head gasket sealant?

[jren0780]

Well chaps- nearing the completion of my engine and I'm wondering whether anyone reccommends sealant with their head gaskets. Years ago, an old mechanic told me to grease the gasket first. What's the received wisdom on this with TR's

I'm assuming that the folded edge of the gasket goes uppermost?

Thanks for your attention

[robgeev]

Clean and dry we think is best, most importantly check the head is true, and if there's any doubt, get it lightly skimmed by a trusted machine shop.

Not sure about the gasket-generally it's embossed into the gasket anyway!

 

Rob.

[BrianC]

TR2/3 workshop manual says use a light coating of grease but non-setting sealant may be used.

TR4/4A manual says use a sealant. I always used to use grease on the conventional (copper composite) gaskets and Wellseal (NOT the thicker Hylomar or Hermetite) on the thin steel gaskets.

 

As Rob says, check everything is true (including the height of the liners). The correct sequence of tightening and re-torquing after 500 miles should also ensure long-term success.

 

Not sure about which way up, but I seem to recall some are marked.

[Dale Moore]

Would never use anything on head gasket, and as Rob says I would just ensure the mating surfaces were clean and flat. but after having trouble on the 4A with a leakage below the manifolds I now use a light smear of Wellseal, not too close to the bores, but around all the water jacketing, again retorquing up after a few hundred miles

I think the gasket is marked front or top and I seem to remember the plain side to the top Check the liners protude from the block by 5 or 6 thou. though there's not much you can do if they dont

 

Regards

Dale

[Mychael]

My mate always put his head gaskets on with a brush of silver paint that had thickened slightly in the tin.

 

Dunno if it did anything or not, certainly did not seem to do any harm.

 

Mychael

[BrianC]

Check the liners protude from the block by 5 or 6 thou. though there's not much you can do if they dont

If they are flush, - then you may just get away with it - if you are very lucky. However, if the liners are below the block face, then you may as well resign yourself to removing them and fitting new figure-8 gaskets. Otherwise, I believe there will be compression loss into the water jacket, with subsequent loss of coolant. I'm sure this is what was happening on my TR3A engine but I'll never know as the crankshaft broke and the engine is now in a zillion pieces (and many of the parts are shrapnel) awaiting a professional rebuild.

[jren0780]

Thanks for your suggestions everyone. I think my only remaining issue is the orientation of this head gasket. Its an original stanpart item- copper and asbestos- no indication of which side is top, which is my past experience. So still unsure about folded or flat edge uppermost. There does not seem to be a concensus among you chaps on this one?

[Mike Kitchener]

Just make sure that the rocker gear oil feed lines up with a hole in the gasket , although there might be a hole at each end making it symetrical.....in which case it probably doesn't matter which way the folded edge goes as it will squash down anyway.

 

Cheers

 

Mike

http://mikek.9online.fr/index.htm

[Rhodri]

Any writing, or similar, goes face up in general on head gaskets, although the workshop manual makes no mention of this. It does, however, suggest using Wellseal for this joint.

[marvmul]

The standard gasket is fitted with the folded sides to the top. If it has the "Stanpart" mark on it, then this is facing to the bottom.

The liners are protruding from the block between 3 en 5.5 thou (0.075 - 0.14mm) This is all important, it is already difficult enough to get everything tight with the correct measure; If the liners are just flush with the block, the new head gasket will blow, perhaps not immediately, but surely after some time.

If the liners are protruding too far, the engine will loose water to the outside, between engine block and head. To adjust this, you can get figure of eight gaskets with non standard thickness from some TR specialists or engine rebuilders (actually 4 ring gaskets instead of 2 figure of 8 gaskets). If the liners are protruding too far, a machine shop can easily shorten the liners.

[Don Elliott]

And don't forget to torque it following the sequence in the manual. And torque it down again after you have run it in about 100 or 500 miles. This is because the copper/composite head gasket was compressed when you torqued it down the first time and it has compressed a bit more since so the head nuts have become a bit loose.

 

When I did my restoration, I put on head nuts that the TR race drivers use. These are 7/8" high (12 threads) instead of the original nuts which are 1/2" high (only 7 threads) and I haven't had the head gasket leak in over 87,000 miles since then.

 

Don Elliott, 1958 TR3A, Montreal

 

http://www.britishcarforum.com/ubbthreads/...919/ppuser/4127

[BrianC]

Whilst rummaging around the garage yesterday, I unearthed my stock of spare gaskets including a batch of head gaskets. All appear to be genuine StanPart/Triumph items with the part number 202127 and are symmetrical but not marked to indicate which way up they should be fitted.

 

However, since I have owned (and still do) a number of engines with 83mm (1991cc), 86mm (2138cc) and even 85mm (2088cc - Vanguard Sportsman) pistons and liners, I decided to measure them and am now somewhat confused. The minimum (they are not circular) bore diameter is 86mm although the part number indicates they are for the 83mm engines, leaving a generous 3mm clearance.

 

The catalogues I checked suggest that these gaskets are no longer available and the 205481 gaskets should be used. As I couldn't actually lay my hands on one at the time, I assume these must have a hole diameter of around 88/89mm, thus leaving very little gasket material between the bores. Perhaps this is why the TR4/4A manual recommends using sealant rather than grease?

 

So, does size matter? How critical is the extra clearance? Could the earlier gaskets be used on 86mm (2138cc) engines to ensure better sealing, or would they spread when the head is tightened down and encroach into the combustion chamber? Conversely, how reliable are the later gaskets when fitted to the 83mm (1991cc) engines?

[marvmul]

The minimum outer diameter of the liners is 100mm for all liners from 83 mm to 89mm (and beyond?).

If the inner diameter of the gasket holes is 89 mm, about 5.5 mm of the gasket will be squeezed between liner and cylinderhead, so I suppose using the 89mm gasket is safe.

[Ade-TR4]

Hi all

 

I used the aerosol version of hylomar on the head gasket (demon theives sell it).

It produces a very even, thin layer which brushing cannot.

A light "scotchbriting" removes any tarnishing from the gasket.

 

A note about liner protrusion. I recently replaced mine and had to try 3 different sets before I got a set that were parallel between the Fo8 surface and the cylinder head surface. One of the liners had a 10 thou runnout. The head surface and block were straight btw.

The last set were spot on and protruded 5 thou. I had them reduced by a thou to clean up the upper surface and to be on the safe side as the Fo8 gaskets were steel type.

 

all seems fine so far!

btw, how hard is it to run in an engine? Talk abot self restraint...can't wait to "use" it properly

 

cheers

Adey

[jonlar]

Hi Adey, don't be too gentle with it, and don't be afraid to give a few short sharp higher revs bursts. The worst thing to do is to keep the engine at constant rpm.. Progressively increase the rev. limit, but re-torque the head after a hundred or so miles, personally I'd do it again at 500 and 1000, following the prescribed sequence - but I'm old fashioned like that - don't like these new stretchy bolt things!

[marvmul]

Hi all

 

. I recently replaced mine and had to try 3 different sets before I got a set that were parallel between the Fo8 surface and the cylinder head surface. One of the liners had a 10 thou runnout. The head surface and block were straight btw.

Adey

Some weeks ago someone mentioned a set of liners that where different in lenghth by about the same amount : perhaps liners get mixed after they leave the manufacture, because it's unlikely that the manufacturer is selling sets of liners with such big differences. Liners are easily damaged when dropped (I know!), perhaps damaged liners are simply replaced without checking the length.