The Triumph Dolomite Club - Discussion Forum

Anybody got recomendations on where in the UK is best to get a set of head studs for the Sprint? Don't think I can wait for shipping from US or Austraila, etc.

Graham

When I needed replacements for my 1850 about 2 years ago ( 3 snapped ! ) I used Mr Rimmers ones 149080NP which are very similar to the Sprint ones ULC1144P. They fitted; torqued up fine, and retorqued up at 500 /1000 miles later plus at 6000 miles later. I wouldn't go to the USA for something that is available freely in the U.K.
Tony.

So you need more than one set to make up enough for a Sprint though...

http://www.ebay.co.uk/itm/ARP-Triumph-T ... 1488064647

I bought a set of ARP from Ken Clarke

I currently use standard ones as supplied by Rimmers on my race car engine that was rebuilt about three years ago.

I've used a number of parts from sprintspeed.co.uk and found them first class (blockbrace, lightened flywheel, 7.25in clutch, centre release slave). I see he does high quality head stud sets. Can't see you would find better anywhere else.

I've also previously used HT bolts (ex Caterpillar dealer) and cap screws with complete success.

Geoff

I must admit to some trepidation at buying OEM ones from you know who. Steve at S&S says he uses good original used ones, and offers to sell me a set. But I'm going to try another re-torque and bottle of bars, and see if that helps. If not, then it's a head off, new gasket, and look for studs and bolts.

As luck would have it, I also now have a full spare engine if needs be. It's one that was built properly, and has only done about 35k, from the fake TR7 Sprint DHC.

So I've also got a set of 6x13 Minilite sports, in fairly good nick, and with new centres; a plastic hardtop in need of a clean and paint; and the registration A TR7 16V. The wheels won't fit the Doly without work on the arches, though. The reg won't fit even then, and I don't see a lot of use for the top either, without a DHC 7. So if anyone's interested...

Graham

Being the fact that a sprint head is made from soft alloy and the studs are too thick to act as a spring (like Pug 205 GTI for instance) I see no real reason not to use standard studs as the good old Sprint needs a warm up to expand the head and firmly clamp the gasket hence no heroics before its all nice and hot.

trackerjack wrote:Being the fact that a sprint head is made from soft alloy and the studs are too thick to act as a spring (like Pug 205 GTI for instance) I see no real reason not to use standard studs as the good old Sprint needs a warm up to expand the head and firmly clamp the gasket hence no heroics before its all nice and hot.

I wasn't really thinking of higher spec studs and bolts, as such, but of ones where the quality is more nearly guaranteed than it would be with stuff off eBay or Alibaba or through You Know Who (YKW).

And while you can get stuff from YKW that will meet spec., I'm afraid that too much of it doesn't. I know of one guy who got a set that, he said, yielded (permanently stretched) before they reached standard torque. That wasn't a problem, because he just got a refund. But if they yield somewhere between the stress at cold torque and hot running, when the head has expanded more than the studs, or even at the stress of slightly over-hot running, then that will be an expensive problem.

And making sure that stuff reliably meets spec., as the CAA insist we have to with aircraft parts, is an expensive business - proving it's been done is even more so. So not doing it, or not doing it properly, is an easy way to cut costs. But that means you can get/supply stuff that's only nearly good enough, and just not know.

At least, if you buy higher spec stuff, you've some reasonable expectation that someone is interested in it meeting that spec, and therefore, generally, standard spec. The testing may not be perfect, but I'd expect there to be some.

I think what Steve is working on with the SH originals is that, if there length is still in spec., they very probably won't yield or brake. There's some question about if they are original ones. But I hope he has the experience to spot the copies, etc.

Graham

Well I tried re-torquing the head and more leak stopper, but the head gasket has just gone proper, and blown all the coolant out the expansion tank. Ran it a bit with the cap off and I can see loads of gas bubbling up.

That gasket lasted 15,000 miles, so I don't reckon it's the head or block that aren't flat. I reckon it's either the gasket was crap, or the studs are yielding a bit - hence the nuts end up turned a flat or two more than they were each time I re-torque.

So I'm going for a set of good SH original studs 'n bolds and a Payen head gasket, and see what happens. Even if I only get another 15,000 miles out of that, it'll probably be worth doing that rather than pulling the lump.

Graham

When a gasket looses its clamp and cylinder pressure gets under it to the coolant, it can cause a "track" which wont seal again. So far on my carmine sprint, after I built the engine Ive re torqued the head 3 times (when cold after a few days) and each time so far the nuts and bolts have moved just a little bit more. I think this is crucial to the life of the gasket to obtain the maximum crush that it can after initial warming/cycling.

I doubt whether theres anything wrong with your bolts or studs as others have eluded and better the devil you know comes to mind in light of the crap we get sold from some suppliers. Assuming (dangerous) that your rad, thermostat, and water pump are all in top condition I would be inclined to check the head for flatness while its off and re-use the bolts studs and go through the re torque procedure until no more extra movement occurs. I'm due to re do mine in the next couple of weeks and am hoping no more yielding takes place then I'll have an idea of how many times to do it after a rebuild.

Tony

Well it's only rationalization of what I've already decided, but here is my thinking on the issue:

As the head's got to come off, the studs and bolts that are in are going in the bin: I don't know that they're duff ones. But they took about two flats (24 thou extra streach) to come to torque, twice, 15,000 miles after they were torqued down and re-torqued as per the ROM when the head was skimmed. And I, and others, think that too much, and could well mean they're yielding as a result of the thermal cycling TrackerJack referred to. I've certainly heard about Sprint studs bought in Lincolnshire that yield overmuch before. And while I've no specific reason to believe such as them were put in at a previous engine rebuild, I don't know anything about the engines history at all.

So considering the replacements are to be SH original spec ones – not any old crap that originally came off Alibaba –, I can't see it's worth keeping the ones I suspect; nor why anyone should try to persuade me I ought (that's what eludes me).

The cooling system may not be tip-top, but the worst thing about it is it's been leaking water through the head gasket into the cylinders and steaming out the exhaust (which I could and did live with for a while – but now the gasket is dead). And that's a pre-existing problem not a consequence. So I don't think I'll bother looking at another head skim. I could be wrong; but I pays my money, and I makes my choice.

As to checking the flatness of the top of the block: If it's not flat, and I can detect that in the car, it would mean pulling the lump anyway - unless you're suggesting I "have at it" with a b'stard file or sumert [why'd it do that: "b'stard" is a genuine grade of file between middle and second cut]. And if I pull it, the spare's going in anyway.

So even if it's not perfectly flat, as I got 15k from it with a head skim and gasket, and it's not overheated since; I'm going to try one more time, and hope to do better with a Payen head gasket and SH original spec studs and bolts. If I get another 15k that way, I'll count it a win. If the gasket goes again straightway, then I'll pull the lump, drop the one I know about in, and still think it was worth a try. After all, I bought the car knowing I knew nought about the engine, and thinking to run it till it died. If that bell tolls, I don't need to ask why me.

If I do have to do an engine swap, I may have the old one looked at to see if it worth aught. That may show where the problem lies - block not flat or head warped, etc. Then again, I may just keep it for spares, and check each bit as they're used.

Graham

Graham I had all sorts of problems getting my head to seal down against the block after I rebuilt my engine. Most of the problems were my doing and had nothing to do with gaskets, bolts or studs. In my case it was the front timing cover sitting slightly proud of the block and when I identified and rectified that problem it turned out to be the very fine copper O-rings which had been let into my block to form an additional crush on the head gasket itself. I will not be doing that modification again and fitting those copper O-rings!

My engine reconditioning specialist, himself a Triumph Stag owner, recommended that I avoid putting any antifreeze in the cooling system until after I had gone through the retorquing sequence as the glycol is, apparently, very good at creating that sort of tracking to which you are referring.

Some of the problems are I suspect created by the engine designer who because there was on other better way of doing things used that asymmetric head stud arrangement. The downwards clamping force is somewhat less than what you apply to the head bolts for the studs are tending to pull the head sideways rather than pulling it down directly.

Geoff has been using Rimmers sourced head studs in his racing Dolomite and I would have to say that if they are good enough for him they will certainly be good enough for me. My bolts and studs are torqued down to about 10 pounds more than recommended. So what I am suggesting that unless you are sure that you have over torqued and therefore stretched the head studs then I think the problem is probably elsewhere.

You will sort it! I had my engine out of the car seven times before I sorted mine, and believe me it is sorted very satisfactorily now. And yes I do have antifreeze in the cooling system but it was only added after then engine had done about 5,000 miles.

Robert

Thanks for the tip on the glycol – I hadn't heard that before –, and it sounds well worth some consideration and research.

If it's of any interest, I've done something around half a million miles in Sprint engined cars over the last 25 years: a TR7 Sprint, 4 TR7 Sprint conversions, and 2 Doly Sprints (there was also a TR7V8 that wasn't really my main car and a beige 1.6L Ford Crapi with an interesting number plate – A TR7 16V – but which was so horrible that when it got stolen, they brought it back). I've done or had done the Sprint head gaskets at least 10 times – including scratch builds, recons and overhauls, and replacing pistons (I'm unlucky with / hard on pistons). I've always done the re-torquing, and I've only ever followed the ROM in that process. While I've never followed a rigorous programme of re-torquing every so many miles, etc., I've sometimes re-torqued when the rocker cover has been off, e.g. for a chain or follower, etc. And this is the first Sprint engine that's ever blown a head gasket on me, let alone two.

As to this last gasket going, I'm absolutely convinced it's not an assembly error: I do not believe that, were it misassembled, it would have lasted 15k. I'm absolutely certain I did not over torque the studs. I can't be absolutely sure that the garage didn't over or under torque in the first place. But I did the re-torquing specified in the ROM, and I don't remember thinking they took an unusual amount of torquing down.

Hence, it must, in my mind, be a component failure: I've enough experience of the Triumph slant four Sprint engine to have faith in Lewis Dawtrey, Harry Webster, and Spen King's designs, and don't think that's a likely the cause of the problem. You can diss them if you like, but I won't. I don't like where Dawtrey and Webster put the water pump, but I don't know what their problems were in designing for a range of four and eight cylinder engines that could both be built on the same production line, etc.

Considering how thick, and as TrackerJack points out, un-springy the studs are, 24 thou (0.61mm) of permanent strain seems a heck of a lot to me, and well enough to allow tracking past the gasket. So to see anything like that much permanent extension twice is surely more than worrisome. And these studs and bolts are going in the bin; they just are. I think I'd need my own head examining if I thought any different.

Where I started this thread was the question of where to get replacements from a supplier in the UK that I would trust. I wouldn't have minded over spec ones, as long as I could trust their source; though I still agree with TrackerJack that standard ones are well good enough. In lieu of any such source, I've bought the SH original spec replacements. If it goes again, I'll have some belief that they are not the cause. But I was and am not asking whether to risk re-using the ones that are in – that's a done deal.

Graham

Graham

Just a thought based on my own experience would be to have the head tested for hardness if you do in fact end up taking it off. Just that simple drop ball test.

After years of no issues, I started to have similar problems to you but on my race car. Changing the gasket (which I too have done a few of) just wouldn't cure it. While the hardness test registered close to 100 around the edges, near the two centre bores, this plummeted to in the 30s. Minimum recommended is around 65. I reluctantly bit the bullet and built up another head, ported and polished to the same specs, and that has had no issues over the last three years of racing.

Hopefully what you are planning will sort the problem, but if you know whether the head is soft or okay, that may help point you in the right direction should you need to investigate further later on.

I've also moved to an electric water pump and that seems to keep the engine temperature fluctations much more under control.

Geoff

One of the problems with threads on "our" slanty engines is that faults are often down to more than one failure.
Head gaskets are one such item. I had a head gasket fail and when I removed it I found that the steel fire ring was only on one side and the metal folded round to the other, unlike a Payen type which has a steel fire ring that is folded round and has another steel fire ring which it also folds over ie a lot more robust.
So for a reliable life all items need to be of good quality and try to lessen the weak links that various bean counters have tried to fool you with.
I have quite a few old head studs that I have collected over the years but have been lucky with overheating as I wired in a warning light and this has meant that I never have had an angry slant boiling over, though I have had very hot engines.