Distributor for carbed engine

[Stuart Lehr]

I know this has been discussed ad infinatum, but isn't the 050 a better choice than the 009 for a carb equipped engine? Thanks for the opinions... also, at what rpm would you adjust the advance to? I want to show my two sons what a timing light is for! They think it looks like an old radar gun...

[HarveyH]

The most common word is that the 009 distributor was designed for an industrial engine that would be operated under fairly constant speed and load conditions, nothing at all like a car. It is strictly mechanical advance with very limited advance characteristics. I've heard rumors that some variants have a vacuum can on them but I don't really know. It was picked up by the VW Type I people who needed a cheap mechanical advance distributor, and it seems to work fairly well in that role. The 050 distributor is also only mechanical advance, but the curves are much better suited to the Type IV engine. Another option is to use the stock 914 distributor. If your carbs don't have a vacuum port, or you don't want vacuum advance, just don't connect to the vacuum can. There are variances in the advance curves of the various 914 distributors (Dave Darling has a chart of the advance data on one of the other 914 sites, but I don't remember where it is) but any of them are much superior to the 009 for the Type IV. I have a 2055, cam with 40 IDF Webers. The car came from the PO with the 009, but he also gave me the original FI distributor. After reading all of the threads in the various BBS's and lists I decided to try it. My carbs have vacuum ports so I have hooked up the vacuum advance port also, and there is a very noticeable improvement to low and mid range running over the 009.
As for timing, you can either use the stock timing specs for your engine, or try the modified instructions for timing carbed engines from the PelicanParts technical articles.
Good luck,
Harvey

[yoh!!!]

"If your carbs don't have a vacuum port..."

I know the 32/36 progressive carbs have vacuum ports, but I always thought that the Weber IDF and the Dell Orto DRLA carbs did not have any ports. Who can clarify the vacuum confusion???

[BenI]

My Weber 40 IDFs and 44 IDFs both have vacuum ports. Been awhile since I owned Dells so I cant remember.

[Dave at Pelican Parts]

Some carbs do, some don't. The newer Webers have provisions for the ports, but they are plugged when you get the carbs. You have to remove the plugs (screws??) to use them.

They are not that hard to add to carbs that don't have them. At least, not if you've got a similar carb with the fittings in the right spots to use as an example.

--DD

[Eduardo Castrejón Elbjorn]

Another distribuitor question ?

If the vacuum advance distribuitor is calculated to work the advance at certain rpm (vacuum), when you increases the displacemnt the vaccum is higher ?
Example:

In a stock 1600 engine with stock distribuitor when the engine is in 2000 rpm range makes I don´t know you supose that is 10 of vacum. an the distribuitor begin to advance the timing with this vaccum.

In a 2180cc type 1 engine with the 1600 stock distribuitor at 2000 rpm the engine makes more vacuum that the 1600 ?
if yes, the performance of the distribuitor is not good, then what I need, a harder vaccum spring ?
Where I can buy one ?
Thanks

[DDS]

This thread is if great interest. I'm building a 2056 with dual Weber 42DCNFs (no provision for vacuum).
I bought the carbs on their original Maserati manifold. There are fittings on the manifold for connection of hoses of some sort.

1) Can one install a fitting on the intake manifold for a vacuum line advance?

2) What are the implications of using the vacuum from one cylinder vs 4 to eduardo's point above about displacement?f

3) I note that in line 'pulse eliminators' are available for vacuum lines - I presume this mimics a plenum to a certain extent.

4) I've been reading that the 050 is the mechanical advance dist for carbed engines, but read in a weber hot rodding book that they (Bob Tomlinson, CB performance) considers the Bosch 205 to be the ultimate because of its vacuum assisted advance/retard under load features. I note that one of the part numbers on my 914 dizzy has a 205 at the end. Could it be that it is one and the same and that I already have the 'ultimate'?

Many TIA

[retro74]

I have been following the distributor issue with great interest. My 74 2.0L D-Jet just got a rebuilt Cardone unit and it is not quite right. So I did some research and found a tuner (Ray Greenwood and others) to give me some feedback via email. THE hot setup is the Mallory unit which will not work on D-Jet FI due to the trigger points for the FI. Check out these links for greater insight:

http://shoptalkforums.com/bbs/NonCGI/Forum1/HTML/002090.html

http://shoptalkforums.com/bbs/NonCGI/Forum1/HTML/002057.html

http://shoptalkforums.com/bbs/NonCGI/Forum1/HTML/001967.html

http://shoptalkforums.com/bbs/NonCGI/Forum1/HTML/002069.html

Despite fine German engineering, it appears that the accuracy of the Bosche units SUCKS! With such a small motor, the consistency and accuracy of the firing adds to more power.

Joe

[Dave at Pelican Parts]

Actually, I think that the phrase is, "Even German engineering couldn't overcome 30 years of wear."

The Mallory is supposed to be the The Thing for Tpye IVs, if you don't have D-jet FI trigger points to worry about.

The 205 is the 1.8's stock distributor, and is supposed to be one of the best ones out there for carbs.

I don't know how changing engine displacement would affect the vacuum signal. Probably not that much--after all, we don't usually hear of any kind of "vacuum gauge reading == displacement" formulas. I think that changing the cam to one with a bunch of overlap will have much more effect on manifold vacuum than changing the displacement. Remember, you are bleeding air past the (closed) throttle valve when the engine is at idle, to keep the engine running at ~900 RPM.

DDS, you might get a very laggy vacuum signal to the distributor if you use the manifold vacuum ports on the manifolds for vacuum retard. If there is a lot of air volume in between the throttle plate and the distributor, it will take a while for the change in vacuum to propogate to the distributor and change the timing.

You can try it and see, but you might wind up with an off-idle "bog". See the earlier thread about single-barrel carbs.

--DD

[larrym]

how many times do we have to go over this??? the oo9 has only 1/2 the advance of any 914 unit; it also comes with 4 degrees retarded advance on the vw bug cyl that has the oil cooler over it; DON"T EVEN THINK ABOUT USING AN 009!!!!!!!!!!!

you can use any 914, type 3 or type 4 d-jet unit & just ignore the FI points or simply remove them:

buy the 914 specs booklet & reads all about all the 914 advance curves.. it's worth 10x what it costs

[Ron Meier]

Vacuum will not change with engine displacement. How "tight" your induction system is will.

Distributor advance - whether it is mechanical or vacuum related, it is supposed to start somewhere and end somewhere based on rpm (must fire earlier at higher rpm to burn fuel = less time for fuel to burn). Want the real deal ~ get the advance specs for the engine you have, take the dizzy to a shop with a distributor machine and PAY to have it recurved for what is necessary (street engine). Recurving can involve changes in weights, springs and stop holes in the plates. Without a machine - you're guessing.

OR buy an aftermarket electronic system with a programable EPROM, buy an EPROM burner, buy blank chips, set up a computer to read the program or buy a previously written program and modify it ~ then reburn it to the EPROM. Lock the advance plates in the dizzy so they don't move.

And as far as buying "rebuilt distributors" from A-1 Cardone or any other remanufacturer - you wanted a good price ~ you probably got it. Production rebuilding will involve cleaning of the housing, replacement of the shaft bushings, cleaning of the point plates (advance mechanism) so they are free, replacement of the advance springs (if necessary), FI trigger points (if necessary) and ignition points. They do not have the time to run each one on a distributor machine to verify advance/retard curves.