Douglas SV54

[will]

Good afternoon everyone,

Might anyone be able to provide tappet clearances for the Douglas SV54 engine?

Thank you
Will

[will]

In the end I used 10 thou inlet and 16 thou exhaust (not sure why 16 exactly!). With a hone and new rings it now has huge compression and runs beautifully

[sidevalve5]

Hi Will,

Did not see your posts until this morning. I set the tappet clearances on a Jap 5 & 6 to 10 thou on the inlet and 20 thou on the exhaust. These figures are stamped on the inside of the inspection cover. Have also fitted new rings if required and can vouch for the increase in compression when this is done. Have two Douglas SV54 engines that I got when I purchased a couple of Trusty’s that were taken apart so that they could be stored. Intend to reassemble the machines one day and will make sure the engines perform well. If they need new rings, I will fit them. Out of interest, where did you get the rings from.

Best wishes,

Grahame

[andyfrost]

Grahame , Cox and Turner should be able to help you with SV54 rings.

Andy.

[trusty-bloke]

PM me you e-mail and I’ll send a pdf of the 2No. SV54 manuals that I have ..

[will]

Hi Grahame,

Cox and Turner supplied the rings. £55.20 inc delivery. I’m so pleased with the engine – now the rings and valves have been done I can hardly wind it over the compression is so good. Ready for many more years!

Regards
Will

• This reply was modified 2 weeks, 1 day ago by will.

[will]

Thank you!! I’ll do that now

Regards
Will

[sidevalve5]

Hi Will,

Many thanks for that. Cox and Turner is one of the suppliers I have for parts and they are usually my first port of call for engine spares. Can get rings a bit cheaper from a manufacturer, but prefer to use Cox and Turner because they are fellow enthusiasts.

Have fitted new rings and ground in the valves on many engines. But some I have worked on have been left stood for years in damp conditions. The valve contact surfaces and the seats have become very pitted with corrosion. Managed to lap most of them out, but the contact surfaces widened, ridges and grooves formed too. Got good compression to start with, but after some hours work it tailed off. Put a thin rubber glove over the exhaust and the carb inlet, it blew up when the engine was near the end of the compression stroke. Am going to get the valve seats cut and the valves themselves re-faced. But as the contact surfaces are now so wide, am going for a 3 angle cut. When I have it done will post something on the forum to share my experience. If anyone has had this done, would like to know what they thought of the results.

Best wishes,

Grahame

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