pappyl

350 rocket.

Have the car on the road finally - but now my distributor is showing its age. Bumped the timing down to compensate - but its advancing way too far (getting backfires on high acceleration, etc).
Everything looks ok (no excessive play, etc). Believe could be points or internal weights/springs, SO

Was looking at pertronix electrical adapter originally, thinking maybe whole distributor now vs. rebuilding old one.

Had a quote for a speed-fx distributor - whole thing cheaper than pertronix (didn't get price on rebuild kit for stock distributor) ! But i don't know how good that distributor is and the clerk wan't sure about the fit to the firewall???

Questions:
1. Anyone use the Speed-FX distributor or recommend other models?
2. Pulling distributor - worried about room getting it out - do I need to pull the engine mount bolts?

pappyl

Well I guess no one knows. Closing thread.

Fun71

I thought I replied to this yesterday but I guess it didn't go through.

You don't need to do anything with the engine mounts. Just remove the hold down clamp, cap, wires, and electrical connections and pull the distributor straight up.

MDchanic

I don't understand what the problem is - you say it backfires at high RPMs - How do you know that the problem is the distributor?

Have you checked the mechanical and vacuum advance at various RPMs and vacuum levels and compared your reading to the stock specs?

What are your dwell and timing settings?

Does the shaft have any axial play?

If it's advancing too far or too soon, a distributor tune-up kit from one of the major suppliers will provide new springs that you can use to get it just right.

You can install a Pertronix pickup (if that's the sort of thing you like to do), but it won't affect the advance any.

And, yes, if you must replace the entire distributor (and they seldom actually "wear out"), just remove the cap, remove the clamp bolt and clamp, and yank that suckah out, keeping track of the rotor position as you do.

- Eric

tru-blue 442

I would start with a good known condenser 1st. Check those points too.

pappyl

Just checked back in. Thanks for your comments. So this should come out without shifting the engine around (had to do such things prior).

Eric - hope I can answer your questions on this clearly...
- Backfire on acceleration being timing - that's my assessment. I don't think I have a timing gear/chain issue, bad valve, etc based on how it runs.
- I retarded the timing way back, (4 BTDC) ran it up and down the road heavy acceleration, seemed ok then. Started up later and didn't it just act up again! It's like the weights are all over, sticking, whatever.
- I do have replacement points and condenser to try. I do believe a bad condenser could cause this, but everything I've run had HEI. This ain't points on my lawnmower... lol Anyways, I'm not a fan of points that's why I was looking at the pertronix.
Also, thanks Ken/True-Blue

My plan is to pull the unit and give it a good inspection then make my decision on what to do next based on what I find.
- If lots of play, signs of wear, replace whole distributor
- If not, price out the rebuild kit, put in the replacement points, set dwell etc. Yes - will need to read up on doing that - know enough to set initially at 17 degrees and I have an old engine analyzer that I should be able to set the dwell with (30-32 degrees?)

Things I don't know:
- Will this distributor be stuck in there and require some persuasion to get out?
- Will I need to pull the hood off just because this will turn out to be a major PITA?
- Is the timing mark on the balancer accurate?

What I plan to do:
- Pull of cap and manually rotate to #1 TDC, rotor pointing to #1, and see if the mark lines up close to 0.
- Use some penetrating oil, rubber mallet, and some good luck.

pappyl

Oh yes, what I've read up on

Note: I have already put in new stock plugs, wires, cap, rotor

1. Pertronix should work to replace points and be very reliable. No special work - don't even believe I need to worry about the resistor. price about $125

2. Can swap in an HEI distributor from a 73-78 olds 350 from wrecker.
- do believe I then need to change my wires, plugs (or at maybe can regap)
- do believe I have to switch to an internal regulated alternator
- Do believe I need to run a line to "IGN" terminal fuseblock for power (bat terminal on distributor), seal off the one line going to the starter.

3. Buy a new aftermarket Distributor (already pointless) like a speed-FX. The price is about $110 (or possible others)

Bennyboy2

Just a point I was going to go with pertronix then found New HEI distributor from Barnett Performance for Half the cost of pertronix and it has adjustable Vacuum Just my Two Cents!!

Bennyboy2

Barnett Performance was 49.00 with shipping!

pappyl

In ontario, will check out a few other options.

I'd like to avoid throwing away my new plugs and wires though.

Fun71

Doesn't have to be from a 350, any Olds HEI prior to the transition to the CCC system would work (the non-CCC has a vacuum advance canister). I have one from a '78 403.

Wires are different between HEI and points, but you can use the same plugs and gap. I opened mine up slightly to .045".

Internal voltage regulator is not needed; my car has done fine with the original mechanical external regulator and HEI since the mid-80s.

Yes, you will need some way to give the HEI a full 12 Volts. Some replace the original resistor wire with a regular copper wire; others run a new wire from 12 Volt source. Some use a relay triggered by the original resistor wire, I ran a new wire from the IGN spade terminal in the fuse block; rolled up the resistor wire and hid it behind the wiper motor in case I ever put a points setup back in.

MDchanic

Just bear in mind that if you install HEI, it will not be properly curved for your engine, so you will have to buy a kit and get it set up right.

By a strange coincidence, if your original distributor is having the problems you believe it has, the fix is to buy the same type of kit and do the same work (only without replacing the distributor, cap, and wires, and re-wiring for a non-resistor source).

Your choice.

- Eric

pappyl

Gents,

I know the post is old, but I finally got some time to take a look at the distributor.

First thing, I tested vacuum advance with a hand-vaccum pump - and its NOT holding any vaccuum. So that's not right...
- weights and springs look ok
- base plate can move a bit (ie: vaccuum advance)
- Looks like there are 2 scews on top, not sure about the plate connection though.

The second thing, I'd like to be sure about this vaccuum line routing I have. I'm a bit suspicious that its not 100%. Does anyone have a vacuum line diagram for a '72?
I have intake vacuum T off to the advance, then to the base of the carb.
I've another vacuum feed on the rear near the nipple for the breather. It feeds into a temp unit in the front of the engine, with 2 lines running to the carb.
The temp unit has mulitple ports, one pair is bypassed with same vacuum line connected with both ends.
Just doesn't seem right...

As for the $ on the distributors. Looks like they are bit more costly in Canada - ok - a lot more.

I've not fixed anything as yet. I still have to do the #1 TDC set check to verify the timing marks - just to be sure the balancer is not out at all, and swap out the points.

Just looking to get the time to do it.


Appreciate your help. If no one comments may be it is because it is an old thread. I'll repost to a new one.

Bennyboy2

Pappy the HEI distributor with adjustable advance is on EBAY for 46.00 for our Oldsmobile's it works fine on my 70 just thought I would let you know!!

Bennyboy2

Sorry just rechecked the price the blue one is what I bought it is 52.49 with free shipping ! And the vacuum set up you described is what I have good luck!

pappyl

That's a ProComp distributor right?
Did you run the feed from the fuse block or use a relay off the old line?

I need to ship to canada, ontario as well

mrolds69

I would look closer at the weights and springs. There is an inner and outer shaft there, that has to be able to move freely. You should be able to move the weights out and they should snap back in. Under the weight pads there is a plastic bushing that falls off or breaks. That bushing limits your advance. There's another plastic bushing on the vacuum control that limits advance and breaks or falls off.You don't need to worry about that if it's not working. Like Eric said, I would at least check the specs on the points, maybe replace those and the condenser. A stock distributor that's working right, actually works pretty well. The key words are "working right"!

76olds

pappyl, I'm about 2 hrs north east of you in Orangeville . I have an original HEI distributor out of my 76 olds that I pulled a few weeks ago. It had new springs, weights put in last summer. Also accel coil and module with red cap and rotor ( brass terminals). In addition I have ( blue ) 8mm taylor spiro pro wires in which I am still running but will be changing them to the new thundervolts that I have. I'm currently running a DUI distributor that I purchased from Summit that looks great and seems to run much better. Could be just because its new LOL.
If your looking for a good HEI complete distributor DUI seems to work great.
Let me know if my original distributor could help you in any way.

Eric