There is also a modified gearchange shaft on the right of the picture (made from thin solid rod) which then attached to the remote change part of the Hewland gearbox at the rear of the box.

[sico24]

6. Swept forward upper wishbones (rockers)

 

I struggled how to deal with this! You can see in the picture from Michael Oliver's book that they are definitely swept forward, although the lower arms seem still to be perpendicualar to the body (so it would chage the caster to help steering?)

 

In the end I decided to cut the original upper wishbones in half and join the inner halves to the outer halves from the Lotus 72 kit, and then glue the upright original mounting points (the 'dishes' at the ends shown on the right of the photos) back on. Then cover everything with chrome foil. I was reasonably happy with the results in the circumstances - if anyone has done it better please let me know!

 

 

 

 

[sico24]

7. Increased size of front fairings

 

The 49B had larger front fairings forward of the upper wishbones and, as well as the air ducts on the top of the nose, had NACA ducts in the sides of the nose. Also there were increased size of front wing mountings. These are shown in the book;

 

 

So I used Milliput to form the fairings (judged by eye) and also the front wing mountings. Then I cut the NACA ducts in the sde and also used plasticard to cover the gaps in the sides (as the nosecone in the kit is based on a Lotus 49)

 

 

 

 

[sico24]

8. Electronics in the 'V' of the engine

 

Originally on the Lotus 49, the electronics were mounted on top of the gearbox behind the engine, and this was carried over by Tamiya from the 49 kit, even though the electronics were mounted in the 'V' of the engine in the 49B. Luckily the Lotus 72 had a electronics box (with distributor) that was very similar so I just had to alter this slightly rather than scratchbuild it. The expansion tank on the right of the engine is wrong and I replaced it see step 10)

 

 

 

 

Edited June 29, 2020 by sico24
Spelling!

[sico24]

9. Water pipes and expansion tank

 

The expansion tank was a slightly different shape on the 49B and the metal water pipes went to both heads. Therefore I filed the expansion tank from the kit and also got two pieces of rubber tubing and sprayed them steel colour and joined them. I  put a hole in the left hand head to match that in the right hand head already there.

 

 

[sico24]

10. Oil tank and pipes

 

The oil tank needed to mounted on top of the new Hewland gearbox - it was tricky to get it exactly right. Also, there were no oil pipes coming from the oil tank (and there was an extra filler that shouldn't have been there). Therefore I made two unions to mount on top of the tank and then connected these to some clear 1.5mm soft plastic tubing. The pipes then ran under the injectors to the front of the engine to unions and then into the body.

 

 

[sico24]

11. Front nosecone is in two halves.

 

The nosecone on the 49B Mark III was separated into an upper and lower half for easy access. You can see this here in MIchael Oliver's book;

 

 So I needed to cut a zig-zag line as shown in the picture. I wasn't sure how I was going to do this as I had had trouble cutting lines with a Dremel before (it melts the plastic and is too wide). I went into Wonderland Models in Edinburgh and the guy there was really helpful and recommended these Tamiya tiny saws that are 0.1mm wide

 

These were just the job, but it took AGES to actually cut both sides in the correct lines (zig-zags aren't easy!). But the final results were pretty good I think

 

 

 

 

 

[sico24]

So that's all the major changes needed. But there are some others too;

 

Wheels

The wheels for the 49B were different to the 49. Once again the kit had the old wheels so I needed to change them. The perfect solution would have been to buy the correct ones online but they are very expensive (over £50 I think) although good quality. So I decided to modify the originals by including the inner bolt ring from the Lotus 72 wheels (the actual wheels were completely the wrong size). I carefully separated these and the g;lued them into the original wheels;

 

 

Result;

 

It's not ideal (as the inner profile hasn't changed as it should) but for the cost it's Ok and actually looks better on the model than this photo

 

[sico24]

 Brake Discs (rotors) and Calipers

 

The brake discs are slightly different on the 49B so again I used some parts from the 72 kit. Also, like my previous build on the Lotus 49, I had to build the other half of the calipers as the kit only comes with one half. These are available but again cost money, so I built my own from plasticard.

 

 

 

[sico24]

Rear of the Body Tub

 

Just like on my Lotus 49 build I needed to put the brake lines on the back of the tub. There are no photos in the book for this in the Lotus 49B so I just replicated those for the 49 as shown in this photo;

 

 

To get this

 

 

You can also see the channels at the bottom of the tub in this view

[sico24]

Exhaust pipes

 

The exhaust manifolds and pipes on the 49B were black instead of the white of the 49. Again you can see the water pumps and oil filter etc on the sides of the bottom of the engine

 

 

[sico24]

Side water pipe

 

Again, as in the Lotus 49 I used some 5/32 inch aluminium tubing for the water pipe that runs on the side of the tub. But it also had to be fitted very carefully into the nosecone as the gaps are much smaller than the 49 (and the suspension is different). So thisis how it ended up.

 

 

[sico24]

Interior

 

Like on my Lotus 49, I used an old leather glove for the seat. On the 49, there were quilted padded sides to the cockpit so I hand-stitched (I don't have a sewing machine) some lines to represent the quilting lines. I also did the wires behind the dashboard as they can be seen through the 'slot' windscreen. And the gearknob had a yellow top and the yellow Lotus decal was added to the steering wheel centre

 

 

 

 

 

[sico24]

Finally I needed a Black Badge to go on the nose. The kit only comes with a yellow one, so once again I fouind a pitcture of the correct black one in the interweb, reduced it and then laminated it.

 

 

There were also some black badges on Lotuis production cars (e.g. I had one on my 1968 Europa S2) and the myth is that these were made to commemorate the death of Jim Clark. However, I went to a Lotus show around 2000 and heard Graham Arnold (ex Lotus Sales Director) say that this was not true - they just changed the design and needed to use them up before the next order.

[sico24]

I think that's everything, so I'll give you a taster of the finished model (more photos in the completed forum). All in all I think it took me about 9 months to do. I used Tamiya spray paints for the large areas (Red and White) and  airbrushed Humbrol enamel for other parts (engine, gold stripe on body, radiator, exhausts etc). I hope you enjoyed the build - please let me know if you have any thoughts. On to the next kit...... a 1969 Tamiya Matra MS11 bought yesterday.

 

 

[Schwarz-Brot]

Hope to see a WIP thread on the next kit as well. You show some fine work and the pointing out of the differences to the 49 is surely helpful to those tackling such a project as well.

[theplasticsurgeon]

Top post! Thanks.

I received a Tamiya Lotus 49B for Christmas about that time.  Mine was motorized, and had all the differences you mentioned.

 

I thought the black badges came out following the death of Jochen Rindt in the Lotus 72, and were for him and Jim Clark  - thus the 49 only raced with green/yellow.

My uncle had a Lotus 7 around that time, and wanted a black badge on it.   They were VERY rare, and he never found one.