Head Gasket failure after on 1500 miles

[Lebro]

A local Friend (Mike) returned home last weekend in his TR3A & it was doing a pretty good impersonation of a steam engine.

 

It has a TR2 engine, re-built some time ago, but fitted with new head gasket (after checking liner heights) only2 years (approx 1500 miles) ago.

 

Took the head off this afternoon, and found this:

 

Water had been getting into No. 3 pot through a burnt away section of the gasket. No. 2 was not far off the same fate.

 

The head looked OK , no sign of any crack between the water holes. We cleaned everything up:

 

 

and observed that No. 3 liner had eroded away at the flat which is in the centre of the block, leaving a very thin area for the gasket to seal on.

We also observed that the compression sealing rings in the gasket were of a larger diameter than on an old (unused) copper / asbestos type gasket Mike had in stock. It looked as though the copper gasket would have sealed OK.

The gasket which failed was an expensive one (£90 ish) from the TR shop, so not very impressed.

We are going to re-build with a copper type, as it would seem to fit better:

 

 

So, I'm looking for advice as where to get a good gasket from, & what (if anything) we can do to prevent a re-occurance.

We do not really want to remove the liner (I know we could turn it round) as it is all sealed up nicely below.

 

There is some slight rust erosion on the block face between the two water holes in the photo above, wondering if anything could be user to build up the level a bit, apart from sealant.

Finally what's the current recommendation re using sealant (wellseal etc) on the new head gasket.

 

Bob.

[Don H.]

I've often thought that "fire rings" soldered around the block-side cylinder openings from dead-soft annealed 0.018-inch copper wire was an interesting idea to improve sealing. It's been done by some folks over here with reportedly good results.

[iain]

Hi Bob

 

I use a Solid copper gasket at 1mm which works very well if the liners heights are correct. I thought they were very expensive so I had a couple made locally. If interested PM me.

 

Iain

Edited August 2, 2017 by iain

[RogerH]

Hi Bob,

that pock marked surface will always be a weak point.

Ideally it needs skimming. Whatever the pocks need leveling.

 

Have you considered a temporary fix with JBWeld. It will be under compression, so shouldn't move.

 

Just use a bog stand cheapo gasket - £90 = ridiculous

 

Roger

[TR 2100]

Bob,

 

TR3A with a TR2 engine? I assume it has been retro-fitted

with camshaft bearings (though that is not a suspect in the

blown head gasket problem).

 

I don't pretend to be an expert with lots of experience, but I

do have some experience. So - some thoughts.

 

I don't know what kind of gasket it was from the TR Shop,

but I would suspect the workmanship rather than the gasket.

ALL gaskets should work in normal use unless there is some

shortcoming in the workmanship or other components.

 

Looking at the photos, my prime suspect would be a warped

cylinder head. This can be very critical. I've had problems

with a warped cylinder head that blew gaskets even though

I had checked it as OK with steel straight edge.

Better to give the head a light skim at least.

 

The problem of a warped head can be exacerbated if the

gasket used is of the steel type - they can be useful with

a highly modified engine, but they make sealing very very

critical.

 

I'm assuming the liners/liner height are checked and OK.

Just that there are 'rebuilders' out there that do not check

everything properly.

 

I don't think "building up" the liner is a viable option.

Rotating through 90° may be, but then you would have

limited sealing in another area.

Liners are not so expensive.

 

Sealant is not required. That's not to say the right sealant

(whatever that may be!) doesn't help.

I don't like the idea of "fire rings", even if some owners

have had positive results.

 

AlanR

 

 

 

 

[Don H.]

Well I don't, and won't have "fire rings" on my car either, Alan! But as a mod to a cheap head gasket in an effort to avoid more extensive engine repairs, it might be worth a punt.

[Alec Pringle]

Clean up and fill the pock marks and gaps round the liners, Wellseal both sides gasket, find a pukka nos 83mm gasket as opposed to 86mm current stock.

 

Cheers

 

Alec

[TR 2100]

Hi Don,

 

Well, it may suit someone who wants to "invest" in a cheap

head gasket and has easy access to welding equipment!

 

Seriously, though, I haven't heard of that mod before, but

I'm not an engineer,so I shouldn't comment.

 

AlanR

[TomMull]

Plus 1 on the 83mm gasket as well as scrutiny of the head surface. Also, I think the "fire rings" were intended as a work around for low liner protrusions. Tom

[Don H.]

Plus 1 on the 83mm gasket as well as scrutiny of the head surface. Also, I think the "fire rings" were intended as a work around for low liner protrusions. Tom

 

Yes, you're right there, Tom. And Alan, they're not welded -- simply soldered. Definitely shade tree mechanic stuff.

[Lebro]

Thanks for replies so far, more specific questions:

Where to get a good 83mm gasket

What to use to fill the gaps, & eroded surface (I'm thinking a metal dust filled epoxy ?)

 

And some answers:

The liner heights were OK (we checked with straight edge & feeler gauges)

Head was skimmed before the recent fitting with the blown gasket

Block skimming definitely a last resort.

 

Bob.

Edited August 2, 2017 by Lebro

[Motorsport Mickey]

That's "orrible".

 

Take a step back and measure the liner protrudences, until you've measured yourselves (with depth micrometre) you can't work out what the fix is to be. Don't fear removing a liner (or liners), having done it loads I know we all would like it to be ok without touching, but not knowing and rebuilding it and having another failure is the worst possible result. I suppose the engine had a retorque at no more than 500 miles after it's previous rebuild ?

 

As posted if 83mm pistons and liners are being used then that's the gasket size to use, oversize gaskets allow too much flame front to squeeze into the space and often cause burning of the gasket and failure. The copper composite standard gasket is loads more forgiving than these other offerings.

As for the compression surface on the top of liner...Ha, when the steel double ring head gaskets are used (originally part of the decompression kit with steel shim and another gasket), part of the "black magic" fitting of it include cutting through the first ring and halfway through the second ring so you only seal the gasket on HALF of one sealing ring...about 1mm, and they seal, BUT that depends upon a closely controlled liner height, that's why you are going to check it.

The original Standard Triumph workshop manual 60 odd years ago states a 2 thou variance between 3 and 5 thou between the heights of the liners ha...yeeeaaah bob ! when the blocks were freshly bored with vertical liners and the block surface being exactly 90 deg to the vertical plane exactly the same height from the liner shoulders at the spigot at the front to the rear liner shoulders of the block maybe. Then factor in millions of hot cold cycles warping the engine blocks so the liners now stand like Ken Dodds teeth ! not only twisting the axis front to rear but also side to side and you should be able to see why we need apply tighter tolerances, the factory had it easy !

If when you measure the liner heights using a depth micrometre (dirt cheap now, probably less than £20 off e bay) at 4 positions around the liners the heights need to be 5. 5. 5. 5. or 3. 3. 3. 3. that is the 2 thou variance the factory meant.

If you get a 5. 5. 3. 5. it's still within the original 2 thou workshop variance but because the 3 figure is within two higher 5 thou liner heights in the centre of the engine, even though the gasket will be compressed it's prevented reaching the same clamping force and so a weak spot exists which is likely where the gasket will blow in future.

 

If a workmanlike repair is to be occasioned measure the liner heights to allow you to plan your reconditioning.

 

Mick Richards

 

Edit: been interrupted and Bobs posted again, what EXACTLY were the liner heights then Bob, if you read the above you may have other thoughts now.

Edited August 2, 2017 by Motorsport Mickey

[Lebro]

Mick.

Yes, head was re-torqued, we did measure the liner heights very carefully at 4 places per liner, & results were well within tolerance.

But we will do it again.

 

Only gasket I can find to specify TR2 low port use is this one:

 

https://www.rimmerbros.co.uk/Item--i-501678

 

Others seem to claim to work on all sizes.

 

Apart from the obvious shortcomings of the old block, I think the main reason for failure was the use of the TR shop expensive gasket which I now realise is meant for the larger bores 87, & 89mm

 

Bob.

Edited August 2, 2017 by Lebro

[iain]

That will I fear still have an 86mm gasket, but will include low port manifold gaskets.

 

Worth a check before ordering.

 

Iain

[Motorsport Mickey]

The Rimmer part number 501678 is shown as a 83 mm gasket, worth a phone call to check though. I note you say the liner heights were within tolerance Bob and if that means they comply as I described then they will be ok, if not..

 

Mick Richards

[Lebro]

Iain.
Will give them a ring in the morning.

 

Mick.

Yes they were checked against those figures when they were being discussed on here a while ago.

 

Does anyone know the correct part No. for an 83mm composite copper gasket ?

 

Bob.

 

P,S.

seem to be a couple on ebay at present

 

http://www.ebay.co.uk/itm/TRIUMPH-TR2-TR3-TO-TS13051E-ENGINE-HEAD-GASKET-SET-501678/351811818842?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2055119.m1438.l2649

 

http://www.ebay.co.uk/itm/TRIUMPH-TR-HEAD-GASKET/162157608137?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2055119.m1438.l2649

Edited August 2, 2017 by Lebro

[BlueTR3A-5EKT]

What about the Ferguson T 20 with 85 mm TVO/petrol engine?

Peter W

[BlueTR3A-5EKT]

Iain.

Will give them a ring in the morning.

 

Mick.

Yes they were checked against those figures when they were being discussed on here a while ago.

 

Does anyone know the correct part No. for an 83mm composite copper gasket ?

 

Bob.

 

P,S.

seem to be a couple on ebay at present

 

http://www.ebay.co.uk/itm/TRIUMPH-TR2-TR3-TO-TS13051E-ENGINE-HEAD-GASKET-SET-501678/351811818842?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2055119.m1438.l2649

 

http://www.ebay.co.uk/itm/TRIUMPH-TR-HEAD-GASKET/162157608137?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2055119.m1438.l2649

The second one 202127 looks like a goer

I knew the smaller bore head gasket as GEG343

Peter W

[RAHTR4]

Hi Bob,

 

The original Standard Triumph part number was 202127.

 

The Payen part number was 1A549.

 

I think that I have at least one spare if it of use.

 

Regards, Richard

[RAHTR4]

Hi Bob,

 

Go for the one on eBay as the one I have is part of a Decarbonising set.

 

But do make sure that the gasket is clearly stamped either 1A549 or 202127.

 

Regards, Richard

[BlueTR3A-5EKT]

I have found a copper composite gasket in the garage marked 'Not 86mm TR'

Will measure the liner hole and let you know.

I suspect it is vanguard though as the liner hole is not round.

Will PM my info to you Bob.

Peter W

[Guest ntc]

There is no such thing as a good composite gasket.

[Lebro]

Hi Peter.

 

Mike has now sourced a gasket set - from Moss - he spoke to them & they were sure it was for the 83mm bores only.

It arrived this morning, & we have check it's fit on the liners & the head. It should be fine, it sits on even the worn liner well within the damaged edge.

It is copper top & bottom, but not solid. No part No's stamped in it, but it loos to be of good quality & fits well.

We will re-assemble tomorrow after the wellseal has dried !

 

I am now convinced that the problem was that the gasket used last time was for a big bore TR ie 87+mm & being steel did not help.

 

Bob

[Lebro]

Head back on, All torqued up Ok except front stud on LHS (nearside) it felt wrong when tightening,

so stopped at (guessing here) around 80 ft LB.

added a second nut, & tightened up to the first, alighing the flats, the re-torqued on both, felt better, so continued to around 90,

then chickened out.

Will investigate further on the re-torque in 400 miles or so. Hopfully it's the nut starting to go, & not the stud or block

 

Bob.

Edited August 5, 2017 by Lebro

[TR 2100]

Bob -

 

Hope the re-torque goes as you hope - helpful

if you report back on your success.

 

and - the sooner the better so take advantage

of any sunny weather!

 

AlanR