|1967 Lamborghini Miura P400 (Topo)
|Restoration log by Dan Mooney
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 a while
||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
over 40 years
|Carbs have suffered from corrosion and
|Previous epoxy repairs at the base of the
|This is just the 16th Miura Weber carb
||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
|This modification is necessary because of
upgrade to valve seals
|Machining a mock-up valve
|Machining a tappet guide from bearing
|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
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
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
|Badly damaged original rear hub carrier
||Thankfully a good replacement hub carrier
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
|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
aluminum outer skin
|The rear cover skin weighs a mere 21 lbs
|Removing the steel wire from the bottom
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
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
coat of paint
|The aluminum panels that form the rear clip
suffered only very minor damage
|Note magnet attached to the steel brace
|The panel behind the rear window is also
||Time to strip the bonnet!
|Rear bumper grille appears to be in its
||Interesting that it does not have the
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
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