1938 SS Jaguar 100
Total restoration
Restoration Log by Dan Mooney



We are thrilled to have this spectacular SS100 in the CJ Workshops awaiting a total restoration. Chassis number 49050 was the last of only twenty one 2.5L SS100s built in 1938. The car retains its original matching number engine, all of its original sheet metal and virtually all of its original ancillary components.

49050 has an interesting history, having been used for promotional purposes by Jaguar alongside the newly launched XK150 model at the 1957 RAC Diamond Jubilee Cavalcade, celebrating 60 years of British motoring. Apparently they (Jaguar) gave the car something of a cosmetic restoration for the event. Once the RAC cavalcade concluded, one of Sir William Lyons' senior managers suggested to Sir William that 49050 should be the first car in a new Jaguar museum. Sir William, apparently not terribly keen on the idea of a Jaguar museum, told his manager that if the car hadn't gone by Monday, the manager would be out of work.

Shortly thereafter, the car was sold to a US airman stationed in England, who brought it back with him to the United States, where it has been in the hands of the same owner for more than 55 years. In 1966 the owner took the car apart with the intention of repainting it, but never completed the task.



Putting the finishing touches to the SS100 engine rebuild.

Block now ready for assembly
Hanging rods on pistons

Measuring crank thrust
Measuring camshaft endplay

Installing oil pump drive
Oil pump pick up screen as delivered

Oil pump screen after spending some time with
Jake in the Coachworks

Installing the cylinder head
Degreeing cam

Adjustable gear for precise cam timing

We have made lots of progress with our SS100 engine rebuild, although it has been necessary to fabricate and machine several custom components.

Custom rear seal housing machined to fit
inside engine plate
Trial assembly of valve train

Damaged pulley from front cover

Machining grooves for O rings

Custom seal race pressed into front cover
Installing the modified pulley

machining washers for head studs
Washers are grooved for O rings

Repairing drain tap threads

We have been making steady progress with the SS100 engine rebuild. Parts availability is a real problem in a rebuild such as this. Our friend Alan Gibbins (SS Spares) in England continues to be an invaluable source of parts and information, providing the CJ machinists with lots of guidance along the way. Thank you, Alan. Your enthusiastic participation in this project is much appreciated.

Corey assembling the valve train
The cylinder head rebuild is now virtually complete

We had new custom push rods fabricated

Kevin fabricated several new cylinder head studs
A precious and rare set of original bronze
bearings supplied by Alan Gibbins

Just one example of several pieces of great advice
received from Alan
Kevin machining custom washers to Alan's design

The finished article -  a set of custom forged SS100 pistons.

The following sequence of photographs show the new one piece rear crankshaft seal that Corey designed and fabricated, and the process of creating a piston mold from which we will manufacture a set of custom forged pistons for the SS100 engine.

New uprated one piece rear crank seal
Piston mold allows us to optimize the design of
the forged pistons we will make for this engine


Huge thanks to Alan Gibbins of SS Spares in the UK who time and again has come up trumps when we have needed rare and obsolete parts for our SS100 restoration. Alan has also been kind enough to share his encyclopedic knowledge of the SS100 with me, which is very much appreciated!

One of our challenges with this particular engine rebuild is taking ancient old bearings and machining them to a specific 'eccentric' shape. This is not something typically discussed in modern engine building, although in vintage engine building it is sometimes necessary to take an oversized bearing and bore it until you have the desired clearance. This is a tricky enough operation to begin with, made even more so because the bearing surface itself has to be eccentric (not cylindrical). Half shell rod and main bearings do not have a wall of uniform thickness. The wall is thickest at the point of the split and tapers off a prescribed amount towards each parting line. This taper, or drop off, is called eccentricity. Eccentricity in the SS engine application is designed to promote oil film formation by creating a wedge shape in the bearing clearance space. In these circumstances, bearing clearances must be measured at 90 degrees to the split line.

I have included a short video clip below demonstrating how Kevin machined the bearings within the rod housing.

Alan Gibbins at SS Spares in England came up
with these ancient NOS bearings

Non-destructive testing of rod bolts

Checking rods for straightness

Grinding rod caps square

Sizing rods

Identifying bearing center line
Click on the thumbnail to view a short video
of the process

Setting up to surface cylinder block

Corey has been busy in the CJ engine shop machining your cylinder head back to pristine condition.

Intake and exhaust flanges surfaced on the mill

Surfacing the cylinder head deck surface
Deck surface and chambers literally as new

CC'ing chambers
Checking original alloy rods for straightness

Align honing the block, designing a one piece rear crank seal, damaged valve cover and oil filter housing...

Grinding main caps square

Align honing in progress

Unusual looking cooling fan
Oil filter housing is damaged

Note damaged lip on filter housing
Water pump will be rebuilt

We have decided to fabricate an upgraded one
piece rear seal

Plotting out center lines for new one piece
rear seal upgrade
To be continued...

Kevin's notes having measured the camshaft
and crank
Unfortunately the valve cover is damaged
beyond repair

A replacement valve cover will be required
Original alloy rods will be rebuilt

Taking a closer look at the crank, rods and main bearings.

Magnaflux checking the block for cracks
Time to take a closer look at the crank

Part number 43055
Main bearings look to be in exceptional condition
at first glance

Main bearing part number

Various stampings on the rods
Alloy rod part number

Engine tear down, continued....

Cam chain and sprocket

Missing rod cap

Oil pan baffle

Rear seal housing

Crankshaft journals all standard

Pistons are also standard

Interesting oil feed system on alloy rods
Separating piston from rod in order to remove it

Cylinder head tear down underway
Measuring stem height

To be continued...

Almost time to get a much needed engine rebuild underway!

Examining the tool roll in detail: I believe the canvas roll itself is from a very early XK120, as are most of the tools. Unfortunately, I don't think any of the tools were originally supplied with our SS100.

As delivered, late on Wednesday evening
Lowering the engine into position

Cylinder head and carbs installed

Original oil pan and radiator
Slimline chassis looks to be in great shape

Original SS spinner holding the spare wheel
in place

Original generator, water pump and oil filter housing
Note July 1937 date on the generator plaque

One of the most beautiful and recognizable
grills in the automotive world

A very full looking tool roll

Original top and side screens
Car looks rather better with the top and screen folded!

Original SS gauges
Glovers of Ripon apparently sold 49050 when new

The ceramic Glovers of Rip badge was attached
in the center of the dash
Original data plate

RAC badge was installed on the left side of the dash

Starting to look more like a car
We look forward to getting the restoration of this very
special car underway some time in the future!

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