Author Topic: Engine cover stainless allen screw sets  (Read 1334 times)

Offline Josh Cox

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Engine cover stainless allen screw sets
« on: 17.08. 2009 10:23 »
Hello,

Have purchased a Stainless allen screw set for my engine covers, there are three screws that I have not idea where they belong.

Three 5/16 by 18TPI by 1-31/32 ?.

Sent the guy that sold them to me an email and his response was:
Quote
Dear joshua3608,

they usally go on clutch side on chain case the first 3 where the dome is thanks

I can not see were they live, anyone have a part number ?.
Black 1953 Golden Flash Plunger

Offline Brian

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Re: Engine cover stainless allen screw sets
« Reply #1 on: 17.08. 2009 10:48 »
Your bike is a plunger model isnt it Josh, they dont use the three screws in question, there only for the s/arm models. If you have a carefull look at a picture of a s/arm model, or a real one if someone you know has one, you will see the front three screws in the primary cover are larger than the rest.

Offline Josh Cox

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Re: Engine cover stainless allen screw sets
« Reply #2 on: 17.08. 2009 11:13 »
Thanks Brian.
Black 1953 Golden Flash Plunger

Offline snowbeard

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Re: Engine cover stainless allen screw sets
« Reply #3 on: 19.08. 2009 05:54 »
I bought some concentric screws from a fellow who told me they didn't know a good source for the primary threads, etc.  might I inquire where you got yours?
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Online BSA_54A10

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Re: Engine cover stainless allen screw sets
« Reply #5 on: 19.08. 2009 11:18 »
www.stainlessbits.com

dose kits for just about every British bike  and goes to the effort of makinf sure that the  bolts are the correct thread and length
Bike Beesa
Trevor

Offline Josh Cox

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Re: Engine cover stainless allen screw sets
« Reply #6 on: 19.08. 2009 13:42 »
Snowbeard,

I'm pretty sure you'll be able to find the bolts you want often locally, how much do you know about threads ?.

The Primary case bolts are 1/4 BSW, which is 20TPI (60 degree pitch).

1/4 UNC is also 20TPI (55 degree pitch).

The pitch makes F/all difference in this case.

I went to a local bolt place and they wanted $1 per bolt, cheaper to buy the pack off ebay.

http://www.classicfasteners.com.au/TechData/THREADCH.PDF
Black 1953 Golden Flash Plunger

Online RichardL

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Re: Engine cover stainless allen screw sets
« Reply #7 on: 19.08. 2009 15:29 »
Josh,

I can't really say I know a "wit's worth" of actual fact about possible damage from using UNC screws in Whitworth holes, but I am, at first, put off by the idea that it is OK as standard practice. It seems unnecessary since so many sources can provide the original-thread screws.

Richard L.
 
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Offline alanp

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Re: Engine cover stainless allen screw sets
« Reply #8 on: 19.08. 2009 16:11 »
Just a point of personal preference chaps, nothing looks better than using slotted stainless screws for chain/timing case fixing, preferably from Simon Barleycorn. They look classic and the strong stainless he uses resists damage to the slots from hooligan screw driver use. They are not to be confused with the screws made of age hardened cheese which BSA used to use. Hex socket screw heads just don't look right on old Brit bikes and you definitely don't need the torque that you can generate with hex socket heads which can easily strain/strip the threads in the aluminium if you're not careful. The makers of thread insert repair kits for stripped threads would love you to keep on using hex sockets.... nuf said.
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Offline beezalex

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Re: Engine cover stainless allen screw sets
« Reply #9 on: 19.08. 2009 16:27 »
I agree, alanp.  Over here, I can get them from McMaster-Carr by the box.  If you have a poperly fitting screwdriver, they hold quite well.  And, yes, you can put a 1/4" UNC screw in a 1/4 BSW thread if you chase it.
Alex

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