Daddylonglegs
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| posted on 9/11/13 at 09:00 PM |
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Good day, bad day
Apologies for the essay, but it may help with diagnosis 
Thought I was going to make another milestone on the Midget restoration today, but it was not to be. Got everything ready to start and discovered a
water leak from the weep hole in the water pump. Bought a new one, fitted it and after around 30 mins was ready to go again. Car started within about
15 seconds which aint bad for a car that's not run for 5 years! It ran for around 10-15 secs then died, but I think I flooded it. Anyhow, turns
out the settings on the SUs were waaaay too rich. Leaned out and tried again. Car started straight away but was lumpy as hell! Removing plug leads
one-at-a-time proved 3 & 4 were not firing. I thought it might be a carb issue as each one feeds a pair of cylinders. But I did a compression test
on them and 3 & 4 have zilch! So I'm guessing the head gasket has gone between 3 & 4.
Anyone had that happen on a newly rebuilt engine before?
I'm just hoping it ain't something more sinister 
It looks like the Midget is winning at the moment......
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rusty nuts
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| posted on 9/11/13 at 10:00 PM |
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Might just be a sticking valve on each cylinder, lift the rocker cover and check the valve clearances, if the valve clearances on cylinders 3 and 4
are very loose it may be possible to free off the offending valve
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JeffHs
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| posted on 9/11/13 at 11:12 PM |
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Don't, discount spark plugs. I chased my tail for a while with my pinto and twin 40s. Turned out the brand new Bosch plugs were no good, fixed
with correct NGKs
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chrism
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| posted on 10/11/13 at 12:27 AM |
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quote:
Originally posted by JeffHs
Don't, discount spark plugs. I chased my tail for a while with my pinto and twin 40s. Turned out the brand new Bosch plugs were no good, fixed
with correct NGKs
Did you miss the bit where he said there was no compression on 3 and 4.
Could be a couple of sticking valves as said above, also were the block and cylinder checked for warpage, as if they are not flat it could stop the
head gasket from compressing and hence sealing correctly.
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A little hard work never killed anyone, but why take the risk!
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Daddylonglegs
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| posted on 10/11/13 at 08:17 AM |
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Yep, as Chris said, there is no compression on 3 or 4. I did take the rocker cover off and checked 'off-rock' for gaps on the rockers. i
didn't measure them, so they could be a tiny bit high and I guess a valve doesn't have to stick by much to lose compression? But they do
seem about right so I will have to check with a feeler gauge.
I did not check the head for warpage though which I am regretting. So going to have to whip the head off anyhow if the valve gaps are OK. Hey Ho,
gotta love cars!
It looks like the Midget is winning at the moment......
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rusty nuts
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| posted on 10/11/13 at 08:24 AM |
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If you can beg, borrow or steal a cylinder leakage tester it will identify the problem straight away. IIRC British Trident may have posted about a
D.I.Y tester. My money would still be on a valve stuck open , if , when the engine was running it was spitting back through the carbs then suspect the
inlet valves. Have also had similar problems with badly worn cams and tight valve clearances but on a rebuilt engine that shouldn't be the case
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JeffHs
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| posted on 10/11/13 at 09:19 AM |
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Oops! Must read the post properly.
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02GF74
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| posted on 10/11/13 at 03:11 PM |
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Comp test remove all plugs turn engine over with ful throttle this ensures you get air so it can be compreesed.
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Daddylonglegs
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| posted on 10/11/13 at 08:15 PM |
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Well, loosened the valves to 3 & 4 to make sure they were not sticking down, still zero compression, also noticed No.2 had dropped from 120 to
90psi!! So, off with her head as they say, and what did I find? Looks like it was only a matter of minutes bofore 1-2 went as well
 
Description
 
Description
 
Description
Anyhow, I'm a tight a**e and begrudge parting with her majesty's coinage when I can do it mysel 
So....I have a decent sized engineer's plate, and being a Locoster I thought I'd have a go at trueing the head myself
I stuck aluminium oxide to the plate with grease, used light oil on it and spent 1 1/2 hrs pushing the head backwards-and-forwards on an ever
decreasing pile of paper utnil I got the results below. I reckon another hour should see it about right, I measured the gap in the middle of the head
against a straight edge and reckon I've got about 3-thou to remove
Still, gives one a great sense of well being 
Before:
 
Description
After:
 
Description
[Edited on 10/11/13 by Daddylonglegs]
It looks like the Midget is winning at the moment......
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