Sudden engine noise

[Motorsport Mickey]

Sorry you couldn’t pin it down Ian, just an idea but have you got the crank “ dog” bolt ( fits in the end and holds the front pulley on) torqued up extremely well ?

I have a small collection of front pulleys which weren’t torqued high enough ( not by me, I use 120 lb ft). When the bolt loosens off it allows Microscopic movement of the pulley on the crankshaft woodruff key which carries out some extra machining on the keyway slot, battering a 6 mm section out of the keyway walls. Damn noisy, maybe worth checking.

Mick Richards

Edited June 13, 2020 by Motorsport Mickey

[Tom Fremont]

1 hour ago, Ian Vincent said:

 Strangely the results showed a variation across all the valves from 0.277" to 0.295"  which is much more than I would have expected and in any event even the minimum figure is greater than the specified lift for the cam (Newman PH1) of 0.270".

I

0.018" would be unacceptable for me, whether worn so rapidly or as new. NEWMAN lost me many years ago ( saga in the archives here? ) so am curious whether it is the former or the latter.

 

Tom

[Ian Vincent]

On 6/13/2020 at 7:43 PM, Tom Fremont said:

0.018" would be unacceptable for me, whether worn so rapidly or as new. NEWMAN lost me many years ago ( saga in the archives here? ) so am curious whether it is the former or the latter.

 

Tom

Tom,

Based on your comment I went back and checked my numbers and I had left a number out.  The variance across all the measurements was 2 thou. with a mean around .278" lift.

Rgds Ian

[Ian Vincent]

Right, so the timing cover is now off and whilst the tensioner is nearing the end of its working life, nothing appears broken.  The chain was new about 5000 miles ago and if I recall was a NOS Renolds item.  It seems quite slack but when I turn it on its side there is minimal sag.  This is the way I have always measured wear in chains in the past.  The sprockets are also good.

Is there a view on the best place to buy a new tensioner from?  and if I wanted to replace the chain because it is not nearly as tight as the one in Marco's video post, where did that come from please Marco?

In terms of the noise I think it must be back to the cam followers and give them a closer look.

Rgds Ian

[iain]

Ian, i had a chain tensioner go very quickly, bought a replacement one from Somerset and its fine.

Do the cam followers have any marks at all on the side walls? I suspect they might.

Iain

Edited June 16, 2020 by iain

[Ian Vincent]

4 hours ago, iain said:

Ian, i had a chain tensioner go very quickly, bought a replacement one from Somerset and its fine.

Do the cam followers have any marks at all on the side walls? I suspect they might.

Iain

Thks for the recommendation Iain.

When I re-checked the cam followers very carefully there was possible evidence of scuffing on the side of a couple and the wear pattern on one did indicate that it hadn't been rotating properly but more to the point when I got my crack detecting microscope out - dating from when I was a civil engineer doing an investigation into crack widths in reinforced concrete - I was able to detect very fine cracks at the peak of the lobe on lobe number 1, which probably dates back to when I had coil binding as a result of a higher lift cam not being compatible with the three spring arrangement used on the exhaust valves for the TR3/TR3a.

I haven't found anything else that I could definitely point to as the source of the noise and the crankshaft pulley was nice and tight.

Rgds Ian

[Motorsport Mickey]

58 minutes ago, Ian Vincent said:

Thks for the recommendation Iain.

When I re-checked the cam followers very carefully there was possible evidence of scuffing on the side of a couple and the wear pattern on one did indicate that it hadn't been rotating properly but more to the point when I got my crack detecting microscope out - dating from when I was a civil engineer doing an investigation into crack widths in reinforced concrete - I was able to detect very fine cracks at the peak of the lobe on lobe number 1, which probably dates back to when I had coil binding as a result of a higher lift cam not being compatible with the three spring arrangement used on the exhaust valves for the TR3/TR3a.

I haven't found anything else that I could definitely point to as the source of the noise and the crankshaft pulley was nice and tight.

Rgds Ian

80 lbs ft ain’t tight enough, what was it ?
Is there any signs of fretting on the pulley keyway where the Woodruff key sits ?

Mick  Richards

[Ian Vincent]

1 hour ago, Motorsport Mickey said:

80 lbs ft ain’t tight enough, what was it ?
Is there any signs of fretting on the pulley keyway where the Woodruff key sits ?

Mick  Richards

None at all Mick.  I had to use a puller to get the crankshaft pulley off the crankshaft.

Rgds Ian

[Motorsport Mickey]

2 hours ago, Ian Vincent said:

None at all Mick.  I had to use a puller to get the crankshaft pulley off the crankshaft.

Rgds Ian

That's good,...but you often need to use a puller to remove the pully because of the surface drag around the crankshaft circumference. We are still left with...80 lbs ft ain’t tight enough, what was it ?

If you didn't measure it (keep applying increasing torque until it moves) you still don't know if it was tight enough, this dog bolt is 5/8th UNF with a max torque of 150 lb ft and a crankshaft of suitable material to take it. At 120 lb ft torque (your head bolts torque to 105 lb ft) the dog bolt is the same as for a Stag (where it is specified at 120 lb ft) it thinks you are being a pussy !

Any thoughts of why the manufacturer fitted these expensive fastening parts if you can get away with small amounts of torque using a smaller dia bolt and thread ? it's possible you caught it before it's had chance to dig out the keyway but was starting to make the noise. Keep that in mind as you try and define what this noise in.

Mick Richards 

Edited June 16, 2020 by Motorsport Mickey

[Ian Vincent]

Hi Mick,

I admit I don't tighten the bolt to a specific figure, I just pull it up tight with a large spanner.  If I put 120 ftibs on it how will I hold it? just with the car in top gear and the handbrake on?

Rgds Ian

[Motorsport Mickey]

17 minutes ago, Ian Vincent said:

Hi Mick,

I admit I don't tighten the bolt to a specific figure, I just pull it up tight with a large spanner.  If I put 120 ftibs on it how will I hold it? just with the car in top gear and the handbrake on?

Rgds Ian

Yep, halfway there, add the wife or friend with big foot on the brake and also add a choc or brick or two in front of the rear wheels to finish it off. 

The dog bolt is a peculiar beast, a throwback to when a starting handle was still available and used, from memory it is 1 1/8th AF (check it to make sure) and the bolt has rounded off corners probably to avoid the starting handle snagging on it and being snatched from your hands as the engine fired. That means you need a quality flat drive socket and then take up the torque in 3 steps, 80/100/120 lb ft  when you put it back together. Hope that this or the other fixes you will apply will sort that noise for you.

Mick Richards

Edited June 16, 2020 by Motorsport Mickey

[Ian Vincent]

Hi Mick,

My car has a narrow belt conversion so the bolt is not the dog bolt but a 15/16 AF head.  I already have a 15/16 six sided socket which I use for adjusting the tappets so no problem applying the necessary torque, just stopping the engine turning.

Rgds Ian

[iain]

15/16 tappet adjusters cripes they wont move! 

[Lebro]

[Ian Vincent]

It's a while ago but things get in the way - like jobs around the house.

When I lifted the head and stripped front to remove the camshaft I found a number of issues - listed below:

1. One of the cam followers had small gouge marks in the side which suggested it may have been sticking as a result of a foreign body getting in the way
2. A number of the followers showed evidence of not rotating fully
3. The timing chain tensioner was definitely knackered
4. The electric fan, which was retained by plastic ties through the radiator cooling fins was loose and the chafing of the ties had started to damage the fins
5. One of the radiator retaining bolts was missing
6. One of the rocker shaft retaining studs had stripped its threads - the nut end, not the end that goes into the block.

Everything has now been corrected and it is all bolted back together with new followers (from Newman) and the fan retained by some brackets that I fabricated and welded to the radiator and having taken it for a 50 mile run - it is ticking over virtually silently.  I suspect the guilty party making the noise was a cam follower and hopefully it won't re-appear

Very many thanks to all who contributed their advice.

Rgds Ian

PS the crank pulley bolt has been torqued up to 120lbs-ft. 

Edited July 8, 2020 by Ian Vincent

[Hamish]

Well done Ian a very successful job(s)

H

[Motorsport Mickey]

2 hours ago, Ian Vincent said:

It's a while ago but things get in the way - like jobs around the house.

When I lifted the head and stripped front to remove the camshaft I found a number of issues - listed below:

1. One of the cam followers had small gouge marks in the side which suggested it may have been sticking as a result of a foreign body getting in the way
2. A number of the tensioners showed evidence of not rotating fully
3. The timing chain tension was definitely knackered
4. The electric fan, which was retained by plastic ties through the cooling fins was loose and the chafing of the ties had started to damage the fins
5. One of the radiator retaining bolts was missing
6. One of the rocker shaft retaining studs had stripped its threads - the nut end, not the end that goes into the block.

Everything has now been corrected and it is all bolted back together with new followers (from Newman) and the fan retained by some brackets that I fabricated and welded to the radiator and having taken it for a 50 mile run - it is ticking over virtually silently.  I suspect the guilty party making the noise was a cam follower and hopefully it won't re-appear

Very many thanks to all who contributed their advice.

Rgds ian

Good job Ian, as you say likely the noise was an errant cam follower.

Following on from our earlier discussion about the "dog bolt" which holds the front crankshaft pulley on and the torque required to do it. As said the torque required is not shown on any manuals including workshop copies and the absence of the figures in black and white and owners reluctance to use "big numbers " when torquing it up often leads to ongoing damage when it becomes loose (and they do). This "absence of proof" puzzles many owners and I was asked again about it on the US Triumph Experience forum, I quoted 120 lb ft and had a couple of replies but then yesterday received this answer to my post on the thread.

 

Re: TR3 crank extension bolt torque value

#4

LionelJ rudd Lionel Rudd

Perth, Western Australia, Australia   

1970 Land Rover Series IIA

Jul 6, 2020 12:29 AM

The TR2 (with TR3 supplement) specifies 140 ft lb for this bolt.

Regards, Lionel.

I've asked Lionel if he can take a photo and send me a copy or an e mail so I can bring my workshop manuals up to date, I'll advise if and when I receive it. 

Now 140 lb ft is getting VERY close to the 5/8th UNF on Grade 3 (which I think the Dog bolt is) bolts stripping torque which I've seen recorded at 150 lb ft, so if the dog bolt has been replaced with a lesser grade 5 or 8 bolt for example I think this torque is too much. I would not torque up at more than the suggested 120 lb ft.

Mick Richards  

   

[RobTR3]

Mick

I have an original copy of the WM referred to by Lionel. Pages 13-15 give all the torque numbers, but there is nothing on the extension bolt (dog bolt) or the sections dealing with the fan assembly and engine assembly? Perhaps it's hidden elsewhere in the WM!

Rob

[Motorsport Mickey]

43 minutes ago, RobTR3 said:

Mick

I have an original copy of the WM referred to by Lionel. Pages 13-15 give all the torque numbers, but there is nothing on the extension bolt (dog bolt) or the sections dealing with the fan assembly and engine assembly? Perhaps it's hidden elsewhere in the WM!

Rob

Thanks Rob, nobody over the years has been able to find it and many owners have never given it a thought about the correct torque to bolt the pulley on with, which for a 5/8 UNF threaded Grade 3 bolt is up to 150 lb ft. Manufacturers don't fit that grade unless they think it really really needs it...they cost.

Maybe Lionel has a "colonial" copy which was upgraded with the dog bolt torque when all other countries have not had that benefit, I'll advise if he passes more info on, in the meantime I'll continue to use 120 lb ft which seems to do the job, that doesn't come loose and I doubt another 20 lb ft on top will give a benefit.

Mick Richards

[ianc]

Like Rob, I have the Service Instruction Manual 502602, which incorporates the "Supplement for TR3 Model".  Mine is Third Edition, Sixth Printing, and is hardbound with a nice red cover.  Nothing in pages 13-15 about that dog bolt.

In paragraph (xxxiv) of the description of engine re-assembly, it states: "fit the Woodruff key to the crankshaft, offer up the pulley assembly and secure with the extension bolt.  Shims are placed behind the head of this bolt, which incorporates the starting handle dogs, to provide the correct relation with the starting handle and the engine compressions".

The TR4 WSM likewise fails to mention the dog bolt in Nut Tightening Torques.  Ditto for the TR5-PI WSM Supplement and TR6 WSM Supplement - yes, I realise it's a different engine, but thought it worth a look as I have had the WSMs (and Parts Manuals) since I was the Technical Editor through the 1970s to 1986.

Ian Cornish

[Motorsport Mickey]

So to finish off this post and finally put to bed what the relevant torque is for a 5/8th UNF Grade 3 bolt which holds the crankshaft front pulley on Lionel from Aussie land has come up trumps.

Much mutterings and swearings from both of us to convert i pad images to work on good ol Microsoft but please

My Lords Ladies and Gentlemen, Chief Burgomaster and lodge captains,  inspect the attached images, and for your own edification, using prestidigitation  and with not a little legerdemain print and add to your workshop manuals of the free world an updated copy of page 13 (6th printing, substantially later than IanCs) now transported BACK to the free world from the colonies which shows the required torque for the crankshaft pulley of the 4 cylinder wet liner engine in TRs 2/3/3a/4/4a.

 

 

 

 

 

 

 

  So if your front pulleys are held on by the paltry application of a BA socket set (...in 1 1/8th across the flats ?) and the merest suggestion of torque numbers which only approach the bra size of Sabrina (rumoured to be 44 inch) cry God for Harry, England and St George and take a large torque wrench and substantial 1 1/8th 6 sided socket (the corners are radiused on dog bolts) and putting your car in 4th gear and with your significant other or friend standing on the footbrake apply substantially more torque to the bolt.

As stated previously my engineering workaround was 120 lb ft which agreed with the Stag application for the same purpose and has never yet proved to be wrong on the TR 4 cylinder engines I've built, the 140 lb ft shown here in the tables approaching the 150 lb ft engineering thread limit rather too closely for my liking. 

Mick Richards     

Edited July 28, 2020 by Motorsport Mickey

[stillp]

Thanks Mick. Now I have to take my radiator out again!

Pete

[Z320]

Sorry me Mick,

I did not read too much of the post above, perhaps I repeat what others said, but allow me to mention:

I had this bolt out for about 4 or 5 times, only 1 time with the rad out.

And I tightened it always with a 28 mm (or 29 mm?) spanner and some "Loctite medium" just "tight", without any special torque and without problems.

Good to know about the torque but I don't worry.

 

Allow me jus one thought without reading to much in the crystal ball:

The max possible torque for bolts and nuts increases with the diameter. Why has this bolt this diameter?

Because of the force needed to get a tight fit? Or because of the size of its head for the starter handle with its dog?

Edited July 29, 2020 by Z320

[Motorsport Mickey]

2 hours ago, Z320 said:

Sorry me Mick,

I did not read too much of the post above, perhaps I repeat what others said, but allow me to mention:

I had this bolt out for about 4 or 5 times, only 1 time with the rad out.

And I tightened it always with a 28 mm (or 29 mm?) spanner and some "Loctite medium" just "tight", without any special torque and without problems.

Good to know about the torque but I don't worry.

 

Allow me jus one thought without reading to much in the crystal ball:

The max possible torque for bolts and nuts increases with the diameter. Why has this bolt this diameter?

Because of the force needed to get a tight fit? Or because of the size of its head for the starter handle with its dog?

Hi Marco,

As you say It is only the possible torque that increases with the fastening increase in diameter or material grade, the setting for the torque required is set by the manufacturer with the purpose in mind for which the fastening is being used.

As you suggest the bolt diameter I think is chosen at this size (I'll have to check the across flats size now, it's ages since I've looked, I just keep using the socket that fit's !) because it transmits the torque required to the end of the crank when cranking by hand easier through the bigger dia bolt head with it's formed "dog end fitting" which gives a better fit on the crank handle "dog". 

The high torque setting is to counter the possible reverse torque encountered when the engine is in use. I had a small collection of front pullies where the dog bolts had been replaced with a normal hex headed bolt probably at some time during a rebuild, and the idea of hand cranking the engine had been abandoned. When I stripped the engines expecting a normal struggle I nearly fell on my back because the torque used to retain the pulley was so low,... probably only 40-50 lbs ft. This lower torque used was not sufficient to keep the pullies tight and the keyways were damaged severely with a wider groove formed in the thrust side by about 6mm in some cases, by the Woodruff key in the crank. In at least one engine it made a loud and worrying "clack clack" noise suggesting something more serious wrong within the engine inside, easily cured by a replacement pulley and Woodruff key...oh and retorqueing to 120 lbs ft. It may be if you have torqued your pully to a lower figure and also used Loctite (which only prevents it loosening from the torque you chose) that the friction clamp will be sufficient to avoid side forces against the woodruff keyway in the pulley...or maybe not. Because these pulley components are necessarily a slide fit onto the crankshaft nose and the Woodruff key there's a degree of play between the components and this is exacerbated by the sideways forces imposed by the engine impulse being resisted through the fanbelt which imitates an impact drive force upon the key and keyway, even if very softly, it wants to come undone.  

Using your same crystal ball Marco the torque for a Triumph Stag front pulley is 120 lb ft but they never considered using a hand crank on it, there is a normal high grade 5/8th headed bolt, why would they fit that if a smaller bolt 1/2 dia or even less with a lesser torque requirement could be used, without the pully loosening ? 

Mick Richards 

Edited July 29, 2020 by Motorsport Mickey

[Z320]

what I want to say (to Pete):

don't worry too much if it is tight but not exactly with the demanded torque