1974 911 with Webers

proporsche · proporsche's Garage

Hi boys..
any idea what distributor should be in 1974 911 with carb. Webers?
I am trying to set it up for a friend and the distributor in the car is Bosh 0231 184 001
with a vacuum advance unit.
There is no vacuum to connect to on the webers. Is this the right distributor?

The engine seams a little under power..timing is set carbs adjusted to perfections.Runs great but i have a feeling it should have more power.The main jets are 1,35 already..

Ivan

moparrob · 05-20-2018, 02:39 PM

Contact Jerry Woods for the proper setup of distributor and curve settings. He is the master.

Trackrash · Trackrash's Garage

That is probably the original distributor. I don't know of a distributor that would work in your situation, without being modified.

Typically the vacuum advance is disabled and the centrifugal advance is re-curved to meet the needs of the carbs.

proporsche · proporsche's Garage

thanx guys for the advice, i dig into it...

Ivan

zedsn · 05-21-2018, 03:18 AM

You might want to send your distributor out to Jeff at advanced distributors. I had the same issue as you. His price was very reasonable and he rebuilt and recurved mine awhile back and made me a happy camper.

BURN-BROS · 05-21-2018, 06:20 AM

Hi Ivan,

The 001 has approximately 15 degrees of distributor advance (30 crank)

You would set timing between TDC and no more than 5 deg BTDC

This setting would be valid for the stock compression and cams.

I would not utilize the vac retard with carbs. It retards too much.

chrismorse · chrismorse's Garage

Isn't the advance really a retard
, for emissions, on the 74?
Recurving and a proper vacuum advance should sharpen up the response,power AND the mileage.
Chris

BURN-BROS · 05-21-2018, 06:31 AM

Hi Chris,

Vac advance was not used until the 1980 SC 3 liter. All previous models that had Vac pots were for retard @ idle.

The most common curve I put into the 184 001 is a modified RS curve. It has the same amount of advance, it come "all in" sooner than the RS.

You would set that between 8 and 12 deg BTDC depending on the build.

proporsche · proporsche's Garage

Hi Aron..that sounds like a good idea..I have set the timing 38 at 6000 , or tdc ..i will try the 5 btc.
I got to this in Czech last week on one guys 911.Someone was messing around with it and it was 10 after, horrible.
maybe i call you when i get to the 911..;-) no worries i know it is 9 hours difference;-)
I miss those Camarillo strawberries...

When i get back in a month i will try to do this.......

Chrismorse ,no chance for me to do vacuum there`s none ...

Ivan

BURN-BROS · 05-21-2018, 06:39 AM

LOL, I think we had a strawberry festival last weekend Ivan, you just missed it!

38 deg @ 6K would give you too much timing @ 2K-2.5K (possibly)

If you know what the engine specs are, it would be easier to give out suggestions.

Jack Stands · Jack Stands's Garage

Couldn’t the intake manifolds be tapped for a vacuum takeoff? My 914-6 has nipples on the two outer manifold runners that provide a vacuum source. I seem to remember they’re used for a throttle closing attenuator for emission control.

proporsche · proporsche's Garage

Aaron..i used to live in Agoura Hills for a while before all my moves;-)
I will try your suggestion...when i got to this 911 it had 10 after timing..it ran horrible..I would love to know what year it is but there are no numbers on the engine.I went by black shroud so i am thinking 1974 2,4 911.The car it self is 1978 911..so imagine trying to set it up.

Jack..i played with the idea about the vacuum but did not want to drill before any other ideas;-)

thanx

Ivan

BURN-BROS · 05-21-2018, 08:13 AM

Quote:

Originally Posted by proporsche

I will try your suggestion...when i got to this 911 it had 10 after timing..it ran horrible..I would love to know what year it is but there are no numbers on the engine.I went by black shroud so i am thinking 1974 2,4 911.The car it self is 1978 911..so imagine trying to set it up.

10 ATDC would be horrible I bet! Sounds like a basket case. I would start at TDC timing and work from there, with no more than 5.

proporsche · proporsche's Garage

yup that is what i actually did after i played with it at 6000 rpm....guy was happy with it ..but me not yet ..with webers it has a potential being more powerful...
i will keep you posted next month.
Yes it is bizarre what can be registered in Europe?I think it went trough Holland buyer who buys from from USA.

thank you all

Ivan

Jack Stands · Jack Stands's Garage

If it has the original pistons and cams, your improvements will be limited as the original CIS cams were very mild (necessarily to minimize the pulsing in the metering plate).

proporsche · proporsche's Garage

Hi Jack,.... as i have mentioned ,there is no way to know what is inside the engine.No numbers at all.

My next thought would be to set up the cam timing over the summer..then i will see what is inside...

thanx

Ivan

Trackrash · Trackrash's Garage

One other variable to consider is the size of the venturis. They should be at least 32s on that motor. Worth checking, I think.

I went through this with my current 3,0L.

I eliminated the vacuum unit on the distributor. I then marked off my pulley every 10 degrees from TDC to 30*.

I put a timing light on it and recorded my advance from idle to 6000 RPM every 1000 rpm. I then compared that to what the old carburated motors had originally. The work shop manuals have the advance curves. If you do that you will be able to understand if the timing is working the way it should, or if you need to re-curve the distributor.

proporsche · proporsche's Garage

thanx Gordon, it is noted..i will check it too;-)

Ivan