New head gasket leak?

EntonoX · Postby **EntonoX** » 25 Apr 2008 07:41

Hello all,

Just took some days off to get my TR7 starting for the first time in i think 10 years. Engine is fully restored with all bits you can think of all new! got the block bored, new pistons, head skimmed, new valves, new valve seats, new bearings, etc...

I was about to fill up the cooleant in the system yesterday when i noticed that it leaks liquid through the head gasket! just a few drops on both sides of the head... [:(]

The engine did not run, so we decided to get the head off once more. After looking carefully at the head gasket we could see that the head gasket had no flattening spots so it must be that the head wasn`t torqued enough to fit thight.

We assembled the head and torqued the head with the factory 75nm, in order from the inside out. When finished we turned every bolt slightly loose to releive the statis tension and the retorqued it. We were confidend that this would solve the leaking but when filling up again, the damn think leaked again! not as much as first but we could see a few spots.

Must these head gasket be torqued again when engine has run? or is anything else wrong? head was skimmed and is flat.

TR7, ACG 2700L

Beans · Postby **Beans** » 25 Apr 2008 14:04

I needed to torque down my Sprint to 95 Nm before it stopped leaking (started with 75 Nm, ran the engine till on temperature and retorqued after it cooled down, still leaking slightly. Repeated cycle with 80Nm the same. Went up 5 Nm each time till it stopped at 95 Nm). That was 13 years ago, no problem since.

On the other hand my 8V is (re)torqued to 75 Nm and never any problems

<center>

1981 TR7 FHC Sprint (better known as 't Kreng)
1981 TR7 DHC (not very well known yet, but back on the road)
Also a 1980 TR7 DHC, 1980 TR7 DHC FI, 1981 TR7 FHC
http://tr7beans.blogspot.com/</center>

EntonoX · Postby **EntonoX** » 25 Apr 2008 15:49

Well, just got back from Nicobaas here in holland to get some head gaskets and new head bolts. I 'll try to get the new gasket on this evening or maybe tomorrow. I have got a standard gasket and a thickend one. My head is skimmed but my valves lay flush or deeper than the head surface so i presume to take te standard gasket.

Maybe the head gasket was faulty, 'll see, to be continued.... [:o)]

TR7, ACG 2700L

srrutter · Postby **srrutter** » 26 Apr 2008 00:38

I remember a similar problem when the head was put back on KBA's engine with coolant leaking out onto the side of the block.

Ally was speaking to someone (can't remember who) who said they'd had engines back fresh from the engine shop before that leaked when torqued to factory settings.

The advice she was given at the time was to torque the head down a bit at a time till the leak stopped, think we ended up at 85 or 90 Nm and with the (admittedly little) running since then the problem hasn't resurfaced. In other words to do what Beans needed to do on his Sprint

So if the new gaskets don't sort the problem, just try torquing it up a bit more and it should solve it!

Simon

Keeping KBA on the road!

My Wedgeblog: [url="http://kba.psy-online.co.uk/blog/"]http://kba.psy-online.co.uk/blog/[/url]

Rest in Peace [url="http://www.forum.triumphtr7.com/topic.asp?TOPIC_ID=5890"]Ally[/url], you shall never be forgotten.

EntonoX · Postby **EntonoX** » 26 Apr 2008 18:02

Thanks for the reply Simon and Beans!

We did pull the head again once more and we cleaned the head and stud holes. With a new head gasket and standard torqing it almost stopped leakin, except for some minor side leaks. I 'll follow your advise for retorqing the head evenly with steps of 5 Nm till it stops leaking.

Only concern right now is that the inlet is leaking cooleant! we put a new O-gasket in but it still leaks. fix one problem, get one back [:(!]

TR7, ACG 2700L

Beans · Postby **Beans** » 26 Apr 2008 19:36

As an after thought ...

Don't over do the retorqueing. I think 100 Nm is pretty much the maximum you should go. After that you're risking damage to the head. Also use a good quality torque wrench.

<center>

1981 TR7 FHC Sprint (better known as 't Kreng)
1981 TR7 DHC (not very well known yet, but back on the road)
Also a 1980 TR7 DHC, 1980 TR7 DHC FI, 1981 TR7 FHC
http://tr7beans.blogspot.com/</center>

EntonoX · Postby **EntonoX** » 26 Apr 2008 20:22

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Beans

As an after thought ...

Don't over do the retorqueing. I think 100 Nm is pretty much the maximum you should go. After that you're risking damage to the head. Also use a good quality torque wrench.
<hr height="1" noshade id="quote"></blockquote id="quote">

Thats true Beans, but we have some nice equipment here. As i happen to have a car/truck workshop at work [;)]. still need something to fix the leaking inlet / cooleant o-ring.

TR7, ACG 2700L

FI Spyder · Postby **FI Spyder** » 26 Apr 2008 20:32

Another thought is: how clean are your bolt and hole threads and are you using anti sieze lube or the like. Contrary to popular belief the correct way to torque heads is not to measure the torque (as this is dependent on a number of factors) but to measure the stretch of the bolts/studs. There are instruments that measure this that professionals now use. Torque is a secondary way to measure stretch but will vary for a given amount of stretch depending on these other factors. I'm not saying go out and buy these expensive tools but be aware torque required to do the job can vary from engine to engine.

TR7 Spider - 1978 Spifire - 1976 Spitfire - 1988 Tercel 4X4 - Kali on Integra - 1991 Integra

John Clancy · Postby **John Clancy** » 27 Apr 2008 09:24

Last year my car's head gasket was done. Had to do it twice though in the end (not for gasket leaking problems I hasted to add but tappety tappety noises which turned out to be the buckets - a long story!). The first head gasket was only in place for a couple of weeks at the most and saw less than 100 miles. However, when I removed the head to be returned to the engine specialist that carried out the skimming and rebuild that first head gasket just fell apart. This may be normal but I felt that after being on there for such a short time it shouldn't have been in quite such a mess. So, I got the next head gasket from Robsport - told them about the problem and they recommended a more expensive gasket. Bear with me...

Now this has turned out to be very interesting as the gasket has a rubbery appearance and I'm sure many of you reading this will know a lot more than I, but in my current research for the CODE NAME: STAG DVD I have learned that Triumph did solve the head gasket problems on the Stag during development. It was solved by using a more expensive rubbery type of head gasket (two of them, obviously!). Sadly, this modification wasn't sanctioned before production commenced as the accountants said it was too expensive.

My TR now has this rubberized head gasket in place so we'll see how well it works in the long term. It could be just the solution you're looking for EntonoX to solve the leaking issues you're having.

With regards to the O-Ring just plaster it with mastic sealer before reassembly. That always holds it in place.

<center>[url="http://www.triumphtr7.com/documents/sales/codenamebullet.asp"]Buy the story of the Triumph TR7/8 on DVD here[/url]</center>

EntonoX · Postby **EntonoX** » 27 Apr 2008 10:15

Interesting story John!

After fighting with the 7 for two days, i'll begin with it again tomorrow. I'll try your suggestion with the sealer, i'll keep you updated.

TR7, ACG 2700L

Orophin · Postby **Orophin** » 28 Apr 2008 20:46

My head gasket has just been done. I should be getting the car back in a day or so. I have heard that I should go easy for a few hundred miles to ease it in and then get the head tightened once again.

Beans · Postby **Beans** » 28 Apr 2008 21:03

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by John Clancy

...My TR now has this rubberized head gasket in place <hr height="1" noshade id="quote"></blockquote id="quote">
Is it a Payen head gasket ?
They seem to be pretty good.

<center>

1981 TR7 FHC Sprint (better known as 't Kreng)
1981 TR7 DHC (not very well known yet, but back on the road)
Also a 1980 TR7 DHC, 1980 TR7 DHC FI, 1981 TR7 FHC
http://tr7beans.blogspot.com/</center>

John Clancy · Postby **John Clancy** » 29 Apr 2008 07:56

I think you're right Beans. Payen rings a bell!

<center>[url="http://www.triumphtr7.com/documents/sales/codenamebullet.asp"]Buy the story of the Triumph TR7/8 on DVD here[/url]</center>

dctr7 · Postby **dctr7** » 29 Jun 2009 18:18

John, it's been a few months since your last post, how has the head gasket worked out?
Have you had to retorque, any leaks?
Is the rubberized head gasket the solution?
Does anyone sell them state side?

1980 TR7 Spider DHC 2.0 Ac Delco Electronic Ignition.

John Clancy · Postby **John Clancy** » 30 Jun 2009 07:08

No problems so far. Just did 400 miles in the hottest weather for years and the Kenlowe fan hardly had to work at all even when in traffic queues.

<center>[url="http://www.triumphtr7.com/documents/sales/codenamebullet.asp"]Buy the story of the Triumph TR7/8 on DVD here[/url]</center>

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New head gasket leak?

New head gasket leak?

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