Studs

[hdavy]

Anyone got cyl head and/or manifold nuts. I have read old posts and saw Mike's comments, which lead me to ask possibly daft questions. Are these M10 metric fine threads the same as the M10 nuts and bolts which one can easily buy (and are all over modern rowing boats) or does one have to find special fine ones, if so where? See Mike also says there are 3 different lengths of head studs. they all look the same to me, i.e. 2 1/2 ins long. Where do the different sizes fit?

[hdavy]

I meant cyl head studs .

[mike.perry]

The top of the cylinder head slopes, it is highest on the manifold side where the valves are so you will need 4 long studs on that side, 5 medium in the middle and 4 short studs for the other side. The threads are M10 x 1.5 pitch with 5/16 whit heads on the nuts.
If you replace the studs with bolts they will have a 17mm head. The strength needs to be a minimum of 8.8

[hdavy]

Thanks Mike. Is that 1.5mm pitch the standard one one the nuts and bolts generally available or is 'fine' something different? O do have metric taps and dies so could clean up some of my graunched ones if there are standard metric thread. Can you tell me the lengths of the 3 different sized studs?

[mike.perry]

1.5mm is the standard pitch as far as I am aware. I will try to find some old studs on Monday to measure.
Graham has been trying to contact you, can you phone him?

[RobThomas]

Hugh. How is the rebuild going?
Cheers
Rob.
(Alta-less in Cardiff)

[hdavy]

I have found 15 studs of various lengths and thread condition plus 2 very long ALTA ones which still stuck in the spare engine.Nex step to clean them up wiht my die. Mike how do I check that any bolts I may buy are 8.8 strength? I also have 2 manifold nuts and one twice the length. How long should these be?

[RobThomas]

Hugh. I'd avoid a die if possible beacause, by nature, they cut into the structure of the stud whereas the original manufacture was done by pressing/rolling the thread in with a machine. The rolling thread then has no sharp edges to make the studs shear off (Hmmmm. )
Finnigans make a liquid stuff that you can soak steel items in to remove the corrosion. Contains phosphoric acid. I've used it a lot in the recent times.
Another option is to buy really long metric bolts, cut off the heads and then run a die down the top of the stud so that it will shear high up if over torqued. The original metric ones were hollowed out all along whilst my Whit ones had solid outer ends.


I had a mix of some metric and some Whit manifold studs so, eventually, made some new studs and nuts using metric bolts and brass hex rod




[frame][/frame]

[mike.perry]

[quote="hdavy" Mike how do I check that any bolts I may buy are 8.8 strength?
8.8 is stamped on the bolt head. Discuss technical stuff like that with Graham, he knows far more than I do.
I put my back out during the week so have not dug through my boxes for studs

[hdavy]

Thanks for all that. I did find 8.8 stamped on the metric bolts I have. Sorry about the back. I wrecked mine over 40 years ago but have survived with diligent application to stretching exercises. (Am now going rowing in the sun.)

[rayofleamington]

lengths of head studs:
4 off 2.5"
5 off 2.75"
4 off 3"

studs and correct sized nuts are available off the shelf from a Morris 8 supplier. PM me or Mike if ypu want supplier details.

[hdavy]

I was getting on until one of my studs sheared off level with the block. As a matter of interest I have been roaming around metric fine on google. Found a piece called mad metrics by Roger Furneaux of MG club T type section. Also found metric fine bolts and screws on Nmarick.

[RobThomas]

How is it all progressing, Hugh? Did you manage to extract and replace the studs in the end?