Eric,
You are quite right, I made a major mistake here. I should have checked
various applications first before leaving my comment.
My comment was more for high revving short stroke engines. I should have
known better.
Apologies.
Kees Oudesluijs
NL
Eric Frenken schreef:
> Kees,
>
> I have to disagree with you in that point. First it is most likely that
> older, used vac units all leak or do not work properly unless they've been
> rebuilt. Secondly the Lucas DM6A maxes out at about 4,000 rpm crank and last
> but not least the vac unit on DM6As does not retard but advance the ignition
> (right at the moment I don't know how much but I think it should be in the
> region of 10-120), mainly under part load, when vacuum got to its max.
>
> Dizzys on Cal. TR6s were equipped with 2 vac units, one for advancing, the
> other for retarding the ignition. This was done for emission reasons, which
> was never a concern as long as our Healeys had been built.
>
> Eric
> D
>
> -----Urspr|ngliche Nachricht-----
> Von: healeys-bounces@autox.team.net [mailto:healeys-bounces@autox.team.net]
> Im Auftrag von Oudesluys
> Gesendet: Dienstag, 8. Dezember 2009 08:57
> An: richard mayor
> Cc: healeys
> Betreff: Re: [Healeys] Distributor vacuum units
>
> There are plenty of used units about that can be used as a donor, e.g.
> from Triumph, Mini, Morris, Landrover, MG etc. I do not know if they
> differ a lot or at all in spring rate, but I would guess they are all
> more or less the same. May be left and right handed units have different
> vacuum units.
> However if you set the ignition dynamically, e.g. at 2500rpm (about when
> usually the max advance is reached) you can do away with it alltogether.
> Most performance engines do not use them. They are there to retard the
> ignition (about 4 degrees) when idling to reduce emissions somewhat.
> Kees Oudesluijs
> NL
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