Britbike forum Forums British motorcycles in general British motorcycles in general Informal survey: How many do head bolt RE-Torque?

I have to admit I have only done it once at the beginning when I was still doing stuff I was told, and it was such a hassle I decided to blow it off unless “for cause”. Often referred to as On Condition. I have an A65 that will make oil on the top fins after a long run. I’ve seen others here reference a head re-torque when chasing oil leaks. On a Triumph you have the push rod tubes as most likely the cause, and maybe the head. I expect on an A65, the head is about the only suspect! So has that been successful? Haven’t seen much follow up on after the work results. Anyone have a comment?

Depends on the gasket, composite yes, copper maybe not.

On previous rebuilds, I would tend to just CHECK torque settings on my A65s, and I would typically find that they didn't need re-torqueing, but then I took advice from others on this forum that the bolts should be cracked loose and then re-torqued. I did that after the last rebuild, and found that the bolts turned about another 1/8" turn or so when re-torqueing. This last time I also used a custom-made head gasket, which is thicker than the typical pattern gasket. I also re-surfaced the head and the cyl. barrel mating surfaces on emery cloth on a marble slab.

This is a BSA problem, as the gasket encompasses the pushrod tunnel and the two oil drain passages from the front valve wells. As you noted, on a Triumph, all the oil from the head drains through the external pushrod tunnels and not through the head gasket and cylinder barrel. I've had this problem more than once on my A65 bitsa - not since the last assembly, but it's still too soon to say.

Yes. Last year had the head off my TR6. Did an immediate retorque after the first heat cycle, then another after 1000 miles. Really surprising how loose some head bolts were. Copper head gasket.

Re-torquing the head bolts of new automobiles was standard practice for U.S. cars in the 1950s. At about 1,000 miles, as I remember it.

My Triumph with iron head and copper gasket takes a few retorques over a couple of hundred miles before it’s settled.

I re-torque. I'm getting ready to do that on a bike soon.......chasing oil on the fins.

Can't honestly say I've ever cured an oil leak re-torquing. Most of the time it's a re-torque after the top end's been off and almost always at least one bolt/nut seems a bit loose......but not always.

Yes,this.......Contrary to the rules , I apply a touch of lube to the bolts or studs....If I retorque,the Fasteners seem to retain equal torque valves..

Thanks for the feed back notes, all appreciated!
This small unrelated to the leak endeavor has ballooned into much more time and effort than expected……. Kind of a BSA thing it seems.
Anyhow, while at it I may as well tank the tank off, remove the required rocker shaft, and RE torque the head. If nothing else, it will be a good exercise to observe results! Now working outside, so will take some time.

There are two issues here, the need for re-torqueing, and oil seeping past the head gasket. Triumphs are more prone to the need for re-torqueing, IMO because of their bolt-on rocker boxes, an extra layer of gaskets, and their much lower torque specifications than those of BSA unit twins.

BSAs, on the other hand, are uniquely prone to seeping oil past the head gasket, for reasons already mentioned, and it's not clear that re-torqueing or the lack thereof is either a cause of or remedy for this problem. In my experience, once oil starts seeping past the gasket, it will continue to do so until you tear it down, replace and/or anneal the head gasket, re-surface the head and cylinder barrel if needed, and put it back together.

There was a thread a while back on the oil seepage problem in which it was revealed that most pattern head gaskets are thinner than OE gaskets, and the oil drain holes are larger in diameter. Among the recommendations was to put O-rings in the oil drain holes. I was able to source a custom made head gasket from an outfit in Phoenix Arizona which is of the correct thickness and which has smaller diameter oil drain holes. As I mentioned above, it's too early to tell if this will prevent the oil seepage problem, but so far, so good.

I've always checked the head bolts after my first ride. As I remember the outer head bolts on my A65 were still tight, so I didn't bother to remove the rocker shaft to check the ones under that. PITA! Never saw any serious leakage around the head gasket, but I'm not looking for hospital grade cleanliness.
I've only had the head off my T120 once, torqued it once, done.
The Trident is another matter, torque once after the first run, torque again after 100 miles. I've used both composite and copper gaskets on these, doesn't matter. I actually prefer the composite gasket on these, I never had any leaks on my first Trident until all I could get was a copper head gasket.

I've always checked the head bolts after my first ride. As I remember the outer head bolts on my A65 were still tight, so I didn't bother to remove the rocker shaft to check the ones under that. PITA! Never saw any serious leakage around the head gasket, but I'm not looking for hospital grade cleanliness.
I've only had the head off my T120 once, torqued it once, done.
The Trident is another matter, torque once after the first run, torque again after 100 miles. I've used both composite and copper gaskets on these, doesn't matter. I actually prefer the composite gasket on these, I never had any leaks on my first Trident until all I could get was a copper head gasket.

There’s a similar thread on the BSA Board regarding thickness of the washers, the late washers should be 0.09” thick though most supplied from vendors are not to that spec. I made the ones for my oif to this spec from 316 (from memory) stainless.

Though my 68 Lightning uses what ever came from SRM (I will measure them and replace if they are of thinner size). In the last 12 months it’s started showing a reduced top speed and some incontinence from the head. It’s that one bike where it’s got a race cam, and high compression and when im alone on an open road…. I forget I have responsibilities and a family. Thought it’s not done too bad, I did the head 6 years ago and it’s only just started getting incontinent. 🤷🏻

i do the head twice whenever its been off.

and later on if it looks like i need to.

got to do my T120 now. its been a few years and its seeping. time to take it off, clean it up, and check the bore on the pistons. theyve been there for some 35 years and only do 155psi.

still good for 117, but its the principle of the thing

The original washers appear to be rather hard as well, and I would think that's important as well as the thickness. After so many years and so many reuses, the originals show no signs of galling or squishing. Allan, I don't know my metals, but I know ordinary stainless hardware can be quite soft; is 316 hard?

My cylinder head remained oil-free for about six years too; I guess that's not so bad, huh?

303 can be quite soft I think, a decent 303 is easy machining. 304 can be a bit harder to machine and I’ve received what I beleive is 304 when I have ordered 303.

316 is similar to 304 but with higher tensile properties compared to 304. I’m thinking now and trying to remember if it was 316 I used, I did some reading up at the time and decided that it seemed the best choice as far is stainless is concerned. I don’t beleive its yield strength is as high as the grade 12 bolt which is clamping it down but i think the threads in the barrel would fail before the washer would deform.

I’m all for original hardware. Finding it sometimes is the hardest part and with something like a washer, you don’t always know what your being sold.

I hear that. On a friend's recommendation, I ordered thick washers for the head bolts on my T120V from a vendor who shall remain nameless (starts with S and ends with T.)
What I got were nice thick washers in 5/16", totally worthless for 3/8" head bolts!
I can't blame them. Those washers are probably among the Fasteners which are mysteriously absent from the specifications index in the back of the parts book. It's always the one fastener which you can't find listed there which is missing.
Then you find out that your '71 model, made two years after the official switch to Unified Fasteners, STILL has BSF bolts!

David, that's disgusting !

The seller should have attempted to put one of those washers on a REAL head bolt before listing them for sale.

As to bolt threads, that is why I have removed one of each type of bolt from the '70 TR6R I'm playing with, to measure the length of them, and the thread types.
That's how I discovered that the head bolts still had British size hex heads and threads.

David, that must be an old story; that is, you must have known for a long time that BSA & Triumph didn't retool for their engine parts, and it would not have made good business sense to do so. Chassis, yeah - mostly through-bolts and new frames in '71, and forks and wheels supplied by Girling, who had converted years before.

Unlike Triumph, the '60s BSA Spares books did not list hardware specifications, so I always relied on outfits like British Cycle Supply to send me the right stuff, which they invariably did - I would just say, send me head bolts with washers for a '67 A65, and so on. After a while, I started ordering hardware from British Tools and Fasteners, where you order by type, size, thread form, and material. The thing that's "special" about many of the flat washers is that they have small outer diameters, compared to the "standard" hardware for a particular i.d., and British Tools and Fasteners has accommodated me on that score as well. Head bolts and washers though, I've always sought as BSA parts.