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Discussion Starter #1 (Edited)
Hi All,

A question, Can the head gasket be changed with the engine in place or better take the engine out for this job?

A few days ago I noticed a puddle forming under the "link pipe" while the engine was running (yes she runs properly . finally) the liquid smells and tasted like cooling fluid. The exhaust fumes remained white even when warm.
10 years of standing still and then on-off to dial in the carbs did not do her good. I am pretty convinced the head gasket is the cause of the symptoms and not condensation even if it is freezing in the shop at the moment.

I will use the opportunity to go over the head but does it require taking the engine out?

Thanks,

V
 

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I've done it with the engine still in the frame on my Daytona 900. The rear engine mounts will support the cases but put a substantial block under the sump. It's a tricky manoeuvre because the front of the head has two big mounting lugs to the frame. Eth the can cover and cans removed, there's enough room to ease up and back from the frame then put to the side. Also, note that the head bolts go down through the coolant into the lower case so if there's been bad coolant they can corrode and weaken quite significantly. Doing it in the frame will restrict access to the heads of the bolts to an extent so if they are corroded it'll be more of a struggle that way. You should be ok though.

Ps Don't forget the M6 screws on the RHS of the head.
 

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Just done mine again(twice in 3yrs! But coolant issue might be reason for failure? See my earlier post in this section) Invest in a good tx50 torx bit! Agree with above. Easily do-able in frame.
 

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Hi Vaporlock, Yes, the head can be taken off while the engine is still in the frame. Here's the bad news. You said the bike has been standing for 10 years. That means the antifreeze probably wasn't changed out either. The anti corrosion stuff in the antifreeze only lasts for about 3 years, then the corrosion starts to happen and the aluminum head is the loser. Don't surprise if the head surface has holes and pits in it. The head on my bike had to have the holes welded to fill-in the holes and then resurfaced. Antifreeze getting into the combustion chamber cleans the carbon out. Antifreeze getting into the engine oil kills the crankshaft bearing quickly. You will need to reseal the base of the cylinder liners. Have a schematic of the engine head will help you find some of the hidden bolts. 2wheelpros.com has good Triumph schematics.
 

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Discussion Starter #6 (Edited)
Hi All,

Thanks for the info. I have been away, apologies for the late reaction.
I'll see what damage the anti freeze has done but it also means that a head inspection is a good thing. need to have a look at the "resealing the base of the liners" thing. I had not planned on pulling them. Any more info on that?

I will order a gasket pack and get on with it in a week or so.

Cheers

V
 

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Resealing the liners means putting Hylomar around their bases and is only really necessary if you lift them out of the block. Hylomar is a kind of flexible sealant that won't harden off despite operating in high temperatures, developed by Rolls Royce.
 

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To reseal the base of the liners you will be taking the liners out and applying a bead of sealant at the liner base. Good time to inspect the crosshatching on the inside of the cylinders. If the crosshatching is still there you are good to go. Triumph had a special sealant for the liner base. Other sealants work well also, RVT silicone or is it RTV?
 

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Discussion Starter #10
cool, thanks. So if crosshatch is ok, no need to pull them . not pulled no reason to reseal. Correct?
 

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No, Not correct. Taking off the head changes the downward pressure of the head onto the cylinders. Will it break the seal at the bottom of the bottom the liner? Maybe. Why take that kind of chance? Lifting the cylinders out is not that hard. It gives you the peace of mind knowing that you can inspect the pistons, move the ring gaps into the right place, and put a good seal on with Hylomar. If antifreeze gets past the liner seal the antifreeze will go into the engine oil. It won't take long for the crank bearings to get ruined and along with the crankshaft.
This happened to my brother Super III.
 

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Discussion Starter #13
Reading up on the whole procedure it seems logical to give everything a good "once over" and to re-sealing the liners. Only benefit zero negative.
 

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Discussion Starter #14
Hi All,

Back on the headgasket replacement and I have a few questions. before taking the head off, I checked valve clearances. exh is about in spec with 5 readings of 0.18mm and one of 0.15mm. inlet are tight with 0.08 for 1 and 3. number 2 read 0.1 and 0,12.
reading the shim thickness left me with a question. they are 2,65mm for the most part except two 2,70 and one 2,60.
the question: I use a vernier caliper since I do not have a micrometer. and all pics i have found on the net use vernier.
Do shims wear in the cam contact area? if that is the case, using vernier would give me a false reading since they will measure from the untouched exterior area of the shim?

Also, does anyone know the torx size for the engine and head bolts?

Ta,

V
 

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Hi Vaporlock, Head bolt is either a T50 or T55. If I were at home I could tell you exactly what it is. Cam cap torque is 10Nm. That's not much, remember you are tightening a bolt into aluminum. I couldn't get a good torque reading on the cam cap bolts so I with switched them over to regular hex head bolts. As for them shims. They just don't wear out. Sometime the size markings get worn off. Put the size marking down into the cup, I can't recall the name of it right now. The sizes you wrote are typical. Usually the exhaust valves don't need much adjusting. The intake valves are bigger and they do wear a little bit. I'm in the USA so my brain thinks in inches. I set the intakes between 0.005 - 0.007 inches. Exhaust are between 0.007 - 0.009 inches. I usually go the the middle number.
Greg
 

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Discussion Starter #16
Hi Greg,

Thanks for the confirmation of the shim wear and the measurements, lets see if someone pipes up with the TRX50 or TRX55

Leon
 

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Hi Leon, The head bolt is a T50 torx head. Do you have a Haynes service manual? The torque sequence is weird. The last step is to turn the bolt 90 degrees. I got a reading of 40 ft.lbs. when doing it. I'm a little disappointed that nobody else chimed in about the torx wrench. I don't want to be hogging in on so many answers.
 

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The extra 1/4 turn after torque reading is achieved is following the manual instructions.

Edited here: bad memory about reusing bolts. Sorry about that. As long as the threads are ok, all good.

When I did mine, way back in 1996, I reused the bolts and it was fine. However, I knew for sure it had never been done before because I had full history for the bike and it was only 18 months old when I did it. Working on an old motor, makes sense to check the condition of the bolts carefully.

I'll see if I can attach a picture of the relevant page in the manual later.

Cheers
 

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Discussion Starter #20
Quick update:
head bolts are indeed TRX50. i bought a mediocre socket and it snapped on the first bolt. When will i learn. Went out and bought a decent one. all good.
The head was a bit difficult to take off, the dowels were rusty and held it in place. took the head of, gasket looked a bit dodgy but not too bad (the leak was very small). took the liners out, looks like there is no hylomar on the base. took the pistons out which was difficult for #1 and #3 due to lack of space. I have decided to bring the head to a specialist and have it checked and the valves done while its open.

Liners look good, clear crosshatch. I do not have any marking on liner #2 though. should have a green dot or a size marking according to haynes.
Piston skirts are clean, very light scratches front and back skirt , opening of rings #1 and #2 on all piston measure between 0,5 and 0,8 mm. should be good. manual stated less than 1mm which seems rather large.

V
 
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