A Couple of Coventry Twin Cams

Patrick heads off on a road test in a series 1 4.2 E-type

All good repairs begin with a road test.  In this case the repairs will be quite extensivebecause this E-type Jaguar is coming apart for painting and structural & mechanical reconditioning.  It was worthwhile, for instance, discovering ahead of time that the gearbox was jumping out of 2nd & 4th on the overrun, but taking off the console and the shift boot fixed that, and we have a good general sense of what we’ll be working over on this end after Jason Marechaux at East Coast Collision has worked over the sheet metal and paint work on his end.

Butch runs a compression test on this 4.2 E-type

Butch runs a compression test on this 4.2 E-type

You’ve heard it on these pages before, Road Test & Compression Test.  This Jaguar was losing coolant and overheating,  so it also got a cooling system pressure test which revealed several loose hose clamps and a slight head gasket leak under the exhaust manifolds.   Butch tightened the hose clamps, but we’ll be dealing with that head gasket leak when we strip the engine.

Patrick marks out the bonnet for replacement hardware

Sheet metal screws don't cut it. Patrick marks out the bonnet for new hardware

Since everything was thrown together quickly, it’s also coming apart quickly.  The headlights were held in with sheet metal screws, very classy !  Patrick has marked out the bonnet for the correct replacment hardware.

Back in the day there was another Coventry in-line twin cam with hemispherical combustion chambers in as well…

4 cylinder Lea-Francis Twin Cam

Twin camshafts clearly visible just below the deck

While Bill Lyons was building his SS 100’s in the late ’30’s, over across town another manufacturer was building a four cylinder twin cam hemi which Lyons and his director of engineering Bill Heynes were paying very close attention to.

While Jaguar were building their quasi-bespoke SS & Jaguar cars, Hugh Rose, a former Riley engineer, designed a very spanky 1500 cc engine for the Lea-Francis firm.

Lea Francis cam timing arrangement

Lea Francis cam timing arrangement

Does this timing arrangement look familiar ?  The nose of the idler sprocket shaft is housed in the timing cover, which has been removed for access.  A small amount of  vernier adjustment is available via the slotted bolt holes on the idler chain wheel.

David adjusts exhaust cam timing

With the idler sprocket removed, David adjusts exhaust cam timing

Utilizing “the wrong tool”and with the idler sprocket removed, your scribe has clamped the intake cam position while he adjusts exhaust cam timing.

look carefully, this is a Laystall crankshaft

Look carefully or enlarge the picture, this is a Laystall crankshaft

Something interesting is going on downstairs, too.  Underneath the legend 584-550 (no, it’s NOT a Moss Motors part number !) is theLaystall Engineering trademark.  This was an expensive top of the line crankshaft forged from EN 16 alloy by the same manufacturer who built the cranks for the Formula One Cooper Climax race cars.

vintage Laystall crankshaft ad from "The Autocar"

Vintage Laystall Engineering ad from "The Autocar"

An ad placed by Laystall Engineering in “The Autocar” commemorating the launch of the Aston Martin DB 4.

“T” series MG guys are always on the lookout for “Laystall-Lucas” high performance alloy cylinder heads.  I’d be looking for the cranks

Lea Francis 14 H.P. (R.A.C. rating) Sports

Lea Francis Sports

A Lea Francis 14 Sports, resplendent in deep blue, at Sports Car Services.

Next up:  Triumph, Healey, Morgan.  Some cars in the pipeline at East Coast Collision & Restoration in Mount Holly

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