[Healeys] Rebuilt Engine Compression

[Kees Oudesluijs]

That is easy to check. With the TDC mark aligned at 0 degrees no:1 
cylinder boths valves should be fully closed. Turning  the crank shaft 
about 170 degrees forward and the exhaust valve should begin to open. 
turning another 180 degrees and the exhaust valve should start closing 
and the inlet valve opening, depending on the overlap.

Kees


Op 12-6-2023 om 15:15 schreef Bob Spidell:
> Almost sounds like the cam is /way/ out of phase (I think even 
> unlapped valves would seal better than that). The 'count 13 links' cam 
> install 'system' is wonky at best and confusing. Fortunately, I don't 
> think the Austin is an interference engine.
>
> On 6/12/2023 3:50 AM, Kees Oudesluijs via Healeys wrote:
>>
>>
>> Hello Patrick,
>>
>>
>> Between 5 and 10lbs can barely be called a compression so something 
>> serious is amiss. It should be well above 5bar for any engine. 
>> Depending on C-R and wear. Even with a slightly burned or not lapped 
>> in valve.
>>
>> If it is not the clearances it really looks like a head off job to 
>> investigate and sort the valves. Luckily not too big a job on the A-H.
>>
>>
>> Cheers,
>> Kees
>>
>>
>>
>> Op 12-6-2023 om 12:01 schreef Patrick and Caroline Quinn:
>>>
>>> Hello Kees
>>>
>>> Thank you for your response.
>>>
>>> I’m afraid I tried all that. Plugs are wet! Even made sure the earth 
>>> strap was earthing properly. Also used a starting fluid called 
>>> “Start ya Bastard!”
>>>
>>> I did a compression test and each cylinder was between 5 and 10 lbs. 
>>> Not quite what it should be.
>>>
>>> When the engine expired last year, the first thing I did was to have 
>>> the cylinder head pressure tested. It was okay, but I suspect that 
>>> when they put it back together the valves were not lapped in. The 
>>> head comes off next weekend to check.
>>>
>>> Hoo Roo
>>>
>>> Patrick Quinn
>>>
>>> *From:*Healeys <healeys-bounces at autox.team.net> *On Behalf Of *Kees 
>>> Oudesluijs via Healeys
>>> *Sent:* Monday, June 12, 2023 6:43 PM
>>> *To:* healeys at autox.team.net
>>> *Subject:* Re: [Healeys] Rebuilt Engine Compression
>>>
>>> Did you check the firing order, camshaft timing, valve clearances? 
>>> Does the distributor shaft turn when the engine is turning over?
>>>
>>> Check the bypass wiring of the ballast resistor. Check the correct 
>>> wiring of the coil, you would not be te first to have the polarity 
>>> wrong.
>>>
>>> The compression on a freshly rebuild engine is lower than on an 
>>> engine that has been properly run in. It also depends on the 
>>> tolerances and surface finishes used in the rebuild. Assuming that 
>>> it is a proper rebuild the compression should not be an issue here. 
>>> Whatever the compression the engine should start.
>>>
>>> Timing and fuel cannot be spot on as the engine is not running and 
>>> fine tuning of mixture and ignition should be made on a running 
>>> engine.  It is however not an issue either as you set ignition 
>>> initially statically as you do with the adjustment of the carbs and 
>>> it should at least run on that.
>>>
>>> Are the spark plugs wet or dry after churning? Try spraying some 
>>> easy start fluid (mainly Aether) into the throat of the carbs during 
>>> turning over and see if you get some life.  If so it is a fuel issue.
>>>
>>> Good luck.
>>>
>>> Kees Oudesluijs
>>>
>>> Op 12-6-2023 om 07:41 schreef Patrick and Caroline Quinn via Healeys:
>>>
>>>     Hello
>>>
>>>     No amount of churning over with a new battery will induce the
>>>     BN3’s rebuilt engine to fire. Even towing the car up and down
>>>     the road failed to instill any life into the engine.
>>>
>>>     Everything is spot on – timing, spark and fuel.
>>>
>>>     Anyone have an idea as to what the compression be on a rebuilt
>>>     engine should be?
>>>
>>>     Many thanks
>>>
>>>     Patrick Quinn
>>>
>>>     Blue Mountains, Australia
>>>
>>>
>
>
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