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Hello All,

After finally cracking the issue I had with my coil overheating on my 1963 3TA (changed the points for a PowerSpark EI) I had a few pleasant rides at the end of last year. Over the winter I did some maintenance including replacing head gasket due to signs of some oil on the cylinder block.

All back together now but the bike sounds very different. Its hard to describe but it sounds "raw" (not in a good way!) and very loud (rattly bangs) at the front of the bike (down pipes). Reving the bike when stationary sounds awful. Also, after only few miles of riding, my previously perfect chrome pipes have tarnished (reddish staining) quite badly. It ticks over ok and doesn't stall. I haven't noticed any big change in power when riding but to be honest I haven't pushed it due to the nasty noise.

I don't think it is a mechanical noise (bearings etc). The engine was professionally rebuilt a few years back and hasn't done many miles since. All new lubes when I did the head gasket too.

I have rechecked the timing using a timing light and it looks ok. Static timed at TDC and moves to around 30 deg BTDC when rev'ed reasonably hard.
I have rechecked the valve clearances. Lightly finger tighten the tappets then backed off 1/4 turn (with the engine cold).

I am now wondering if the bike is running lean. This would account for the tarnished exhaust I think but not sure about the noise.
The spark plugs look good, although I haven't done many miles since the noise started.
I have discovered that I don't (didn't) have an air filter. The bike has a half bathtub, so the filter is in a metal airbox inside the bathtub. Turns out this was empty of any filter material. I have cobbled together a filter from a paper one for a car that will at least stop anything sizable getting sucked into the carb. Not sure if this would have caused it run lean though.

The needle is in the middle position (3). The Manual I have says that it should be in position 4 for the first 1000 miles then position 3. As the bike has only done around 350 miles since the rebuild I wondered if I should move the needle to position 4 (richer)?

I have been told that the quality of the petrol we get today is variable and not as good as it was in 1963, so do the original settings still hold true (e.g. the needle position)?

Any thoughts, comments, suggestions gratefully received.

Many thanks
Peter

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Originally Posted by Peter Williams
Any thoughts, comments, suggestions gratefully received.

Many thanks
Peter


Peter,

FWIW, a blown copper head gasket can make a pretty nasty, high pitched, squeaky sound. If you are hearing something similar, you may have that issue.


Jon W.


1957 6T Thunderbird 650
1968 T100R Daytona 500
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Quarter of a turn seems like quite a large valve gap? Try closing them up, I usually just adjust them so there is a very slight click only.


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Originally Posted by Jon W. Whitley
Originally Posted by Peter Williams
Any thoughts, comments, suggestions gratefully received.

Many thanks
Peter


Peter,

FWIW, a blown copper head gasket can make a pretty nasty, high pitched, squeaky sound. If you are hearing something similar, you may have that issue.
I think Jon may be correct in his assessment. It's not the end of the world, just remove the head and do it over. Make sure to anneal the gasket and remember to re-torque the top end after the first warm-up.
But there's another possible cause, squeaky valves. This comes from gummed up valve stems or scored valve stems due to lack of lubrication. The age old trick is to block the return orifice in the oil tank with your finger until the noise goes away. This will flood the valve gear temporarily. If it helps, run it, if it comes back you need to investigate why.
Originally Posted by tiger_cub
Quarter of a turn seems like quite a large valve gap? Try closing them up, I usually just adjust them so there is a very slight click only.
Cub, if he's running the original ramp type cams, he's correct to use those valve clearances. Your method is good with the sports cams.

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Hello tiger_cub, your bikes are almost certainly E3134 profile cams, so 2 thou inlet 4 thou exhaust, while I think a 3TA might have ramp cams, circa 10 thou? Worth checking.

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https://www.denniskirk.com/motion-p...-and-005-in-08-0053.p28375.prd/28375.sku

These also come in a .002/.003 size and others. Takes the guess work out of adjusting valves. Small and easy to use.

Last edited by desco; 04/20/21 1:46 pm.

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Thanks all for the responses.

I will give the head gasket another go. Couple of questions on that, if you don't mind?

I have 2 options for the head gasket (thick and thin). The one fitted when the bike was restored was the thin one (0.7mm). However, I have seen somewhere that pre-1964 it should be a thick one (1.2mm). I have both available, any ideas which is correct for a 1963 3TA? Also should I anneal a new gasket?

torque settings I have are either 200 lbf. ins. (22.6 N.m) according to Instruction Manual No. 4, 18 lbf. ft. (24.4 N.m) according to Haynes Manual or 25 lb./ft (33.9 N.m) in the Triumph Workshop Manual Supplement. Quite a range but none seem very tight for head bolts but clearly I don't want to over tighten them. Can anyone confirm what they should be? NOTED - recheck / tighten after first warm up.

The valve clearances are as per the Manual. Quarter turn should be around 10 thou. The cams are standard for the bike.

The head and valves don't look gummed up at all. Only a few miles since rebuild, so should be good there.

Thanks again all.
Peter

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Hello Peter,
If everything else is as it was, and you have the timing right as you say, then it has to be something you have done (or not done) to make the difference, not carb settings per se. I know you have an ok tickover, but I would be looking at air leaks at the carb (O ring?) as well as re-torqueing the head - it has to be something fairly simple!
Cheers,
Mick.

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Yes , anneal solid copper head gasket, even if its new.


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Hi Peter,
Originally Posted by Peter Williams
I have rechecked the valve clearances. Lightly finger tighten the tappets then backed off 1/4 turn (with the engine cold).
Originally Posted by tiger_cub
Quarter of a turn seems like quite a large valve gap? Try closing them up,
According to the workshop Manual (Section B5, page B9), 1/4 turn (~10 thou.) in. and ex. is correct for standard 3TA cams.

Originally Posted by Peter Williams
Torque settings
18 lb.ft. is correct, the 25 lb.ft. in the '63-on Triumph loose-leaf workshop Manual was subsequently reduced in a Service Bulletin ...

Hth.

Regards,

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Thanks again for all the responses, all very helpful.

I shall refit the head gasket again at the weekend after annealing it and re-torque it once the engine has been warmed up.

I don't see any mention of using any sealant. I assume this is only for engines where you have oil / water ways through the gasket? I was planning to clean everything carefully and assemble dry. Is that ok?

I have a new carb 'o' ring, so I'll double check for air leaks when I reassemble.

I will let you all know how it goes!

Best regards
Peter

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Permatex Copper Spray-A-Gasket is good insurance against a leak.


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I've had great luck sealing with the different Loctite 510, 518 or 574. (note copper is a catalyst so it speeds up the setting time, I add the Loctite bead to the steel/ aluminium side and then build quickly, 510 has the highest heat rating and the slowest setting).
Conversely ive had bad luck with the spray a gasket, but that might have been due to crush issues. It certainly did not work on the rocker box copper gaskets I use. I prepared everything well and it was leaking soon after the first start but YMMV.


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I can't get hold of any Permatex Copper Spray-a-Gasket before the weekend. Doesn't seem to be widely available in the UK.

I have got some Locktite 5990 Silicone Copper Gasket Sealant which is good to 300 deg C.

I thought I might put a very small bead on the block where there is a small indented ring around each cylinder. Good idea?

I don't think I need to coat the whole of both mating surfaces as there are no obvious defects in the block or head and I'm concerned that if it cures quickly I will struggle to get a good, consistent thin layer between the block / gasket / head.

I am planning to try the thicker gasket (1.2mm) this time too.

Regards
Peter

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Originally Posted by Peter Williams
I can't get hold of any Permatex Copper Spray-a-Gasket before the weekend. Doesn't seem to be widely available in the UK.

I have got some Locktite 5990 Silicone Copper Gasket Sealant which is good to 300 deg C.

I thought I might put a very small bead on the block where there is a small indented ring around each cylinder. Good idea?

I don't think I need to coat the whole of both mating surfaces as there are no obvious defects in the block or head and I'm concerned that if it cures quickly I will struggle to get a good, consistent thin layer between the block / gasket / head.

I am planning to try the thicker gasket (1.2mm) this time too.

Regards
Peter

First of all, if you're planning to use a thicker head gasket than you used before, check the "crush" that you will get by putting all gaskets in place on the pushrod tubes and assembling your head so you can see and measure the crush as seen here:

[Linked Image from i.postimg.cc]

I found that the thicker (.125") white silicone lower push rod tube seals on my T100 were too thick (I left the lower steel band off for the photo), which would have required crush of over .050" while .030-.040" is desired. I inserted four of the head bolts and just turned them in by hand to make sure I was getting the head pulled down evenly on all four corners. I was able to get the thinner ones (.100") to achieve the desired crush. If you change from a thin .026" thick head gasket to the thicker .050" head gasket, you may loose the crush on your pushrod tube seals. If so you may have to get the thicker lower seals.

2ndly, be very careful that your gasket surfaces are perfect. Here you can see where I had a small leak at the side of my head gasket after just 10 miles after a complete rebuild. You can see oil and discoloration where the oil leaked out. You can also see traces of the Permatex copper spray I used on an annealed head gasket (thick one, .050") to no avail.

[Linked Image from i.postimg.cc]

And here you can see the culprit. A very small scratch in the head surface.

[Linked Image from i.postimg.cc]

That small scratch was where the oil was leaking. I re-glass sanded the head on 125 grit, then 400 grit sandpaper. I only re-assembled it yesterday and only got about a 10 mile run up the road and back, so the jury is still out on whether I succeeded or not.

Tom

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Hi Tom,

Really helpful information that I hadn't considered. Thank you for taking the time to provide the detail and the photos.

I bought the thicker gasket as part of a kit which included the push rod tube seals. I need to check if these are specific to the head gasket or not.

When you talk about the desired "crush" of 0.030" to 0.040" is that overall or per push rod seal (top and bottom)?

I will assemble as you suggest and check before final assembly.

Good information on the scratch. Looks very small but clearly big enough to cause a leak. I will have another good look at my surfaces.

Thanks again and I hope your leak is sorted.

Regards
Peter

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Hi Peter,
Originally Posted by Peter Williams
Really helpful information that I hadn't considered.
You don't have to, Tom has a later engine with different PRT and seals.

Originally Posted by Peter Williams
I bought the thicker gasket as part of a kit which included the push rod tube seals. I need to check if these are specific to the head gasket or not.
For each PRT, the seals should be:-

. E3547 - about 1/10" thick and a little under 1-1/4" OD before stretching over the top of the PRT;

. E3758 for the bottom of the PRT - I don't have one to measure but, if you Google the part number, the returned images show a much thicker seal; for this reason, "crush" shouldn't be an issue, the tiny difference in head gasket thicknesses notwithstanding. thumbsup

Originally Posted by Peter Williams
desired "crush" of 0.030" to 0.040" is that overall
Yes.

Hth.

Regards,

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The petrol in England is perfectly good and so this wouldn't have caused any problem.

Dave

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Update on progress (sort of)

Refitted the head gasket and the bike does sound a bit better now and runs ok. Haven’t had a proper ride out yet though.

However, I am now getting oil leaking (weeping) around the two nuts/studs each side of the bottom of the inlet pushrods tube. At first I thought it was the pushrod tube leaking but I’ve cleaned it all up, run it for a while and it does seem to be coming from these nuts/studs. I haven’t touched these nuts at all, so nothing should have been disturbed there.

I have had a bit of oil coming out the overflow on the tank, so wondering if I overfilled it a bit. I put the recommended 5 pints in but that did leave the level only about 3cm from the rim of the filler hole (the Manual says it should be 4cm). I syphoned a bit out and have stuck a tube on the overflow temporarily to stop it going everywhere.

Just wondering if overfilling could cause a leak at the bottom of the block?

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Final update on this issue and all a bit embarrassing really. Lesson learned is look at the obvious things and don't make lots of changes at the same time!

Bottom line is the LHS exhaust tappet adjustment was way out - much too loose. I adjusted this a couple of times but he rocker arm was stiff enough that when I tried to lift it with my finger I felt resistance and assumed it was at the top of its travel, then did the adjustment from there. When the bike first started up it was ok but as soon as it was rev'ed I got a terrible noise. Seemed to be in the exhaust but was actually in the exhaust rocker cover.

So, no issues with the head gasket (now replaced), no issues with fuel mix or timing, just incorrect valve clearance! I am surprise the bike ran at all, it was that far out!

Anyway, thought I would 'fess up to stupid fault finding and jumping to the wrong conclusions.

Thanks for all the tips and suggestions above...a valiant effort to help given my poor description of the issue.


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