DB18 Spark Plugs

[marchesmark]

Hi Stan,

That might be a good idea! Although in another club of which I am a member, it is difficult even to give stuff away. I have thrown out lots of parts because no one wanted them, even a perfectly good starter motor which sells through the specialists at £400 used. No one wanted it.

Mark

[GrahamH]

Stan I thought my consort only had an air silencer as I can’t see anything to change/clean, are we saying that it does need to be washed out?

[Stan Thomas]

Hi Graham,

Yes you are right - it is listed as an air silencer in the parts list.

The device was a fairly common fitment to many makes of car of the period and some hand-books advised lightly oiling, hence sometimes being called an air cleaner. Sorry for the confusion.

Eventually they get blocked and its best to cut through the "window bars" (as I can best describe them), remove the gause and wash it in solvent, after replacing it, carefully solder some small strips over the window bars to join them back up. However, I also seem to recall the main body had an internal felt lining so it could not be simply immersed in solvent to clean. If the gause gets clogged it will richen the mixture especially at higher speeds due to the restricticve influence to air flow. For that reason, they were not the best of ideas - but par for the course at the time.

Perhaps the best device available then was the oil bath air cleaner/silencer whereby the incomming air flow was induced to turn 180 degrees - thius propelling impuries into a shallow pan of oil. So efficient were they that it was often necessary to dig out the accumulation of hardened crud with a scraper if the car had not been serviced for a long time.

Air filtration was not considered too necessary back in those days - yet it was the gradual introduction of modern air (and engine oil) filters which played a principle factor in extending the service life of engines to what we have come to expect today.

[grahamemmett]

Amazing. As always.

[Mark Bullen]

I wonder if anyone has found a modern air filter that could be hidden inside the air silencer, thus providing good filtration without altering the flow significantly and helping with engine life. I must admit I was surprised that there was not any type of gauze or similar when I cleaned mine out.

Slightly off topic, it always surprises me when I see any kind of engine without an air filter, often with open trumpets or just large mesh that would only stop rocks and not the abrasive dust that can ruin an engine. I was always led to believe that a good quality and clean filter had a minimal impact on air flow and so should always be used.

Sounds like I should, post lockdown, take some measurements and see what I can do.

[Stan Thomas]

Sounds a good idea Mark, and I'm sure a "tubular" type paper filter would be ideal.

Why not estimate the shape and available space inside your air silencer canister then contact one of the filter maker's technical department?

It is supprising how helpful they usually are. I recently contacted a carbon graphite manufacturer for info to make a water pump seal for my sleeve valve - and they put me straight through to their technical director who sent me the requisit grade of resin impregnated material F.O.C.

All you need is size, shape and maximum air flow, which they will have. It may mean changing the needle in the carb (dead easy to do on an S.U.) - but that has always been the method used ever since Mr. Skinner joined with his son to make carburettors - Hence "Skinners Union".

Stan.
Supplier of useless information and bottled paraffin to the former King of Siam.