1970 Aston Martin DBS (DM)
Major mechanical rebuild


 
 

 
Specification (briefly) for this project is as follows:

This car is receiving a major mechanical rebuild in the CJ workshops. The work includes an engine and transmission rebuild as well as a major service and upgrade of the suspension, braking, cooling and ignition systems.
 

 
 

 
We have now completed our DBS engine rebuild..

 
   

 
 
 
 
 
   

 


Putting the finishing touches to our DBS engine rebuild...

 
 
 Ready to start assembling the short block
Forged CJ/Ross pistons 

 
 
 

 

 
 
 Pistons and rods now installed

 
 
 

 

 
 
 Ready to install the previously rebuilt head


Cylinder head rebuild completed....

 
   

 


Cylinder head rebuild underway...

 
 Pressure testing the cyl head
 
Testing head on flow bench

 

 

 
 
 In stock configuration, head put
up some pretty big numbers
 Cutting out the old seats
 

 

 

 
 
 New custom seats and valves
 New seats installed
 Porting about to get underway


Time to clean and paint the block...

 
     
     
 
     


After honing the cylinders, the liners were removed and the block was thoroughly cleaned. The block was then heated, the liners cooled, and new O rings installed at the bottom of each liner. The following photos and video show Kevin installing the liners.

 

 Block is heated in the oven
Bare block is extremely light 
O rings installed at the bottom of each liner
are wiped with soap for lubrication







 
 
 Nice 'back lit' shot of a honed liner
Liners sit about .0015" proud of
block deck
Kevin installing the first liner 
 






 
 
 
 Heated soap escapes from weep holes
 


We have now honed the cylinders to fit the custom forged pistons.

 
 
     

 
 



The video below shows Chris fabricating a custom torque plate that will be used when we hone the cylinder walls to fit the new forged pistons next week.

 



We have now align honed the block. All mains now within spec (measuring between 2.9157" and 2.9159") with less than one tenth of one thousandths of an inch (.0001") variation across all seven capa.

 
     


We have now received the block, connecting rods and crankshaft back from the machine shop in California. Unfortunately, the newly honed cylinders were inexplicably covered in deeply ingrained surface rust so we are obviously going to have to re-hone them. Also, three of the main caps were a few tenths too loose, and the front cap was .0005" too tight, with a .0006" taper across the cap. Needless to say, we are obviously going to have to redo the align hone, too. All a bit disappointing, to put it mildly, but nothing we can't put right in the CJ machine shop over the next few days.

Newly honed sleeves were covered
in surface rust
Crank has been ground and cut for
upgraded rear seal
Block and main caps could stand
a good clean...
     
Unfortunately, the block will have
to be align honed...again
Cleaning the main caps
After a good scrub, the block is put
in the align honing machine
     
Caps being cut square
New aluminum expansion tank
Beautiful new aluminum radiator


One step forward, two steps back....

The good news is that this is a totally, one hundred percent, rust free Aston Martin DBS. The bad news is that the car, as purchased, needed a complete mechanical rebuild. Having rebuilt the carbs and automatic transmission, installed a new stainless steel exhaust and sorted out the mess of wiring left by a previous (presumably pyromaniac) mechanic, I then decided to fix a few minor cosmetic issues that had been bugging me. As well as re-trimming the dash top, we also put some nice black hide on the shifter console, and spent an obscene amount of money on a new steering wheel. The old windscreen seal was leaking so we removed the screen in order to fit a new seal - and somehow managed to break the old screen in the process. A new Triplex screen was obtained at great expense, and thankfully installed in one piece. And so the challenges kept coming...

Anyway, at about this point I became flushed with optimism and actually washed the car, foolishly thinking I might take it home that evening. Noticing that it was all it could do to pull itself up one of the ramps (a very modest gradient) outside the CJ workshop, I began to doubt whether it was really going to be up to the task of my planned afternoon commute. A glance under the bonnet revealed a huge amount of oil blowing past the piston rings, and a compression and leak-down test confirmed my worst fears - engine rebuild time.

Looking for positives in all of this, I do at least take some comfort from the fact that I should end up with one of the very best DBS Astons out there when my work is done. That I may have to sell an organ or two in order to fund the project is a mite unfortunate...Obviously, my next job is to pull the engine. While I have the engine out, I have decided I might as well go ahead and restore the engine bay.... and have a nice aluminium radiator made.... and maybe some cool aluminium coolant tanks....and...

Center console will be trimmed
Wiring was a nightmare in this car
 
 




   
Installing a new SS exhaust
 
World's most expensive exhaust hangers
 




   
 
Interior starting to look quite nice
World's most expensive steering wheel
 




   
Washing the car .....ahead of pulling 
the engine
   
 

Dashtop retrim completed - center console next!
Finishing off the dash retrim
   
     
Front edge of retrimmed dashtop
now looks factory
Cutting out speaker hole
 
     
     
     
I don't think this is an original speaker grill
so I am holding off on installing it
Center console also needs some help!
Switch panel will be restored


All sorts of stuff going on with the DBS this week! We have replaced the engine mounts, repaired the broken engine mount brackets, removed the front screen, removed the transmission for rebuild and removed the center console and dashtop for a retrim.

 
Engine mount bracket cracked
 
Simple weld repair was all that
was needed
 




   
Time to remove the screen
 
Sam razors the dry, old seal off
 




   
Most of the chrome retainer clips were rotten
and will be replaced with new stainless ones
 
Dashtop really needs a retrim
 




   
Shoddily recovered in the past, the vinyl
was lifting pretty badly
Front spoiler was removed for a little
cosmetic help
Seats removed in order to remove the
huge auto transmission cover
 




   
Peeling away cheap old (non-original) 
vinyl
The foam used around the leading edge
of the dash was far too thick
 
 




   
     
 




   
Chassis number on a piece of masking
tape has survived through the years
Number also stamped in the dash
Cleaning away all the old glue
 




   
The factory 'shaved' leading edge foam would
make for a much sharper leading edge
We etch primed the stripped dash frame
We couldn't resist saving the old factory
masking tape
 




   
   
New closed cell foam will be used on
the curved parts of the dash
   

 


The suspect shape on our DBS bootlid ended up being incidental scarring caused by the heavy handed use of a grinder. We also found some seriously thick bondo at the back edge of the bootlid, where the car has obviously suffered some minor collision damage in the past - probably a low speed parking incident.

 
Aircraft stripper paint remover used to
strip the paint from the bootlid
Suspect shape is bondo based.....
 
     
Car was originally Olive Green
Ultra thick bondo on the back edge
of the bootlid
Yikes! This is REALLY thick!
     
 
Stripped bootlid sealed with BASF
etching primer
Back edge of bonnet has been bumped
at some time in the past


The boot lid on our DBS Aston has always been a source of annoyance to me because of some extremely poor bodywork done in the dim and distant past. Somebody had previously wiped bondo over the two holes where the Aston Martin emblem should have been mounted, and some strange bondo shrinkage has led to the formation of various weird shapes and forms showing through the paint. With the worst of these (outlined in the last photograph below) looking uncannily like a certain male appendage, I decided it was time to restore a little dignity to this particular body panel.

 
Only a half hearted attempt was
made to paint under the boot lid
At least the boot lid is original
to the car...
Emblem holes filled up with
bondo
     
Removing the bondo
Once we have repainted the boot lid, we 
will install the correct emblem
The least said the better about this
particular manifestation...


This is basically a great car that needs a major mechanical service and thorough fettling. Cosmetically, the car is obviously very presentable, but is let down by its weak mechanical condition. A tentative test drive before work began revealed a host of mechanical woes, not least of which the almost complete absence of any brakes! Add to that the need for a transmission rebuild, complete suspension overhaul, carb rebuild, new exhaust, etc, and you can see that we have quite a bit of work to do before this car can become the frequent driver it was intended to be at the time it was purchased.

 
 Rear brakes will be serviced first
 
Rear seat is removed to access
the rear brake calipers
   
 
 Car has newish hide interior
Access panel for rear brakes 
 
   
 
 Brakes were sticking and pads
had been fried
Cleaned up, SS pistons, new seal 
kit.... 
Rebuilt calipers reinstalled 
   
 
 Rear springs to be replaced next
Horrible, rusty aftermarket exhaust
being cut away...
 New SS exhaust system on order
   
 
 Who would do this to an Aston Martin?
 Engine not sitting square in engine
bay - LH engine mount shot
Loose fasteners everywhere....
 
 
 
 Front shocks and springs will be 
replaced and upgraded
Swaybar mounts were broken and had
to be replaced
This explains why no handbrake! 
   
 
 Both doors need adjustment help,
especially the LH...
LH striker was loose - literally held in
place with some jerry rigged wire
Once removed, we found the backing
plate threads were stripped out
 
 
 
RH door adjusted - now fits, opens
and closes perfectly
 Repaired LH striker reinstalled
 Front screen was leaking and will
be treated to a new seal

 

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