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fordpop
Joined: 23 Aug 2011 Posts: 18 Location: Devon
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Posted: Mon Jan 23, 2012 12:39 am Post subject: Tired E93A - Compression Pressures? |
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My 103E Pop engine seems a bit tired. Power doesn't seem to be all it should be - I'm needing to drop down a gear (embarrassing when you've only got three) for main road inclines that i would expect it to take in top. I don't know the history of the engine but it seems to run sweetly enough. It doesn't burn any oil, just rattles a little bit when the engine is neither pulling nor on the over-run. I've tried altering the timing within the limits of the normal adjustment but it doesn't seem to make very much difference. I thought a compression check might be a good idea and find that I have 75-80 psi on each cylinder. Is this about what it should be? Anyone have any further thoughts? |
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Jim.Walker
Joined: 27 Dec 2008 Posts: 1229 Location: Chesterfield
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Posted: Mon Jan 23, 2012 11:57 am Post subject: |
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From memory it should be about 100 psi I think. But make sure you are testing with the throttle wide open!
Jim. _________________ Quote from my late Dad:- You only need a woman and a car and you have all the problems you
are ever likely to want". Computers had not been invented then! |
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RUSTON
Joined: 07 Mar 2011 Posts: 144 Location: Matlock.
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Posted: Mon Jan 23, 2012 12:37 pm Post subject: |
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If you have the starting handle give it a turn over, two full rotations, you will feel all four compressions and also feel if one is weaker than the others. Of course if it turns like a Singer sewing machine then you KNOW that something is wrong!
Pete. _________________ Measure twice...cut once! |
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Rick Site Admin
Joined: 27 Apr 2005 Posts: 22451 Location: UK
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47Jag
Joined: 26 Jun 2008 Posts: 1480 Location: Bothwell, Scotland
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Posted: Mon Jan 23, 2012 2:54 pm Post subject: |
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Have you checked the ignition timing. It may be a bit retarded causing power loss.
Art |
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fordpop
Joined: 23 Aug 2011 Posts: 18 Location: Devon
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Posted: Mon Jan 23, 2012 6:07 pm Post subject: |
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Thanks for the helpful replies. The concensus seems to be that the compression pressures are a bit down, but I must confess that in my ignorance, they were all taken with the throttle closed - I'm not sure how much difference that might have made?
I have been reluctant to start stripping the engine but think that I will have to take a look at the valves. It will also be a good opportunity to inspect the bores and find out what size pistons are in there!
Alan |
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Jim.Walker
Joined: 27 Dec 2008 Posts: 1229 Location: Chesterfield
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Posted: Mon Jan 23, 2012 10:22 pm Post subject: |
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fordpop wrote: | Thanks for the helpful replies. The concensus seems to be that the compression pressures are a bit down, but I must confess that in my ignorance, they were all taken with the throttle closed - I'm not sure how much difference that might have made?
I have been reluctant to start stripping the engine but think that I will have to take a look at the valves. It will also be a good opportunity to inspect the bores and find out what size pistons are in there!
Alan |
Throw those results away!
If air cannot get into the cylinders there is little to compress and the results will reflect that. A wide open throttle is ESSENTIAL.
Jim. _________________ Quote from my late Dad:- You only need a woman and a car and you have all the problems you
are ever likely to want". Computers had not been invented then! |
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Churchill Johnson
Joined: 11 Jan 2011 Posts: 359 Location: Rayleigh Essex
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Posted: Mon Jan 23, 2012 11:26 pm Post subject: |
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RUSTON wrote: | If you have the starting handle give it a turn over, two full rotations, you will feel all four compressions and also feel if one is weaker than the others. Of course if it turns like a Singer sewing machine then you KNOW that something is wrong!
Pete. | So what is wrong with a Singer sewing machine one of the best in its time!!!!!,an engine should run like a sewing machine. |
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fordpop
Joined: 23 Aug 2011 Posts: 18 Location: Devon
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Posted: Mon Jan 23, 2012 11:55 pm Post subject: |
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Jim.Walker wrote: |
Throw those results away!
If air cannot get into the cylinders there is little to compress and the results will reflect that. A wide open throttle is ESSENTIAL.
Jim. |
Thanks Jim - ok, before I get the spanners out I'll do the compression tests again with the throttle wide open this time, and report back...
Alan. |
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fordpop
Joined: 23 Aug 2011 Posts: 18 Location: Devon
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Posted: Tue Jan 24, 2012 12:06 am Post subject: |
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47Jag wrote: | Have you checked the ignition timing. It may be a bit retarded causing power loss.
Art |
Art - I'm wondering if it's me - I used to be fairly advanced - quite a bright spark too - but these days am definitely feeling a bit retarded, with usual signs of power loss...
Alan |
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Roger-hatchy
Joined: 07 Dec 2007 Posts: 2135 Location: Tiptree, Essex
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Posted: Tue Jan 24, 2012 7:17 am Post subject: |
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Alan
It's called depreciation. |
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47Jag
Joined: 26 Jun 2008 Posts: 1480 Location: Bothwell, Scotland
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Posted: Tue Jan 24, 2012 8:19 pm Post subject: |
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Alan,
Welcome to the club.
Art |
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Greg
Joined: 03 Dec 2007 Posts: 445 Location: Dreamland Margate
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Posted: Thu Jan 26, 2012 2:39 pm Post subject: |
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Hi Alan,
Maybe you've just got too used to the phenomenal power of the Pop!
I had simular problems, lack of power and on hard acceleration, pinking !
I thought obviously the timing needed adjusting but no matter where adjusted, couldn't get it to run as good as before.
I ended up giving the engine a de-coke and has been great ever since!
Hope this helps,
Greg |
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fordpop
Joined: 23 Aug 2011 Posts: 18 Location: Devon
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Posted: Thu Jan 26, 2012 4:19 pm Post subject: |
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Greg wrote: | Hi Alan,
Maybe you've just got too used to the phenomenal power of the Pop!
Greg |
Thanks Greg - you may well be right...!
I can feel a de-coke coming on.
Alan |
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ka
Joined: 03 Dec 2007 Posts: 600 Location: Orkney.
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Posted: Thu Feb 02, 2012 8:43 am Post subject: De-coke |
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Whilst you are in there, it may be worth removing the pistons and checking ring gaps, and replacing if necessary. If you use new rings remember to glaze bust the bores.
If you have not removed the valves before, the mushroom tool is an absolute must, (the exhaust collets will be tighter than the inlet), and it is well worth either marking or keeping everything in the same order as you removed it, this will make valve clearances easier to re-set when rebuilding.
Do you have the valve guide tool?, this helps no-end when grinding in the valves. If not clean up the collets and use the pair with the valve to hold the valve when grinding in.
Gaskets and rings are readily available. Best of luck. _________________ KA
Better three than four. |
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