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What size is this 'ole?
David Jenkins - 5/4/08 at 04:58 PM

This is a question for those with experience of crossflow engines...

My existing inlet manifold has a union for the hose from the crankcase PCV. I don't need that connection any more, so I want to unscrew it and put in a plug.

Can anyone tell me what thread it would be? (probably something like BSP, NPT, Unified Cycle Gas Thread, or similar).

Cheers,
David

[Edited on 5/4/08 by David Jenkins]

MikeR - 5/4/08 at 05:05 PM

I asked this question a couple of years ago - i was trying to find something to plug it with. In the end i bought something from Burton (i think).

clairetoo - 5/4/08 at 06:32 PM

quote:
Originally posted by David Jenkins
This is a question for those with experience of crossflow engines...

My existing inlet manifold has a union for the hose from the crankcase PCV. I don't need that connection any more, so I want to unscrew it and put in a plug.

Can anyone tell me what thread it would be? (probably something like BSP, NPT, Unified Cycle Gas Thread, or similar).

Cheers,
David

[Edited on 5/4/08 by David Jenkins]

Since crossflows are all UNF - then probably NPT , allthough if you just want to block it off the BSP would do the job - just measure across the hole , if its about 1/2" then it will be a 3/8" thread , if its 3/8 then it will be 1/4" .
Hope this helps !

rusty nuts - 5/4/08 at 07:45 PM

Since when have crossflows all been UNF threads ? IIRC a lot of the threads are UNC. Suspect the PCV connection may be the same as the oil gallery plugs possibly 1/4"BSP?

snapper - 5/4/08 at 08:49 PM

The threaded connection you take out is the one you ant, so take that to a local engineering firm and they will be able to tell you what the thread is and probably make up a plug for you.

David Jenkins - 5/4/08 at 09:04 PM

I was planning to make my own - but I might visit my local Pirtek (sp?) shop next week.

rusty nuts - 6/4/08 at 08:29 AM

Bit of a bodge I know, but as the manifold is only going back on as a temporary fix till you get the bike carb conversion sorted what about a bung in the hose?