The Triumph Dolomite Club - Discussion Forum

The Number One Club for owners of Triumph's range of small saloons from the 1960s and 1970s.
It is currently Fri Mar 29, 2024 6:55 am

All times are UTC




Post new topic  Reply to topic  [ 26 posts ]  Go to page 1 2 Next
Author Message
PostPosted: Tue Jul 05, 2022 5:51 am 
Offline
Future Club member hopefully!
Future Club member hopefully!

Joined: Sun Sep 20, 2009 4:27 pm
Posts: 362
Location: Perth, Australia
My Sprint broke down just as we arrived at a Classic Car meet on Sunday.

It's the first time it has ever let me down anywhere, ever. Sad face.

I'm curious what people think it might be.

Circumstance - 20km Freeway run followed by queue to get in followed by dodging queue to a different entrance, waiting at lights for a minute and then turning in at which point significant loss of power, reluctance to keep running without some accelerator depression and a fairly awful noise from the engine

Pulled over. Bonnet open. No leaks. Brief hot smell but not major, barely caught on the breeze. Still runs. Can stop and restart. Engine runs ok but at the same time a noise which is either clattery from the top or reminiscent of noise of exhaust leak. So not knocking, not a deep noise, always had some noise from tappets/shims top end and that still there but this additional "something isn't right" noise. Seems more from top than bottom.

Nothing visible. No leaks still.

Car doesn't get used much. It was a bit of a blast of the Freeway but only by West Australian Stds. Perhaps doing 110kmh. And it has OD. Head has not been re-torqued in ages.

Have not got under it and inspected anything yet although like I say it seems nothing visibly obvious.

Since it seems to run mechanically I am ruling out dire mechanical drivetrain problems. Likewise no sprayed leaks of oil or water.

I'm thinking it blew the head gasket but as I've never experienced that to date (30+yrs ownership) I don't know what the practical symptoms are. I'm thinking the lack of power is consistent with loss of compression due to head gasket failing. And that additionally this might happen with engine still being able to run and without any external indication

Would welcome any thoughts before I crawl over it

Thanks


Top
   
PostPosted: Tue Jul 05, 2022 5:44 pm 
Offline
TDC Member

Joined: Sun Mar 16, 2008 2:52 pm
Posts: 2303
Oh dear. Sorry to read about that.
How about the basics first ?
Is the oil level in the sump O.K. and is it the right colour ?
Are the water levels in the thermostat filler and the header tank O.K.

Then I'd go on to having a look under the rocker cover.
Then perhaps a compression test.

Then try one of these compounds that tell you whether you have exhaust gasses in the coolant.

My experience of slant 4 head gaskets failure is that they fail gradually and they run hot with no output from the heater . As they cool down they suck the water back, you can then fill up again when cool and continue for a short while.

Good luck with it,
Tony.


Top
   
PostPosted: Wed Jul 06, 2022 2:15 am 
Offline
Future Club member hopefully!
Future Club member hopefully!

Joined: Mon Dec 03, 2012 6:04 pm
Posts: 1549
My money is on the ignition system, with a sudden failure like that. When my timing was out, my engine sound like a bag of spanners and a misfire could have a similar effect.

If it was the head gasket I would expect some evidence, like loss of coolant, especially if it was severe enough to reduce compression.


Top
   
PostPosted: Wed Jul 06, 2022 3:27 pm 
Offline
Future Club member hopefully!
Future Club member hopefully!

Joined: Sun Sep 20, 2009 4:27 pm
Posts: 362
Location: Perth, Australia
More significant investigation will still have to wait until the weekend but I just checked a few things on the car :

1. no sign of any leaks anywhere although haven't been under the car with a torch
2. oil full to top level on dipstick and fairly beautifully clean oil also
3. nothing odd inside oil filler. timing chain on sprockets although whether it could have jumped one I have no idea
4. coolant in expansion tank is antifreeze green, normal level, no sign of contamination
5. coolant under thermostat housing filler is also green no sign of contamination and sitting at a level consistent with the top of the inlet and outlet pipes
6. spark plugs not removed and checked but HT leads were properly connected and no sign of any oil down the tubes

Ignition system is electronic. At the weekend I will check it's connections are good, confirm sparks and then take the cam cover off to see if anything shows up. In that process I will also check the plugs

Still all a bit mysterious

mark


Top
   
PostPosted: Thu Jul 07, 2022 3:02 pm 
Offline
Future Club member hopefully!
Future Club member hopefully!

Joined: Sun Sep 20, 2009 4:27 pm
Posts: 362
Location: Perth, Australia
I checked the plugs earlier this evening.

They all looked like the attached when removed.

So basically
- every plug had slightly oily threads, the rear two slightly worse. I daresay small leaks through plug tubes
- they were all very tight
- all were quite black and carbon sooty
- when cleaned with cloth and then white spirit toothbrush and cloth again the central insulators are a light brown
- I did not check the gaps but none of them looked wrecked. I will do so at some point

So the car is running rich I would say. It doesn't surprise me. It barely gets used. But at the same time it was last tuned in the UK 19 years ago.

Not ideal but it ran smoothly and I think not our problem here


Attachments:
ScreenShot690.jpg
ScreenShot690.jpg [ 64.99 KiB | Viewed 411 times ]
Top
   
PostPosted: Sun Jul 10, 2022 5:16 am 
Offline
Future Club member hopefully!
Future Club member hopefully!

Joined: Sun Sep 20, 2009 4:27 pm
Posts: 362
Location: Perth, Australia
I don’t think its good news

See the pics

I took the cam cover off and all seemed well. No signs of major carnage, but then I noticed that one of the pallets on cylinder 2 was still down despite the camshaft lobe not being in contact.

Any thoughts welcome but I imagine this is going to get quite ugly


Attachments:
cyl2 B.jpg
cyl2 B.jpg [ 132.27 KiB | Viewed 370 times ]
cyl 2 A.jpg
cyl 2 A.jpg [ 140.77 KiB | Viewed 370 times ]
Top
   
PostPosted: Sun Jul 10, 2022 7:53 am 
Offline
TDC West Mids Area Organiser
User avatar

Joined: Thu Sep 28, 2006 1:13 pm
Posts: 13317
Location: Over here...can't you see me?
You have a sticky bucket, or a broken valve spring under there! You'll need to lift the cam out to find out which and then most likely head off to rectify...

Is that a wear pattern on top of the buckets?

You also have a hot cam 8)


Top
   
PostPosted: Sun Jul 10, 2022 10:45 am 
Offline
Future Club member hopefully!
Future Club member hopefully!

Joined: Sun Sep 20, 2009 4:27 pm
Posts: 362
Location: Perth, Australia
I'm thinking once you've loosened half of the head studs to get the cam off then you've potentially compromised the head gasket anyway?

Given the valve is stuck in the down position - although really hard to be stuck in the up position I guess - I am assuming the bad noises were the valve hitting the top of the piston. Given both those thoughts I am more than likely just going to remove the head and attend to all and everything that may arise when I do so.

There is a shiny wear area on the cam lobe. All of the buckets have a sort of visible ring shape on them but its not a groove or worn area as far as I can see at this stage.

From memory it is a fast road cam. I'm impressed you can tell by looking at it. What gives it away.

The head had a skim years ago. I can't remember how much. So I am thinking a thicker head gasket.

Do we have views on the current Rimmers head gaskets - thicker or otherwise? Any other sources receommended?

Thanks

mark


Top
   
PostPosted: Sun Jul 10, 2022 11:32 am 
Offline
TDC Member

Joined: Sat Jan 05, 2008 3:52 pm
Posts: 281
Location: North Yorkshire
Quote:


From memory it is a fast road cam. I'm impressed you can tell by looking at it. What gives it away.
I didn't spot it until it was pointed out but I reckon the giveaway is the very small difference between the base circle and main shaft diameter. Most high lift cams are made from standard ones, the way you win the extra lift is to reduce the height of the lobe opposite to the peak.

_________________
1977 1850 HL manual O/D


Top
   
PostPosted: Sun Jul 10, 2022 12:50 pm 
Offline
TDC Member
User avatar

Joined: Tue Oct 03, 2006 5:48 pm
Posts: 8446
Location: Winscombe, North Somerset, England
Quote:
I'm thinking once you've loosened half of the head studs to get the cam off then you've potentially compromised the head gasket anyway?
Yes, you are correct.
Quote:
Most high lift cams are made from standard ones
I'm not sure that is strictly true. I did have one once but never again. It's a false economy as first you need to source really thick shims and the cam and the rocker fingers wear out quite quickly.

_________________
Sprintless for the first time in 35+ years. :boggle2: ... Still Sprintless.

Engines, Gearboxes, Overdrives etc. rebuilt. PM me.


1997 TVR Chimaera 450


Image


Top
   
PostPosted: Sun Jul 10, 2022 5:47 pm 
Offline
TDC West Mids Area Organiser
User avatar

Joined: Thu Sep 28, 2006 1:13 pm
Posts: 13317
Location: Over here...can't you see me?
Quote:

... but I reckon the giveaway is the very small difference between the base circle and main shaft diameter.
Got it in one!


Top
   
PostPosted: Sun Jul 10, 2022 8:34 pm 
Offline
TDC Shropshire Area Organiser

Joined: Sun Aug 21, 2011 5:12 pm
Posts: 7014
Location: Highley, Shropshire
Quote:
Quote:
I'm thinking once you've loosened half of the head studs to get the cam off then you've potentially compromised the head gasket anyway?
Yes, you are correct.
Quote:
Most high lift cams are made from standard ones
I'm not sure that is strictly true. I did have one once but never again. It's a false economy as first you need to source really thick shims and the cam and the rocker fingers wear out quite quickly.
Mostly, you get what you pay for! it's possible to get a fresh ground cam on a new billet - but these are commensurately expensive, a reprofile like this one is a lot cheaper, but nothing like as good.

I'd have rejected that particular one out of hand, the base circle is far TOO close to the lobe for comfort. And they must have ground masses off to get one that far down which means the lift is so big it's probably caused spring bind and a busted spring as a result.

Steve

_________________
'73 2 door Toledo with Vauxhall Carlton 2.0 8v engine (The Carledo)
'78 Sprint Auto with Vauxhall Omega 2.2 16v engine (The Dolomega)
'72 Triumph 1500FWD in Slate Grey, Now with RWD and Carledo powertrain!

Maverick Triumph, Servicing, Repairs, Electrical, Recomissioning, MOT prep, Trackerjack brake fitting service.
Apprentice served Triumph Specialist for 50 years. PM for more info or quotes.


Top
   
PostPosted: Mon Jul 11, 2022 9:00 am 
Offline
Future Club member hopefully!
Future Club member hopefully!

Joined: Tue Sep 25, 2012 2:08 am
Posts: 386
Location: Christchurch, New Zealand
Valve springs do break and when they do I can confirm that when it happened on my Sprint the noise was similar to what you have described here.

In my case I consider myself lucky for it cost me a new exhaust valve, guide and collet. I think if you read the thread on the restoration of my car https://forum.triumphdolomite.co.uk/vie ... &start=135 starting about page 10 you can see and both read about the outcome. I did, of course fit a new head gasket.

I cannot offer any comment about cams and profiles but the engine reconditioner where I went for advice commented that it was in his opinion quite rare to break a valve spring in a stock standard engine. I fitted a replacement spring along with the parts mentioned above and the car has run very satisfactorily since.

Robert


Top
   
PostPosted: Mon Jul 11, 2022 1:58 pm 
Offline
Future Club member hopefully!
Future Club member hopefully!

Joined: Sun Sep 20, 2009 4:27 pm
Posts: 362
Location: Perth, Australia
Y'all made me look back at the really old Moss catalogue I have to remember what the cam is

It's only a fast road cam TT10204. It has been on the car about 20 years so I don't think the risk is high although to be fair the car does very low miles/kms.

I'm pretty sure it had uprated valve springs. I don't remember them being double springs and it doesn't look like double springs on the car. Although, ahem, its equally possible I'm remembering uprated suspension springs anyway......... I will need to examine my paperwork though because if I need to replace one I assume it needs to be the same; could be awkward.

It wasn't an exchange cam because I still have the original somewhere. I had always believed the fast road one was new.

Hopefully it will be just a new valve, guide and collett... and spring I assume.

I'd welcome any views on sources for parts including head gaskets and particularly viz Rimmers who are of course the easiest to order from

Thanks


Top
   
PostPosted: Mon Jul 11, 2022 2:15 pm 
Offline
Future Club member hopefully!
Future Club member hopefully!

Joined: Sun Sep 20, 2009 4:27 pm
Posts: 362
Location: Perth, Australia
OK let me rescind part of that. I read from the wrong part of the Moss catalogue.

Plus.... I just checked the box the cam was delivered in because for 20 years the original has been living in it.

It was a TT10105N fast road cam. N denoting that it was new.

I also found a bit of paper for their TT1507 valve springs. These are uprated single valve springs.


Top
   
Display posts from previous:  Sort by  
Post new topic  Reply to topic  [ 26 posts ]  Go to page 1 2 Next

All times are UTC


Who is online

Users browsing this forum: AhrefsBot [Bot] and 29 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Limited