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'51 Chieftain


PhilAndrews

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A new arrival today prompted me to remove my distributor.

20200220_160305.thumb.jpg.87d43000a6fd86742452306c18d10e55.jpg

 

I stripped it down enough to be able to change out the swashplate for the points.

I may have become a little carried away and cleaned the ride and remains of old paint off.

20200220_162437.thumb.jpg.45dcd5cfdd13083fc4b9c8400b3f020f.jpg

 

Got a coat of new paint on and left it to dry. Refit comes a little later on tonight, hopefully.

 

Phil

20200220_164518.jpg

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On 2/21/2020 at 8:31 AM, Summershandy said:

Good to hear! Where does one acquire dual points? I have a few gremlins hiding around and I'm wondering if this would help get some of them out. 

 

Wherever you can find them, I think. I got lucky.

 

What gremlins do you have though?

 

Phil

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18 hours ago, PhilAndrews said:

What gremlins do you have though?

 

At times (not every time) I have a hesitation at take off. If I don't feather the throttle it can stall. I've tried both light and heavy throttle. I naturally feather it now when I take off from a stop or red light. Another is after a good hour of cruising around town or on the highway, the engine feels like it's lightly missing. The engine is telling me that's good for the day and it's time to head home.

I've cleaned, rebuilt and adjusted the carb best I can. Fuel pump is rebuilt with all new lines and filter. All new plugs/points and wires. All vacuum lines are new and tight. I've pretty much tried everything I've read on this forum aside of an engine rebuild. I can still make it to the shows and go for Sunday cruises without a break down. Sometimes if it ain't broke......I can live with my gremlins and thought maybe dual or electronic ignition could improve performance by the sounds of your results.  

Edited by Summershandy (see edit history)
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That leaves only a few things.

 

Poor mixture (air leak or under-/over-fueling)

Poor spark

Poor compression

 

Mine would randomly lose compression when hot, but you could hear the valves getting all clicky as they were getting sticky. I also had a new spark plug that was cracked on the nose that was causing intermittent misfire too.

 

Phil

 

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1 hour ago, PhilAndrews said:

Poor mixture (air leak or under-/over-fueling)

Poor spark

Poor compression

 

I still attribute it to the carburetor

Thought dual points or electronics would make a better spark

My compression is on the low side when hot but everything still sounds good. 

I would imagine the engine could use a rebuild one day. 

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IMHO get it running right on the single points first. More levels of complication just make your life harder when the car is not running quite right yet.

 

Dual points (and electronic ignition) do have advantages, but nothing you would notice in normal driving if the points ignition is working properly, and just set up. Thats especially true on something like a Pontiac Eight. It doesn't turn fast enough to show the driver a difference.

 

Dual points (and electronic ignition) will run more miles without any adjustments to the ignition or carb. Dual points should be an advantage over the long term. Electronic ignition, while theoretically better, seems to produce nothing but bad reviews on 6 volt cars.

 

 

 

Edited by Bloo (see edit history)
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I agree- I only changed this because the swashplate had been butchered and was loose enough to tilt and cause the points to close up.

 

As you hear, it is actually quite a lively engine for what it is. It'll rev up hard if you ask it to if it is set up right. Are your valve clearances set right? The original valves have a significant coefficient of expansion (which is why I am running stainless valves, they expand much less) and if you have them adjusted tight then they'll not seal and you'll end up with a hot misfire. I found doing them is difficult without a set of go-no-go feelers (available online, Lisle make a nice set).

 

I would definitely get a compression gauge and test both hot and cold compression. Valve job isn't difficult but takes time and is fiddly. I found that to be the most worthwhile rebuild on the engine yet.

 

Phil

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Not sure why one would add the complexity of dual points unless trailered race car.

 

If you should decide on an electronic whizbang, upgrade from your generator to an alternator FIRST.

 

If you decide not to get the alternator, and do get the electronic whizbang, don't call when you have an erratic or no idle.

 

Jon.

Edited by carbking (see edit history)
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11 minutes ago, carbking said:

Not sure why one would add the complexity of dual points unless trailered race car.

 

It's what was available in my case. But, also my car is running 12V on an alternator too. 

Electronic doodads really do not like the constant switching of the high-voltage cutout on the regulator for a dynamo; the gradiated electronic regulator of an alternator is mich more smooth despite it being more RF noisy. A looped ferrite core on the output lead helps significantly for that.

 

I know originality etc but heck, alternators are so much better that dynamo generators, particularly on a slow-turning engine.

 

Phil

Edited by PhilAndrews (see edit history)
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Thanks gang, informative as always! I'll double check the points before summer.

I always wanted to check the valve clearances. Maybe will do that one day too. 

I always thought that the engine should work as designed or they wouldn't have designed it to begin with. 

Adding "whizbangs" just doesn't seem right or turning a 6 volt into a 12 or converting drums to discs.....besides, where's all the fun in that??

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Valve clearances are critical on this engine, being as it it's slow and has a large overlap with a relatively soft cam- having them set wrong affects when they open by quite a margin. While not really perceptible at speed, it really makes a difference to low speed running and idle.

 

Phil

Edited by PhilAndrews (see edit history)
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10 hours ago, carbking said:

Not sure why one would add the complexity of dual points unless trailered race car.

 

If you should decide on an electronic whizbang, upgrade from your generator to an alternator FIRST.

 

If you decide not to get the alternator, and do get the electronic whizbang, don't call when you have an erratic or no idle.

 

Jon.

no complexity to going with dual points, first point does the opening, second point does the closing equals less wear on the points, gap adjustment last longer, and the coil builds up max voltage. I prefer old school technology in automotive ignition system. 

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A Pontiac 8 doesn't turn fast enough to really take advantage of the extra coil charging time, so the chief advantage of dual points will be that they will run a lot longer between tune ups. That would be a good reason too do it.

 

On the other hand thinking dual points might solve driveability problems is a recipe for disappointment. It wont help, and it might complicate efforts to find the original problem.

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Thinking on the original complaint, it may just be something as simple as a failing coil; sudden change in timing and combustion pressure may be causing the spark to blow out when pressing the gas to pull away (vacuum advance kicks in when coming off idle). Coupled with heat soak after a long run making it break down and become unreliable.

 

I would say pull a plug and spin it over when you can, take a look at the spark and see if it's a good strong bluish white, if it's bordering on orange, change the coil and try again.

 

If not, try tweak the distributor clockwise a fraction and see if it improves...

 

Phil

Edited by PhilAndrews (see edit history)
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5 hours ago, PhilAndrews said:

I would say pull a plug and spin it over when you can, take a look at the spark and see if it's a good strong bluish white, if it's bordering on orange, change the coil and try again.

 

You know now that I think about it, I think that's the coil that came with the car. I pretty much replaced everything but that. I remember taking off the NAPA sticker on it so I assumed it was a newer part. It never hurts to replace old with new especially when it don't break the bank.  

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6 hours ago, Bloo said:

A Pontiac 8 doesn't turn fast enough to really take advantage of the extra coil charging time, so the chief advantage of dual points will be that they will run a lot longer between tune ups. That would be a good reason too do it.

 

On the other hand thinking dual points might solve driveability problems is a recipe for disappointment. It wont help, and it might complicate efforts to find the original problem.

a Pontiac 8 doesn't turn fast enough ?, 4,000 rpms isn't fast enough ?

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Do you spin it 4000 very often? I was advised by more than one Eight owner to keep it under 3000 for extended periods. Nevertheless, I did not mean any sort of slight to the Pontiac 8. I am a fan of that engine.

 

Even at 4000 rpm on an 8 cylinder I can't imagine having too much trouble keeping a decent spark with a single point ignition. Over 5500rpm it might be really sketchy.

 

I'm not arguing against dual points either. If one of those dual-point aftermarket breaker plates were ever made for my 1936 Pontiac 6, I would be very interested. The 6 cyl. kits I see only fit the distributor Pontiac used from 1937 forward. What I am suggesting is that it is unlikely to fix anything that setting up the stock ignition wouldn't fix. Also, that if you miss somehow setting up the new dual points setup, you have added a second problem and may not know it. If you start with a good running car, you can instantly tell if something is not quite right with the new setup.

 

To paraphrase (heavily) 1990s ignition guru Christopher Jacobs, "The best thing an ignition system can do for you is light the fuel on time, every single time. If the engine is running well, you are already 98 percent there." In other words, beware of any claims of large percentage gains in horsepower, gas mileage, or driveability from an aftermarket ignition system. This coming from a guy who, by the time he said it, was selling aftermarket ignition systems....  All the best.

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7 hours ago, Summershandy said:

It never hurts to replace old with new especially when it don't break the bank.

The only time it hurts is the time it dosen't solve a problem that you have.  Then you don't know for sure whether it is aiding or abetting the problem.  

I have seen many people change too many things at one time and almost making it impossible to solve the real problem.

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4 minutes ago, Tinindian said:

I have seen many people change too many things at one time and almost making it impossible to solve the real problem

 

I do agree. That's why before my car was road worthy but knowing the engine ran, I decided to rebuild/replace as many parts that I could before heading out and test driving it. I was never a fan of just driving a used vehicle not knowing how good the parts could be, especially a 65 year old one. My coil was one item that was overlooked. 

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7 hours ago, PhilAndrews said:

4000? I've never had mine above 3000.

 

No idea what the max sustainable RPM is but I'll take reliability and longevity, thanks.

 

 

--Phil

I have had my 53 268 with 3.08 gears up to 97 mph once, 80 mph was 3016 rpms, 90 was 3393 rpms, I think my 59 389 engine going into my 53 and changing the gears to 3.23 at 90 mph the rpms would be 3555 a long ways down from a 6500 rpms reline. 97 mph works out to be my old 53 268 was turning 3657 rpms.

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On 2/22/2020 at 12:05 AM, pontiac1953 said:

Yes, sure looks familiar, my 1955 287 Pontiac distributor with the same dual points conversion. 

20200221_235820.jpg

I was able to find and buy a nos Mallory dual point conversion for 1950 to 1956 Pontiac distributors, even came with the nos big trash can condenser that Mallory made. can't wait to get it in the mailbox.

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Yes. One should be sure there is grease/oil on the balls and races so they don't rust. Ball bearings are more mechanically stable. Factory setups with ball bearings had trouble due to rust and wear (usually caused by lack of maintenance), and in some designs the damage would be to the housing itself. The factory systems on some makes switched from bearings to a pivot. Pivot systems last a lot longer when neglected, but the dwell changes when the vacuum advance moves.

 

That looks like a very nice high-quality piece in the pictures.

 

Edited by Bloo (see edit history)
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  • 2 weeks later...

20200320_213255.thumb.jpg.5c8682fa4db1048c1241b319b8118f42.jpg

My spark wire carrier was all dented up courtesy of the previous keeper (engine must've fallen over onto it) so I took it apart and beat on it with hammers.

 

Question for y'all, what shape should the lower part of the distributor lead-out there be? A mirrored curve or a flat piece? Mine is missing and I've no idea what it should look like to make another.

 

Phil

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7 hours ago, Bloo said:

This picture is the best I could find. Looks probably flat.

 

9746133_0.jpg

Yeah, I'd found a couple pictures like that but all a bit inconclusive.

 

Thank you though! I may end up making a flat piece, we'll see. Unless somebody has a spare?

 

Phil

Edited by PhilAndrews (see edit history)
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