One of the things I think I need for my side-draft conversion is a mechanical advanced distributor. If any of you have one you're willing to part with, let me know what you want for it.
Thanks
John
Thanks
John
distributor with mechanical advance
- Thread starter JFENG
- Start date
Option to the mechanical advance
BTW, I'm also looking at the newer 123Distributor units that are field programable via a laptop. IIRC, these have a vacuum advance pod, but I believe you can program in enough advance to make them work without the vacuum connection. A little pricy though.
John
BTW, I'm also looking at the newer 123Distributor units that are field programable via a laptop. IIRC, these have a vacuum advance pod, but I believe you can program in enough advance to make them work without the vacuum connection. A little pricy though.
John
Mike Goble
Well-Known Member
You can put a lot of advance into any mechanical distributor but you won't duplicate the function of vacuum advance.
Understood but with sidesdrafts...
It's tempting to go to programmable ignition. But I don't want to end up on a slippery slope that leads to making the powertain modern. So, no rpm &TP sensors into a mappable digital ignition system. I'm just trying to avoid spending $500 for a new Bosch M-A distributor
It's tempting to go to programmable ignition. But I don't want to end up on a slippery slope that leads to making the powertain modern. So, no rpm &TP sensors into a mappable digital ignition system. I'm just trying to avoid spending $500 for a new Bosch M-A distributor
I want the 123 distributor also and it will be my next major purchase. My DCOM's have ported and manifold vacuum ports to use with the advance function of it.
I hope you are the Pioneer on this system Steve and I will benefit from your R&D!
jmackro
Well-Known Member
Did BMW make a distributor without vacuum advance? I.e., that is mechanical only? And if so, do these advance over a wider range than the mechanical + vacuum could achieve on mechanical only?
If you can't locate the rare beast defined above, why not just use your existing distributor without vacuum? As Mike Goble wrote "You can put a lot of advance into any mechanical distributor".
The 123 is a neat product. Given the difficulty of getting a clean vacuum signal from carbs with one barrel/cylinder (e.g., Weber DCOE or DCOM's), even with the 123 you might want the non-vacuum model.
If you can't locate the rare beast defined above, why not just use your existing distributor without vacuum? As Mike Goble wrote "You can put a lot of advance into any mechanical distributor".
The 123 is a neat product. Given the difficulty of getting a clean vacuum signal from carbs with one barrel/cylinder (e.g., Weber DCOE or DCOM's), even with the 123 you might want the non-vacuum model.
Any good hot rod/speed shop with machine capabilities, can change the weights and springs in your distributor and dial in more or less advance and how fast it comes on. I haven't had this done for a while but should be less than $50. I did have it done to my old etype with Webers on it.
There is no vacuum advance on any CSL or CSI.
That is vacuum retard you are seeing.
That is vacuum retard you are seeing.
The most interesting dizzy to me is the 745i turbo with the Jetronic OS.
35 degrees of timing at 2200 rpm
Has vacuum retard
Has vacuum advance
Has mechanical advance
Has 10 degrees of retard at boost
In that exact order not counting the crank timing....
That's what you can do with 7:1 compression
Or that's what you have to do with 10psi and 7:1 compression
35 degrees of timing at 2200 rpm
Has vacuum retard
Has vacuum advance
Has mechanical advance
Has 10 degrees of retard at boost
In that exact order not counting the crank timing....
That's what you can do with 7:1 compression
Or that's what you have to do with 10psi and 7:1 compression