55k engine - need help with supercharger drain bolt!!!

[V8 Supercharger]

Somebody has very kindly taken one out of their supercharger over in the Americas and measured it for me. The measurement seems different to what i was given earlier. Not knocking anyones efforts here but does it make more sense from this picture, because i know some of their measurements are different to ours.

 

[V8 Supercharger]

He's also written this along with the above image, again it probably makes more sense to you lot then it does to me right now:-

"It measures to be a 3/8" allenscrew and hard to say what thread pitch but on my gauge 20 looks about right."

 

[hotrodder]

3/8" (0.375", 9.56mm) suggests unified thread, 3/8 UNC = 16 tpi and 3/8 UNF = 20tpi (unified coarse and fine respectively)

'Standard/coarse' M8 threads are 1.25mm pitch which is a gnats over 20TPI
M9 does exist* (lots of fun to find though!) and the 'standard' pitch is also 1.25

1/8" BSP is 28tpi with a major diameter of ~9.7mm. There's also the Septic equivilant... 1/8 NPT is tantalisingly close but has a pitch of 27 tpi

While not impossible it'd be very unusual (and cruel) to make an UNF fastener with a metric 5mm allen key head and 5mm doesn't have a common imperial equivilant...




* there's about eleventy billion metric threads including half sizes like m3.5 and way too many thread pitches- often 3 different fine pitches so M10 for example can have a pitch of 0.75, 1.0, 1.25 or 1.5

 

[b1g1an]

You could get one of those usb probe camera/grabber things and have a look about where you think it's gone. Something like this...

USB Inspection Camera - EXIBEL | Clas Ohlson

 

[SavMan]

Try one of the Hobby stores I used to race RC cars and M9 set screws were quite common. I still think it is a 1/8 tapered pressure plug though

 

[V8 Supercharger]

Iv managed to "borrow" a supercharger nut, take it to an engineering firm and they have confirmed its a 10x1.0 nut, commonly used in high pressure hoses and connections.

Regular threads on M10 nuts are either 1.5 or at best 1.25. These are a little unique in that sense that its only a 1.0 pitch. I was told this is because of the pressures these nuts have to take, which i can only assume will be high in that supercharger, especially with all that heat.


But MANY MANY thanks to all who have helped, without your information and guidance i would have been completely and utterly lost . . . . and more than likely be crying like a little girl right now.


Thanks chaps.

 

[b1g1an]

Well done, must be a relief, have you got a source too or are they making you one?

 

[V8 Supercharger]

Well done, must be a relief, have you got a source too or are they making you one?

Relief is not the word, :bannana:

The cars been stranded for nearly 5 nights.

Im gona go around a few places today with this info and see what i can get, or the guy at the engineering firm says he has a link to where i can get these from if i dont source anything locally.

I need to do this today or tomorrow really as the nut i have currently is only borrowed and so effectively im still in the same situation.

Will let you guys know what i find.