[Healeys] Engine temps too low.

Chris Dimmock austin.healey at gmail.com
Sun Oct 3 00:56:01 MDT 2010


There is a huge ignition static advance anomaly between the factory  
specs for a BJ8 and every earlier 12 port 3000.
The closest explanation for this i can offer is that the later 12 port  
heads are machined incorrectly by the factory where the spark plugs  
screw in. If anyone on the list has a bare later 12 port head, you can  
confirm this. A fully screwed in spark plus will not screw all the way  
into the combustion chamber.
It screws in all the way on every other westlake designed head ive  
ever seen  There are a few threads still exposed in the head on the  
late 12 port heads. Meaning the plug has to fire earlier because it is  
further away.
I thought this issue was the reason for the bizzare amount of static  
advance on a bj8, but apparently the same late model head is used on  
pre BJ8 cars.
Either way, a total of 34 - 36 total advance "all in" at 3,000 -3,500  
rpm is correct for all bmc c series engines. How you achieve it is up  
to you (I.e combination of static advance plus distributor advance)
I have very little advance in my distributor compared to a std BJ8  
(changed the distributor cam, and no vacuum advance)
Chris
www.myaustinhealey.com.
Sent from my iPhone

On 03/10/2010, at 3:42 PM, Richard Kahn <tahoehealey at hotmail.com> wrote:

> I was told this by the highly respected dizzy re-builder who  
> probably rebuilt
> most of those rebuilt for people  on this list.  I have adjusted it  
> back to 16
> with no change in temps or performance. The
> books say 15 degrees at 600 RPM.
>
>> From: frogeye at porterscustom.com
>> To: tahoehealey at hotmail.com; healeys at autox.team.net
>> Subject: RE: [Healeys] Engine temps too low.
>> Date: Sat, 2 Oct 2010 11:56:34 -0600
>>
>> Rich,
>> Healeys, due to a big thick and heavy cast iron block and head are
>> notorious for masking detonation noise (pinging). I can't remember  
>> exactly
>> what the number of total advance that the Austin engine will handle  
>> is, but
>> if you start at 19 and run the car for long periods at around  
>> 3000RPM you
>> ARE exceeding the total advance and you will eventually destroy your
>> pistons.
>> If you set it at 6-8 degrees at 750RPM and it idles well, then it  
>> will run
>> just as good as it does now with TOO MUCH advance.
>> Just saying that who ever told you to set your timing that way is  
>> dead
>> wrong. The manuals were written to keep folks from making dumb  
>> mistakes
> when
>> tuning their cars.
>> dave


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