1939 Wraith Engine Overhaul
Detroit, Michigan

Part I - Disassembly


This 1939 Rolls-Royce Wraith Park Ward Enclosed Limousine arrived at her new home in the Spring of 2006.

The engine is a 4,227 cc inline six with cast iron block and an aluminum crankcase split horizon-tally. The head is also cast iron with a cross-flow design.

In otherwise fine shape, she smoked quite a bit from the crankcase breather tube and this did not improve with use. Further invest-igation revealed zero compression in the first cylinder. A leak-down test suggested broken rings or a hole in the top of the piston.

May 3, 2007

Day 1. Take a deep breath and dive in!

As a first step, removing this center apron seemed innocuous enough.
Removal of the headlights and stanchion tubes was next.

May 4, 2007

Removal of the bonnet is easy, but a two person job, nevertheless.

May 6, 2007

The throttle and choke linkages have to be carefully removed and catalogued.

May 12, 2007

The castellated nut that ties the left hand fender to the stanchion tube assembly would not release. If it had, I believe it is possible to remove the grill and radiator as an assembly.

This case became rather involved, but the recent delivery of Tom Wernholm's engine lift made life a bit easier.

May 21, 2007

In order to remove the front engine support, the side steering tube has to be disconnect at the ball joint in front. This requires heat and a 1-1/8 inch forked wedge.

This is the front engine support. The side steering tube minus ball joint is in the lower left hand corner. Ball joint is resting upside down in the lower center.

The temporary support is visible behind and runs to the garage floor.

May 27, 2007

Engine removal day. Also Indianapolis 500 day, so we get a fairly early start.

Very thankful to have Todd Nagler (l) come down from Rochester. He has forgotten more about small HP Rolls-Royces than I have yet to learn!

Between our good luck and some rain delays at Indy, we get to enjoy the majority of the race including Marco Andretti's spectacular crash and Dario Franchiti's win.

The author (r) models the latest in shop wear.

Wherever there is an ambitious automotive project, Dave Hollister can be counted on for expert advice and support.

Dave's smile is a counterpoint to my anxiety over getting this engine quickly to a firm resting place. There were only 492 of these cars made, after all!

The engine leaves quite a large space behind. This is a prime opportunity for some heavy cleaning and some long overdue rewiring.
Here we have the engine attached to the stand. The engine is so damned long, I am concerned about its center of gravity relative to the length of the stand's feet. The engine lift will stay in place until a suitable brace can be constructed.

May 29, 2007

One of the first orders of business is to remove the pushrods. The no. 4 pushrod has a funny flange to it but the cup itself looks otherwise undamaged. Not sure how this would happen given the shape of the rocker assembly. Perhaps it was made this way??

The engine lift is used to remove the head. It is fairly heavy and darned awkward.

This is the cylinder that had no compression. Certainly no hole in the piston! Also appears awfully clean indicating precious little combustion is taking place.
This is what the remainder of the piston tops look like.

Note the angle iron stand used to aid in support of the engine.

Generator and water pump have been removed.

May 30, 2007

All of the water jackets look relatively clean.

June 1, 2007

With the engine now rotated upside down, the engine lift is used to provide some preload to lower crankcase half while the studs attahced to the upper half are tapped with a drift.

June 4, 2007

With the lower crankcase shell off and out of the way, the big end bearing caps are accessible. Three pistons including #1 had broken rings.

The big end bearing on #4 had fractured and begun to spin.
Close-up of upper hald of big end bearing #4.
Nice view of crankshaft with connecting rods removed.

Next task is to remove the vibration damper from the nose of the crankshaft.

Removing the front third is a simple matter of removing the twelve 2BA nuts (with 3/16 BSF heads) and locking tab washers (LTW's) from the outer periphery and the four 1/4 BSF nuts and LTW's from closest to the center.

June 7, 2007

The rest requires a special tool from the dark recesses of Dan Docherty's shop in Windsor, Ontario. Thank you Dan!

Although you cannot tell from this distance, I did mark the relative positions of the crank pinion and cam wheel so that everything will have the proper timing upon reassembly.

June 9, 2007

Crankshaft is marked with engine serial number.

Main bearing caps are off. No ugly surprises.
Note huge bearing surface on #7. Wow.
Crankshaft is ready to come out.

June 23, 2007

Remove carburetor from intake manifold.

Also removed exhaust manifold from head. Intake manifold doesn't want to come off yet... letting that fester with some penetrating oil.

June 24, 2007

Crankshaft removed from upper crankcase.

Measuring bore diameters. Largest measurement an inch down from the top is 3.5100 with 3.5035 typical. Will measure bottom of bores tomorrow.

June 30, 2007

There are 13 sludge traps in the crank shaft. One for each big end and main bearing.

They are sealed by pairs of conical plugs pulled into their seats by a long bolt and castellated nut.
How much sludge could there be? Apparently, quite a bit. This trap is 60% filled with sludge.
This handlful of detritus is all from the trap concentric to big end bearing #1.

July 4, 2007

Time to bring out the big guns. I want to put in a new pilot bearing and to do that the flywheel must be separated from the crankshaft. The flywheel is attached to the crankshaft with 12 bolts that are peened over onto their nuts.

Here's the pilot bearing hidden by the crankshaft.

July 5, 2007

Planned to remove the dynamo drive gears this evening but it looks like I will need a small gear puller.

With Joe the Housepainter's help, the block is lifted off of the upper crankcase.
This exposes the tappets, which were numbered and removed.
Since the crankcase is aluminum and all of the studs are steel, all need to be removed before chemical cleaning.

July 6, 2007

Each of the camshaft bearings is held in place by a dowel pin. The middle five dowel pins are inserted from the top of the crankcase and visible only with the block removed.

Fortunately for removal, the pins are hollow and threaded. If you happen to know all this, removal is straightforward.

And there they are!

July 7, 2007

After returning home from the 2007 RROC Motor Region Annual Picnic, I discovered a disconcerting puddle of gasoline forming underneath the Silver Shadow.

Wraith work is suspended for a few days to attend to this.

The tank forms part of the boot floor. Once the gas line is disconnected from underneath the tank comes up and out.

July 10, 2007

Back to the distributor drive: the flexible drive and shaft have been removed.

After the keeper is removed, that large nut is next.

I wish someone had told me that the G. D. nut was left hand thread!

The gear itself is proving to be very stubborn. It's been sitting like this with pressure from the gear puller for about 24 hrs. or so...

July 15, 2007

Well, I'm know when I'm beaten. I have dis-mounted the upper crankcase so that I can take it to Dan Docherty in Windsor tomorrow. He knows more about Rolls-Royce gear cases than anyone I know and owns a transmission shop full of gear pullers.

The block, fan pulley, vibration damper pressure plate, crank-shaft and flywheel are at B&F Machining in Ply-mouth for cleaning. The block and crank will be analyzed and the flywheel turned down to a fresh surface.

This is the center and rear plates of the vibration damper. The eight (actually sixteen) springs need to be removed to get the plates apart and remove the old cotton duck friction material.
One side of each spring rests in a spring pocket and the other does not. Pays to know which is which so you can pry the little boogers out!

Success. The center friction plate is in great shape with 0.1275 thickness. Minimum is 0.6200, so we're good.

Didn't have a chance to measure depth on the rear, but I'm guessing we're good there as well.

Next is the lower crankcase. A few items need to removed before cleaning.

Oh! By the way, I got the refurbished fuel tank for the Silver Shadow back on the 12th and had her back together and running like a champ Saturday morning.

This is a close-up of the float mechanism that registers the oil level. This all comes out. The float is made out of wood.

Update on subcontracted items:

The flywheel, wheel case cover, block and all four pieces of the vibration damper are at B&F to be cleaned and machined.

Dan has the upper crankcase at his shop in Windsor and is endeavoring to remove the cam gear and distributor drive gear.

Dave Cunningham is refurbishing the carburetor.

This is the lower half of the rear main seal. The seal set into the channel is made from felt.

July 21, 2007

No before photos, but here is the chassis undertray that goes beneath the transmission.

This took quite a bit of work to remove decades of crud. It's made from stamped aluminum with steel reinforcements on the edges where it is attached to the frame.

Undertray that is positioned beneath engine. Largest cutout is for front exhaust silencer.

July 22, 2007

Rocker cover has nasty brazed repair to left side. The cylinder above it is the intake silencer with a rudimentary oil mesh air cleaner on the left hand side of the photo.

All of this has been disassembled to facilitate making a nicer repair and repainting the lot.

This precision leveraging device was used to separate the intake manifold from the head.
This upper radiator hose connection (and fan bracket) is attached to the head with eight 1/4 BSF nuts. It also serves as a cover over the water passages at the front of the head.
Front of head: not too much corrosion. Head is cast iron.
This is the back of the head with inspection cover removed. The eight slot head countersunk screws are a little more of a challenge to remove.


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