81 F100 flare side custom with 300 six & T18

You would think for the money they would give you a bracket for mounting it
I have to dig through my stash of stuff to see what I have for mounting it.
Dave ----

Yes, you are right!  I'd forgotten that.  I found an old meter bracket and used it.  Sure would seem like for that much money they'd send one.

I fussed with the truck today but did not get the AFR gauge installed as much as my son wanted me to.

I have heard more pinging of late and wanted to see where the timing was set at as I have not checked since I bought the truck.
With the cheap flash light battery powered one I have it was up around 16* to 18* bumped it back to about 12* to 14*. It is a lot better but still hear a little pinging so will bump it back a little more.
Factory should be 6* but I am sure I can go a little more.
I need to get a timing light with dial back to do it right.

I also looked into the PCV to see if that is why I am getting the milk shake on the oil fill cap.
It looks like it is working as it should but I also see I have a little more blow by than I would like.
When I first got the truck I checked the compression and I was happy with it so don't know why the blow by.
Dave ----

That's not so much timing that I'd expect pinging on a 300 six.  If I remember correctly, we had David/1986F150Six's up to about that at one point but didn't have pinging.

But if you are still getting it at 12 - 14 then I'd suggest you change the vacuum advance and not the initial timing.  If your vacuum advance can has the adjustment most do just take a turn or two out and see if that doesn't help.  That way you'll still have the earlier timing everywhere but at part throttle in a tall gear, which is where I'm guessing you are getting the pinging.

Gary Lewis wrote

That's not so much timing that I'd expect pinging on a 300 six.  If I remember correctly, we had David/1986F150Six's up to about that at one point but didn't have pinging.

But if you are still getting it at 12 - 14 then I'd suggest you change the vacuum advance and not the initial timing.  If your vacuum advance can has the adjustment most do just take a turn or two out and see if that doesn't help.  That way you'll still have the earlier timing everywhere but at part throttle in a tall gear, which is where I'm guessing you are getting the pinging.

When I first got the truck on the road the pinging was worst and I adjusted the vacuum back a good amount to stop most of the pinging.
I did think about adjusting it again as it is easy to do and as said would keep the timing earlier.
It did start with just a tap of the key when it was up pretty high, still not bad where its at.

Before the adjusting yesterday it would ping at about 1800 RPM @ 45 MPH in 4th gear -back roads.
After I got a little pinging at about 1400 /1500 RPM @ 68 MPH in 4th over drive - high way, did not ping at the 1800 RPM/45 MPH so going in the right direction.

Do you remember when working on David/1986F150Six's what octane was used and if it had ethanol?
I am using regular so low octane and it does have ethanol. I have run a tank(s) of mid grade octane and had no pinging before I did the adjusting yesterday so octane dose make a difference in my truck.
I am also guessing the blow by has to be making pass the rings and a part cause of the pinging also even if I don't get any oil smoke out the tail pipe.

A little more time and a good timing light we will get her dialed in
Dave ----

David was running 87 octane pure gas.  No ethanol.

On yours, you may be getting carbon deposits from the oil.  Or maybe running way rich.

Gary Lewis wrote

David was running 87 octane pure gas.  No ethanol.

On yours, you may be getting carbon deposits from the oil.  Or maybe running way rich.

Ethanol must have some part in the pinging?
We do have non-ethanol gas but to go through the trouble of getting it and may be some where were I cant get it I want to tune for Ethanol.

Still working on the "way rich" part, got to get the AFR gauge installed.
As for the oil guess I will just dial back the timing if that is the cause.
Dave ----

Ethanol shouldn't contribute to knock.
Motor fuel is blended to make an octane grade  (R+M/2 here in the states)

Dave, your drag racing experience should tell you that alcohols like methanol, ethanol and E85 can make tremendous power without knock at their stochiometric ratios (which is like 1/2 that of gasoline)
...or twice?.... closer to 7:1 than 14.7:1


But oil in the chamber(s) will act just like a diesel engine.
Clapped out 5.0's were notorious for this, because the PCV went to one runner instead of the plenum.
One melted piston or shattered top ring lands.

Fix your dizzy.
It's not pump gas causing knock.

ArdWrknTrk wrote

Ethanol shouldn't contribute to knock.
Motor fuel is blended to make an octane grade  (R+M/2 here in the states)

Dave, your drag racing experience should tell you that alcohols like methanol, ethanol and E85 can make tremendous power without knock at their stochiometric ratios (which is like 1/2 that of gasoline)
...or twice?.... closer to 7:1 than 14:1

But oil in the chamber(s) will act just like a diesel engine.
Clapped out 5.0's were notorious for this, because the PCV went to one runner instead of the plenum.
One melted piston or shattered top ring lands.

Fix your dizzy.
It's not pump gas causing knock.

But it take 2 times as much alcohol than gas to make the same power and what if the 10% listed on the pump is on high end of teens?

I am going to pick up a timing light later today and hope it warms up some, was 25*f when I went out at 2am and is only 28*f now.
Maybe I will move the Javelin out so I can fire up the heater in the garage?
I have other things that I can also do to the truck today.

I will got to the bottom of the ping.
Dave ----

It doesn't take two times as much alcohol to make the same power, it takes twice as much alcohol to have a stochiometric burn.
(Edit 11.7:1 for isopropyl, 9:1 for ethanol and 6.45:1 for methanol)

Alcohols have a much higher octane than hydrocarbons.... like somewhere above 110
That's how alcohol dragsters can run such high compression, and make so much power.
But that also means they get 1/2 the fuel mileage they would get on hydrocarbon race fuel.
This doesn't matter much if you only have to drive 1/4 mile at a time

The corn subsidy is federally mandated at 10%.
It costs more than petroleum. The oil companies aren't interested is using any more than they have to.

Methanol has 110 octane rating and ethanol 114.

The E10 fuel we buy today is blended to 84 octane and the 10% ethanol brings it up to 87 R+M/2 which is sold as regular.

Gary Lewis wrote

David was running 87 octane pure gas.  No ethanol.

On yours, you may be getting carbon deposits from the oil.  Or maybe running way rich.

Sorry that I am late to the party...

When I first arrived in Skiatook, the timing on a recurved distributor was @ 17+ degrees BTDC. The fuel mileage was good, but there was an occasional drag when starting. The ignition was handled with a MDS 6A ignition box.

Gary did magic on the vacuum advance. We drove while Gary monitored AF ratios [up to 17:1]. When I left, the timing was a "fat" 14 degrees BTDC.

The truck routinely consumed 87 octane gasohol.

Gary, when you and I had our gas mileage comparison between my truck and "Blue", we both used 100% regular [87 octane] from the same pump. This was to limit the variables and that was the fuel you use in your truck.

Thanks for the correction on the gas, David.  I knew we filled up at the same pump and it was 100% gas, but forgot that we did the adjusting and testing on an earlier tank.

Gary Lewis wrote

Thanks for the correction on the gas, David.  I knew we filled up at the same pump and it was 100% gas, but forgot that we did the adjusting and testing on an earlier tank.

Yes, earlier year, when we met at your home! OK GTG!

Thanks guys.
I picked up a timing light so I just got to get the truck in to install the AFR gauge and go over timing more.
Don't think I will get to it this weekend cold & raining calls for staying in the dry warm house. LOL
Dave. ----

I just found this:

9-13-2014, 08:33 PM
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Results

We played with David's truck today to determine what his AFR is and what his timing is. First, we installed my AEM wideband meter and looked at the AFR:
Idle: Once warmed up it was about 12.5:1
Cruise: At 62 where he ususally runs it was in the mid-15's on level ground, but climbing hills it got as high as 17.0 at one point.
Power: Once the throttle was open it went as low as 11.5 but normally at about 12.0 - 12.5.
That said the carb, a 1970 YF carb off of an F350, is jetted just right. It really shouldn't be any leaner, but the truck runs well so it isn't too lean. And it certainly isn't rich.

Then we checked the timing. The initial timing was set at 18 degrees, which was getting good MPG but made the engine slightly hard to start sometimes. And, it pinged at full throttle, so the overall timing was too much.

As for the mechanical timing, at 1700 RPM where David cruises it was giving 10 more degrees advance. Then we checked the vacuum advance and found that it was starting to advance at 10" and was giving a total of 18 degrees 16" of vacuum, and at the 14" of vacuum the truck had at 62 MPH the advance was 12 degrees. So, total advance at 1700 was 18+10+12=40.

Then we turned the vacuum advance two turns clockwise, which made the vacuum start coming in at 8", gave the full advance of 18 degees advance at 14". Then we set the initial timing to 17 degrees, and the drive determined that it pinged both at part throttle as well as full throttle. So we put the initial timing at 14+, giving a total of 14+10+18 = 42 degrees at 1700 RPM. And the truck felt happier with that setting than it has.

And this:

 
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Old 09-14-2014, 07:00 AM
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David is on his way home as of about 6:00 this morning. And, he was wearing a smile.  His only concern was whether to get gas here, making this tank lower MPG due to the ~40 miles of testing we did, or getting gas at the end of the range to pull this tank's average up. Obviously there are swings and roundabouts in that, but the fact that he's thinking about those things shows his attention to detail.

And, he is very thorough. He pulled receipts from his wallet for the last six or so tanks of fuel and each had notes on it describing the conditions under which the tank was burned. Like "hot" or "75 miles of city" or "all highway". And one notes when he re-installed the chin spoiler, which has made a noticeable difference. So, I'm confident we will get a good and accurate report on his MPG.

For the records, here are our notes:
Overall Timing
On arrival:
Initial: 18 degrees
Centrifugal: 10 @ 1700 RPM/62 MPH
Vacuum:12 @ 14"
Total: 40 degrees @ 62 MPH on level ground
On departure:
Initial: 14+ degrees
Centrifugal: 10 @ 1700 RPM/62 MPH
Vacuum: 18 degrees @ 14"
Total: 42 degrees @ 62 MPH
Vacuum Advance:
On arrival:
10" = 8 degrees (advance starts here)
12" = 10
14" = 12
15" = 16
16" = 18 (max)
On departure (2 turns)
8" = 7 degrees (advance starts here)
10" = 10
12" = 14
14" = 18 degrees (max)

Who is THAT Gary Lewis!  What did he do to get a spectacular reputation?  

Anyway, good find, David.  Good documentation for Dave.

Thanks for the information going to have to read it a few time for it to really sink in.

In the first post on the timing you went from a total of 40 and pinging to a total of 42 and no pinging?
Again I have to re-read but was the timing at 1700 driving RPM now lower but higher at a higher RPM?

I also see I need to break out the vacuum gauge and do a little driving to see where the motor is at for the RPM / MPH

What I may do is stop the pining for now, recheck with dial back light and adjust vacuum can, then when my work hours are less and I have 2 day weekends I will get into it deeper.
Dave ----

Dave, did you replace the front cab supports when you did the floors, rockers and cab corners?  I’m looking for information on how easy or difficult that was.  I think I will have to replace all of those things in my future.

Thanks!