Washer thickness

[Jasonking]

Could some kind soul tell me the diameter and thickness of the stock head bolt washers please, thanks

[Rolandino]

Hi, sorry for tardy reply, kept going into my garage to measure the washer, and promptly forgot why I was there!

The head washers are :
od 19.7mm
Id 10.0mm
Thickness 1mm
But they are slightly dished.
Minispares sell them C-AHT288 at £3 a set
Roland

[AndyPen]

Hi, sorry for tardy reply, kept going into my garage to measure the washer, and promptly forgot why I was there!
Roland

Thanks for the huge grin that just gave me Roland

[InnoCooperExport]

Not just me then, and still south of 40 so not even that old! I have been known to realise I needed a certain tool, crawl out from under the car and then wonder what it was I needed again...

[NZmember]

Measured the ones on my S engine. 1/8" thick and 3/4" wide. I think these are the standard ones on 60s engines.

[Exminiman]

Dont just use any washer of the right size, they should be hardened, if you are not sure might be worth buying some to be sure…..

[Ronnie]

ST just supplied Belville washers under part # C-AHT 288 (Head washer set, discs).

[Exminiman]

ST just supplied Belville washers under part # C-AHT 288 (Head washer set, discs).

Why would you use Belleville washers in this situation, what would be the benefit ?

Were they worried that the thermal expansion would effect the torque setting........ I must be missing something

They also used to use soft lock taps on main bearings......

Personally I would rather use a decent solid washer

[Peter Laidler]

Nope......, me neither Exminiman. Belville washers, being slightly conical, simply load the nut and add to the torque being applied. To achieve what?

Just been through 'machinery's hhandbook'....., a thicker version of the Zeuss guide. And according to machinery's, belvilles act as a shock absorber/buffer. I certainly wouldn't be using them as a cylinder head washer set. I wonder what metallurgy maestro 1071 Bob says

We know now that ST had some strange ideas

[BAD942B]

Hi, sorry for tardy reply, kept going into my garage to measure the washer, and promptly forgot why I was there!

The head washers are :
od 19.7mm
Id 10.0mm
Thickness 1mm
But they are slightly dished.
Minispares sell them C-AHT288 at £3 a set
Roland

if your measuring used washers at only 1mm thick then they will be dished (1mm is nothing but an ornament, no clamping load at all) , they will also have a larger ID at 10mm not a shade over 9.525mm which is 3/8" which is what the stud is, I would suggest nothing less than 3mm thick of proper steel say EN24 not mickey mouse chinese tin

[Rolandino]

If you are daft enough to ignore the Special Tuning engineers who drew up these washers, than it's up to you. It's amazing, it worked. Just don't bother to put any washers on, see what happens

[Ronnie]

ST just supplied Belville washers under part # C-AHT 288 (Head washer set, discs).

Why would you use Belleville washers in this situation, what would be the benefit ?

Were they worried that the thermal expansion would effect the torque setting........ I must be missing something

They also used to use soft lock taps on main bearings......

Personally I would rather use a decent solid washer

The washers when compressed are well flat, (they are not being used in packs as springs) so would not effect the induced bolt tension on the applied torque they would provide a hardened (spring steel) interface between the cast iron head and the steel nut, looking at in period pictures of my car engine I would suggest they were used by comp's in 66.

[BAD942B]

ST just supplied Belville washers under part # C-AHT 288 (Head washer set, discs).

Why would you use Belleville washers in this situation, what would be the benefit ?

Were they worried that the thermal expansion would effect the torque setting........ I must be missing something

They also used to use soft lock taps on main bearings......

Personally I would rather use a decent solid washer

The washers when compressed are well flat, (they are not being used in packs as springs) so would not effect the induced bolt tension on the applied torque they would provide a hardened (spring steel) interface between the cast iron head and the steel nut, looking at in period pictures of my car engine I would suggest they were used by comp's in 66.

possibly because they were an easy source of hardened washer, however things move on all the time & EN24 is tough but not hard which is actually what is needed