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Working on a "Headless" Engine

Posted: Fri Feb 19, 2016 8:46 am
by theoldman
I thought I'd kick off this section with a "how to" article on dismantling a headless engine. This specifically applies to the E20/18 but equally applies in principle to any of the headless models of the 1930s. I hope it will be of use to someone.


E20/E18 Engine Dismantle and Rebuild (Initially done for valve replacement)


1. Drain Engine Oil
2. Drain Water
3. Remove Sump
4. Mark con rods and caps by number and mark “F” for front (they must be put back the right way. I used Tippex to mark them) Remove big end caps and store in correct order.


5. Remove bonnet Complete
6. Remove bonnet stays
7. Slacken air silencer pipe from carburettor and pull off
8. Remover rocker cover complete with air silencer
9. Slacken Fan belts and remove
10. Slacken top jubilee clip on top hose
11. Remove the two set screws which attach the fan assembly to the block and remove fan assembly complete with top hose, gently bending temp gauge pipe and tie out of the way
12. Remove petrol pipe from pump to carburettor.
13. Remove manifolds from block and tie out of the way, taking care not to bend throttle controls
14. Remove water connection between block and water pump (pump on end of dynamo)
15. Remove oil feed pipe to rocker shaft
16. Remove the two set screws attaching the plug lead tube to the block, take plug leads off plugs and HT lead off coil, remove distributor cap and take away entire lead and cap assembly. Remove Low Tension leads from Coil
17. Remove the spark plug and brass protecting cover from No.1 cylinder
18. Remove the 11 set screws attaching the valve chest plate to the block and gently lever cover off its pegs (this is only so you can get at the push rods should they fall out)
19 Twist springs on rocker shaft to bear against the push rods
20. Undo cylinder block holding down nuts
21. Sling block centrally from engine crane and gently lift it off the crankcase, ensuring the pistons come off the crankshaft and stay in the bores.


22. Remove No.1 Piston
23. Slacken No1 exhaust valve rocker to its fullest extent, tilt rocker and remove push rod.
24. Apply special valve tool to spring and holding valve from underneath (a valve grinding tool is ideal) remove collets and compressed springs
25. Remove circlip
26. Remove valve through the bore
27. Check valve seat and re – cut if necessary
28. Grind in new valve
29. Hold in valve with the grinding tool, replace circlip, springs and collets. Take off special spring compressor.
30. Tighten rocker and make spring come to bear on push rod.
31. Replace piston, ensuring it faces the right way


32. Smear a thin film of blue gasket seal on the crankcase face. Sling block and gently lower it down towards the holding down studs.
33. A volunteer grovels under car and as the block is lowered, places the big ends back on the journals.
34, When block is fully down. Replace the big end caps and the sump.
35. Tighten block holding down nuts
36. Set tappets roughly (52 thou Inlet, 54 thou Exhaust)
36. Reverse the dismantling procedure to reassemble. Fit, but do not yet screw down rocker cover
37. Fill with fresh oil and water.
38 Start engine and get up to temperature. Stop engine. Remove rocker cover.
39. Re – set tappets and replace rocker cover and air silencer

NOTE - If anyone needs to do this job, I do have the special spring compressor which I am willing to loan.