49 replies to this topic

[Rubbershorts]

I have a spare MS spacer with the barb/nipple on it if you need (you can take it out and fit it you your spacer?) - I bought it for exactly the same reason and it was too thin.  I fortunately had the nipple on the HS4 so just used that for the vacuum gauge.

Hi David, I've sent you a message. Daz.

[gazza82]

You can get thicker spacers with the adaptor fitted.

Thanks Gazza. Deleted my first answer as I mis read your answer. I'm struggling to find anything apart from the Minispares offering.

This one?

https://www.minispar...vacuum-take-off

[Rubbershorts]

You can get thicker spacers with the adaptor fitted.

Thanks Gazza. Deleted my first answer as I mis read your answer. I'm struggling to find anything apart from the Minispares offering.

This one?

https://www.minispar...vacuum-take-off

That's the one I was looking at. It's too thin unfortunately.

[timmy850]

You can drill and tap the manifold or a different spacer and add the vacuum port.

It might give better results in the spacer or the manifold compared to using a vacuum port right near the throttle blade

This is an example - the manifolds have a 5/8unf port for the booster, you can get an adapter like this to a barb fitting
https://www.hampdon....to-male-adaptor

[miniGTS]

I connected one of those big vacuum gauges to the inlet manifold (Twin SU HS2) to see what readings I get.

 

At 1000rpm idle it bounces quite fast between between 5 and 10 (in Hg Vac) which according to the gauge markings is late valve timing or leak at the intake.

 

Then taking revs up to between 2 and 3000rpm it goes to 15 and sits there fairly steady so that suggests late ignition timing.

 

Anything over 3000rpm it sits steady in the normal motor range.

 

Any suggestions for how I should address these timing issues?

 

I don't know what cam is in there (and don't have the tools to check), the igition timing is set to 10dgrees at 1000rpm. I have an accuspark electronic ignition in a 45D distributor and the centrifugal advance is stamped with 11. All the 45D distributors I have is 11 so I assume those were standard on the mini in SA.