This is a read-only archive of the old Madabout Kitcars forum. New posts and replies are no longer possible, but every thread is still here to browse and read.
...I have just come in from fitting the new coil, and while its not cured it, (and this may sound stupid) but it seems to be running smoother on whatever cylinders are still working. So it is a slight improvement...
FWIW Scottie, the last time I encountered these symptoms was when a Jago came stuttering into the Donington Show. The owner had stripped down the carb and found no problem- the car was just about drivable.
I took off the distributor cap and found that the points had closed up.
The Ford pre-crossflows (certainly my 105E Anglia) used a 0.015" gap whereas the cross-flows need 0.025".
Well, I have just done a compression test on all four cylinders, the engine was cold, and according to the online pundits, I should have been looking at around 80 to 90 psi per pot cold, on a basic Triumph 1500 engine.
On a normal 1500 hot engine,the reading should be between 120 and 150psi.
Having said that, going by my engine number, I have a Dolomite HE engine,
which I believe is a higher compression engine. So not sure what I should be seeing.
These tests were done with the engine cold, all the plugs out, and the throttle wide open to allow air flow.
Here's what I had:
No1= 20psi
No2= 20psi
No3= 150psi
No4= 165psi
I then did a "wet" test, with a bit of oil in the pots to seal the rings,
and I got:
No1=25psi
No2=25psi
No3= 195psi
No4= 230psi
On numbers 3 and 4, the pressure was so great, I had trouble keeping the gauge in place!
I am no expert, but am thinking, perhaps the valves, are to blame for numbers one and two, but cannot explain the huge rise in pressure on three and four?
I am pretty sure that these readings will make sense to Swifty, and perhaps some other clued-up fellahs?
Looks like a head off job? All good suggestions most welcome.
Go for it Swifty!!
As you say, head off. My money would be on the head gasket.Low pressures are leaks between cylinders. High pressures are often a sign of excessive carbon build up, oil leak or water leak into the cylinder.
It all points even more to head gasket, who would have believed a Triumph with a head gasket issue?
As you say, head off. My money would be on the head gasket.Low pressures are leaks between cylinders. High pressures are often a sign of excessive carbon build up, oil leak or water leak into the cylinder.
It all points even more to head gasket, who would have believed a Triumph with a head gasket issue?
Scottie was the engine burning oil prior to problem and can you start the engine and check for excessive pressure in the rocker box cover by removing the oil filler cap and placing your hand over the hole with the engine running there will be a slight pressure but if its excessive then the rings in No 1 & 2 cylinders have an issue (badly worn or cracked, both mean engine out and repair).
The compression test in a healthy engine will have all cylinders within 5-10% of each other and while I'm not familiar with the dolly engine it looks as if there was two, one low compression and the other high compression which i assume yours is so the indicated cylinder pressure when hot is 175 psi or 12 bar give or take 5-10%.
If this draws a blank i think you will have to remove the head as two cylinders down on pressure is not good especially side by side but before you do remove the head i would remove the rocker cover and turn the engine over by hand so that No1 cylinder is at top dead center after the compression stroke both inlet and exhaust valves should be fully closed (remove all the spark plugs first to make it easier to turn the engine over by hand), check both inlet and exhaust valve rockers have the correct gap between the rocker and valve stem top, i say this as the check nut may be loose and the tappet adjuster may of screwed itself down so keeping the valve/valves open (both inlet and exhaust rocker's should be able to be rocked slightly when at TDC on compression stroke) OR if the gap is massive then the valve has seized open but i am not to sure that if this were the case then the piston and valve head may make contact as it generally does on modern engines but in some older engines this was never a problem. The repaeat on cylinder NO 2.
If it is just a simple rocker re adjust then this will save you removing the head.
If you do have to remove the head then it's pretty straight forward and as suggested by others if the head gasket has blown then a re-skim with the appropriate thickness head gasket supplied is a good thing to do and have the head converted to run on unleaded is a wise move, it cost me £250 for this to be done on my 6 cylinder engine, they cut out the exhaust valve seats and fit hardened seats in place.
Thank you Ox, Ian and Landmannn for your input, like I said, it is most welcome.
And Swifty, a special thanks to for the very detailed write-up you posted.
In answer to your question "was it burning oil"?
I will go in depth on that one:
During the slow drive back home, I had to climb a mile-long hill about ten miles from my house, in the slow-moving juddering car, the engine overheated, and the rad-cap did its thing and let out the pressure, and all the water, but I made it to the crest.
After it had cooled a bit, I removed the cap and re-filled the system with water from a close-by cafe.
I managed to start the car, and went down the other side of the hill and got home on the flat without more overheating or water loss.
I had not thought the car was burning oil, but on checking the oil having reached home, the level was below the "low" mark! So I suppose the answer is yes it was,and in some style.
I had done an oil change and filter, plus put in some "active 8"
before I drove the finished car, so the oil was used in only 600 miles of driving.
I don't know whether this extra info will mean any thing to you, but today I will try to start sorting out the mess and taking your advice on the tappet bit first.
And, if and when the head comes off, I will have it skimmed and converted to unleaded at the same time.
Used it for years and years Ian, it saved one engine already when it sprung and oil leak, and I lost it all, without realising, until I reached home, so I know it works.
I am not a mechanic, as you may have realised, but looking at what Scottie described it seems to me that something failed rather than wore out.
It worked and then it didn't.
From the list of suggestions so far I would say it was likely to be the head gasket. All the other suggestions might cause the same symptoms but would happen gradually rather than suddenly.
As I said, I am not a mechanic and happy to be contradicted. I just plug a cable into mine and it says if anything is wrong. So much less romantic I know but also easier.
Good luck fixing it. After the effort you have put into the bodywork you deserve more than 600 miles of fun.
Ahh the story unfolds, by what you say about overheating loosing all the water along with most of the oil i would think you have cooked the engine and blown the head gasket, hopefully the crank bearing liners etc are ok. With this in mind i would be checking the whole cooling system including the rad making sure its fit for purpose, did you flush the block etc with clean water during the build also adding anti freeze helps with the cooling by lifting the boiling point of the coolant.
If you are unsure what a blown head gasket looks like google images is a good point to start with.
Happy engine stripping and i hope you find the problem, adding photos of the engine strip to the forum would be good.
Yes I did flush the engine and re-fill with anti-freeze prior to use Swifty, and at the point of the crest of the hill, I decided to get home at all costs even at the expense of the engine, and just went ahead!
Will post the pics you would like. And report work done,
this will be my first engine-strip so don't expect too much!
The head removal is pretty easy and there's load of info on the net along with the guys on here who will be more than happy to give advice, hope it's not too long before we see the beast back on the road.
Sorry to hear your bad news on the engine front. Such a bummer when now is the time to enjoy it. Hope you can get away with just doing the headgasket in the short term and maybe a rebuild later when off the road for winter. Good luck.
This will show you how it's done!! https://www.youtube.com/watch?v=daVDrGsaDME
Thanks Swifty for your help, and all the rest of the post too.
Well, having had lots of much-needed advice on what the problem could be, I have done a bit of thinking, and tried to figure out what it could be.
The two rear cylinders have such good compression that logically, I would assume that both rings and valves are in good order.
The front two are so low on compression, it would be against all odds to imagine that TWO separate lots of rings or valves have failed at exactly the same time, so I will stick my neck out and say that logically, I think the head gasket between the front two pots has blown.
And also. I would think that the gasket blew before I cooked the engine, And that is what caused the breakdown in the first place.
hope to start a strip-down in the next couple of days, so will post in due course.
(I was secretly hoping that Swifty's scenario of the tappets coming loose on one and two would be the answer, but the odds on that happening I thought would be far too high!!) Boo-Hoo!!
Well I finally got the head off the engine, and found it hard not to have a smug grin on my face!
The failure gap between cylinders one and two on the gasket was enormous, see the pictures!
No wonder changing all the ignition system had no effect.
The gap between 1 and 2 and 3 and 4 is really narrow, and an obvious weak point, if it were the same as the gap between 2 and 3 it would most likely not have gone so badly.
Can anyone out there recommend a really robust head gasket, as I obviously don't want to have to do this again? ( A multi-layered job made out of armoured plate!!)
I will try to get the head stripped off and to an engineering company for a crack test, skim, and lead-free re-build tomorrow.
The pots don't seem to have much wear, and going by the comp test, the rings are really good too.
Great to see the problem has been found, regards head gaskets if you have the head skimmed by a motor engineer they will supply you with a new gasket most likely to the correct thickness in relation to the amount they remove to keep the original compression the same, it usually depends on how much material they remove.
.