430 Miura originality/preservation/restoration details thread.

What a special thread, thank you for sharing, the restorative process is an important factor in the future desirability & value of these cars.

 

I understand there were three different alternators used in the Miura throughout the production, each with successively higher amps to accommodate the added electrics (windows, radio, A/C). Does anyone know the Bosch part numbers for the three types and the amperages?

 

It’s been a while since I posted so here is a quick update on the restoration. Below are photos of the epoxy primered front and rear bonnets. As primers are catalyzed, it’s important to provide them enough time to dry completely, to insure shrinkage is complete. Often times, a shop will rush this process. Without sufficient drying times for materials, paint flaws can appear down the road. Patience!
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Primering the chassis. This is done on a rotisserie so every surface can be properly accessed and coated.
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Original P400 muffler outlets rusted and unavailable? No problem, Cairati just manufactures new ones templated from the originals!
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Refurbishment and pre-fitment/adjustment of all interior components and panels prior to trimming.
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Enough of the boring stuff. Who wants to see the rebuilt P400 engine in the dyno room for two days of proving???
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P400 engine setup and breaking in...red hot process!
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You asked for it. Here is a video of the engine setup and break-in period. This is where the engine is set up, the carburetors are adjusted and tuned, the timing checked and corrected, and the engine is broken in. Turn up the sound!

 

Ok, one more P400 engine dyno video. This one was taken after the engine was broken in and preliminary adjustments were done. Here, they are doing engine pulls to specified RPM's.

 

Sounds like an angry bull!

 

It’s been a while since I updated this thread. The bodywork is now complete and below are pics of the “body in white.” Gaps have been set, blocking complete, and now the body is in final primer coat and curing for a total of 75 days to insure all shrinkage occurs before final finish scuff and then color coat. Next, I will post a video of the finished body after final pre-assembly.
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Quick video of the "body in white" after final pre-assembly:

 

Excuse my ignorance but why so long for the curing process?

 

That is a great question! The answer is a little complicated, but I will try to boil it down.

All modern automotive primers (and paints) are catalyzed, meaning when they are mixed with a catalyst (hardener) and exposed to air, they dry. Things can be done to speed the drying time, such as using a heated booth or additives. Now, primers dry to the touch in x amount of time, and dry to the point you can sand them in y amount of time. However, just because they are dry to sand in y amount of time does not mean they are completely dry. They continue to dry for a period of time past both x and y. In summer months, the time is shorter due to the heat. In humid climates the time can be a bit longer. In winter months, due to the cold, longer still. Why is this important? Because as they dry, they shrink...it's a natural byproduct of the catalyzation process (in which heat is released as well). Good primers will shrink very little. Bad primers will shrink a lot. This is the name of the game in the primer "chemical" business.

Now, most quality shops will do a final "scuff" sanding of the final primer coat once it has dried to sanding point ("y" above)...usually a couple days after it the primer was applied. Then they will paint the color coat, and clear coat (if two stage), and once dry (usually a couple days), they will cut and buff it to a glorious finish. Some even sand between color coats/clear coats as well. When done, it will look perfect...like a mirror. HOWEVER...there is always a "but."

But the problem that can result is, if the primer below that color coat (and clear if two stage) continues to catalyze (dry) thereafter, flaws will begin to appear in the paint surface after you have cut and buffed it. Sometimes it will take days, sometimes months. Sometimes after a car has been left out in the hot sun all day (facilitating catalyzation). Have you ever gone to a shop (and I am not talking about low-level collision shops, I am talking about high quality restoration/paint shops) and seen a car under final assembly after paint and polish? Have you ever looked closely at the paint, from an angle, with proper lighting, and seen sanding marks, etc., in or below the surface? This is how that happens. It's not the quality of the paint work. It's the lack of adequate drying time. Either the primer below has continued to catalyze after color coat, or the color coat was not given enough time to dry properly before it was cut and buffed, or both, and it/they shrank afterwards, resulting in a finish that shows sanding marks.

Why do shops do this? Simple...time. Most shops do not want to have a car sit at their shop, being stored, for weeks or months while the final primer coat, or color coat, fully catalyzes and dries.

Another reason to allow a long drying time is because sometimes, there may be flaws in the primer itself, or in the application process (greasy fingerprint under the primer for example) that will cause it to flaw, or even crack, several weeks after application, after full catalyzation. If you paint the color coat too quickly, that will happen after you have painted, cut and polished the car. Then, it will require a repair which includes sanding the area, potentially blending, etc., and if the car is assembled, that means dust, potential for scratches, and a paint finish that shows the repair. Not a good thing. If you discover it after this longer drying time, but before color coat application, it can easily be remedied before color coat is applied, while the car is still disassembled.

So, the short answer is time heals all wounds. If you have the time, it's best to allow primers and paints time to catalyze fully before moving onto the next step. It results in a much better and more reliable end result. In the meantime, parts and other systems can be worked on so the restoration project moves along.

 

It's been a while since I posted an update, yet again, so here we go! I am happy to report that the primer has cured, the body panels have undergone final blocking, and paint has begun. The chassis has been painted. The front and rear bonnets will be painted this week, as well as the doors and trunk lid. Here is a short clip from Cairati Milano showing the completed chassis with the bonnets in the booth being prepared for paint. The red paint on the chassis has not been cut and buffed yet. That will be done after a bit more curing time. I will be traveling to Milan this week and will post some high resolution still shots when I return. Enjoy!

 

Amazing Vince.

 

Beautiful, and thank you for taking the time to share such educational posts as always.

 

Vince,

We are also restoring 2 Miuras, hence my intense interest in some of the decisions made by a reputable company like Cairati. Your posts are extremely helpful, thank you for making the effort!
May I ask some technical questions?
- Did Cairati strengthen any part of the original chassis (transition cabin to front upper frame rails, rear lower frame rails, rear triangular engine mount)?
- Did the test fit include side windows with winding mechanism?
- Was the engine sump split?
- Any other engine modifications / improvements?
- Did they drill the overflow prevention holes on the carburettors?
- What pistons were used (manufacturer?)
- What valve stem seals were used (manufacturer?)
- Did they install electronic ignition?
- Will the car get extra cooling and if so, which alternator will you use?

 

My responses are typed in after your questions above.
Where are you located? Which cars are you restoring? Great to hear...good luck!!

 

Thank you for your responses, I would love to expand on some of the points. I am not comfortable disclosing chassis numbers in a public forum. UnfortunatelyI don't see a private message function in this forum. Any chance I can contact you offline via e-mail?

 

Sure just email me at [email protected]

 

Vince, can you upload some photos from the current painting process of the frame here?
Best,Leo

 

Yes sure Leo! The chassis has been sanded and painted black. This was done after the red was completed. The car has now begun assembly. Here are a few photos! (The Bendix sticker on the fuel pump is in the wrong position and will be moved). The car will be wet sanded and buffed after full curing.

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There was a very important marriage at Cairati today!!!
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