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Old 12-05-2017, 08:36 PM   #1
In The Ten Ring
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What points gap for 250 I6?

Dad thinks it's supposed to be 0.030 (30 thousands) but he's not sure.

So what points gap for a 1972 250 straight six?

Also.....

These are the parts I bought:

Points, condenser, rotor, distributor cap = BWD Select & BWD by Carquest

Spark plugs = AC Delco

I don't like the new spark plug wires as these are grey instead of the original orange....I'll take those back to the store.

Where can I get OEM-colored (orange) spark plug and coil wires to fit my stock 1972 250 straight six?
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Old 12-05-2017, 09:54 PM   #2
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Re: What points gap for 250 I6?

>> OEM-colored (orange) spark plug and coil wires <<

You are kidding, right?
Unless you're looking for some kind of color co-ordination, use the Grey. They'll stay cleaner, longer.
Dwell is 31 - 34 degrees. Try for 31 as dwell will increase as point rubbing block starts to wear-in. Point gap is .019" New and ,016 " used. Point gap decreases at the same time as block wears and dwell is increasing.

In the '60s and before, tune-ups were performed every 10-15,000 miles. New points set with a gap of .019" should have a dwell reading of 31 * and stay within the 34* max by the time of the next tune-up.

I looked at a couple of FLAPS web pages and couldn't find the grease for the point block. Summit lists it, but says no longer available.
Any kind of heavy grease should work as long as it isn't flung off. Apply only a thin coat on the cam.
Some points used to come with a small plastic capsule of grease. Some points had a small cotton wick that dragged on the cam. A drop of oil on it was sufficient for the life of the points.

You need a service manual. There are links to .pdf files on this forum.

http://67-72chevytrucks.com/vboard/s....php?p=5781194
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Last edited by RichardJ; 12-05-2017 at 10:04 PM.
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Old 12-05-2017, 11:30 PM   #3
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Re: What points gap for 250 I6?

Quote:
Originally Posted by RichardJ View Post
>> OEM-colored (orange) spark plug and coil wires <<

You are kidding, right?
Unless you're looking for some kind of color co-ordination, use the Grey. They'll stay cleaner, longer.
Dwell is 31 - 34 degrees. Try for 31 as dwell will increase as point rubbing block starts to wear-in. Point gap is .019" New and ,016 " used. Point gap decreases at the same time as block wears and dwell is increasing.

In the '60s and before, tune-ups were performed every 10-15,000 miles. New points set with a gap of .019" should have a dwell reading of 31 * and stay within the 34* max by the time of the next tune-up.

I looked at a couple of FLAPS web pages and couldn't find the grease for the point block. Summit lists it, but says no longer available.
Any kind of heavy grease should work as long as it isn't flung off. Apply only a thin coat on the cam.
Some points used to come with a small plastic capsule of grease. Some points had a small cotton wick that dragged on the cam. A drop of oil on it was sufficient for the life of the points.

You need a service manual. There are links to .pdf files on this forum.

http://67-72chevytrucks.com/vboard/s....php?p=5781194
If I was kidding the question would have ended in a Did the question end in that? I like to be as original as possible and these wires are no exception.

Now, questions for you.

1). What is "dwell?"
2). What is "FLAPS?" (Something tells me these are different than how airplanes increase lift at low speeds).
3). So I need to set my points gap for 0.019 inches?
4). My points kit came with a capsule of grease. I told the clerk, "is that a pill the owner takes to give him extra energy when doing a tune up?" *That time I was kidding and we both laughed.
5). I may have a service manual, I'll have to look. No way to print right now but thanks for the link, I have to buy a new printer this month anyway.

*I just showed dad my new points. He said "these are heavy duty!" The armature side of the points has a hole in the center...dad says that is to allow heat to better dissipate.
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Old 12-05-2017, 11:34 PM   #4
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Re: What points gap for 250 I6?

Your original plug wires were black.

Set your points using a dwell meter. 360 degrees in a circle, the dwell is the number of degrees the points are open. If you don't have a dwell meter, you need one.
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Old 12-05-2017, 11:39 PM   #5
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Re: What points gap for 250 I6?

Kinda hard to use a dwell meter without one I guess.

Jokes aside, can't you set points using a gauge, the thin metal strips you slide in there with that screw thingie loosened? Feeler gauge! That is the term I couldn't remember. Why can't you just use a feeler gauge for setting the points gap?

I'd ask dad if he replaced the wires but he probably won't remember.....OK who sells orange spark plug wires?

Last edited by In The Ten Ring; 12-06-2017 at 01:28 AM.
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Old 12-06-2017, 12:57 AM   #6
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Re: What points gap for 250 I6?

Nah, you gap 'em with a match book cover....
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'70 Nova 406"sb, 13.5-1, solid roller, Brodix, p.glide/t.brake, back halved, 9" Ford, spool 4.88, cage,ladder bar/coilover, 10.5 tire....... SOLD!!
'67 C10 short/step side mount spare -- SOLD!!
'72 Jimmy 2wd, 350/350, ps, pb, fun driver, lots of bondo & a shiny red paint job..... SOLD!!
'69 Nova 350, 4spd, A/C, ps, p.b, ...SOLD!!
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Old 12-06-2017, 02:12 AM   #7
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Re: What points gap for 250 I6?

I was able to find an old used dwell meter in a pawn shop. Cost me about $10 & it works great.
Maybe worth a look.
I usually set my points with the feeler gauge, but once I fire it up, I use the dwell meter to get it right where I want it.
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Old 12-06-2017, 03:05 AM   #8
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Re: What points gap for 250 I6?

Quote:
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I was able to find an old used dwell meter in a pawn shop. Cost me about $10 & it works great.
Maybe worth a look.
I usually set my points with the feeler gauge, but once I fire it up, I use the dwell meter to get it right where I want it.
Dad bought this truck new and owned it for 20 years before I got it and (unfortunately) socked it away in a garage. He never had a dwell meter, as far as I know.

Let me ask you, would you adjust points first and then carburetor or vice versa?
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Old 12-06-2017, 03:35 AM   #9
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Re: What points gap for 250 I6?

If I was changing the points and it was running ok otherwise, I would
get the points adjusted, check & reset the timing if needed & then adjust the carburetor.
There's plenty of people on here who know way more about these trucks than I
do & I would like for them to weigh in if there's a different & better way, but that's how I would do it.
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Old 12-06-2017, 11:45 AM   #10
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Re: What points gap for 250 I6?

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Nah, you gap 'em with a match book cover....
Folded over that is.
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Old 12-06-2017, 12:37 PM   #11
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Re: What points gap for 250 I6?

My two cents.

Black plug wires were original. Use the color you want.

Points gat at .019

Dwell is 32'. (My dwell meter has grown legs and walked away it seems.)

Adjust the points with an allen (socket) wrench in that little socket head screw on the points. I have a tool that looks like a flexible screw driver with a hex end on it.

If yo have a tach, or by ear, with the truck running turn the point adjuster screw in until the idle drops, then out until idle drops, turn the screw half way back in and you will be close.

The adjust the carb.

Ask ten people, get ten opinions. Now it's your job to sort it out.
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Old 12-06-2017, 01:07 PM   #12
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Re: What points gap for 250 I6?

Quote:
Originally Posted by davischevy View Post
My two cents.



Adjust the points with an allen (socket) wrench in that little socket head screw on the points. I have a tool that looks like a flexible screw driver with a hex end on it.

I've had a couple of 250 6cyl's and neither one had a window in the distributor cap to adj. dwell while the engine was running... making it kinda a PITA to
set, run, check, adjust, run, check, adjust some more..... had one in a '69 Nova with factory A/C. Dist. was squarely under the BIG A/C compressor, had to adj. by feel 'cause you couldn't see it. Fixed it a 350/Muncie 4spd. swap.
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Current toy trucks:
'71 GMC 1500 SUPER CUSTOM short/step, orig. dk. blue, 350/700r, ps,pb, A/C
'72 Blazer 2wd, ochre & white, 454, tremecTKO 500 5spd. ps, pb, A/C, tilt

Last 10yrs of hobby vehicles, had a FEW more in the 50yrs. before these:
'66 Plymouth Belvedere City of Miami cop car clone.
'70 Nova 406"sb, 13.5-1, solid roller, Brodix, p.glide/t.brake, back halved, 9" Ford, spool 4.88, cage,ladder bar/coilover, 10.5 tire....... SOLD!!
'67 C10 short/step side mount spare -- SOLD!!
'72 Jimmy 2wd, 350/350, ps, pb, fun driver, lots of bondo & a shiny red paint job..... SOLD!!
'69 Nova 350, 4spd, A/C, ps, p.b, ...SOLD!!
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Old 12-06-2017, 07:38 PM   #13
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Re: What points gap for 250 I6?

Thanks man. Dad bought it new off a lot in 1972 for $2300.00. He had talked the lot owner down from $2700.00, it was a very small lot across the road from the grocery store mom and dad had gone to that day.

Dad drove it for 20 years, never once taking it into a garage for anything, doing all his own work to it (aside from a crappy bondo and paint job in 1990). He gave it to me as per our deal....I promised to never drink, smoke, dip, chew, or use any drugs at least until I was 21. In return I got the truck and an all matching vet bring back P38 pistol. I still have both and never had to lie to dad.

I didn't taste alcohol until I was 23....my first taste of it was a cup of straight brandy at 37,000 feet, back when airlines used to treat you like you were somebody!

(That was a terrible choice of alcohol by the way, burned all the way down!)

I just spoke with dad again and he suggested me to use the feeler gauge first and a Dwell meter later but he's forgotten how to do that. I won't get to that until spring anyway.
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Old 12-06-2017, 07:51 PM   #14
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Re: What points gap for 250 I6?

I've been using the dirty one since the early 70's.
I found the new one at a flea market for $10.00.



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Old 12-06-2017, 08:23 PM   #15
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Re: What points gap for 250 I6?

Be sure you have the points on top of the lobe before setting them.
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Old 12-07-2017, 02:04 PM   #16
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Re: What points gap for 250 I6?

Quote:
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Be sure you have the points on top of the lobe before setting them.
What's a lobe?

I think a "lobe" is one of the 6 points of the hexagonal nut the armature rides on.

So the points are best set while in the open or closed position?
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Old 12-07-2017, 02:27 PM   #17
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Re: What points gap for 250 I6?

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What's a lobe?

I think a "lobe" is one of the 6 points of the hexagonal nut the armature rides on.

So the points are best set while in the open or closed position?
Yes, set the gap with the points open (on top of a lobe). When they are closed, there is no gap -- because they are closed.
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Old 12-07-2017, 05:08 PM   #18
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Re: What points gap for 250 I6?

.019 New, .016 Used. As a starting point. You may have to close the gap to get a higher dwell degree setting. To bump the rotor, I use a Remote Start switch with gator clips on Positive [red] and Solenoid [purple] terminals on the starter. This will get it in the ballpark. Fine adjustment to get the breaker arm on the highest of the 6-sided distributor cam can be done with a 5/8'' socket on a 1/2'' drive breaker bar on the harmonic balancer bolt head. [If your 250 has a bolthole in the crankshaft. Otherwise the HB itself can be rotated.]
Dwell/Tach connections [going by memory here] are Pos [+] and Neg [-] on the Batt and Coil Neg [-].
Plug gaps are .035 for points, and .045 for HEI.
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Old 12-08-2017, 11:03 AM   #19
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Re: What points gap for 250 I6?

Dwell is actually the degrees the points are closed. One advantage of using a dwell meter is you don't have to remove the distributor cap to adjust the points and the reading is more accurate once the points begin to wear.
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Old 08-29-2019, 07:21 PM   #20
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Re: What points gap for 250 I6?

Dwell meter is hooked up with green lead to the negative side of the coil and the black lead to ground, never hook it to the positive side of the coil.
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Old 08-29-2019, 09:31 PM   #21
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Re: What points gap for 250 I6?

The attached image will show you the main parts of a Kettering "points" style ignition system.

The points are shown open with the rubbing block of the points sitting on top of the lobe of the shaft. This is the correct place to set the gap of the points...in your case, to 0.019 in.

Hope this helps

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Old 08-29-2019, 10:33 PM   #22
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Re: What points gap for 250 I6?

Waking up a dead 2 year old thread ?
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Old 08-30-2019, 12:26 AM   #23
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Re: What points gap for 250 I6?

Why not, follow up info is always good.
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Old 08-30-2019, 01:10 AM   #24
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Re: What points gap for 250 I6?

Quote:
Originally Posted by Jeff M. View Post
Dwell is actually the degrees the points are closed. One advantage of using a dwell meter is you don't have to remove the distributor cap to adjust the points and the reading is more accurate once the points begin to wear.
The L6 Delco-Remy distributor doesn't have the sliding window to adjust the point gap with an allen key, like the V8 does. So Yeah, you do have to pull the cap.
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