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AMT 1979 Penske PC6 Indy Car


Darin Bastedo

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I'm embarking on a project that will really test my skills as a builder. I had foolishly attempted this when the kit first came out 37 years ago. It's the AMT 1979 Penske PC6 Indy car. On the box it clearly states for ages 10 and up, so I thought that being 13 at the time I should be able to build this no trouble right? Ha Ha Ha AMT you got me...yeah. A ten year old Andy Granitelli couldn't build this kit.

Before I get into what's bad about this kit, let me tell you the good part. The kit is full detail and includes a very detailed ford dfx Cosworth turbocharged V8, the basic kit scales out well, and the parts included allow you to build a reasonable facsimile of the car pictured on the box top.

Now for the bad news. The design and execution of the kit are horrible. The assembly process is unnecessarily complex, and given the construction of the real car, poorly planned out.

For those unfamiliar with Indy cars of the late seventies, they don't have an actual chassis. The car consists of a monocoque tub to which the front suspension mounts to and mounted of the rear of the tub is and engine and transmission, that acts as a stressed member of the chassis to which the rear suspension mounts as well as the rear wing.

The issue with the kit is that everything depends on the tub, engine, and transmission being assemble squarely and securely. That said had I designed this I would have made the engine block and transmission assembly a two piece affair like AMT's late 80's Indy car series. Instead this kit has a two piece Trans-axle, and five piece engine block with no locator pins or anyway to ensure the block is square, so very careful assembly is essential.

To make things worse, even though the kit I have is first run, there is a lot of flash and none of the parts fit together without adjustment. It's almost as if it is a box full of Indy car parts and you need to engineer them all to fit together. The exhaust system alone has 8 pieces, and no positive positioning of the parts but because the turbocharger is part of the trans-axle part, the alignment is dependent on the fit and alignment of the engine block, tub and trans-axle.

See where I'm going with this? this kit is very susceptible to tolerance stacking.

 

Here is the Ford / Cosworth DFX V8 and Hewland LG500 transaxle. I cut the turbo housing off the transmission casting, and glued it to the completed exhaust system. I pinned the mounting points for the exhaust to give it positive location and to make mocking up and final assembly easier. I'm also scratch building the cooling system since other than the twin radiators none was provided.

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The detail on the the Hewland LG500 4-speed was pretty weak and inaccurate I sanded it off, reshaped the basic casting and I'm adding correct surface detail. Normally I wouldn't sweat it but on the finished model the trans-axle is prominently visible.

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A great deal of effort (about 6 days of work has gone into assembling and correcting the fit of the cowl and the front wing to the main tub.

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i added a lip to the front edge of the cowl to keep it lined up with the nose piece, and still keep it removable.

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I also cut open the scoops and the fuel filler.

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I'm going to be watching this closely to see what all has to be done to make one of these go together nicely.  I've got a couple of them started, but as you said, it'll take some diligence to get good results.  It's been a while since I last looked, but it seemed like reference pics were kinda scarce last time I had one of these on the bench.

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I'm going to be watching this closely to see what all has to be done to make one of these go together nicely.  I've got a couple of them started, but as you said, it'll take some diligence to get good results.  It's been a while since I last looked, but it seemed like reference pics were kinda scarce last time I had one of these on the bench.

Good reference photos of the car itself are pretty rare, but luckily very little other than the basic tub and bodywork are bespoke to this car. For the engine if you search for Ford Cosworth DFX you will find photos of that, If you look for Hewland LG500 it brings up the trans-axle. etc. You do have to fill in the blanks a bit. but a knowledge of the basic car helps. 

One thing that keeps me going on this is my first Indy Car race was the Kent Oil 150 at Watkins Glen in 1979. The handsome gent standing by the rear tire is a 13 year old me. I was so enthralled with the car, that I didn't even notice the hideous outfit of the lady in the foreground.

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The radiators lacked any way to plumb them to the engine so I added that detail.

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I also added some material to the assemble so that the radiator meets up with the body work the way it does on the 1:1

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I modified the the exterior side with photoetched radiator screen detail and i'll replace cross brace with some plastic rod.

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Once the part is glued in the gaps and tolerances will be very tight like on the 1:1

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The finished Radiator now looks like an integral part rather than an add on.

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Considering this is an open wheel car I felt it deserved a much better detailed front suspension. My piece is on the left. The front wheels will be steerable.

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The wheels will mount Tamiya style using posts and poly caps. The spindle and the brake are one piece for strength, and the pivot point for the posable steering is reinforced with metal tubing for durability.

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The lower A-arm has been modified to accept the pivot gear for the steering and to make more solid and accurate mount for the spindle.

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The interior tub has been drilled out for accuracy.

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As you can see in this photo I've started detailing out the fuel cell I added a photo-etched piece for the fuel filler plate. I will be scratch building the fuel filler, fuel pump, fuel filter as well as the swirl tank to add here. As you can imagine that is a lot of parts in a small area. So I wanted to assemble and test fit the roll bar so I knew what space i had to work with. I stripped the chrome from the roll bar, and cleaned it up, bit the rear uprights don't fit well to the front hoop...

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...So I added some gusseting and filed it to shape. not only does this make it look better but strengthens that joint as it is a very delicate part.

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I also wanted to make sure that the modified cowl fits over the roll bar. Because it does I know if I keep the fuel system withing the space of the roll bar I won't have any fit problems later.

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I also cut away the top of the foot box so that I can detail that area after I've glued the tub together...

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The stock kit provides no pedal detail and very little in the way of cockpit detail at all, which on an open cockpit car can make it look very toy-like...

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Now i will have access to that area right up to final assembly.

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I made a filler tube by heating and bending Evergreen™ plastic rod to shape...

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I added more structure to the roll cage...

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The pin fits into a recepticle I made in the fuel cell...

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It weaves though the roll cage...

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And meets up with the filler bung in the cowl...

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Thanks I'm really enjoying this one. The most challenging part for me is that nearly every part of this car is clearly visible when the model is finished. I'm used to being able to, on a closed car only do a little paint detail on the interior, or on some modern engines skip a lot of the engine detailing, but on this you will be able to see everything including the back of the dashboard.

 

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