360 Fe issues

[FordmanShane]

Hello there fellow ford fans I am having trouble reviving my 1975 F250 360 FE So the problem is with the harmonic balancer when im trying to set the timing i painted where the 0 degrees is so its easier to time. I noticed where 0 should be consistent.. its not.. I had someone tell me its the timing chain, swapped that out and now the mark will be consistent for a second and then jump around.. The chain was a double roller summit timing chain
so what do you guys think?

 

[Mil1ion]

What rpm,
What is the condition of the distributed and vacuum advance?
Both can wear out and V/A can sieze or the diaphram can tear

 

[FordmanShane]

I never used the V/A until lately, seems to work just fine..but that makes sense.. what if its jumping around with out the advance connected? probably sill leaks right.. hmm.. thanks for the fast response btw.. Ill pick up a vacuum advance tomorrow Ill post results..

 

[Fellro]

When checking timing with the timing light, the vacuum advance needs to be disconnected, unless you are looking for total timing. I would sooner say you have a bad rubber belt in the harmonic balancer.

 

[FordmanShane]

The RPM had to been around 600 to 700 when I noticed it jumping

 

[FordmanShane]

When checking timing with the timing light, the vacuum advance needs to be disconnected, unless you are looking for total timing. I would sooner say you have a bad rubber belt in the harmonic balancer.

seems pretty soling and tight...I will double check where would the rubber be?

 

[FordmanShane]

BTW I did my own vacuum advance test ..its just sucking air

 

[Blue Goose]

seems pretty soling and tight...I will double check where would the rubber be?

Here ya go.....

How a Harmonic Balancer Works

 

[FordmanShane]

I meant to say solid haha

 

[FordmanShane]

Thanks for the link BG, I have some good news I did some trouble shooting because I was concerned with the HB and timing chain. I plugged both V/A and the carb and checked the timing on the, I started with an initial of 16 and when I put the light on the HB the needle was pointing 0* does this sound right? Also it was consistent so the jumping was defiantly from the V/A..

 

[Blue Goose]

Sounds like you got her, Shane!!!

 

[FordmanShane]

Thanks for the help

 

[Blue Goose]

Anytime..... Now, just because ya got your one problem solved don't leave us! Hang around and join in.... You may be able to answer a question that someone else has...

 

[FordmanShane]

Well I thought I had her running good with an initial of 20 last night.. so I fired her up this morning and she backfired a couple of times and started running real rough. So I reset the timing what an initial of 14 and when I got the light the 0* mark was pasted the needle? so I turned the dizzy clockwise she ran a lil smoother I got the light back on it and sadly I seen the mark jump again, wtf?!? Ill get the HB off today and let you guys know anything...
Also I did a dry compression test all eight spark plugs were out and at wot here are the numbers..
#1 - 92 psi
#2 - 88
#3 - 63 I think/herd this is the backfiring culprit...
#4 - 91
#5 - 91
#6 - 90
#7 - 89
#8 - 90

 

[Mil1ion]

IMO,you probably need some engine work from those #'s

The HB'S tend to have the rubber separate from the steel.

You have to set all mechanical items first..before any final settings


Are you using an adjustable timing light?

 

[Fellro]

Initial of 20 degrees? You definitely have issues, balancer is just one. One thing about FE's is that from the factory they did not have hardened seats. They had to be run on leaded gas. Since that hasn't been available for a long time, running these engines on modern gasoline will case the valve seats to fail, making a burned valve over time. If by chance the heads have never been updated, they will suffer this issue. BTDT. Had a 390 that had burned a couplevalves as well as 2 wrist pins that had the snap ring fail and wore deep grooves in the cylinder walls.

 

[FordmanShane]

IMO,you probably need some engine work from those #'s

The HB'S tend to have the rubber separate from the steel.

You have to set all mechanical items first..before any final settings


Are you using an adjustable timing light?

No just an old sears light..

Initial of 20 degrees? You definitely have issues, balancer is just one. One thing about FE's is that from the factory they did not have hardened seats. They had to be run on leaded gas. Since that hasn't been available for a long time, running these engines on modern gasoline will case the valve seats to fail, making a burned valve over time. If by chance the heads have never been updated, they will suffer this issue. BTDT. Had a 390 that had burned a couplevalves as well as 2 wrist pins that had the snap ring fail and wore deep grooves in the cylinder walls.

Damn, the cyl heads on this old truck are D2EA-AA and on the passenger side C8EA-something.... I'm assuming its been a long time haha well I guess its time for a rebuild, I knew it might come down to this so a wile back ago I picked up a 428 crank

 

[Fellro]

They just rebuild the heads, but sounds like one has already had issues.

 

[Mil1ion]

Both those heads were designed for a car engine
On the D2AE head you need to check the actual cast date to check how much emission related things are on it. I say it is a 1973 head

There is static timing , dynamic timing and vacuum assist timing

Static is determined by the timing chain/gears set.
Dynamic is running engine w/o vacuum
Vacuum assist you know already

Hopefully you got a straight up timing set

Test the dynamic timing from idle to 2500 rpm while looking for jumping around by the timing mark

Test the VA timing from 750 rpm to 2500 rpm
I will post tune-up chart for you.

In regards to timing numbers think about this.

A circle is 360*
8 cyl divided into 360 = 45*
so once it hits 25* BTDC it is more than half way to the previous cylinder

Here is your chart

 

[Mil1ion]

Do you have a points distributor or a breaker-less Dizzy ?