Oil filler cap

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Paul Wilks' Javelin was shortlisted for Classic Car of the Year 2013.
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nigel jarrett
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Oil filler cap

Post by nigel jarrett »

Hi ,can anyone tell me what size breather hole is in the engine oil filler cap please ?
have just purchased a javilin and will need all the help i can get
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Forumadmin
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Re: Oil filler cap

Post by Forumadmin »

I will check tomorrow, but it is small from memory about 1mm, I have no idea why it is there as really the intake air should come through the tappet cover felts. It might possibly reduce the water condensate in the top of the oil filler cap. I do not think the hole goes through the fibre seal anyway.

P.S Just checked Amy's Jav does not have a hole!

I have seem some with holes but there is no reason to have one IMHO.
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PAUL BEAUMONT
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Re: Oil filler cap

Post by PAUL BEAUMONT »

And for Heaven' s sake don't drill one in a Twin oil filler cap. Twins MUST have a sealed crank-case or they pee oil out of every nook and cranny!
Paul Beaumont
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Jack
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Re: Oil filler cap

Post by Jack »

Keith, were you wearing your glasses when you checked amy's javelin?

The hole is smaller than 1mm to my eye, but there definitely is one!

Jack.
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Tony Fearn
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Re: Oil filler cap

Post by Tony Fearn »

Jack wrote:The hole is smaller than 1mm to my eye ...
?? Should have gone to Specsavers??
Tony.
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Forumadmin
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Re: Oil filler cap

Post by Forumadmin »

The only possible use for such a hole is to relief pressure from behind the washer in the cap preventing it from being blown into the sump when the air behind it heats up. Since Amy's one has a hole in it, the hole in the cap does not serve any purpose.
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PAUL BEAUMONT
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Re: Oil filler cap

Post by PAUL BEAUMONT »

Or someone has fitted a Bradford fuel filler cap which is identical except for the discussed hole. Obviously a fuel filler cap needs one!
Paul Beaumont
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nigel jarrett
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Re: Oil filler cap

Post by nigel jarrett »

Thanks for the replies ,the hole in mine is approx 3-4 mm so someone must have drilled it out at one time
have just purchased a javilin and will need all the help i can get
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Robin Fairservice
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Re: Oil filler cap

Post by Robin Fairservice »

I have a 1950 Javelin and there is a 1/8" dia. hole in my oil filler cap.
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