Timing chain

[anotheralan]

HI

Can anybody tell me the allowable slack in the timing chain to judge whether it needs replacing?

 

Also the material of the new gaskets available from Moss is porous and within a matter of a couple of days showed oil seeping across its width when i removed the cover again. (don't ask):

 

The engine had not been run so the oil was simply from the lube i put on when inserting the pulley in the seal

I used hylomar on the gasket but of course that only goes on the faces, not the edges. Over time I would expect a weepy wetness at the bottom of the cover. Is there a gasket available in a better quality material rather than the 'recycled newspaper' in the ones I have sourced.

cheers

Alan

[Dave Larnder]

HI Alan

 

I did mine late last year as the tensioner was badly scored so replaced it for safety. I only used a silicon sealant with no gasket material at all and there is no sign of a leak in the timing casing, which was the reason I took the cover off in the first place.

 

Dave

[anotheralan]

Thanks for the idea and I would do the same, but I have fitted a speedi sleeve on the pulley where it contacts the seal and so I don't want to change the position of the seal towards the engine. there is little tolerance in the width of the sleeve i used. Should have bought a longer one really but we are where we are at this point.

Cheers

[RogerH]

Hi Alan,

Moss do at least two types of timing chain cover seals.

The one normally in the kit is a very thin brown paper gasket - I don;t like that one.

The other is a thicker grey fibrous material - much nicer.

 

Roger

[Alec Pringle]

Wellseal might well do the job better than Hylomar on a thin gasket, and if it's a troublesome spot then wet the gasket first . . . . . allow some water to soak in and then bolt it down.

 

As ever, is the cover flat to the block face ? As in less than 5 thou gap when applied dry ? And bolted down in sequence to correct torque ?

 

Cheers

 

Alec

[TomMull]

HI

Can anybody tell me the allowable slack in the timing chain to judge whether it needs replacing?

 

Alan

 

I don't know of a measurement for the slack in the chain. A better test might be to look for scoring on the cover or the front plate near the tension spring. If that's the case replace the chain and spring. (once you've got it all apart you might just replace anyway)

Tom

[anotheralan]

Hi Alan,

Moss do at least two types of timing chain cover seals.

The one normally in the kit is a very thin brown paper gasket - I don;t like that one.

The other is a thicker grey fibrous material - much nicer.

 

Roger

Hi Roger

Yes I used the grey fibrous one but it clearly was wicking oil from inside towards outside. i will check with a feeler to see how unflat the cover is as Alec suggests. I am sure it is not perfect, why would it be at nearly my age. Although it was off the road for 25 years with PO.

Perhaps doubling up on the gasket might help if not flat enough? It will still be porous though, and with a thicker pathway.

Alan

[anotheralan]

 

HI

Can anybody tell me the allowable slack in the timing chain to judge whether it needs replacing?

 

Alan

 

I don't know of a measurement for the slack in the chain. A better test might be to look for scoring on the cover or the front plate near the tension spring. If that's the case replace the chain and spring. (once you've got it all apart you might just replace anyway)

Tom

 

Thanks Tom

no signs of rubbing. i was tempted to replace it anyway but it has only done about 12k so i think i will leave it be.

Alan

[RogerH]

Hi Alan,

doubling the gasket is not always the answer.

 

If you can check the contact surface of the cover and try flattening it.

Using one of the Silicon sealants with one gasket may help.

 

Did you have the cover tightened down correctly when you discovered the wicking. It sounds a touch loose.

 

Roger

[Alec Pringle]

Doubling the gasket is NOT the answer !

 

You need flat mating surfaces . . . . .

 

Yesterday I was refitting the Super Snipe sump, supervised by my semi-retired garage proprietor mate Jeff, who has built more than a few race winning engines in his time. Jeff cheerfully hands me a couple of small dollies, a toffee hammer, straight edge, tin of 'blue' and the feeler gauge.

 

The sump flange has to be flat enough, sitting on the upturned block, not to be able to get a 5 thou feeler between the two at any point . . . . .

 

Then it's a thin paper gasket and Wellseal both sides, torque up gently, and it won't leak.

 

Treat a timing cover in the same way.

 

Cheers,

 

Alec

Edited March 24, 2017 by Alec Pringle

[Z320]

Hi,

 

please see my video of my old timing chain, with broken and new tensioner.

 

 

You can feel the slack with to cover on the engine.

 

See also my video with my new timing chain, it is a quality n from IWIS

 

 

Ciao Marco

Edited March 24, 2017 by Z320

[BlueTR3A-5EKT]

Interesting videos Marco.

Chromed tensioner and an IWIS chain - where were they supplied from?

 

I see you have a non TR but original Triumph timing gear fitted to the cam. One of the 4 drill holes in the face aligns with the oil slot in the cam end - They are blocked usually to reduce oil flow from the cam front bearing. Looks like your are.

 

Did you fit a cam lock tab?

 

Cheers

Peter W

[Nick Webster]

I could not tell you how much wear is too much slack as a measurement, but I was taught to assess chain wear against a new chain by gripping a link of the chain and holding the whole thing up flat (i.e. link face upwards) and compare how much it droops compared with a new chain. Takes a bit of finger strength for larger chains but is a good way of spotting how much wear has taken place on each link. Ultimately it was just common sense judgement of course. The worst of worn things were always archived in a black museum.

 

Nick

[stuart]

I could not tell you how much wear is too much slack as a measurement, but I was taught to assess chain wear against a new chain by gripping a link of the chain and holding the whole thing up flat (i.e. link face upwards) and compare how much it droops compared with a new chain. Takes a bit of finger strength for larger chains but is a good way of spotting how much wear has taken place on each link. Ultimately it was just common sense judgement of course. The worst of worn things were always archived in a black museum.

 

Nick

Thats exactly how we used to judge Jaguar XK engine timing chains back in the day when we raced them.

Stuart.

[Z320]

Hi Peter,

 

thanks for your advice, but I don´t understand what you try to tell me.

I refitted the timing wheel and the sprocked on the crankshaft as I fond them.

In the workshop maual and at spare part lists I can find no plug.

 

The tensior I realised it as dull stainless steel, I know some are black.

I bought it together with die IWIS chain from a TR-workshop next to Heidelberg (D).

http://www.racinggreen.de/Call for Robert.

 

Ciao Marco

[anotheralan]

Thanks to all for the advice.

The bolts were properly torqued but when i removed the cover the gasket delaminated leaving half the thickness on each face, as you would expect. That is when i could see the permeating oil halfway through the lower part of the joint.

I am working on improving the flatness as, with a compressible gasket, each time the bolts are tightened the flange is distorted locally to the bolthole. That gives peaks and troughs for the next fitting. Basically the tin flange is not stiff enough to transfer the clamping force over the space between the bolts without distorting. So i can see a case for a paperthin gasket with some sealant, provided the flange is flat enough to start with.

So far i have used a vice on each hole with a machined stiff steel block on the screwhead side to space the jaw off the flange lip. But i think i need to go a bit further with the ball end of a hammer as a dolly to remove all the 'swelling' local to the hole. Then i will get the feeler guage in action. I think it unlikely i will get it sufficiently flat to go paperthin though, so still thinking about the wicking problem and maybe some larger 'washers' to spread the load.along the flange.

I really don't want to be taking the apron off again!

Thanks again

Alan

[anotheralan]

I could not tell you how much wear is too much slack as a measurement, but I was taught to assess chain wear against a new chain by gripping a link of the chain and holding the whole thing up flat (i.e. link face upwards) and compare how much it droops compared with a new chain. Takes a bit of finger strength for larger chains but is a good way of spotting how much wear has taken place on each link. Ultimately it was just common sense judgement of course. The worst of worn things were always archived in a black museum.

 

Nick

Thanks for reminding me of that one which i recall from 1998 when i did the engine right through. As it has only done the 12 k since i won't remove it to test for droop for the hell ofit, and i would have to buy a new one to compare. On the other hand it is only a tenner. Decisions, decisions.

Cheers Alan

[anotheralan]

Hi Alan,

doubling the gasket is not always the answer.

 

If you can check the contact surface of the cover and try flattening it.

Using one of the Silicon sealants with one gasket may help.

 

Did you have the cover tightened down correctly when you discovered the wicking. It sounds a touch loose.

 

Roger

Hi Roger

Yes it was tightened with a t wrench as spec, but as i have said elsewhere it was not prperly flat.

What silicone would you use?

Alan

[BlueTR3A-5EKT]

Hi Peter,

 

thanks for your advice, but I don´t understand what you try to tell me.

I refitted the timing wheel and the sprocked on the crankshaft as I fond them.

In the workshop maual and at spare part lists I can find no plug.

 

The tensior I realised it as dull stainless steel, I know some are black.

I bought it together with die IWIS chain from a TR-workshop next to Heidelberg (D).

http://www.racinggreen.de/Call for Robert.

 

Ciao Marco

Correction Marco,

I have now looked more closely and you timing gear is not the Triumph type with the drilled through lubrication holes the markings on the face are not the filled up holes - sorry for the confusion.

Did you fit the tab lock washer?

Sorry again

Peter W

[RogerH]

Hi Alan,

the gasket maker on here http://www.moss-europe.co.uk/shop-tools/consumables/gaskets-sealants

 

or whatever Halfords have on the shelf.

 

Roger

[Z320]

Hi Peter,

with the new chain I used NO tap lock washer - but Nord-Lock securing washers.

Ciao Marco