The BSA A7-A10 Forum

Technical => A7 & A10 Engine => Topic started by: Peter Gee on 28.09. 2018 08:36

Title: SOLVED w/ Thanks Dimensions and thread of Tappet Screws 67-299 & 67-276
Post by: Peter Gee on 28.09. 2018 08:36
Need these and thread type with extreme urgency kindly for a show deadline rebuild tSunday!!
Title: Re: VERY URGENT: Dimensions and thread of Tappet Screws 67-299 & 67-276
Post by: duTch on 28.09. 2018 09:30
Parts list and basic web search shows these to be the valve lifter/cam-followe (tappet) retainer grub screw in the bottom of the barrels- 1/4"BSC/BSF (which is what I have)
 67-299 & 67-276 ....also

67-0949

 67-0299
 67-0276
Title: Re: VERY URGENT: Dimensions and thread of Tappet Screws 67-299 & 67-276
Post by: duTch on 28.09. 2018 09:43
 If it's so very extremely pressingly uncompromisingly expressly urgent and what you need, you *may* get away for a short time with a M6 whatever (6mm grub-screw/set-screw/socketcap.....), as far as I can tell it really only holds a locating ball to hold the lifters from falling down when the barrels are lifted.... *dunno*

 ^^  **ABSOLUTELY NO RESPONSIBILITY ACCEPTED**- JUST A SUGGESTION   ^^^
Title: Re: VERY URGENT: Dimensions and thread of Tappet Screws 67-299 & 67-276
Post by: Peter Gee on 28.09. 2018 09:48
Hi thanks so far.  All I really need now is the length and diameter of the unthreaded portion. Yes it's 1/4 BSC I have a ton of them......

(a) overall lenghh plus length and dia of threaded for the 67-269

(b) Ditto for 67-299

Thanks help so far
Title: Re: VERY URGENT: Dimensions and thread of Tappet Screws 67-299 & 67-276
Post by: duTch on 28.09. 2018 10:05

 Pete, since you give two part numbers, unless I'm looking at the wrong part, does it really matter about specifics if it's so urgent?

 Maybe you can be more specific in the location of the part and why you give two different numbers if it's the same screw?

 I've had a grub screw about 1" long in there for 14,379Miles (+10% for speedo inaccuracy), and it still works fine...
 
 
Title: Re: VERY URGENT: Dimensions and thread of Tappet Screws 67-299 & 67-276
Post by: Peter Gee on 28.09. 2018 10:09
Dear Dutch,

There are two slightly shorter screws that locate the tappets from r side, and one longer one + ball that enters from the top. They are clearly shown in the parts list as 67-299 being the side tappet locator and the longer one being the top locator untering between the barrels with it's ball. I have the ball
 No screws.
Title: Re: VERY URGENT: Dimensions and thread of Tappet Screws 67-299 & 67-276
Post by: JulianS on 28.09. 2018 10:19
The side ones 67 299 - overall length 11.5 mm. Spigot 5 mm long x 3.75 mm diameter.

The centre one (67 949 A10 and  67 276 A7) this is for 67 949  thick flange barrel 1/2 inch flange, adjust for thin flange - overall length 16mm spigot length  about 6 mm 5mm diameter. Needs to be hard or will splay on the ball.
Title: Re: VERY URGENT: Dimensions and thread of Tappet Screws 67-299 & 67-276
Post by: duTch on 28.09. 2018 11:05

 
Quote
Dear Dutch,

There are two slightly shorter screws that locate the tappets from r side, and one longer one + ball that enters from the top. They are clearly shown in the parts list as 67-299 being the side tappet locator and the longer one being the top locator untering between the barrels with it's ball. I have the ball
 No screws.

 Ok Pete, now I'm with you- was only thinking of the centre/top one, which as I say can be whatever takes your fancy as is easy to replace at whim, but from memory is about ~3/8"- 1/2' long with about 1/8" unthreaded (just a wild guess, and I'm sure someone will clarify)...the side ones are probably not much different but maybe more internally 'critical' for no reason, but so long as they don't protrude outside the lifter flangey thingo, should be easy enough to sort out....I'm sure they'll be listed in a size list somewhere though *dunno*

Title: Re: SOLVED w/ Thanks Dimensions and thread of Tappet Screws 67-299 & 67-276
Post by: duTch on 29.09. 2018 15:55
 I just remembered I mined a 67-276 top/centre screw out earlier today from an old barrel and with a ruler measured 19/32" overall- 3/8" threaded + 7/32" unthreaded  reduced spigot bit.

 ** The two 67-299 side ones are rusted in, and I'd be guessing if I say are much the same, but as the slotted ends are 1/16" protruding about from the casting I will also guess that section on each is intentionally unthreaded so the ends don't screw right in and mangle stuff (the top centre pin can screw in as the ball and pin stop it, and it stops flush), I'll suggest measure the thickness of the casting and add 1/16" for the 'head' end and 3/16" or so for the spigot end *dunno2*

 I had other things to tend to so no time to spend longer for then....but did take a not-very-clear pic though the screws can just be seen....
 Also forgot Julian already addressed this