mill pins

[Paul Amey]

Are Mill pins used on the rocker shaft end caps because they are much tougher then split pins?

[JohnD]

Roll pins. ROLL pins.

You pull out Mills pins, and count to five.   Or is it three?

John

Edited Tuesday at 21:41 by JohnD

[trigolf]

8 hours ago, JohnD said:

Roll pins. ROLL pins.

You pull out Mills pins, and count to five.   Or is it three?

John

Too late- BANG!💣💥

Gav

[Pete Lewis]

roll pins      just a cheap fixing  in one operation quicker on production 

Pete

[Paul Amey]

I should chuck it after three and hope they don't throw it back!  But none the less James Paddock refers to a roll pin as a mills pin. Can you use split pins is my question?

Edited Wednesday at 14:27 by Paul Amey

[JohnD]

Thank you, Paul, I didn't know that a "Mills pin" was a thing!   I find from an old post on the TRR board that "A "Mills pin" is a solid tapered pin so you need to tap it out from the tapered end with a small drift.. A roll pin is slit down the side to compress slightly when tapped in to hold in place. These can be tapped out from either end with a small drift and then compressed with a pair of pliers to withdraw the rest of the way."   Thank you, "Stuart"!

So my apologies, Paul, for the mock!   A split pin is intentionally soft, so I'd use a pin.

John

 

Edited Wednesday at 09:57 by JohnD

[Pete Lewis]

there are a good few rocker shaft end caps held on with split pins   probably used a lot on early   and roll pin was a mod introduced at some time .

there is little wear it does hold the end cap on cant see a split pin failing here .

Pete

[Peter Truman]

Surely a split pin would let the oil leak out of the end caps where it’s all needed at the rockers

A roll pin fills the hole out and leakage would be miniminal 

The last rocker shaft I brought a couple of years ago had end caps that were an interference fit really damned hard to get on

[Paul Amey]

Thank you chaps, don't worry about the humour, all taken is good stead! Opinions on both sides there, so I still don't know for sure. I can say the end caps needed a fair tug to get off though. So, I suppose my next question would be is a roll pin as good as a mills pin? 

Edited Wednesday at 14:44 by Paul Amey

[daverclasper]

8 hours ago, Peter Truman said:

The last rocker shaft I brought a couple of years ago had end caps that were an interference fit really damned hard to get on

The last one I bought a few years ago had internal fixed end caps. I hoped there wasn't any crap left in there. All the rockers were dripping oil from their holes when fitted. Had the cover off the other day and no oil dripping from the top holes on front rockers 1-10, apart from no 2 (so assume has oil pressure along the full length?). Oil drippling from the bottom of all but one of the rockers and pooling around the pushrod holes. Maybe some crap has been pushed along to the front the shaft by the oil and blocking oil access at the top off the further along rocker top holes? ?.

I understand some of rockers didn't have the top holes anyway, and I cant be bothered worrying about it!

Edited Wednesday at 21:31 by daverclasper

[PeteH]

Historical Note:- ( or perhaps Hysterical?)

The solid Tapered pins, John refered to, where in frequent use in factory machinery in the past. In order to get the correct fit the holes where reamed with a tapered reamer, the pin driven in for an interferance fit and frequently peened on the small end to prevent them coming loose. The method was a hammer (large) on the larger end and a small ball peen hammer used (ball) to "mushroom" the small end. Also fitted as "sheer" pins, when removal, post failure, meant aligning the shaft/wheel/cog/cam whatever before the old broken pin could be removed and a new one inserted. Somewhat tricky laid on one`s back halfway into a machine.

It`s too cold/wet/dark to go check , but I think I still have some smaller one`s and the taper reamers somewhere in the dim receses of my garage?.

Pete.

[68vitesse]

Is it a mills pin used to hold the quarter light catch.

Regards

Paul.

[Pete Lewis]

yes  its a solid pin driven in and can be a swine to remove

Pete

[Colin Lindsay]

6 minutes ago, Pete Lewis said:

yes  its a solid pin driven in and can be a swine to remove

Pete

Better done off the car, much easier.

[DanMi]

I had to get the machine shop that was doing my rebore etc to get them out. I think that they are only on the earlier engine rocker shafts eg 1147cc

[Colin Lindsay]

I have a variety of old rivet stems that I use to drive them out; always plenty lying about of different sizes.

I nipped out to check just now; all my Herald rockers are roll pins, I have two 6-cylinder rocker shafts, one is roll pin and one split pin, but no idea of the age of either to try to pin them to any model. 

[Paul Amey]

I'm thinking roll pins with a spot of loctite stud lock may be the answer?