boese1978

Got the car started today! rough idle- attempting to set the points and the set screw bottoms out ( the tension spring is fully compressed)and I only have about 15* dwell angle. No way to tighten anymore to raise the dwell to the 30* or so needed. Considered they were wrong or broken points tried another set with the same results. Am I missing something obvious? It's been a long day ( I won't mention wondering why the spark was gone all of a sudden after a points adjustment attempt, as the rotor lay right there on the cowl
Thanks for any input.

Sugar Bear

Does the dwell meter have a setting for the number of cylinders? Is it on the correct scale? Try setting the gap with a feeler gauge @ .019". The meter should then read between 28-32 degrees. If the dwell is off that much the timing is off a lot also. Dwell setting affects timing, timing does not affect dwell angle.

Good luck and keep us posted!!!

boese1978

I am using the 8cyl numbers, I had to crush the spring to get it to .020 or so, barely able to turn the allen wrench at that point. I understand the effects of dwell and timing. Being that the car will run and idle ( no road time at all) is it safe to assume the dist is stabbed correctly? Car starts right up with a pump, having never heard this set up before I do not know how rough an idle it should be with the cam from Mark.....wrong points? incorrect (ie:so large it holds the points open approx 1/8") octagon on the dist shaft?
Thank you for the input!

oldcutlass

Are the points installed correctly?

Sugar Bear

Delco Remy distributor with the window in the cap correct? Separate points and condenser or Uni-Set? Was this distributor in the motor before with the dwell being able to set properly? It is sounding as though the points may have been made with the rubbing block too large or attached incorrectly to the points during manufacture. Were both sets of points the same brand and age?

As far as having the distributor in correctly, it does not matter where it is in as long as you can time it without the vacuum advance hitting something. Good starting and idle is a good sign!

m371961

Are the points the type that has a cam wiper?

boese1978

Yes to the dist- new from Rock Auto, stock replacement- never been installed in this engine until now. The rubbing block appears normal on both sets of points. Both points are new sets. I tried a uni set and a set with the pig tailed condenser. Both same result. I did have the dist 180 off and just switched number one to the opposite cap terminal. And there is plenty of room for the vacum advance to move. When I try adjusting timing ( I know dwell changes timing and should be set first.) the car sputters etc.

boese1978

No wiper. and as mentioned I gapped it to as close to .020 as I could....

boese1978

Hey Eric, They only go in one way! I can take some pics after work today...but what I have written pretty well sums up the issue. Just need some ideas to correct it.....and figure out where the problem lies.
Thanks everyone!!!

boese1978

Another thought, when I was wrenching on the points set screw yesterday at one point the plate that the points mount on seemed to turn a bit too, not the counter weights, the plate that the points are screwed to, is that right?
Thanks!!!!

Sugar Bear

Sounds like either the octagonal cam is the wrong dimension or the mounting holes in the breaker plate are not located correctly. As for the breaker plate moving slightly when adjusting the points I believe, but cannot recall exactly, that some movement is normal.

Please post the outcome.

boese1978

Going to try again after work today, any suggestions on things to try or look for? Is there a diff between a SB and BB Olds as far as internal dist set up?
Thanks in advance.

Sugar Bear

For this issue no SB/BB difference in distributor, advance curves/specs probably a lot. Since you have tried different points I'm suspecting either a problem with the diameter of the distributor cam or the location of the mounting holes on the breaker plate.

Two things you could try 1.) Points from a different manufacturer if the ones tried are the same, and 2.) check to see if the distributor shaft has ALOT of side-to-side play in the shaft.

I'm guessing something is wrong in the manufacturing tolerances of the distributor...Good luck!!!

RetroRanger

Do you have the original distributor to compare to? I'm assuming you got a remanned dizzy from RA? I always try to ensure a replacement part works as advertised before I give up my worn out original.

I recently got a remanned ps pump n res. from RA. When I went to install it was obvious the pump fill would be angled at like 30* when the original was verticle. Inspection showed the reservoir while appearing correct had the pump mount holes in different locations. After a conversation w the rebuilder, I ended up using my old res. w their new pump. When everything worked I sent the old pump w new res back as the core.

boese1978

I'll mic the dist cam lobes and compare to the old one I took out. New Dist and no play in it at all. I'll try another brand of points but have my doubts there. I'll get some pics up later. FYI, when I put a set of points in with the adjusting screw as it came out of the box ( ie: the spring is barely compressed) and I tighten the points down to the mounting plate the gap is about 1/8" almost.

oldcutlass

What I meant, are the points sitting flat over the locating nub?

boese1978

Yes Eric, here is a pic- 3 rd set of points, as you can see it looks to be flat and mounted correctly on the plate. Also note that the spring is compressed all the way under the adjusting screw and zero gap for the points- this ( tightening the screw down all the way) also causes the rubbing pad to move away from the cam, I can get a couple feeler gauges in there. I'm befuddled....I have compared the new dist to the original one and see absolutely no difference in the mounting plate and I measured the cam and they are both the same. AND, now, I have lost spark from the time I parked at last night to trying it now...I have 12 volts at the coil, I'm all ears, thanks for any input.

boese1978

Found this clip/spring inside the dist, under the points mounting plate........

1970-W30

Tightening the screw will move the rubbing plate away from the dist cam as shown in the picture, You need BACK off the screw and the movable part of the points including the rubbing pad will get closer to the dist cam and eventually it will open the points to the desired gap if the rubbing pad is on the high point of the cam, I think you were turning the adjusting screw the wrong direction....

boese1978

by this time I can assure you that i have run that screw in and out, fully, oh, several hundred times now, I had a gap yesterday to run the car of about .022 today I can get no gap on any set I try.

Sugar Bear

Could you put the new points in the old distributor on a bench to see if they will gap properly in the old distributor?

oldcutlass

I'm just posting this to make sure there were no assumptions on what you are doing. The spring loaded arm does not adjust it rides the cam. As stated above tightening the screw moves the top plate with the back half of the point set to close the gap. Loosening the screw moves it away to increase the gap. The wear strip needs to be on a high point of the cam.

joe_padavano

I can't tell for sure without scale, but that sure looks like part of the spring on the point adjusting screw.

boese1978

I went and bought a set of NAPA points, almost 30$ geeesh.....put them in, gapped with a feeler, and the car fired right up. Still a bit rough at idle and I am still not sure what all this was caused by and not too trusting of the ignition system at this point. Need to get a new dwell meter and see if I can get them set more precisely. as far as timing- after I am sure of the points issue, should I just start by ear and make it sound as smooth and high an idle as possible and then turn down the idle? any fine tuning thoughts and suggestions welcome as I have never worked on a non stock motor like this before. My roller valve train sounds a bit noisy, will re adjust and see if the idle smooths out after.
All comments are welcome, thanks for the input.

joe_padavano

Did you verify point gap with a feeler gauge (0.016")?

redoldsman

I only have one word to say, "Pertronix".

boese1978

Yes Joe, I did. My thoughts were to use a dwell meter to fine set before I start figuring timing.

boese1978

Ain't that the truth.......I looked at my various sets of points and there are big diff in material used, rigidity and plain old "feel". The 30 napa ones seem to be the best of the bunch at this point.

droldsmorland

The clip looks like the clip that belongs on the adjuster screw shoulder to keep it captured or stationary while allowing the block to move verses the adjuster screw. Echlin or Standard Blue Streaks are the best points. Vette suppliers have them. You want Vette spec points. High quality, stiffer spring. Make sure the feeler gauge is oil/dirt free. Use contact or brake cleaner. A micron of dirt/oil will cause premature pitting of the contact set. Make sure the engine has a good ground path to the battery.

To tune...
- Set dwell at 30*.
- Get a vacuum gauge and a set back timing light. Hook vac gauge to an intake or un-ported vac source.
- Adjust base timing and A/F carb screws to obtain the highest possible vac reading, stock to mild street cam should be 18-22Hg -ish. Go back in forth between the timing and AF mix until you achieve this highest reading result. (vac advance can disconnected and its source capped off)
- Curb idle should be 650-750 with a sane cam.

Full throttle road test. Readjust until your happy.

note: Fluctuating vac needle indicates a vac leak. Low vac signal = retarded timing or huge cam.

note: Set base timing to 10-12-14* or as much as it will tolerate without knock.

note: No reaction to the AF screws or almost all the way out = vac leak. Should be ~2.5-3.5 turns off the seats.

How I like to see mine is:
- 12* base timing.
- Another 8-10-12* from the vacuum can (limited travel not limited rate vac canister).
- The rest or total (centrifugal) all in at 28-3000 RPMs for a grand total of 36-40*.

note: These settings are on my combo...11.0:1 comp ratio, 2700 stall converter, 93 Octane (E2 free) with either a few gallons of 100 mixed in or 104 booster mixed in. 70-80* ambient, at or near sea level. If your higher in elevation say above 1500' back off on these timing specs on all 3 events.

Fun71

I agree about the Echlin or Blue Streak points. They are the ONLY ones that I used back when I ran a points distributor. Cheap points are just that - cheap points.


I do about the same as this, but in a different order so there is :

- 12* base timing.
- The rest or total (centrifugal) all in at 28-3000 RPMs for a grand total of 36-40*.
- Another 8-10-12* from the vacuum can (limited travel not limited rate vac canister).

This gives ~36º total mechanical advance with ~10º vacuum advance on top of that.

Sugar Bear

"Still a bit rough at idle and I am still not sure what all this was caused by and not too trusting of the ignition system at this point."

It is probably fine but if you haven't done so already, triple check the firing order. Have seen incorrect firing order range from very poor running to a barely noticeable misfire.

boese1978

Did so, thanks for the suggestion. Firing order is correct. Pretty sure timing and perhaps mixture but need to be sure of the dwell and stability there first.

droldsmorland

Rough idle checks:
1. Look down the carb at idle to see if gas is burbling out of the ports above the venturis. If so your rich, verified by spark plug and exhaust pipe reading. Set the float 1 to 2/32nds lower. Keep the drop the same. Todays gas tends to boil over easier causing this problem in Qjets.
2. Brake booster leak. Either the bladder or the vac line or the one way valve.
3. PCV wrong for application or bad. Consider the adjustable unit on the market.
4. Vac leak. Intake, hoses, carb etc...
5. Carb internal troubles. Swap with a known good carb to see if the problem follows.

Side note: Consider eliminating the stove flap in the drivers exhaust manifold, plugging off the crossover in the intake or heads and installing an insulator gasket between the carb and intake. This solved my hard hot starts and boil over. The divorced choke needs to be tweaked to compensate and it will be cold blooded, but I can live with that as it slumbers when its cold here.
All this assumes your running all OEM parts.

boese1978

This is a bored and stroked build, with Prcomp heads and a cam from Cutlassefi. not much OEM left......

Appreciate your input!
Thanks!

droldsmorland

How do all 8 plugs read?
What kind of vacuum do you get at curb idle?
Whats the curb idle RPMs?
How aggressive is the cam?

redoldsman

I am curious with a build like that, why are you running points?

boese1978

Just want to have the car running after 5 years- so I can get the rear swapped, alignment etc. Will swap things such as ignition in the future. I only get to drive about 1/2 a year up here so plenty of down time to do swaps and upgrades.

boese1978

Will get to fine tuning soon, super busy being back at work at the school. Cam is pretty aggressive, I can post specs later.....

oldcutlass

Did you get your dwell issue resolved?

boese1978

Thanks for asking, NOt sure yet, had no time the past 2 days, car does start and idle pretty good. Will dive in again this weekend with ta feeler gauge and will go pick up a tach / dwell meter to double check and fine tune.