|1967 Lamborghini Miura P400 (Topo)
|Restoration log by Dan Mooney
Lots of progress in the Coachworks this week!
Andy continues to make great progress with the rear frame rail fabrication.
The video and photos show Darien installing the pistons and rods to the block.
Andy has been making excellent progress with the rear chassis rail fabrication.
Lots of progress with the Miura in the Coachworks this week!
Andy is currently tackling the repair of the rear frame rails and engine cradle.
We have now begun this Miura body restoration in earnest.
It is now time for Topo to spend some quality time on the chassis table!
The following images show Corey honing the new liners to size.
|Forged pistons are installed at .0035"
||Corey honing liners to size using our custom
Corey has now surfaced the tops of the liners so they are all perfectly square and protrude above the deck precisely .003".
The following sequence of photos show Corey installing the new cylinder liners. During the installation process we used an arbor that Corey designed that is installed inside the main housings. Holes machined in the arbor allow us to insert a large threaded rod which helps Corey position the installation alignment tool centrally in the bore. With the cylinder counter bores heated to about 240 deg C, they expanded to approximately .002" larger than the new liners, which dropped into place perfectly. Once the block cools, the liners are installed at a press fit of at least .0035". The same arbor and threaded rod was then used to make sure that all of the liners were pulled and registered all the way down.
|Preparing to install the new liners
||Corey double checking the sizing one last time
|Confirming the requisite press fit in the
|Special arbor and installation tool for the
|Heating the counter bores to around 240 deg C
||Installing the first of the liners
|The liners will now be surfaced to ensure they
the requisite height above the deck surface
A new set of bespoke ductile liners for the cylinder block.
Corey has now completely rebuilt and reassembled both cylinder heads.
We have now completed all of the machine work to the cylinder heads, which are both ready to be assembled. The first photos in the sequence show the new radiator painted satin black.
|A reminder of how the cylinder heads looked at
the start of this project
|Both heads have now been machined, repaired
|Heads will be assembled in the next couple of
||Some nice gains on the flow bench from Corey's
We have now removed all the old liners and surfaced the decks. Funnily enough the only flaw that remains in the deck surfaces is scarring from an old weld that was undoubtedly done at the Sant'Agata factory in 1967!
|Machine out the original liners
|A rarely seen view of the water jackets inside
Miura cylinder block
|Preparing to surface the block deck surfaces
|The majority of the pitting has now been
and the deck surfaces are smooth and true
|Checking straightness with a straight edge
|Remains of a factory weld!
||Ready for the new liners
Dan Mooney explaining issues with the Miura block and liner replacement
Hanging new Carrillo rods on the pistons.
|Forged Carrillo rod saves over 600g from the
|Comparison with Jaguar rod shows just how
diminutive the Miura rod is!
Honing tappet guides and new forged piston set.
|Honing the tappet guides to size
|New forged piston side by side with the
The following sequence of photographs show Corey machining the cylinder heads.
|Valve seat pockets machined to size
|New custom valve seats pressed into place
|Valve guides installed and honed|
|Machining bores for bronze tappet guides
|Heating head prior to pressing in tappet
|Tappet guides now installed in first head
|Installing guides in second head
||To be continued!
Assembling the carbs with the custom oversized butterflies.
The first five photos in the sequence below show how Corey in the Team CJ machine shop dealt with the serious corrosion and pitting we found inside the Weber carburetors. Rather than go with an alternative set of carbs, we decided to machine the throats of the damaged carbs to eliminate the pitting, then fabricate and use slightly oversized (41mm) butterflies throughout.
|The original carbs were badly pitted and could
not be used as they were
|Corey machined the worst of the carbs first,
just enough material to eliminate pitting
|All carbs were then machined to precisely the
|New butterflies will now be made to
precisely fit the new bores
|Align honing the engine block
|To be continued!
|Align honed to perfection
This week's update is all about camshafts! We had the cams measured and tested and I am delighted to say that we could not have received a better report card. With no discernible wear, all that was required was a light polish of the lobes and journals and all four camshafts are now in pristine, virtually 'as new' condition.
Before the cylinder heads were disassembled, we noted that the camshafts were very difficult to turn in the cam saddles. In fact all four cam tunnels required an align hone, which you can see Corey performing in the photos below the camshaft report. Following the align hone, cam saddle clearances were a consistent .002" across the board and the cams now spin freely.
|Corey align honing the cylinder heads
|One of the cam caps after the align hone
|Trial fitting cams and measuring clearances
With the body now mounted on one of the roller-hoop rotisseries, we have started cutting away some of the obviously corroded panels prior to media blasting everything back to bare metal. Unfortunately, some previously installed repair panels also had to be removed revealing some severe corrosion lurking beneath.
|At first glance, the monocoque doesn't look
|Unfortunately, closer examination revealed
serious corrosion issues
|This panel had been replaced in the past
|Not a pretty sight beneath
|Another suspect looking repair panel
||More rust lurking beneath
|2 of the worst looking repairs I have seen in
||Yet more rust lurking beneath
Earlier this week Josh disassembled the short block and transaxle.
|View inside the crankcase
The following sequence of photographs shows the disassembly and inspection of the Weber carbs. We already knew that this car was one of the first Miuras ordered and built, and the extremely low Weber serial numbers (16, 52, 59 and 88) mean these are almost certainly the original carbs.
|The Miura's carbs have been carefully stored
over 40 years
|Carbs have suffered from corrosion and exhibit
|Previous epoxy repairs at the base of the fuel
|This is just the 16th Miura Weber carb made!
||Carbs now fully torn down and inspected
|All component parts carefully stored
Corey has been busy machining and trial fitting all the various components for the valve train. He has machined custom valve guides, tappet guides, valves and spring retainers.
|Machining the first valve guide
|This protruding step inside the spring pocket
|This modification is necessary because of the
upgrade to valve seals
|Machining a mock-up valve
|Machining a tappet guide from bearing bronze
|Head is counter bored to receive the tappet
|Tappet guide pressed into place
||Mocking up the valve spring retainer
|New retainer design allows the use of
shims to achieve desired valve lash
|Trial fitting valve train
|Smaller, lightweight tappet in place inside
Front and rear suspension has now been restored, rebuilt and loosely assembled.
The first six photos below show Corey dealing with a broken and seized stud. The next photos in the sequence demonstrate how we are going to put the valve assemblies on a strict diet!
The original tappet buckets are unnecessarily large and heavy, and they ride inside aluminum tappet bores that have been damaged due to contact with the steel tappets. The springs are also unnecessarily oversized and heavy, which in turn means the spring retainers are also on the portly side! During the rebuild we will be using smaller, much lighter components in the valve train, and also press fitting new tappet bores. The new custom spring retainers will allow us to use a more effective shim system to set and adjust valve lash, and we also be using custom guides that will allow us to retrofit valve seals throughout. Even before we have compared the weight of the old valves versus the custom valves we are having made, we are seeing a weight saving of 80g per valve assembly, meaning 1,920g across all 24 valves.
|Broken and seized stud
|Installing the new threaded insert
|Putting the valve train on a strict weight
||Original tappets, springs and retainers are
|Original spring retainer
||Custom TCJ retainer
|Original valve springs
||Custom TCJ valve spings
||Custom TCJ tappet
|80g weight saving per valve assembly
Disassembly and inspection of the cylinder heads.
|Removing the large and very
|Original bronze seats and a scary looking
||Overall cylinder head castings are in
condition with no serious corrosion evident
Time to get the engine and transaxle rebuilds underway!
Although we understand this engine had a partial rebuild performed many years ago, it has not been run since and is actually seized at this time. Having removed the cylinder heads, it looks as if the heads have been serviced but the bottom end does not appear to have been rebuilt. Although we have yet to tear down the short block, it appears that the original Borgo pistons are still installed. More on this as the disassembly progresses.
We have now blasted the front and rear bonnet subframes back to bare metal and sealed them with epoxy primer. Both subframes will be repaired prior to painting, especially the rear subframe, which is quite badly corroded in the area where the hinges are attached.
|Front subframe is more complex than its
|Rear subframe has some significant rust that
be dealt with prior to painting
|Corrosion at the pivot point for the hinges
The following photos show the reconstruction of one of the damaged (previously repaired) control arms, and also an absolutely beautiful new fuel tank.
|Damaged control arm had been previously
by brazing washers around shock mounts
|Fabricating a new shock mount
||New shock mount welded in place
|Factory did not clean back welds, so we left
weld beads to look as original as possible
|Shock mount holes indexed and drilled
|Fabricating the new fuel tank
|The finished article
We are very fortunate with this project that the car came to us with a large number of extra spare parts. As we begin rebuilding the suspension and steering, we have already needed several of those replacement parts, including an alternative rear hub carrier and some major steering rack components.
|About to tear down the steering rack
||Steering shaft is badly corroded
|Fortunately we had a good used replacement
|Rack housing blasted and cleaned up
|Original and rarely seen Oralian steering rack
|Badly damaged original rear hub carrier
||Thankfully a good replacement hub carrier was
included in the spare parts that came with car
|Suspension control arms have been crudely
and will need extensive repairs
|This piece has a washer welded in place as
part of a
|Original Armstrong shocks will be replaced
Lamborghini Miura bonnets (and rear engine covers) are extremely susceptible to galvanic corrosion because of the way the aluminum outer skin is fitted over the top of a lightweight steel subframe. The following sequence of photographs show the removal of the bonnet outer skin revealing significant corrosion in the outer flanges of the aluminum panel.
|Preparing to de-skin the Miura bonnet
|Rivets are first drilled out
|Folding back the alloy out flanges reveals
|Galvanic corrosion is present wherever steel
|Lifting away the outer alloy skin
|Extremely lightweight steel bonnet skeleton
||The alloy bonnet skin weighs 32 lbs
|Interesting to note that the chassis black
applied AFTER the subframe and outer skin
were assembled together
|The front wheel arches must have been
prior to any black paint being applied
De-skinning the engine cover has revealed a fair amount of galvanic corrosion everywhere that the aluminum skin came into contact with the steel frame.
|Rarely seen steel structure that supports the
aluminum outer skin
|The rear cover skin weighs a mere 21 lbs
|Removing the steel wire from the bottom edge
the allow panel
Removing the aluminum boot floor assembly and corresponding inner wheel arch panels. The boot floor was held in place with 132 rivets.
Yesterday we were delighted to receive a visit from Topo's owners. Rob and Jan visited the Team CJ Workshop to deliver a van load of spare parts and to check in on progress with the Miura. Among the many boxes of parts were Topo's original seats which had been restored and re-trimmed in Michigan in 1984. Interestingly, there was also a spare (third) Miura seat still in its original hide cover, so we were able to compare the untouched original seat with the restored seats. The Michigan trimmer did an outstanding job and replicated the original factory padding and stitching extremely well indeed. Thankfully, Rob and Jan also did a great job of protecting and storing the restored seats in the ensuing 35 years, so they remain in perfect condition to this day!
The first few photographs in the sequence below show Francis stripping the bonnet back to bare aluminum. The fourth image shows galvanic corrosion at the right/rear edge of the bonnet.
|Francis stripping the paint and primer from
|The green layer is an etching primer that
extremely well to the aluminum
|Typical galvanic corrosion where aluminum
|Bonnet is now stripped to bare aluminum
||Rob and Jan checking in on Topo
|An original factory Miura bucket street
||Interesting to observe the original factory
|Note how the factory finished the trimming
the seat base
|Topo's seats were restored in 1984
|Comparing Topo's restored seats with the
||I'd say the trimmer did a superb job back in
The following sequence of photos show Francis stripping the paint, primer and filler from the rear clip. The rear wings and boot compartment are aluminum, whereas the transverse braces running across the body are steel.
|Francis using 'aircraft stripper' to remove
and primer by hand
|It looks very much like factory primer and one
coat of paint
|The aluminum panels that form the rear clip
suffered only very minor damage
|Note magnet attached to the steel brace panels
|The panel behind the rear window is also steel
||Time to strip the bonnet!
|Rear bumper grille appears to be in its
||Interesting that it does not have the hardwood
noted in chassis # 3186 (also a 1967 P400)
|Comparing the original 'satin' finish to a
traditional 'chassis black'
|Fuel tank is not in great condition and will
Off the road since 1980, this 1967 Lamborghini Miura P400, affectionately known as 'Topo', is about to undergo a total restoration in the Team CJ Works.
The first owner of this special car was legendary racer, collector, raconteur, author and car guy extraordinaire, Toly Arutunoff. Mr. Arutunoff bought the car new in 1967 and immediately took it racing - because that's the type of thing he did!
|Toly Arutunoff with Topo in 1967
||Only Toly Arutunoff would buy a brand new
and take it straight to the track!
|Toly racing in Montgomery, Alabama in 1968|
|In the owner's garage, awaiting restoration
|Loaded up and bound for the Team CJ Works
||Bye for now!
|Safely in the Team CJ Works