DUI HEI non-vacuum advance (1 Viewer)

[1chukar]

Need some advice folks. Rebuilding a de-smoked 1974 F engine and when I got to the distributor it’s a DUI with only mechanical advance. Engraved underneath says 30degrees @ 3000. It basically seems clean, tight and sound - but - I’ll continue to use this rig for daily street driving. What are you recommendations for a dizzy? Keep this, rebuild it or replace?
Thanks

 

[B y r o n]

If it was working before the rebuild then I say keep using it. Was there anything to say it was not working as expected before the rebuild?

 

[brian]

replace.
can get a brand new oem vac advance dizzy from city racer.

 

[1chukar]

If it was working before the rebuild then I say keep using it. Was there anything to say it was not working as expected before the rebuild?

Good point, it’s never really run ‘well’ and often it missed and backfired pretty bad. Decided to tear down the engine due to low compression in two cylinders. The walls were scored badly

 

[1chukar]

replace.
can get a brand new oem vac advance dizzy from city racer.

Thanks Brian
Just placed an order with him this morning. Definitely will look at those

 

[1chukar]

What I’d like to learn is if anyone else uses a mechanical unit like this- and why or why not change back to oem

 

[brian]

its foolish to not have vacuum advance?
there are only a few applications were it makes any sense, normally race engines and boat engines were most operation is at nearly to completely wide open throttle most of the time.

 

[1chukar]

its foolish to not have vacuum advance?
there are only a few applications were it makes any sense, normally race engines and boat engines were most operation is at nearly to completely wide open throttle most of the time.

Thanks- I’m learning. Looks like I’ll be shopping

 

[Downey]

The way I was taught by Toyota is that the Landcruiser engine demands 40 degrees advance spark on hard accelerations. The stock dizzy gives 32 degrees mechanical, you set your static timing at 8 degrees advanced, there's your 40 degrees- - -then the vacuum advance merely works on demand. Your 30 degree mechanical never ever gave you more than the 30 degrees, so you would have had to set your static timing at 10 degree, which might have given you idle/drivability problems, with no vacuum advance for correction ???

 

[1chukar]

The way I was taught by Toyota is that the Landcruiser engine demands 40 degrees advance spark on hard accelerations. The stock dizzy gives 32 degrees mechanical, you set your static timing at 8 degrees advanced, there's your 40 degrees- - -then the vacuum advance merely works on demand. Your 30 degree mechanical never ever gave you more than the 30 degrees, so you would have had to set your static timing at 10 degree, which might have given you idle/drivability problems, with no vacuum advance for correction ???

This is really helpful
So since this rig has a Weber 38 it- do you have any idea what distributor will team up well with it?

 

[pithicus]

The heavier advance spring looks like it could pop off . Might need attention.

 

[1chukar]

The heavier advance spring looks like it could pop off . Might need attention.

Good eye. I’m getting pretty convinced that it’s time to start looking for an alternative to this one

 

[Downey]

This is really helpful
So since this rig has a Weber 38 it- do you have any idea what distributor will team up well with it?

1977 stock Landcriuiser dizzy, small body, vacuum advance, home run!!!!!!!!!

 

[1chukar]

1977 stock Landcriuiser dizzy, small body, vacuum advance, home run!!!!!!!!!

So, I’ll keep an eye out for one of those- and a coil too.
With this rebuild it’d be best to have an easy start up.

 

[brian]

that would be the city racer dizzy

 

[1chukar]

that would be the city racer dizzy

Great thanks- I’ll be contacting him Monday morning

 

[brian]

put a pertronix in it right away too