1986 460 Smog Pump Delete

[Bullnose Gator]

You want to replace the timing chain set with one that's "straight up" (crank keyway pointing directly at the camshaft)

This is how these engines were first built, before 1970's emissions regulations had ford holding the exhaust valve closed to allow more time for the charge to burn.

I recommend a stock double roller timing set for an EFI 460 (1988 & later)

These are longer lasting than a Hy-Vo type chain and factory approved!

As for buying a distributor, you're going to have to give Scott all the information about your truck, how you intend to drive it & its engine.

Weight, gearing, tire size, carburetor, intake, headers, compression ratio, cam, cam timing, etc...

It might be wise to get all that in place before ordering. 💡

Got it, thanks. I've also seen others say they only had to adjust or replace the stock carb and not touch their timing. Should I address the carb first and then see if the timing is an issue, or do they both need to be done in tandem in my case?

[ArdWrknTrk]

Got it, thanks. I've also seen others say they only had to adjust or replace the stock carb and not touch their timing. Should I address the carb first and then see if the timing is an issue, or do they both need to be done in tandem in my case?

Ignition timing and advance always has to be confirmed before any carb adjustments are made. (ignition timing can effect carburetion, but carburetor adjustments can't effect timing)

[ArdWrknTrk]

Ignition timing and advance always has to be confirmed before any carb adjustments are made. (ignition timing can effect carburetion, but carburetor adjustments can't effect timing)

Im sorry if my replies are sporatic.

I've managed to lock myself out of Google so I'm not receiving any Gmail notifications or new posts. .

[viven44]

Well first, I assumed all 4 plugs were drilled out, but just checked the two in the back and they are NOT. So replacing the carb with one you recommended is sounding better and better.

Second, I'm not sure I trust myself to do that recurve properly, and for the price he is selling them already done, it is probably worth every penny in time, frustration, and confidence that it was done right.

Third, I've seen mention elsewhere of replacing the distributor with a "straight up" one, but haven't looked into what that means. Is that similar to recurving the stock dist, or completely different?

If you decide to do the timing chain, this thread might be worth looking at

https://forum.garysgaragemahal.com/460-Straight-up-Timing-Chain-upgrade-tp147525.html

The only thing I wish I did was add some blue thread locker to the cam bolt. I followed the factory instructions completely so didn't add blue thread locker. I did check the torque like 4 times though. There is only 1 bolt holding the cam and we are counting only on friction! There is a locating dowel but it isn't structural much from what I understand.

[Bullnose Gator]

Got it, thanks. I've also seen others say they only had to adjust or replace the stock carb and not touch their timing. Should I address the carb first and then see if the timing is an issue, or do they both need to be done in tandem in my case?

Thanks for that.

I got back in the garage today to start decided which direction I'm going to head with it. I hooked up a vacuum gauge to the carb manifold port (where I moved the vacuum advance) and it reads zero at idle. Few questions:

1) Do I need to hook it up to one of the stems on the manifold tree that i capped and leave the vacuum advance hooked up to the carb manifold port to see what it's at with where the idle mixture screws are currently set?

2) the idle doesn't change whether the advance vacuum is hooked up or not, should it? I didn't think so, but an old guy I saw today said it should, so now I'm confused.

3) If I adjust the vac advance clockwise all the way, any idea how many turns counterclockwise I should make as a baseline starting point?

[ArdWrknTrk]

Thanks for that.

I got back in the garage today to start decided which direction I'm going to head with it. I hooked up a vacuum gauge to the carb manifold port (where I moved the vacuum advance) and it reads zero at idle. Few questions:

1) Do I need to hook it up to one of the stems on the manifold tree that i capped and leave the vacuum advance hooked up to the carb manifold port to see what it's at with where the idle mixture screws are currently set?

2) the idle doesn't change whether the advance vacuum is hooked up or not, should it? I didn't think so, but an old guy I saw today said it should, so now I'm confused.

3) If I adjust the vac advance clockwise all the way, any idea how many turns counterclockwise I should make as a baseline starting point?

1) You have a manual gearbox. There's really no advantage to Ported vacuum for advance, and if you look at the vacuum routing diagram you'll see the distributor connected to red (Manifold) vacuum, through the thermal Vacuum Control Valve.

If you have a stock carburetor, and a stock distributor, the system -as a whole- is set up to perform best like that.

2)edit: yes, it should, but the idle certainly won't change if the distributor doesn't see any vacuum with the throttle closed because you hooked it to the E port on the carb.

Vacuum advance is supposed to be highest with the throttle closed and go away as engine rpms (and mechanical advance) increase.

This is why the routing sticker says to clamp/cap the vacuum line,, make the adjustments then reconnect the vacuum line and readjust your curb idle to 650-700 with the gearbox In neutral

3) You need a timing light to determine the amount and limits of your vacuum advance can.

Mine was rusted so bad inside I couldn't even get a 3/32 Allen wrench to turn. So I bought the Crane can and a MrGasket spring kit and followed the instructions, after bushing my advance plate stop pins so I didn't get so much mechanical advance that I had to limit my vacuum to a few degrees.

As Scott says mechanical advance is twice the number stamped on the plate.

This is why he needs to know tire size, gearing, max rpm's, etc...

With that and a straight up timing set my truck runs well and pulls hard

[viven44]

1) You have a manual gearbox. There's really no advantage to Ported vacuum for advance

Could you explain this a bit more? Why would there be a benefit in running ported vacuum for advance with an automatic?

Reason I’m asking is the 460 truck with auto transmission still wants manifold vac for advance … and it seems like the trans shift characteristics might depend on that choice based on your comment (just a inference/ guess)

 

[ArdWrknTrk]

1) You have a manual gearbox. There's really no advantage to Ported vacuum for advance

Could you explain this a bit more? Why would there be a benefit in running ported vacuum for advance with an automatic?

Reason I’m asking is the 460 truck with auto transmission still wants manifold vac for advance … and it seems like the trans shift characteristics might depend on that choice based on your comment (just a inference/ guess)

Ford set them all up with manifold vacuum, but with an auto tranny you have a tendency to creep or stall when the revs drop and there's no dashpot on the carb, like every aftermarket carb I've ever seen.

[viven44]

Ford set them all up with manifold vacuum, but with an auto tranny you have a tendency to creep or stall when the revs drop and there's no dashpot on the carb, like every aftermarket carb I've ever seen.

It’s a very rare occurrence… happened once on the bronco when the transmission was still coming out of the woods.

My understanding has been that running manifold vacuum would be better for idle cooling characteristics …… recall Bill or you mentioning that

[Gary Lewis]

1) You have a manual gearbox. There's really no advantage to Ported vacuum for advance

Could you explain this a bit more? Why would there be a benefit in running ported vacuum for advance with an automatic?

Reason I’m asking is the 460 truck with auto transmission still wants manifold vac for advance … and it seems like the trans shift characteristics might depend on that choice based on your comment (just a inference/ guess)

I don't like manifold vacuum with an automatic transmission. The reason is that I've seen an unstable idle with it. If something drops the idle just a bit, like the A/C coming on or the idle dropping as you come to a stop, the load on the engine drops and the RPM will increase. With increasing RPM the vacuum goes up which increases the vacuum advance which raises the idle RPM. But that increases the load on the engine via the torque converter and the RPM drops, which reduces the vacuum and that reduces the advance which reduces the RPM, which decreases the load on the transmission, which...

So I prefer ported vacuum for automatics. You get no vacuum advance at idle so the idle is stable. And you get a good bump of advance as you tip into the throttle so you get a good surge of power.