[Healeys] Rebuilt Engine Compression
Bob Spidell
bspidell at comcast.net
Mon Jun 12 07:15:55 MDT 2023
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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