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Manifold gasket sealing


Adrian
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Hello Chaps

 

Probably another T-shirt question.  When I stripped the manifold off there didn't appear to be any gasket seal, (between head and exhaust and inlet manifold and also inlet manifold to carbs) on this basis I intend to rebuild with no seal on the new gaskets. Also the manifold to exhaust also appeared to be lacking any gasket seal.

Am I correct or in your experiences would you add a sealant?

 

Thanks

 

Adrian

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Adrian.

I have never used any sealant on gasket faces concerning the cylinder head to inlet and / or exhaust manifold. It is sound practice to check the flatness of the mating faces, you might be surprised to note the odd high spot and this is what gives some owners 100% sealing issues - hence the necessity for loads of sealant to overcome the issue. If the mating surfaces are "true" then there is no requirement for sealant.

Conversely, I do use a smear of instant sealant for thermostat housing to cylinder head fixings.

From the exhaust manifold joining the exhaust system onwards, I do use exhaust paste to ensure a 100% seal.

Via sound advice I now use Mikalor clamps for securing the sections of exhaust pipe; they are much better than the typical exhaust system clamps - go for the stainless steel ones as and when you get to that stage:  https://www.ebay.co.uk/itm/MIKALOR-W2-Stainless-Steel-Hose-Clamps-Supra-Exhaust-T-Bolt-Marine-Clip/221623600550?hash=item3399cbc5a6:m:m6zPoz8WPOWFwvqri9bSMnw

Just my observations.

Regards.

Richard.

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Manifold gaskets should be assembled dry theres a lot of shuffle and panting goes on between the head and manifold faces

The gasket is made to accomodate this movement

The copper triangle should also seal, dry, if the faces are flat,   most sealing pastes with get cooked and fall out making even better leaks

Sorry I cant agree  . 

Most sealing pastes and products are for sleeved tube joints and it works well in these 

Agree mikalor are well worth the few extra pennies,

Happy christmas   

Pete

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Wow, polar opinions but as always very constructively given and explained. As I had the inlet manifold faces skimmed I’d say probably a good candidate for dry fit. But I’ll check other faces are true as well.

i have got hematite, blue hylomar and welseal, so plenty to choose from if need be!

the rest of the exhaust system is still insitu so it’s just the manifold joints. 

As always, thanks

Adrian 

PS can we start a mini focussed portion of the site as I’m sure many of you have comprehensive experience, not just of bleeding knuckles!

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1 hour ago, classiclife said:

I have never used any sealant on gasket faces concerning the cylinder head to inlet and / or exhaust manifold.

+1 to that. I know of owners who use exhaust paste in these areas but I don't think you need any sealer here, the faces should be flat and the gasket of sufficient quality to seal with just the stud / nut pressure.

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When I said focussed I meant as a topic, not the usual expected thread drift. Looking at the various headings it seems the none triumph projects seems to be the best place. I’ll literally start with an initial assessment and see where we go.

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It's all well and good talking about optimal situations and freshly skimmed surfaces but with due respect I'll stick to using the appropriate modern product in small doses. If you slap it on then you'll have issues with creep and drying out and that's probably why it gets a bad reputation.  

What I judge it by is the fact that 50 year old British cars leaked just about everywhere in factory spec, 50 years on we can do a heck of a lot better. 

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It's not about optimal situations, it's about common sense and checking components prior to fitting which may need slight addressing. If mating surfaces are not flush then no amount of gunge liberal or conservative will overcome an issue on a long term basis.

I will be very impressed if modern cars are still running about in fifty years time; so in hindsight perhaps we may not actually be doing a lot better !!

I  agree most issues with classic cars are the oil leaks due to thin paper gaskets and that is where substances such as Instant Gasket can assist. As mentioned earlier the CORRECT cylinder head to manifold gasket is designed to deal with the specific issues pertaining to such requirements. 

 

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2 hours ago, classiclife said:

I will be very impressed if modern cars are still running about in fifty years time; so in hindsight perhaps we may not actually be doing a lot better !!

I'm confident the v8 jaguar engine in my contemporary car will last at least as well. Better materials, better design, better consumables from day one.

It's too easy to get a rosy glow about these old cars but the truth is they were budget cars based on dated engineering even when new.  It's only weekly maintenance, multiple rebores, rebuilds and skims that's kept them going.

I'm not committing heresy here, just pointing out that they're not inherently special or better just because they're old, and new doesn't always mean worse. 

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6 hours ago, classiclife said:

 

I  agree most issues with classic cars are the oil leaks due to thin paper gaskets and that is where substances such as Instant Gasket can assist. As mentioned earlier the CORRECT cylinder head to manifold gasket is designed to deal with the specific issues pertaining to such requirements. 

 

If you ever find proper OE gaskets, buy them. I managed to find a pack of 7 (box said 10!) OE sump gaskets. They must have been 5x thicker than the ones we get sold now. Likewise thermostat gaskets. I would expect all the others would also have been much better than the current offerings. And goes some way to explain why we now get leaks.

As to modern cars, the biggest improvements have been in build quality and oils. These days it is rare to have an oil change at less than 10K, it used to be 3K and the oil was knackered. Whatever people say, modern oils are streets ahead in terms of protection and longevity, but the "olde fashioned" oils are still liked as they are adequate for the driving many of the cars get, and if they are changed on an annual basis will be OK. However, I maintain that on cars that get driven harder, it is worth getting a classic-orientated performance oil. The semi synthetic in my Toledo has now done 8K, over 2k of that in 48 hours. Still looks just about as it did when put in the car, not something I could say about the £20 oils I have tried in the past, they change colour very quick!

Of course, we are all struggling with poor quality components. Some rubber bushes I replaced n the Toledo 8K/14 months ago are severely cracked and need to be replaced, this time with polybush, purely because it should last rather longer. Likewise the "recon" steering rack that has lasted about 20K and is the source of steering displeasure and needs replacing (a worrying thought given this ones issues) or me to replace the tube bush and inner balljoint cups. Advice about to be sought on this.....

 

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goes some way to explain why we now get leaks."

I beg to differ, Clive!  Some time ago, I posted about how to dress the sump flange, to eliminate the belling that DPOs always seem to produce, by overtightening sump bolts.   I'd post a link, but in the new message board format I can't find how to search for it, will some kind person tell me?

IMHExp., doing this eliminates sump flange leaks.

John

 

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A lot of divergent opinion! Particularly taken with Pete's idea that the manifold gasket "shuffles and pants", or is he on the wrong web site again! I've always used sealant on the manifold, there's plenty out there tell you that's what you should do. Does it do any good, does it do any harm? Probably not a lot in either direction. I've never used sealant on the head gasket or the copper triangle, there's a reason it's copper. As for OE gaskets, there's plenty of good modern gaskets, you get what you pay for. The idea that any gasket is going to stop your Triumph leaking is putting hope before experience, they're Triumphs, they leak.

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most would be amazed at just how much like mainfolds and heads  actually pant and shuffle around with all the heat changes and  detonations 

needs super slo mo camera but they used to film this in my days ,

same as wheels bend something awful on hard cornering .....  never mind how a body or chassis have contortions 

shockabsobers ...amazing what they stop 

sorry more ramblings 

Pete

 

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34 minutes ago, JohnD said:

goes some way to explain why we now get leaks."

I beg to differ, Clive!  Some time ago, I posted about how to dress the sump flange, to eliminate the belling that DPOs always seem to produce, by overtightening sump bolts.   I'd post a link, but in the new message board format I can't find how to search for it, will some kind person tell me?

IMHExp., doing this eliminates sump flange leaks.

John

 

I don't think we disagree in the slightest. I was pointing out that the OE gaskets were FAR superior to what we are sold today. I am guessing you will have used OE stuff when it was available, and understand the difference.

Most seem to be made from thin gasket material, wheras the originals were lovely to tighten up. Yes, I have always fixed distorted faces on sumps etc (took 4 hours to sort a zetec sump, most who try it complain about leaks, in that one it just needed heating to cherry red, adjust, check and repeat. All to clear an oil pump gizmo! But saved £250+ on an aftermarket version.Mine has been leak free....

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I too think we all pretty much agree really. If the surface is bad then fix it. If you can obtain good gaskets you won't need sealant. And in low stress situations then either approach won't make a whole heap of difference. 

In my world the surfaces are ok-ish (flat but micro pitting), they're certainly not bad enough to spend a lot of money sending them away to be machined. My gaskets aren't superduper deluxe items either. So a little smudge of 21st century materials science certainly won't do any harm and might even help.  

Whatever your view we're battling against some fairly primative engineering, steam engine grade cast iron at best, and it needs all the help it can get. Beating that and keeping these cars usable is the challenge I enjoy. When triumph built engines they didn't even have the confidence to spend the extra pound on a 6 digit odometer, so I'll take factory recommendations and doing what they did in the good ol' days with a healthy dose of synicism. 

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Quote, "I am guessing you will have used OE stuff when it was available, and understand the difference."

Nope.  Never bothered.  Just prepare and fit the modern ones properly.

Any modern rubber reproductions are definiteley inferior.    For instance, the Overdrive support bracket.    I just drill them and fit two bolts, because the rubber will detach from the metal (see pic)

Ditto, temperature sensors, that can go haywire in weeks.  I have a small store (like three) used ones that I know are good.  With luck, that'll last my life!

John

Odrive support bracket mos V2 (1).JPG

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