I've seen references before about retarded cam timing, but I'm still not clear on which years/models were affected by that emissions "tweak".

Would my 85 351W HO be one of those? Also, is that tweak in the cam grind itself, or in the timing chain set?

 

Yes, it can cause it to fail. This is one reason why it's a good thing to have one of those exhaust sniffers in the shop.

 

From what i can see its just a timing set tweak, the crank gear has an offset keyway in it, so a strait up timing set shouls change it.

 

That would make it easy enough to deal with then. I'm needing to do a new timing set soon, so a "straight up" set is the ticket.

But the question still remains... Is a 85 351W HO retarded, per emissions? I'd hate to do a timing set, just to see no difference...other than a more stable ignition sequence.

What says youze guyz??

 

Kevin - I would say: Most probably yes, it's retarded, but I don't have the 1985 books to verify that. Most engines of this era were basturdized in Band-Aid® fashions to deal with emissions requirements.

I intentionally misspelled that to keep the forum from starring it out *********

 

I don't know the technical aspects but practical experience with my 85 351W HO.

I am only the second owner and I bought the truck from a guy I worked with.

He had it timed and tuned at the Ford Dealership one week before I got it.

He said he had never been happy with the performance. After driving it for a week, I set the time up,not with light but by ear. Enough to make it come alive but not ping or kick-back against starter.

Has been that way since 96. No problems and I am REALLY pleased with the performance... Just throwing that out there...Good Luck........Trav.

 

I understand what you're saying. I run my truck at 15° ignition advance...but valve timing and ignition timing are two different things. One is where the valves open and close in relation to crank position, and the other is when the spark is delivered in relation to crank position. Two different animals..

 

Thanks for the answers / info.

I took the truck to a shop that does work on old vehicles and found out a few things.

As you said, the emissions sticker says "non-catalyist" so there wasn't a cat on the truck.

What I did find out today is that when the PO changed the carb to an aftermarket Edelbrock it does not have the ports to hook up all of the factory emissions.....and several things were left unhooked.

The mechanic that looked at it disconnected the EGR and a couple other things that were not able to work properly due to the carb change. Everything is marked and re-connectable in the future. It does run a little better, but I would agree that the gains are a result of the system not working as designed due to the carb change and the tampering with the system.

I'm going to have to inventory the system and see what is there and what isn't and go from there. Digging down into it there were several vacum lines missing that I didn't realize from my first look.

I guess one of the first things to find out is what originally hooked to the carb and if there is some way that it can be reconnected to the carb that is on it or if I have to go back to a stock carb to restore all of the system to orignal working order. Then determine if I want to rebuild the emissions or repair what I have to the best working order that I can.

Looks like I am going to have to learn some emissions stuff. Its obvious that the PO didn't know squat.

 

I went through the same thing several years ago after I bought my 1981 F350, but I lucked out cuz I found an ex-mechanic who was working at his grandfather's Ford dealer when these things were new.

That label under your hood is key... what you will learn about those devices is that some of them were for emissions controls, and others were for drivability and operational purposes. It really amazes me what Detroit was able to come up with using only heat and vacuum.

These may help you:

Ford Truck Enthusiasts Forums - View Single Post - Vacuum Diagram Acronyms
Dictionary of Automotive Terms A-Z

 

Thanks Ctubutis.

The diagram under the hood is is good shape and the link to the acronyms will help as well.

I'll start going through it and see where I get.

It looks like if I get stuck there is plenty of help available.

If there is such a thing, a PDF of the emissions & vacum routing would be awesome.

 

You can probably make it run ok with that carb if you treat the whole thing as a early non-emissions type engine, since you have a non-emissions carb. That's probably why the mechanic disconnected some things. You will have to decide to run this engine like a late 60's early 70's model, or get the original carb and hook everything back like it's supposed to be.

 

That is probably where I am going to start. But I've added a stock carb to my junkyard list just incase I run across a good one.

I have to strip it down to get to some other things like replacing the thermostat and heater hoses all of which are buried....

While I am stripping it down I'm gonna identify, mark and photo everything, then store it. I'd hate to have to buy it all if Big Brother got involved

 

maybe to increase horse power and fuel mileage

 

removing emissions when everything is working good is a terrible terrible idea

Removing working emissions systems will cause loss of power, loss of fuel economy, and reliability issues. Also removing emissions is illegal and can cause the law to prohibit the vehicle to be resold ever again.