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Bellisin
Joined: 19 Dec 2010 Posts: 16
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Posted: Mon May 09, 2011 2:45 pm Post subject: 1725 Hillman engine - fumes in rocker cover? |
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I have a MK VI Singer Gazelle that was purchased recently during one of these ebay last minute ebay "what the hell" moments. 1725 Hillman engine.
From day one the car has had exhaust fumes under the bonnet which leak into the cabin. I replaced the exhaust gaskets and exhaust system which partly cured the problem. However, having spotted some fumes rising from the oil filler cap I investigated and found the following:
1. When running the engine pumps fumes out of the oil filler cap under light compression.
2. The fumes at least smell like exhaust fumes.
Thinking with my limited knowledge that this could be a head gasket problem I have removed the head and found that one of the head bolts between 1 and 2 cylander was sheered off. No obvioud signs of blowing on the head surfaces or gasket if this is expected?
I am now at the stage where I have removed the broken bolt from the head but the head is still off. The bores have a slight lip but are not scratched etc.
Question:
Is it likely that replacing the gasket and broken bolt will cure the issue or are the symptoms typical of another problem such as piston ring failure?
P.S. I have never seen so much instant gasket on one car! |
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victor 101
Joined: 03 Apr 2009 Posts: 446 Location: East Yorkshire
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Posted: Mon May 09, 2011 3:38 pm Post subject: |
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I doubt that replacing the head bolt and gasket will cure your problem, it could be something as simple as the crankcase breather being blocked, or it could be down to worn rings allowing the compressed gases down into the crankcase and then finding their way out via the pushrod gallerys. |
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47p2
Joined: 24 Nov 2007 Posts: 2009 Location: Glasgow
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Posted: Mon May 09, 2011 3:54 pm Post subject: |
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Have you checked for excessive wear in the valve stems? _________________ ROVER
One of Britain's Fine Cars |
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Bellisin
Joined: 19 Dec 2010 Posts: 16
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Posted: Mon May 09, 2011 4:21 pm Post subject: |
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Thanks for the quick replies.
I am a novice have a go classic car owner and I am still welding mymain restoration project so my knowwledge of engines is limited to teenage tinkering and car mags. However, I am keen to learn.
1. Is there a way to test the rings without removing the pistons? I am guessing that changing the piston rings will require the engine out? I do have an engine hoist so it could be done although I am all for an easy life!
2. When you say valve gear do you mean the stem seals? I see these are cheap to buy. The valves are in tact but of course caked in soot as are the piston heads. Is there a safe way to clean the pistons and valve surfaces? I am guessing its still ok to grind in seats with the those suction sticks and paste?
3. Is it acceptable to fit new piston rings to lightly worn chambers? I fear that if I have to consider a rebore I then have to consider economics for what is a bit of a banger. |
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47Jag
Joined: 26 Jun 2008 Posts: 1480 Location: Bothwell, Scotland
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Posted: Mon May 09, 2011 6:11 pm Post subject: |
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The easiest way to check for worn rings is a compression test but it's too late for that. Can you move the piston sideways in the bore? That can give an indication of how much wear there is. Worn valve seals wouldn't show as smoke in the rocker cover more likely it would appear on overrun. I agree with Victor101 that you should check the crankcase ventilation system.
Art |
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Phil - Nottingham
Joined: 01 Jan 2008 Posts: 1252 Location: Nottingham
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Posted: Mon May 09, 2011 7:15 pm Post subject: |
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This engine is noted for excess crankcase fuming when piston rings wear to the extent that fumes upset the mixture at idle and cause smoking.
The well known bodge from 1960's to now is to disconnect the breather tube and vent underneath the car and when it starts spraying out oil which it soon does poke the end in an empty lager can to catch it
The Vauxhal?Oepl cam in head engines fitted to old Cavaliers/Rekords and Carltons does the same.
Want the T shirt _________________ Rover P2
Rover P4
Rover P5 & P5B
Land Rover S2 & S3
Morris Mini Traveller Mk2 |
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bob2
Joined: 06 Dec 2007 Posts: 1727 Location: Malta
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Posted: Tue May 10, 2011 8:12 am Post subject: |
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Is this the arrow shape?
My hunter does something similar and it has the 1500cc engine, we did a compression test which gave 135psi on numbers 1 and 2, 150 on number 3 and 140 on number 4 so not too bad considering its over 40 years old.
However it does let out fumes from the rocker cover breather which I had connected back to the air filter housing but now am thinking of putting a pipe from it to below the car as it too sometimes does splatter a little oil.
It also lets out some greyish smoke from the exhaust so if the rings look to be okish it may be the valve seals letting out some oil onto the pistons? |
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Phil - Nottingham
Joined: 01 Jan 2008 Posts: 1252 Location: Nottingham
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Posted: Tue May 10, 2011 7:23 pm Post subject: |
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Same engine used from Series Minxes 1957 to Arrows to 1978 (1500cc to 1725cc) - piston rings/bore wear! _________________ Rover P2
Rover P4
Rover P5 & P5B
Land Rover S2 & S3
Morris Mini Traveller Mk2 |
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Ray the rocker
Joined: 01 Aug 2008 Posts: 187 Location: south wales
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Posted: Tue May 10, 2011 10:04 pm Post subject: post subject |
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rootes group engines---especially the 1500/1725cc suffer crankcase ventilation problems very early (40,000+). normally a sign of poor compression with combustion fumes bypassing the piston rings.If you got plenty of cash --rebore--if not--you can get oil control rings to try and take up the free play on worn bores.I used to use "cords" years ago but i`m not sure if they are available nowadays.good luck with your repairs...
Cheers--Ray the Rocker.... |
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Bellisin
Joined: 19 Dec 2010 Posts: 16
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Posted: Tue May 10, 2011 10:49 pm Post subject: |
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Thank you for all the replies. |
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Churchill Johnson
Joined: 11 Jan 2011 Posts: 359 Location: Rayleigh Essex
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Posted: Tue May 10, 2011 11:02 pm Post subject: |
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I was informed cord rings not made any-more may be some kicking around in their day they were the next best thing to sliced bread and would last for a good many thousands of miles. |
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Ray the rocker
Joined: 01 Aug 2008 Posts: 187 Location: south wales
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Posted: Wed May 11, 2011 11:45 am Post subject: post subject |
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I second that --Monster of time taken to clean the pistons to remove carbon deposits but how important the installation of the "cord rings" being removed from each packet !! each ring segment came in two sections. cup up and cup down as i remember. If you got one wrong--ie--cups facing the same way---they would suck the oil up from the sump and all the hard work results in a heavy thick fog in your locality !!! always double check before assembly was imperative. The good old days of cheap alternatives are long gone i`m afraid--it`s all high tech now--so much money about,cheaper to change your car than spend a fortune on an engine .
Cheers--Ray the Rocker... |
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PAUL BEAUMONT
Joined: 27 Nov 2007 Posts: 1281 Location: Barnsley S. Yorks
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Posted: Wed May 11, 2011 1:01 pm Post subject: |
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This brings back memories! About 25 years ago a mate of mine, in a similar rash moment bought a similar motor, probably through Exchange and Mart in those pre-Ebay days. It looked tidy enough and he was pleased enough with it, but to me it ran on 3 cylinders. I goaded him about this for a bit until he finally gave in and removed the cylinder head. There was no no.3 piston! just a carefully fitted wooden plug. The vendor had even cut off the con-rod and bolted the remains aroung the crank to maintain oil pressure. He was less than amused and my hystertia did not help matters.
So Bellisin, just be thankful that you have compression on all 4!
Paul |
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Daniel H
Joined: 12 Apr 2011 Posts: 61 Location: Herts
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Posted: Wed May 11, 2011 1:34 pm Post subject: |
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PAUL BEAUMONT wrote: | This brings back memories! About 25 years ago a mate of mine, in a similar rash moment bought a similar motor, probably through Exchange and Mart in those pre-Ebay days. It looked tidy enough and he was pleased enough with it, but to me it ran on 3 cylinders. I goaded him about this for a bit until he finally gave in and removed the cylinder head. There was no no.3 piston! just a carefully fitted wooden plug. The vendor had even cut off the con-rod and bolted the remains aroung the crank to maintain oil pressure. He was less than amused and my hystertia did not help matters.
So Bellisin, just be thankful that you have compression on all 4!
Paul |
Reminds me of a letter I saw published in a 1960's Motor magazine, where the reader purchased a Wolseley 6/90 from a car auction which according to the auctioneer was "mechanically sound apart from a slight misfire". After driving the car home on five cylinders he proceeded to investigate the trouble and found out there was no gap on plug no.2, so after gapping and replacing it he turned the car over on the solenoid which caused an explosion inside the engine and the dipstick to literally fly out, spraying him in oil. So after dropping the sump it turned out there was neither piston nor con-rod attached to number 2 journal (which was scored beyond recognition), the oil-way had been clogged with filler and bound together with masking tape (presumably to keep the oil pressure up), and the plug had been pinched together to in order to prevent combustion. |
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JohnDale
Joined: 19 Mar 2008 Posts: 790 Location: Kelvin Valley,Scotland
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Posted: Mon Nov 07, 2011 4:46 pm Post subject: |
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I remember,one or two moons ago, in the days of metalled bearings as opposed to shells, a gent on holiday with his family, & a car with a run big end. No time left to have the car sorted as holiday was nearing it's end. As a swift repair I cut a piece from a large Oxo tin lid & inserted it into the relevant big end after cleaning out the oil passageway in the crank. Engine ran fine, if a wee bit dour to start, but got him home to Cornwall without incident. Happy daze & 'engineering ' at it's best,cheers,JD. _________________ 1958 Ford Zephyr Mk2 Convertible
1976 Ford Granada Ghia. |
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